Research

The Great Lakes Monitoring Program by Great Lakes National Program Office includes both collection of samples from 57 long-term stations sampled every year and a much more detailed survey conducted on each lake every 5 years within Coordinated Science and Monitoring Initiative (CSMI). We participated in these surveys in 2014 (Lake Erie), 2015 (Lake Michigan), 2016 (Lake Superior), 2017 (Lake Huron), 2018 (Lake Ontario), 2019 (Lake Erie), 2021 (Lake Michigan), and 2022 (Superior and Huron). The Lake Michigan survey was cancelled in 2020 due to COVID-19 restrictions and collected in 2021 instead. Both Lake Superior and Lake Huron CSMI surveys were collected in 2022.

Reports available in the Publications.

Photo gallery: CSMI Lake Huron 2017, CSMI Lake Ontario 2018

News articles: Great Lakes Center Awarded $3 Million from EPA in Collaboration with Cornell University; Newsletter #20: GLC continues monitoring benthos of all Great Lakes; Newsletter #20: State of Lake Erie meeting; Newsletter #21: CSMI Lake Huron survey on Canadian boat; Newsletter #22: That’s a wrap: Intensive survey of Lake Superior completed; Newsletter #23: Benthic Palooza in Lake Ontario

Oneida Lake is the largest and best studied inland lake in New York State, with a strong regional, economic, and recreational importance. Frank Collins Baker, a prominent malacologist, conducted one of the world’s first quantitative benthic studies in 1915–1917, finding that Oneida supported the most diverse molluscan communities in the state. Baker provided a very thorough description of his study in two books (Baker 1916, 1918) and several papers. Subsequent studies replicating Baker’s sampling design were conducted in 1967 (Harman and Forney 1970) at the peak of eutrophication, and in 1992–95, shortly after the invasion of Dreissena in 1991 (Harman 2000). This produced a unique historical dataset enabling a rigorous assessment of changes in the structure and species richness of the molluscs.

In 2012, we conducted a detailed historical analysis of the mollusc community of Oneida Lake based on our comprehensive lake-wide study that year and previous surveys dating back to 1915 (Karatayev et al., 2014). In the early 20th century, the lake had high water clarity, abundant macrophytes and benthic algae, supporting diverse molluscan community with 32 gastropod and 9 unionid species. By the 1960s, lake turbidity increased due to anthropogenic eutrophication, resulting in a 38% decline in species richness and a 95% reduction in abundance of native gastropods grazing on benthic algae. Following the invasion of Dreissena spp. in 1991 and subsequent increases in water clarity, gastropods in the lake dramatically increased, and by 2012, their species richness and abundance reached levels similar to reported in 1915–1917. In contrast, filter-feeding unionids were extirpated by dreissenids.

In 2014, another exotic species was found in Oneida Lake. The round goby is a bottom-feeder fish from Eurasia known to feed on molluscs and may change their community composition, abundance, and distribution. To investigate their impacts on Oneida Lake molluscs, in August 2022 we conducted a detailed survey of molluscs at historic stations of the lower South Bay, the best studied part of Oneida Lake, and we collected and identified over a hundred samples. In July through August 2023, we are planning to expand our survey to the whole lake. (see Eutrophication and multiple invasions decimate the most imperiled freshwater invertebrates for further work on this topic)

News articles: Newsletter #21: Molluscs of Oneida Lake; Newsletter #22: Time scales of ecosystem impacts and recovery under individual and serial invasions

This project is investigating stream drift across an array of streams with or without round goby populations. Seasonal drift collections, benthic invertebrate abundances, and fish community structure are being investigated to assess drift response to goby presence. This project also will examine emergence patterns and riparian spider abundance. Emergence specialist spiders (Tetragnathidae) are known to adjust their feeding locations based, in part, on emergence density. We are exploring whether this behavior is evident in stream sections dominated by round gobies.

News articles: Newsletter #20: Freezin’ for a reason: Both gobies and researchers endure winter in local streams

Halogenated compounds and pharmaceuticals in eggs from piscivorous birds nesting in the Niagara and St. Lawrence Rivers. We measured bioaccumulation and potential impacts to future avian predator populations nesting in the Lower Great Lakes region. We have collected eggs of eight species of nesting piscivorous birds and we are analyzing them to map the prevalence of halogenated contaminants and food web biomagnification in the region.

News article: Newsletter #17: Common terns impacted by persistent organic pollutants

In this project, we are testing egg development, hatching success, behavioral responses, and metabolomics of fathead minnows (Pimephales promelas) exposed to ambient Niagara River water and urban effluent purified by advanced oxidation products (H2O2, peracetic acid, UV light). Fish at various developmental stages are affected by contaminants not removed by wastewater treatment plants from the effluent and also by the cleansing and purification methods proposed to further increase effluent quality before it enters the Niagara River.

Many species self-organize into predictable patterns based on a balance of facilitation and competition. We investigated how Dreissena in the Great Lakes organize spatially based on food availability, competition, and hydrodynamic forces. We used video survey techniques (benthic sled transects) to map distributions and self-organization patterns of Dreissena in Lakes Michigan and Ontario. In Lake Michigan, we compared Dreissena patterns with current and bottom shear stress from NOAA’s Great Lakes Coastal Forecast System. We also compared distributions to chlorophyll concentration from monitoring data as a proxy for food availability.

Biomass estimates of individual species are crucial for many applications, including food web modeling, understanding trophic tracers such as stable isotopes, and estimating ecosystem services. However, data for benthic invertebrates in lakes can be difficult to find and individual weights within species may be ecosystem-specific. We compiled wet weights and dry-to-wet weight conversion factors for common benthic invertebrates in the Great Lakes using data from eight years of LTM and CSMI surveys as well as a literature search. Furthermore, we tested for significant differences in benthic invertebrate weights between lakes, depth zones, and basins and will make recommendations of instances in which weights can be generalized across ecosystems or should be kept separate. These data will be made available to managers, modelers, and researchers for use in their own calculations.

We are investigating the possible community-level impacts of a new invasive plant in the region by comparing macroinvertebrates collected from plant stands with varying abundances of stonewort ranging from no stonewort to 100% stonewort coverage. Five lakes were sampled. Although stonewort biomass differed among the sites, macroinvertebrate communities covaried with stonewort biomass. These data suggest most littoral zone invertebrates are probably mostly associated with the abundance of plant structure, and not in macrophytes as food. Thus, at least from a macroinvertebrate density perspective, native or non-native plants seem to be used equally.

Photo credit: Kylie Wirebach

News article: Newsletter #17: Starry happenings on Grand Island

Photo gallery: Studying invasive starry stonewort

This project will investigate the strength of direct and indirect interactions between benthic predators and their snail prey, and the resultant influence on detrital processing rates. Round gobies (an invasive benthic fish) and native crayfish are both snail predators, and snails are important in detritus breakdown in wetland habitats. We used a mesocosm trial to assess the response of leaf litter decay following introduction of gobies. Introduction of round gobies led to complete elimination of snails in all mesocosms. However, we detected no significant differences in leaf litter decay rates among all the treatments, suggesting that snails were not significant litter consumers. A followup laboratory experiment on snail responses to kairomones suggested these snails were very naïve to round goby odor, exhibiting no avoidance behavior, whereas they showed avoidance responses to native predatory fish like smallmouth bass. Thus, prey behavior in response to novel predators (or lack thereof) can have important implications for stream food webs.

News article: Newsletter #17: Snails, Gobies, and Green Beans

In this project, we are looking into the effect of climate change (increased CO2 levels) and human activities in watersheds (logging, acid rain) on calcium levels in soft water. Many lakes in Canada and around the world are soft water lakes, i.e., they have low buffering capacity. One of the problems with declining calcium levels in these lakes is that aquatic organisms that need calcium for their exoskeletons or shells are not able to obtain it from the water and this deficiency may carry up the food web. We are testing, in an experimental setting, calcification in snails that are raised in a soft water medium resembling natural calcium concentrations and exposed to different levels of atmospheric CO2 and calcium.

This project is investigating the cues and pre-migratory behavior of round gobies in Lake Ontario and connecting waters. The activity budgets of fish from Lake Ontario (migratory population) and Ellicott Creek (non-migratory population) are being assessed for movement behavior, distances moved, and seasonal activity patterns to discern the influence of habitat context.

This project was a collaboration with the U.S. Fish and Wildlife Service which began Fall 2019. It assessed all historical records of sturgeon spawning habitat in tributaries to Lake Erie through investigations of NYS Department of Environmental Conservation and library archives. It will revisit those same locations and document any changes in land use condition or in-stream spawning habitats. Ultimately, these activities should allow an update of tributary habitat suitability values for lake sturgeon in the Lake Erie watershed.

News article: Newsletter #17: Moving forward on mapping historic lake sturgeon habitat

In 2017, we received U.S. EPA GLRI funding to create a DNA Barcode Reference Library for Mollusca, Annelida, and minor phyla. This project is one of three funded by the EPA Great Lake Program Office toward genetic barcoding of aquatic invertebrate species from the Great Lakes. Two additional projects target zooplankton and rotifers (PI M. Pfrender, Notre Dame University, and Cornell University), and benthic arthropods (PI D. Lodge, Cornell University). Barcode sequences for collected specimens are generated by the Centre for Biodiversity Genomics, University of Guelph, Canada. The overall goal of the three collaborative projects is to advance the current state of genetic barcode library for invertebrates in the Great Lakes, which will improve our knowledge of Great Lakes diversity and help in early detection of nonnative and potentially invasive species to this important resource.

From 2017 to 2021, we collected multiple samples from the Great Lakes Region and successfully generated nearly 1,000 individual barcodes for many native and invasive freshwater benthic species of Annelida, Mollusca, and minor phyla (Bryozoa, Cnidaria, Nematomorpha, Nemertea, and Platyhelminthes) that, at the start of this project, had fewer than five barcodes. We generated a publicly available barcode reference library for taxa in the Great Lakes basin and updated a species checklist to be used for early detection and monitoring of invasive species.

A value-added product of this project will be a Great Lakes basin-wide species list for the taxonomic groups targeted in this project.

Image caption: Knut Mehler and Leon Katona (Wright State University) collecting mollusks and annelids from the Genesee River in Rochester, NY, in September 2018.

In 2019, we collected benthic samples from 85 stations located in all three basins of Lake Erie. In addition, our collaborators collected samples to study benthic algae and primary productivity (Leon Katona, Wright State University), diversity of Harpacticoida (Joseph Connolly, Cornell University), and Sediment Profile images (Janet Nestlerode, U.S. EPA, NHEERL Gulf Ecology Division) to explore the effect of hypoxia on sedimentary and biogenic features. For Dreissena monitoring, we collected video data using a drop-down camera at 95 stations and video transects at 43 stations. Video data from the drop-down camera were used to test a new method of rapid assessment of Dreissena populations we are developing since all previous population assessment methods were based on bottom grab sampling that require several years to process. At the end of the survey, we produced a map of lake-wide Dreissena distribution in real time. Preliminary analysis revealed a strong decline in Dreissena populations in Lake Erie, especially in western basin, compared to the previous survey in 2014.

We classified benthic habitats based on analysis of the images for presence and relative abundance of benthic taxa, verified images against infauna data from Ponars, and compared results with water quality data collected at each station via the Sea-Bird profiler casts. We found four visually distinct habitat types and communities formed by different species assemblages. Benthic taxa abundant in identified habitat types differed in their tolerance to hypoxia, indicating that near-bottom oxygen availability structures Lake Erie benthoscapes.

This method for Dreissena rapid assessment will be applied for Lake Michigan in 2021 and other Great Lakes in the future as a valuable addition to conventional bottom grab monitoring. (2019-2021)

Image caption: Research scientists aboard the R/V Lake Guardian. Paul Glyshaw (CILER), Elizabeth Hinchey Malloy (EPA), Lyuba Burlakova (GLC), and Natalia Mrozinska (GLC).

In 2018, we conducted one of the largest benthic-oriented surveys in the last decade. During September 2018, we visited 52 stations lake-wide and collected 138 Ponar benthic samples and Ponar video, 52 samples for benthic algae and primary productivity (Leon Katona, Wright State University), and 17 samples for little-studied benthic copepods Harpacticoida (Joseph Connolly, Cornell University). Janet Nestlerode (U.S. EPA, NHEERL Gulf Ecology Division) applied the Sediment Profile Imaging system (SPI) at 51 stations to explore sedimentary and biogenic features and possible relationships between these measures across known stress gradients (e.g., organic enrichment, eutrophication) for development of a SPI-based Freshwater Index of Benthic Habitat Quality. Finally, for Dreissena monitoring, we collected video data from 56 500 m-long transects and from an additional 34 nearshore stations using a drop-down camera (collaboration with Molly Wick, U.S. EPA Mid-Continent Ecological Division). This extensive survey was documented by Yola Monakhov Stockton (Art and Design Department, Buffalo State) and displayed as a photo exhibition and a poster at the 2019 IAGLR meeting. Based on the results of this survey, we prepared a report and several manuscripts for a Special Issue of the Journal of Great Lakes Research.

The benthos of Lake Ontario has been studied intensively in the last six decades and can provide insights into the impact of environmental changes over time. We used the long-term data and results of our intensive CSMI 2018 benthic survey to examine temporal changes in community composition over the last 54 years and to assess the major drivers of long-term changes in benthos. The paper describing this study was recently published in the Special Issue of the Journal of Great Lakes Research (Burlakova et al., 2021). We found that the benthic community of Lake Ontario underwent significant transformations that correspond with three major periods. The first period, termed the pre/early Dreissena period (1964–1990), was characterized by high densities of Diporeia, Sphaeriidae, and Tubificidae. During the next period in the 1990s, defined by zebra mussel dominance, the same groups were still prevalent, but at altered densities. In the most recent period (2000s to present), characterized by the dominance of quagga mussels, the community has changed dramatically: Diporeia almost completely disappeared, Sphaeriidae have greatly declined, and densities of quagga mussels, Oligochaeta, and Chironomidae have increased. Therefore, introduction of invasive dreissenids has changed the Lake Ontario benthic community, historically dominated by Diporeia, Oligochaeta and Sphaeriidae, to a community dominated by quagga mussels and Oligochaeta. Dreissenids, especially the quagga mussel, were the major drivers of these changes over the last half century. (2018-2021)

Image caption: Knut Mehler and Alexander Karatayev working aboard the R/V Lake Guardian, September 2018.

Report: Lake Ontario Benthos Survey Cooperative Science and Monitoring Initiative 2018 Final Report

Photo gallery: CSMI Lake Ontario 2018

News article: Newsletter #18: Long-term benthic data revealed large changes in Lake Ontario ecosystem

GLC researchers are documenting the seasonal population density, size distribution, and nutrient content of round gobies in the nearshore of western Lake Ontario, as well as the lower Niagara River, to understand cues related to their offshore and inshore annual migration. The benthic invader departs the nearshore in later fall, moving off to deeper waters in excess of 100 m over a period of a few weeks, and returns in the spring over a longer period. The project is addressing the contribution of this offshore migration to the offshore nutrient budget by comparing the population density, size distribution, and nutrient mass in the migrating and returning goby population.

In 2017, we conducted a lake-wide benthic survey at 129 stations to assess the status of the benthic macroinvertebrate community in all major basins of Lake Huron, with a primary focus on the invasive zebra mussels (Dreissena polymorpha) and quagga mussels (D. rostriformis bugensis), and to compare the current benthic community with historic data. We found that quagga mussels were most abundant in the main basin, less common in Georgian Bay and almost absent in North Channel. Comparing the 2017 findings to 2012 data, Dreissena density in the main basin in the shallowest (<30 m) depth zone declined by a factor of seven, remained stable at 30-90 m, and more than doubled at depths greater than 90 m. As a result, the bulk of population is now found deeper than 50 m. Diporeia and Sphaeriidae densities continued to decline in all basins including North Channel, where almost no quagga mussels were found. In contrast, in 2017 there was a substantial increase in oligochaetes in all regions compared to the 1970s and 2000s, likely due to an increase in their food resources as associated with quagga mussel feeding activities. These data were recently submitted to GLNPO; data analysis is ongoing and will be summarized in a report and a publication. (2017-2019)

Lake Huron Benthos Survey report 2017

Photo gallery: CSMI Lake Huron 2017

We have found significant levels of antidepressant drugs in the brains of various species of fish from the Niagara River. These fish have been exposed to wastewater outflows from treatment plants and they have bioaccumulated these pharmaceuticals in their brains, where they could alter brain activity and behavior. In the next phase of this study, we will examine what metabolites are expressed in the fish brains as a result to exposure to antidepressant drugs. We will also examine the toxicity levels to fish and zooplankton of the drug cocktail commonly found in wastewater effluent. Predator fish caught as part of diet studies for the Emerald Shiner Project were later tested for pharmaceuticals.

In September 2016, the GLC conducted a lake-wide nearshore benthic survey of Lake Superior as part of the CSMI to assess the status of the macroinvertebrate community with a focus on temporal trends. Benthic samples were collected at 59 nearshore stations, 25 of which were previously sampled in 1994, 2000, and 2003 (Scharold et al., 2009), and the rest were new locations selected using a GRTS sampling design. The most common benthic taxon by density in 2016 was Diporeia, followed by Oligochaeta, Sphaeriidae, and Chironomidae, comparable to the structure found in previous studies. Lake-wide, 94% of the 59 sampling stations in 2016 had high Diporeia densities. However, we found a significant decline of Diporeia densities in 2016 compared to 1994 at 95% of the 25 previously sampled stations, and Diporeia were not collected at three of these stations. In contrast to other Great Lakes, Dreissena spp. have not established a sizable population in Lake Superior and therefore cannot account for the decline in Diporeia abundance, suggesting that benthivorous fish predation or other environmental factors might have caused the changes. This apparent decline in nearshore Diporeia density could be an indication of a long-term trend of decreasing their densities or could be a result of inter-annual variation, reinforcing the importance of frequent monitoring to detect statistically significant temporal trends. Oligochaeta, Sphaeriidae and Chironomidae declined at some of the stations in 2016 compared to 1994, but the changes were not significant. The survey was conducted with the assistance of EPA GLNPO and in collaboration with EPA Mid-Continent Ecology Division (Duluth). This effort was funded by EPA through USGS (PIs Karatayev and Burlakova). (2016-2018)

Lake Superior Benthos Final Report

Photo galleries: Great Lakes Benthos Monitoring 2016

This project is investigating whether the time since colonization or hydraulic conditions correlate with differences in the behavioral responses of the invasive round goby (Neogobius melanostomus). Fish from the newly colonized Lakes Oneida and Cayuga are being compared to fish from Lakes Ontario and Erie, as well as a comparison of upstream and downstream locations on Ellicott and Eighteen Mile Creeks, to determine if differences exist in risk-taking, aggressive, and exploratory behaviors. Determination of behavioral syndromes associated with expanding invasion fronts holds promise as a tool to exploit behavior in slowing the advance of invasive gobies into new habitats.

In 2015, in collaboration with the U.S. EPA, University of Michigan, and NOAA, we conducted the first lake-wide survey of the benthic community of Lake Michigan after the Dreissena spp. invasion. We collected and analyzed 421 PONAR samples from 143 sites located in all basins of the lake, and depths ranged from 10 to 196 m. Over 110 different macroinvertebrate taxa were found in the lake, with Chironomidae and Oligochaeta being the most diverse taxonomic groups. Perhaps the most significant finding in 2015 was the decline in densities of D. r. bugensis at depths < 90 m, while the biomass remained stable or slightly increased compared to 2010. In contrast, both density and biomass of Dreissena at > 90 m increased. Dreissena polymorpha has essentially been displaced by D. r. bugensis and was not found in 2015. The amphipod Diporeia continued to disappear. It was not collected at any sites < 90 m and only at 9 sites > 90 m. Molluscs Sphaeriidae progressively declined as well all depth intervals between 1992 and 2015. Based on comparisons to data collected in the southern basin in 1992-1993 and 1998-1999, densities of oligochaetes have progressively increased in shallower and mid-depth regions likely due to the increased amount of food resulting from the biodeposition of organic material by Dreissena. (2015-2018)

Lake Erie and Michigan Benthos Final Report

We collected and analyzed samples at different trophic levels to determine the prevalence of contaminants in the Niagara River’s fish and wildlife, in particular those that contain halogenated compounds with a tendency to bioaccumulate. These contaminants are analyzed in water collected near wastewater treatment plants’ outflow into the river, and in predatory fish and avian and mammal wildlife. In particular, we are focusing on pharmaceuticals that enter the river routinely and may affect animal behavior. Our focus will include one of the most commonly prescribed antidepressants, selective serotonin reuptake inhibitors (SSRIs), which may cause impairments in fish and wildlife.

News article: In the News: Alicia Pérez-Fuentetaja

Emerald shiners (Notropis atherinoides) are small fish that constitute the base of the food web that supports many sport fish and fishing birds in the river. They are particularly important in the diet of the common tern, a threatened species in this area, and contribute significantly to their chick-rearing success.

Despite their abundance and importance in the food web, we know very little about the movements of the emerald shiners in and out of the river into Lake Erie. However, observational accounts report that while the adults move into the river in the spawning season, juveniles and larvae swim upstream back into Lake Erie. Unfortunately, the river shoreline has suffered multiple transformations; riprap and bulkheads dominate most of the areas that in a natural river would have slower currents. The concern is that the emerald shiners, and especially their juveniles, may have a difficult time completing their annual migration cycles. A collapse in this species would have negative repercussions to their predators, sport fish and birds that depend on this resource. The impact would be felt by the public as well: sport fishermen and bird-watchers, nature lovers and river users. To address the complexity of this project, we collaborated with scientists from the NYS DEC, US Army Corps of Engineers, and Buffalo Niagara Riverkeeper. 

In this project, we studied the emerald shiner’s use of the upper Niagara River for spawning, nursery habitat, pathways of migration and year-class formation. Results from habitat use by the shiner will be used to determine restoration needs to provide enhanced spawning and nursery areas and to diminish impediments to fish movement in the river, such as high water velocity areas from altered river shorelines (bulkheads, pilings, etc.). We are also studying food availability to larval, young-of-the-year and adult shiners as well as their contribution to the diets of sport fish, adult common terns and their offspring. Our focus is to determine critical habitat for the shiners reproduction and migration, and to evaluate the influence that these fish have on local sport fish and on the brood success of the common tern. Our results will answer questions about habitat conservation, restoration or possible modification to ensure the long-term success of emerald shiners, sport fish, and common terns in the system.

Image caption: Graduate student Jo Johnson seining for emerald shiners.

During the last 50 years, the ecosystem of Lake Erie has experienced major environmental changes, from anthropogenic eutrophication in 1930-1960s, to nutrient and pollution abatement in the 1970s, and then the introduction of exotic dreissenids in the 1980s. Currently, the lake-wide benthic community is dominated by dreissenids. The number of exotic species increases every decade, and their impact has had enormous consequences for the whole ecosystem. In the summer of 2014, within the project “Lake Erie & Lake Michigan Benthos: Cooperative Science & Monitoring Initiative,” we conducted a lake-wide survey of the benthic community using traditional (PONAR grabs, SCUBA) and modern (underwater video) methods, and we are currently working on data analysis. Data from this wide-lake survey will be compared to historical data to assess changes in the benthic community and trends in dreissenid populations that have important management implications.

We are using data collected during the last two decades of Great Lakes benthic monitoring conducted by the U.S. EPA’s Great Lakes National Program Office to describe the spatial and temporal patterns of benthic communities, assess their status, trends, and main drivers, and to infer the potential impact of these community changes on ecosystem functioning. Analysis of temporal trends revealed that the largest changes occurred in profundal communities, apparent in significant shifts in dominant taxa across all lakes except Lake Superior. In lakes Michigan, Huron, and Ontario, the former dominant Diporeia was replaced with Dreissena and Oligochaeta. Profundal species, with the exception of dreissenids, became less abundant, and their depth distribution has shifted. In contrast, density and diversity of native littoral and sublittoral communities increased. The invasion of dreissenids was among the most important drivers of changes in benthic communities. Continued monitoring is critical for tracking unprecedented changes occurring in the Great Lakes ecosystem.

Burlakova et al., 2018. The benthic community of the Laurentian Great Lakes: analysis of spatial gradients and temporal trends from 1998 to 2014. Journal of the Great Lakes Research. In print. DOI 10.1016/j.jglr.2018.04.008. Open Access.

Great Lakes Center researchers were awarded a grant for $835,829 by the Niagara Greenway Ecological Fund to investigate lake sturgeon habitat use, feeding ecology and benthic resource availability in the Lower Niagara River for 2014-2018 (principal investigators Alexander Karatayev, Lyubov Burlakova from Buffalo State, and Dimitry Gorsky from USFWS).

The lower Niagara River provides habitat to one of the few remnant populations of lake sturgeon (Acipenser fulvescens) in the lower Great Lakes. Evidence shows that this population may be in recovery (Buffalo News), but information about sturgeon ecology in this unique system is lacking. In this project, we studied the diversity, distribution and density of benthic forage resources and the biology and ecology of lake sturgeon in the lower Niagara River. We also determined lake sturgeon movement patterns, habitat use, and diet and related it to our benthic habitat analysis to determine substrate and habitat preferences and to predict a carrying capacity for lake sturgeon in the lower Niagara River. To date, we collected over 250 benthic samples and produced a habitat map which will be the basis for future habitat restoration projects in the river. Our study produced an assessment of food availability and habitat preferences of lake sturgeon in relation to restoration of the local population to aid researchers and managers in developing measures to protect and enhance habitat to advance lake sturgeon recovery in the lower Niagara River.

An interesting finding of this study was that two non-native species dominated the diet of lake sturgeon: the amphipod Echinogammarus ischnus and the round goby (Neogobius melanostomus). Stable isotopes revealed that round goby was the primary contributor to the long-term (i.e., fin) average diet whereas short-term (i.e. blood) diet was more diverse. In contrast to findings from other systems, adult lake sturgeon in the lower Niagara River were primarily piscivorous, actively targeting live fish prey. The recovery of this population is potentially supported by high availability of energetically-rich, but non-native food resources. This work has resulted in three publications and numerous talks presented at national and international meetings.

News articles: Buffalo State Experts: Benthic Communities and Sturgeon in the Lower Niagara, Great Lakes Center Conducts Sampling of Lower Niagara River

Starting in 2008, the Great Lakes Center monitored two sites in eastern Lake Erie for the Lower Trophic Level Assessment, a multiagency effort begun in 1999 by the Forage Task Group of the Great Lakes Fisheries Commission. This long-term project coordinates the efforts of state and federal agencies at sampling stations throughout Lake Erie to build a database of biotic and abiotic information and describe annual trophic conditions. From May through October we collected physical limnology data, water samples, and plankton samples biweekly, and take benthic samples three times a year. Because of human resource limitations, 2018 was our last field season for the Long-term monitoring of Lake Erie. Kit Hastings was the project lead, conducting most of the sample collection and processing, and Alicia Pérez-Fuentetaja and Mark Clapsadl were our representatives on the Forage Task Group.

A poster from this project (Documents/MonitoringLowerTrophicLevelLakeErie_FallForum2012.pdf) was presented at the 13th Annual Faculty/Staff Research and Creativity Fall Forum in Fall 2012.

Almost every study of Dreissena in the Great Lakes has relied on bottom grabs to characterize mussel presence and biomass, but until now, the scale at which mussel cover varies has largely been unknown. In 2015, in collaboration with the U.S. EPA, University of Michigan, and NOAA, we collected 421 PONAR grab samples from 143 sites, and 429 underwater video images to estimate the spatial distribution of quagga mussels in Lake Michigan. We developed a novel method, which analyses video footage recorded from a GoPro camera on a towed benthic sled, to estimate dreissenid cover and biomass. We compared quagga mussel cover and biomass estimates based on 3 replicate PONARs versus 500-meter-long video transects.

Overall, replicate PONAR samples yielded very high errors in estimates of quagga mussel presence, especially at sites with low to moderate mussel cover, because mussel cover heterogeneity typically occurs at spatial scales much larger than the sample size collected by replicate bottom grabs (0.052 m2). As a result, this method offers a straightforward, inexpensive method to drastically reduce uncertainty in lake-wide estimates of Dreissena presence, especially in regular monitoring surveys which study a small (<50) number of sites.

We hypothesize that, in the shallow littoral zone, quagga mussels have an abundant food supply but are limited by wave activity and therefore will form large aggregations on hard substrates, but almost no mussels will be found on soft and unconsolidated sediments, resulting in high heterogeneity in their distribution. In contrast, in the deep stable profundal zone with no wave action, mussels are food limited and will form small loose aggregations, which maximizes food consumption and results in low heterogeneity in distribution. The largest Dreissena density will therefore be observed in the intermediate depth zone, where sediment deposition is highest and wave activity does not reach the bottom. Based on these data we have made 8 presentations at various meetings and conferences and submitted a manuscript for publication in the Journal of the Great Lakes Research.

Lake Erie has the longest history of colonization by both Dreissena polymorpha and D. rostriformis bugensis in North America and is therefore optimal for the study of long-term dynamics of dreissenid species. Distribution of dreissenid species in Lake Erie varied depending on the time since the initial invasion, depth, and lake basin. During 2014, quagga mussels were found at various depths and in all basins, while zebra mussels were common in the western basin only and were limited in the central and eastern basins to a very few spots in shallow depths, resulting in almost complete replacement of D. polymorpha with D. r. bugensis. We found that a deep, offshore hypoxic zone restricts Dreissena population to shallow areas of the central basin. Deeper than 20 m, where bottom hypoxia routinely develops, only a small number of young of the year mussels were found, indicating restricted survival of >1 year old mussels. In the western basin of Lake Erie, with occasional episodes of severe oxygen depletion, all mussels were < 3 years old, suggesting die-offs once every 2-3 years. We suggest that monitoring of Dreissena occurrence and length-frequency distribution can be a cheap and effective tool in mapping of the extent and frequency of hypoxia in freshwater.

In the Laurentian Great Lakes, the most severe hypoxia routinely develops in the central basin of Lake Erie, causing strong negative ecological impacts. In collaboration with scientists from University of Michigan, Purdue University, U.S. EPA, and USGS, we measured bottom dissolved oxygen using 19 high frequency data loggers distributed throughout the central basin to validate a three-dimensional hydrodynamic-ecological model simulating dissolved oxygen distribution, and compared predicted values with the distribution of Dreissena. We found that a deep, offshore hypoxic zone was formed by early August, and expanded into nearshore waters by late September, restricting Dreissena population to shallow areas of the central basin. Deeper than 20 m, where bottom hypoxia routinely develops, only young of the year mussels were found in small numbers, indicating restricted recruitment and survival of young Dreissena. Monitoring Dreissena occurrence and length-frequency distribution can be an effective tool for mapping the extent and frequency of hypoxia in freshwater. In addition, our results suggest that an anticipated decrease in the spatial extent of hypoxia resulting from nutrient management has the potential to increase the spatial extent of profundal habitat in the central basin available for Dreissena expansion. Based on these data we have made 4 presentations at various meetings and conferences and submitted a manuscript for publication in the Journal of the Great Lakes Research.

This project compared fish and macroinvertebrate communities in Elton Creek before and after an in-stream and riparian zone restoration project. The original restoration work was intended to improve trout habitat along a 1 km reach. We sampled fish and invertebrates several months prior to the project onset, and six- and 12-months post-project. Sculpins did not respond to the restoration, but trout numbers in the restoration section improved slightly. Macroinvertebrate community response was also assessed.

The round goby (Neogobius melanostomus) has been implicated in the alteration of both macroinvertebrate and fish communities in tributary streams to the Great Lakes. Initial work in this project assessed whether an invasive invertivorous, benthic fish-mediated trophic cascade (fish predator to insect shredders/grazers to microbial communities to leaf breakdown) influences microbial community structure. This was the first application of community respiration profiling to assess a possible cascade effect on microbes in a stream ecosystem.

Later work in this project assessed whether the round goby impacted crayfish foraging, leading to a change in leaf litter decomposition. We used a field mesocosm manipulation to assess whether round gobies or crayfish had different impacts on the benthic macroinvertebrate community and then, indirectly, on leaf mass loss.

Figure 1: Graduate student Allyse Fischer collecting benthic invertebrates in a study stream.

Figure 2: Bags of leaf litter placed in a stream to see the effects of round goby or crayfish on leaf litter decomposition.

Figure 3: Graduate student Stephen Tentinger setting up a goby/crayfish exclosure study to investigate leaf break down dynamics.

The Texas Hornshell (Popenaias popeii) is listed as a Species of Greatest Conservation Need in Texas and New Mexico, as Endangered in both states, and is a candidate for listing in both states under the federal Endangered Species Act. Using an opportunity provided by the U.S. Fish and Wildlife Service for bilateral species conservation effort in New Mexico and Texas, we assessed the current distribution and habitat requirements of P. popeii in Texas, evaluating existing populations and their trends, and studying the species’s biology to develop the recovery plan and management options for P. popeii in Texas. In 2011-2014, we studied the current distribution and population densities in the Devils River and the Rio Grande River near Laredo using mark-recapture methods. We found the largest known population of P. popeii between Laredo and Eagle Pass, which is healthy and reproducing. However, probably due to pollution, the species has not been found downstream from Laredo. We analyzed all historical data and documented long-term changes in the distribution of P. popeii in Texas including range fragmentation and local extirpations to evaluate changes in the population’s size and distribution range over the last 100 years. Sampling over 250 sites in four rivers, constituting the entire historical range of P. popeii in Texas, we found that the species has been extirpated from two rivers, a 75% decrease in the combined total length of the rivers populated by the mussel, and an 72% overall decline in the population size of P. popeii. The results of this project are published in two papers and presented at national and international scientific meetings, and were recently used by U.S. FWS for Species Status Assessment under the Endangered Species Act.

News article: 2012 update

We continued our effort in developing another proposal in the area of chemoprevention, and cancer treatment. The goal of this proposal was to investigate organoselenium compounds containing chalcone scaffold for developing a potential lead to a new generation of anticancer drugs with improved therapeutic index and offer potential to be unaffected by drug resistance often developed during cancer treatment. This work follows “Studies on developing selenium incorporated chalcones as potential chemopreventive and chemotherapeutic agents of next generation” (2010-2013). A proposal was developed and submitted to National Institutes of Health as a potential source for funding. Environmental Toxicology and Chemistry Laboratory.

Lake Erie has the longest history of colonization by both Dreissena polymorpha and D. rostriformis bugensis in North America and is therefore optimal for the study of long-term dynamics of dreissenid species. Distribution of dreissenid species in Lake Erie varied depending on the time since the initial invasion, depth, and lake basin. During 2009-2012, quagga mussels were found at all depths and in all basins, while zebra mussels were common in the western basin only, and in the central and eastern basins were limited to shallow depths, resulting in an almost complete replacement of D. polymorpha with D. r. bugensis in the deep parts of the lake. In the shallow western basin of Lake Erie, zebra mussels represented >30% of the combined dreissenid density even after more than 20 years of coexistence. We found a sharp and significant decline in quagga mussel density and biomass in 2009-2012 that could be explained by Dreissena density-dependent processes, predation, or by a geographical sampling bias. Patterson et al. (2005) sampled the northern littoral zone of the eastern basin with extensive limestone outcroppings and high Dreissena density, while in 2009-2012 we sampled the southern littoral zone dominated by sand with low Dreissena density. In summer of 2014, we are going to collect over 300 Dreissena samples to determine the current status of zebra and quagga mussel populations in Lake Erie.

During 2014, quagga mussels were found at various depths and in all basins, while zebra mussels were common in the western basin only and were limited in the central and eastern basins to a very few spots in shallow depths, resulting in almost complete replacement of D. polymorpha with D. r. bugensis. In the shallowest western basin of Lake Erie, zebra mussels distributed as widely as quagga mussels, but represented <15% of the combined dreissenids density and wet biomass. In addition, to further elucidate the relationship between hypoxia and dreissenid abundance, an exploratory dreissenid abundance/habitat mapping approach was conducted with both underwater cameras mounted on a Ponar grab and on a benthic sled towed by U.S. EPA Great Lakes National Program Office R/V Lake Guardian. Preliminary video footage analysis verified by Ponar grab samples revealed that Dreissena spp. avoid the central basin hypoxic zone and that monitoring dreissenid distribution and size structure can be an effective tool in mapping of the extent and frequency of hypoxia in a large waterbody.

We continued our effort in developing a new area of research in the field of microbiome. It has recently been recognized that human organs harbor commensal bacteria (microbiomes) which outnumber human cells. There is emerging evidence that these commensal bacteria may be playing an important role in maintaining healthy organs free of diseases including cancer, such as skin cancer and breast cancer. The present aim is to identify these probiotic microorganisms and the underlying mechanism by which these microorganisms protect human skin and breast from developing cancer. A proposal was developed to determine the role of microbiome in protecting breast cancer. This proposal was submitted to Department of Army as a potential source for funding. Environmental Toxicology and Chemistry Laboratory.

Efforts are in progress to understand the tumor promoting mechanism of alcohol in PAH-induced carcinogenesis. Interference with PAH-induced cellular protective response of cell cycle arrest/apoptosis and the role of the transcription factor p53 has been implicated in this regard. Environmental Toxicology and Chemistry Laboratory.

News article: Environmental Toxicology Lab Receives Two-Year Grant

Since the introduction of dreissenid mussels into the Laurentian Great Lakes in the late 1980s, the diverse native mussel communities of the region have declined sharply. However, there have been several locales identified as refuges in coastal and nearshore areas. Although these have existed with the ongoing threat of dreissenid mussels in nearby offshore waters for over 20 years, the long-term survival of unionids in these habitats remains in question.

During this large collaborative project funded by the U.S. Fish and Wildlife Service, we surveyed over a total of 198 sites at 88 locations in bays, coastal wetlands, and drowned river mouths in the lower Great Lakes region and collected 4,329 individual unionids of 26 species. This information will help managers develop conservation strategies to sustain existing populations in these refuges. This expansive project also trained multiple undergraduate and graduate students, creating a cadre of future scientists and managers who will work to protect this imperiled resource, including graduate student Isabel Hannes (University at Buffalo) studying the phylogenetic relationship between Lampsilis radiata and L. siliquoidea, the levels of intermixing, and gene flow at different spatial scales. While species assemblages in the lakes have shown major shifts, these findings are especially encouraging given that surveys shortly after the dreissenid invasion pointed toward total extirpation of the unionid fauna. The number and weight of dreissenids attached to unionid shells was found to be tenfold fewer than in the early stages of invasion, indicating that the adverse impact of dreissenids on unionids has declined. We also found that the rate of infestation depends on the dominant Dreissena species in the lake: zebra mussels infested unionids much more often and in greater numbers. Consequently, the proportion of infested unionids, as well as the number and weight of attached dreissenids were lower in waterbodies dominated by quagga mussels. This was the first large-scale systematic study that revealed how minor differences between two taxonomically and functionally related invaders may have large consequences for native communities they invade (Burlakova et al. 2014). Results of the study were published in seven papers and presented at multiple meetings in the US and abroad. 

Great Lakes Unionid Refuge Project

Most of the invasive species discovered in the Great Lakes since 1994 are native to the Ponto-Caspian region, including species that have had strong negative impacts in the Great Lakes (for example, dreissenid mussels and the round goby). The rich biota of the Ponto-Caspian region coupled with a high volume of commercial shipping traffic strongly suggests that this region will continue to be a major source of invasive species to the Great Lakes. We worked on two projects to assess invasion risk in Ponto-Caspian fishes that had not been included in previous studies, “Evaluating Ponto-Caspian Fishes for Risk of Great Lakes Invasion” from 2010–2011 and “Enhanced Early Detection of Invasive Ponto-Caspian Fishes in the Great Lakes” from 2012–2014.

In the first study, we developed biological profiles and a complete listing of high-risk invasive fishes from the Ponto-Caspian region and evaluated the likelihood that current ballast water regulations would prevent invasion of the Great Lakes by these high-risk species based on physiological and ecological data. We reviewed English-language publications and untranslated European literature (published primarily in Russian) to analyze invasion risk for over 40 Ponto-Caspian fishes for which data had previously been incomplete or unavailable. We identified four new species of Ponto-Caspian fishes as having a high risk of invading, spreading, and causing significant harm in the Great Lakes. Those four species are the black-striped pipefish (Syngnathus abaster), Caspian tyulka (Clupeonella caspia), Volga dwarf goby (Hyrcanogobius bergi), and Caspian bighead goby (Ponticola gorlap). Our analysis indicated that current regulations regarding ballast water exchange are likely to be effective in preventing introductions of high-risk Ponto-Caspian fishes based on salinity tolerances and dilution effects. However, more information was needed on larval and egg densities in European ports to fully predict efficiencies of ballast water exchange.

In the second project, we studied the geographic distributions, habitat use, and reproductive biology of high-risk Ponto-Caspian fishes identified in our earlier project and the work of others (e.g. Kolar and Lodge 2002), focusing on areas in and around key European ports. We then used discriminant analysis to identify fishes that had a high probability of becoming established, spreading, and having significant negative impacts in the Great Lakes. Our updated listing of high-risk Ponto-Caspian fishes includes five species identified previously (the Black and Caspian Sea sprat, Eurasian minnow, big-scale sand smelt, European perch, and monkey goby) and five additional species (the Black sea shad, Caspian tyulka, Volga dwarf goby, Caspian bighead goby, and black-striped pipefish). Of these ten species, four (the monkey goby, big-scale sand smelt, Caspian tyulka, and black-striped pipefish) are likely to survive ballast water exchange as eggs, larvae, or adults based on salinity tolerances. We used a variety of sources of information (primarily European literature available in English and Russian) to more accurately assess fine-scale geographic distributions and “propagule pressure” in European shipping ports associated with high-risk Ponto-Caspian fishes to identify spatial and seasonal “hot spots” in and around Great Lakes ports that should be the focus of future surveillance and early detection efforts. The results of the project will improve our estimates of invasion risk by examining not only species characteristics, but also the likelihood of successful introductions based on current geographical distributions and seasonal variation in occurrences in Europe. As a part of the project, we also integrated species identification information and other outreach products in development from our previous GLRI project that target fisheries managers, recreational water users and coastal educators, and made this information easily available.

News article: Spring 2013 Newsletter (PDF, 2MB)

Efforts are in progress to decipher a new mechanistic insight with regard to the role of saturated fatty acids in PAH-induced apoptosis in p53-independent manner. In this context we will examine the effect of modulation of lipid metabolism on PAH-induced apoptosis response. Environmental Toxicology and Chemistry Laboratory.

Studies undertaken include examination of the effect of long chain saturated fatty acids on PAH-induced tumorigenesis. In this context we will examine the regulation of fatty acid desaturase and AGPAT-9 which are involved in fatty acid metabolism. Environmental Toxicology and Chemistry Laboratory.

Exotic species typically lose most of their associated parasites during long-distance spread. However, the few parasites that are co-introduced may have considerable adverse impacts on their novel hosts, including mass mortalities. We conducted a comprehensive inventory of parasites known to infect 38 species of exotic invertebrates established in the Great Lakes, as well as 16 invertebrate species predicted to arrive in the near future, all of them crustaceans. Based on a literature analysis, we identified a total of 277 parasite taxa associated with the examined invertebrates in their native ranges and/or invaded areas. Of these parasites, 56 species have been documented to cause various pathologies in their intermediate or final hosts, with humans and fishes being the most frequently affected host categories. Potentially harmful parasites were identified in 61% of the invaders, with molluscs and crustaceans hosting the highest numbers of such parasites. The results of our study provide a baseline for further assessment and management of the parasitological risks posed by exotic species to the Great Lakes. This work follows “Exotic molluscs host epizootically important parasites” and “Parasites of aquatic exotic species: an underestimated threat to invaded ecosystems.”

The common cladoceran zooplankter Daphnia takes calcium to form their carapace from the surrounding water. They also are an important link at the base of many aquatic food webs. Declining levels of calcium in the Canadian Shield lakes threaten to disrupt trophic interactions and lead to significant changes in ecosystem functioning. We investigated the interaction between food availability and calcium on growth, reproduction, and survivorship of Daphnia. This work follows “Effects of transgenerational Calcium decrease in freshwater cladocerans.”

Image caption: Graduate student Fawn Goodberry examines Daphnia under a microscope.

Identification of gene products modulated by benzopyrene (an environmentally present carcinogenic PAH) by cutting age microarray technique and in vitro analyses of the role of the particular gene in BP-induced signaling with a view to the development of biomarkers

We already have the microarray data of benzo[a]pyrene-induced gene expression in mouse epidermal JB6 cell line performed in Roswell Park Cancer Research Institute. The data include expression level of 50,000 genes. We are now analyzing the data with the objective of identifying the biomarkers modulated in response to BP, an environmental carcinogen. This work follows “Gene expression in benzopyrene treated cells.”

Because of the ability of natural occurring chalcones and various organoselenium compounds to prevent or reverse carcinogenesis or kill cancer cells with high selectivity without showing any genotoxicity and drug resistance, we initiated a pilot study that has been directed toward developing organoselenium compounds containing chalcone scaffold. We believe that such natural product-driven studies may provide important leads to develop an effective anti-cancer drug that has potential to supplement or replace current anti-cancer drugs which are known to produce adverse side effects, mutations leading to cancer and/or drug resistance.

Even though nutrient input target levels in Lake Erie have been reached, significant issues like the central basin "dead-zone," extensive Cladophora growth in the eastern basin and Lyngbya in the west, and repeated outbreaks of nuisance algae continue to occur. The role of nearshore and offshore dreissenid mussel populations and the flux and sequestration of nutrients within mussel beds and sediments remain a priority consideration to understanding the nearshore shunt hypothesis, and to explaining the Lake Erie trophic paradox.

The work conducted in 2011 and 2012 quantified all the major biotic and abiotic nutrient pools, flux rates, and trophic pathways in the nearshore and offshore regions of Lake Erie.

We directly measured nutrient levels in these compartments and flux rates in the most rapidly cycling pools. Additionally, we will couple our data with hydrodynamic models of particle transport and phosphate source tracking using ?18OP to assess whether the pools of nutrients in the nearshore and offshore regions follow the predicted patterns of lake mixing models and the nearshore shunt hypothesis. This project followed The Nearshore and Offshore Lake Erie Nutrient Study (NOLENS).

News articles: LENONS Round 3 Complete, Great Lakes Center Field Station Braces for Busy Summer

Photo galleries: LENONS 2011, Nearshore LENONS project, Offshore LENONS project, and Other sights of LENONS

We sampled sport fish (walleye, lake trout, steelhead trout, smallmouth bass) and their forage fish (gobies, emerald shiners, yellow perch, smelt), and forage invertebrates (dreissenids, amphipods and zooplankton), water and sediment, to determine PBDE congener load at all these trophic levels. Stable isotopic determination of organisms helped us determine their position in the food web and bioaccumulation coefficients for these chemicals of concern.

Photo gallery: PBDEs in fish

This project examined the role of exotic invertebrates in Lake Erie benthos that increased dramatically during last decades. Our 2009, 2011, and 2012 benthic survey of Lake Erie has shown that benthic invaders currently constitute 40% of total benthic density, and over 95% of the total wet biomass. Benthic community structure and dominance has changed significantly since 1979, and the community is currently dominated by exotic species, resulting in dramatic changes in the food web dynamics of the whole lake. This project used data collected during the Lake Erie Nearshore and Offshore Nutrient Study (LENONS) and the Nearshore and Offshore Lake Erie Nutrient Study (NOLENS).

Dreissena polymorpha (zebra mussel) and D. r. bugensis (quagga mussel) are both invaders, co-occur in their native habitat, and have very different histories of invasion. We compared the rates of spread of D. polymorpha and D. r. bugensis at different spatial scales and contrasted differences in their ecological and population characteristics to determine the relative importance of these traits on the success and patterns of invasion for these two species. Although in many waterbodies D. r. bugensis have been reported to outcompete D. polymorpha, local competition may be much more dependent upon local environmental conditions and will determine which dreissenid species will become dominant in a given waterbody, and thus likely to attach to boats and spread. To assess which biological traits allowed different dreissenid species to dominate under different environment conditions, we studied survival and growth rate of zebra and quagga mussels in Lake Erie.

In recent years, D. r. bugensis has been become the dominant species of dreissenids in the lower Great Lakes. However, we found that in glaring contrast to the ratios of the dreissenid species in the Great Lakes, D. polymorpha was found to obtain similar or larger sizes and density than D. r. bugensis on examined boats - the main vectors of spread for the two species. Therefore, Lakes Erie and Ontario are still important sources for D. polymorpha secondary spread in North America.

Photo gallery: Invasion paradox

We have 10 years of research experience in the new and ongoing botulism outbreaks in the Great Lakes basin. Our current role in this topic is to act as a resource for information for federal (EPA) and state agencies (DEC, NY-FWS) as well as the Great Lakes Research Consortium and to the greater research community. Our expertise includes sources of type E botulism in the Great Lakes and food web transmission.

News article: Warmer Summers Increase Likelihood of Type E Botulism in Lake Erie's Wildlife

In our continuing effort to understand the mechanism by which environmental occurring polynuclear aromatic hydrocarbons and their heterocyclic analogs induce cancer, we are currently studying the metabolism of phenanthro[3,4-b]thiophene to its mutagenic/carcinogenic metabolites by liver and lung microsomes from various animal species as well as humans in order to have a better understanding of the carcinogenic potential of this and related carcinogens in various animals. Previously, we completed a new and improved synthesis of the highly potent carcinogen dibenzo[a,l]pyrene and its carcinogenic metabolites. This study was accepted for publication in Polycyclic Aromatic Compounds. In addition, we also finalized and published part of our ongoing research on phenanthro[3,4-b]thiophene, a highly mutagenic compound found in the environment. This study was conducted in collaboration with cancer researchers at the Environmental Protection Agency, RTP, NC. Based on the outcome of these studies, a new proposal was developed for submitting to National Institutes of Health.

This project examined the interactions between invasive round gobies and stream-form steelhead trout. As gobies invade further inland in tributary rivers and streams, their aggressive behavior coupled with their wide diet breadth may result in direct and indirect impacts to other fishes with similar niches.

Photo gallery: Stream mesocosms

The round goby has invaded tributary streams of Lake Erie. As a result, goby diets have adapted to the foods available in the stream. We investigate how this change in diet affects their development and whether the ontogenetic shift observed in gobies with lake diets also occurs in stream gobies.

Exotic species may serve as vectors of introduction for their specific parasites, including highly pathogenic ones, and may also become hosts for aboriginal disease agents. This can result in catastrophic outbreaks of parasitic diseases that would otherwise not have existed in the introduced areas. We found that many exotic molluscs that were believed to be free of parasites have already acquired trematodes native to North America. Some of the exotic molluscs hosted exotic trematodes that are highly pathogenic to their vertebrate hosts. In six of the 12 waterbodies studied, exotic molluscs had a prevalence of trematode infection high enough to pose medium to high risk of parasite transmission to their subsequent vertebrate hosts. We suggest that parasitological assessment should be an integral part of the assessment of the ecological and economic risks these species pose. This work follows “Parasites of aquatic exotic species: an underestimated threat to invaded ecosystems,” and was continued in “Parasites of aquatic exotic invertebrates: identification of potential risks posed to the Great Lakes.”

Efforts were made to identify the phenolic components in tobacco smoke phenolic fraction (TSCPhFr) having tumor promoting activity in PAH-initiated cells. Identification of the phenolic component will help development of chemo-preventive strategy through elimination of the respective phenolic component from tobacco leaf by genetic engineering. This study was linked with Identification of chemo-preventive targets in tumor promotion by tobacco smoke phenolic components.

This project is an EPA Great Lakes Restoration Initiative funded project that aims at deploying three buoys in the Western and Eastern parts of Lake Erie. The project PI and co-PIs from the GLC, Buffalo State, and CILER University of Michigan have worked closely with engineering firms and other Buffalo groups to create a set of custom specific buoys. The near-real time data collected by the buoys is being complemented by the use of an Automated Underwater Vehicle (AUV) that increases the spatial resolution of mapping along the nearshore regions of Lake Erie. A website detailing the equipment and the data will allow stakeholders to access data concerning the state of health of the lake and help improve management decisions.

Image caption: EPA buoy deployed outside Buffalo, NY.

This project determined the seasonal changes in the C:N:P ratios of river seston and the invasive quagga mussel, Dreissena bugensis rostriformis. Understanding the plasticity of body tissue elemental composition can shed light on a species ability to survive under varying food quality regimes, which might aid invasion of new habitats.

Students collecting quagga mussels in the Buffalo River: Cecilia Pershyn, Vanessa Pereira, and Allyse Fischer.

A new invasive species in Lake Erie and other Great Lakes that is also making its way into the Finger Lakes region, Hemimysis anomala is the first mysid to become established in Lake Erie. H. anomala's feeding selectivity carries the potential for trophic cascade effects as their predation may limit the number of important grazer species. However, their adaptive omnivorous diet may allow them to shift their diet to include a larger portion of algae, occupying an intermediate feeding niche. We are examining diet selectivity of this species in laboratory and field experiments.

Figure 1. Jessica Wuerstle, a graduate student of Dr. Alicia Pérez-Fuentetaja, studying diet of Hemimysis anomala.

Figure 2. Hemimysis anomala, a new invasive mysid in the Great Lakes.

Freshwater Unionidae is the most rapidly declining faunal group in the U.S. Among the 52 species known in Texas, there are at least 26 species that require special attention, including six endemic and one federally listed endangered species. Currently we are funded by the U.S. Fish and Wildlife Service and Texas Parks and Wildlife Department (State Wildlife Grants, 2004-2012) to conduct statewide surveys of the rare and the most valuable Unionidae populations in Texas.

As a result of our surveys, of the 46 Unionidae species currently present in Texas, 65 percent were classified as rare and very rare, including all state and regional endemics (Burlakova et al. 2011). In July 2011 using State Wildlife Grants funding we surveyed sites on the Colorado, Frio, Guadalupe, Llano, Neches, Nueces, San Marcos, San Saba, Rio Grande and Trinity rivers to update the status of unionid species of greatest conservation need threatened False spike (Quincuncina mitchelli), Texas fatmucket (Lampsilis bracteata), Texas pimpleback (Quadrula petrina), smooth pimpleback (Quadrula houstonensis) and Mexican fawnsfoot (Truncilla cognata). We found abundant and diverse unionid assemblages, including rare endemic species, in lower San Saba River, in the Nueces, San Marcos, Neches and Trinity rivers. All collected data are a part of the Texas Natural Diversity Database, making the data readily available for conservation, monitoring and decision making. Fifteen rare freshwater mussel species were recently added to the state’s list of threatened species (Texas Register 35, 2010), and 11 of those are currently under consideration for federal listing by the U. S. Fish and Wildlife Service (74 FR 66261; 74 FR 66866). Taxonomic identification of species based on shell morphology is challenging and complicates conservation efforts, therefore we are currently working on molecular taxonomic identification of the most problematic Texas endemic species.

The results of this research was published in the following papers:

Burlakova, L. E., Karatayev, A. Y. Karatayev, V. A., M. E. May, Bennett, D. L., and Cook, M. J. 2011. Endemic species: contribution to community uniqueness, effect of habitat alteration, and conservation priorities. Biological Conservation 144: 155–165. Request a copy.

Burlakova, L. E., A. Y. Karatayev, V. A. Karatayev, M. E. May, D. L. Bennett, and M. J. Cook. 2011. Biogeography and conservation of freshwater mussels (Bivalvia: Unionidae) in Texas: Patterns of diversity and threats. Diversity and Distributions 17: 393-407. Request a copy.

Photo gallery: Freshwater Unionidae in Texas, Diversity, distribution and long-term changes

Efforts were made to elucidate the signaling pathways involved in tumor promotion by tobacco smoke phenolic components. Role of protein kinase C (PKC) and p53 have been implicated in this regard. Ongoing studies include understanding of the role of PKC over-expression in chemo-prevention against tobacco smoke carcinogenesis using in vitro cell culture and in vivo animal models. This study was linked with Mechanism of synergistic interactions of active TSC phenolic component(s) with polynuclear aromatic hydrocarbons (PAHs) (present in the environment) toward potentiation of carcinogenicity.

Woodlawn Beach State Park protects a 12-acre wetland that is listed on the park’s master plan for preservation and enhancement. The project focused on defining the hydrological flowpaths implicated in the transport and fate of E. coli and other contaminants within the Woodlawn Beach State Park. The project was combined with the Pre-Restoration Wetland Characterization and Chemical Mass Balance Study. We undertook an effort to assess both the physical and chemical characteristics of the wetland, followed by the development of an effective management plan. This effort was a collaboration between Buffalo State College and Woodlawn Beach State Park. Proposal priorities addressed a critical aquatic habit where the treatment effectiveness of this wetland was evaluated and compared with alternative approaches for treatment. The results will be used as a benchmark for defining the Strategic Master Plan of the New York State Parks, Recreation and Historic Preservation. As the project reached its final stages, focus shifted to data analysis and publications. We worked on the development of a combined hydrologic and biologic model that will be used to define the hydrologic dynamics required to maintain a healthy wetland ecosystem and one that is able to effectively abate E. coli concentrations and transport.

As part of a collaborative effort with Umeå University, Sweden, this ongoing project three-year collaborative project is looking at carbon and energy redistribution within watersheds affected by permafrost degradation and ultimately the impact on and fate in aquatic ecosystems.

In collaboration with the New York State Department of Environmental Conservation (NYSDEC), this project focused on remapping wetland distribution and boundaries within the Oswego/Oneida watershed. This project involved the digitization of current NWI maps into the GIS databases and field verification of wetland boundaries in order to improve current wetland distribution maps. There was the revision of a large sector of Oneida and Oswego maps, followed up by field ground truthing.

This project examines the different trophic niches that the round goby occupies in Lake Erie and in the tributaries that it has invaded. Through examination of the diet of different size/age gobies and their trophic status (determined by stable isotope analyses) we seek to determine differences among the goby populations that inhabit these very different environments and their impact in invaded streams.

This project will determine the density, seasonal timing, and diel patterns in the drift of larval round gobies in a tributary stream to Lake Erie. These samples will be coupled with lake plankton trawls to estimate the relative contribution of tributary streams/rivers to lake round goby recruitment.

This project will examine the effect of invasive round gobies on stream primary production and leaf litter decomposition by combining field measurements of periphyton standing stock and leaf litter breakdown rates at locations with and without round gobies present. It will also use replicate experimental streams to test the impact of fish communities (either round gobies only, darters only, both, or none) on the same stream processes as the field study (i.e., periphyton production and leaf litter decomposition). Later projects included Round goby-steelhead trout interactions in stream mesocosms and Round goby impacts on tributary stream leaf litter decomposition.

Although the nutrient abatement strategies implemented in the Lake Erie watershed have reduced nutrient inputs to target levels, not all of the anticipated responses have been realized. The central basin hypoxia event (the "dead-zone"), extensive Cladophora growth in the eastern basin, and repeated outbreaks of nuisance algae in the western basin have all occurred since the reduction in nutrient inputs. This project documented the quantity of nutrients present in all biotic and abiotic compartments of the nearshore and offshore pelagic and benthic habitats and pathways for trophic transfer. We measured directly flux rates in the most rapidly cycling pools and use published, scientifically peer-reviewed nutrient flux rates for the remaining biota in the system, coupled with published hydrodynamic models of particle transport, to assess whether the pools of nutrients in the nearshore and offshore regions follow the predicted patterns of early lake mixing models. This project is in collaboration with National Center for Water Quality Research in Heidelberg University, Kent State University, Ohio State University, and Case Western Reserve University. This work was continued in The Lake Erie Nearshore and Offshore Nutrient Study (LENONS).

We are studying how Ca requirements through several generations of Daphnia pulex can impact populations in low Ca aquatic environments. Effects of low Ca include decreased survivorship and reproduction and possibly a vulnerability to impacts of additional stressors. Continued in "Effects of Calcium decline and food levels on Daphnia development and reproduction."

This research is directed to identify chemical constituents in cigarette smoke that may be involved in promoting nicotine addiction by reversibly inhibiting the liver enzyme CYP2A6, a major enzyme involved in the metabolism of nicotine to inactive metabolites, during smoking.

Attempts are pursued to understand the mechanism of tumor promotion by ethanol in benzo[a]pyrene-induced tumorigenesis. Research is in progress to examine the effect of alcohol on cell cycle arrest and apoptosis induction in benzo[a]pyrene treated cell lines with a view to identify the signaling intermediates involved in alcohol-mediated tumor promotion in PAH-induced carcinogenesis.

This organism plays a vital role in the future of lakes that are exposed to acid rain and deforestation and, therefore, have declining calcium levels. Bosmina is small zooplankton species that has low Ca requirements and, therefore, can potentially replace the common grazer Daphnia in many of the thousands of lakes that are part of the Canadian Granitic Shield, altering permanently the structure of the food webs. We are working with researchers at York University, Ontario, to compare in a highly replicated experiment the competitive and environmental advantages of Bosmina in lakes suffering from decalcification and Climate Change.

Nicotine addiction is the primary cause for cigarette smoking which leads to high incidence of lung cancer and other diseases. CYP2A6 has been identified a principal cytochrome P-450 which is predominantly involved in the metabolism of nicotine to inactive products, thereby, removing active nicotine from body circulation. The smokers with high CYP2A6 in liver are prone to higher level of smoking to maintain the desired level of nicotine in the body. Thus CYP2A6 appears to be an excellent target for developing therapeutic agents for preventing cigarette smoking. Thus, our objective is to identify small organic molecules that can effectively inhibit CYP2A6 and, consequently, maintain clinical level of nicotine for a longer period in an effort to reduce frequency of cigarette smoking, especially, for chain smokers.

Attempts are pursued to understand the mechanism of synergistic interactions of active TSC phenolic component(s) with polynuclear aromatic hydrocarbons (PAHs) (present in the environment) toward potentiation of carcinogenicity. We determined the interference of TSC phenolic fraction with PAH-induced p53 response which is known to trigger the cellular protective machinery thereby justifying the possibility of p53's role in this regard. We are in a process to examine the role of p53 downstream signaling events e.g. NFkappaB and MAP kinases with a view to understand the underlying mechanism of tumor promotion by TSC phenolic fraction.

We determined in vitro effect of the PAH benzo[a]pyrene on the cellular expression of several thousands of genes by cutting age Microarray technique. We observed up-regulation and down-regulation of many genes by benzo[a]pyrene. We are analyzing these thousands of gene expression data to sort out the role of particular gene product(s) in benzo[a]pyerene-induced celluar responses (both protective and tumorigenic) with a view to the development of biomarkers.

Exotic species may serve as vectors of introduction for their specific parasites, including highly pathogenic ones, and may also become hosts for aboriginal disease agents. This can result in catastrophic outbreaks of the parasitic diseases that would otherwise not have existed in the introduced areas. A clear understanding of the mechanisms and patterns of the spread of exotic species and their associated parasites is therefore required to predict and prevent such outbreaks. We are assembling a database of parasites of aquatic invaders and conducting field study to determine the prevalence and intensity of infection of aquatic exotic invertebrates by parasites in their native and invaded ranges.

Figure 1: Collecting molluscs in Ontario watershed to study parasites of exotic species. Sergey Mastitsky, Lyubov Burlakova, and Alexander Karatayev.

Figure 2: Trematode cercaria from a faucet snail collected in the Golden Hill Creek, NY.

Figure 3: Trematode cyst found in faucet snail from Lake Oneida.

We are studying the effects of the endocrine disrupting pollutants PCB and PBDE on steelhead trout, common carp, and largemouth bass from eastern Lake Erie. To assess the impacts to reproduction of these chemicals we are measuring the levels of a unique female protein synthesized for egg production in male fish. The effects of these pollutants on fish include the alteration of their sexual characteristics and reproductive fitness.

This project aims to identify physical and biological parameters that cause the initiation of algal blooms within coastal wetlands. Wetlands are often considered traps for excess nutrients and contaminants. However, should the threshold of accumulation be exceeded, these ecosystems may contribute to the formation of blooms, which can be hydrologically transported into the Great Lakes during periods of high flow. This study aims to understand the complex dynamics of algal bloom formation and contribution within coastal wetlands through a combination of field observations and laboratory bioassays.

This study was undertaken to develop a project in the area of chemoprevention. We are currently interested in developing strategy to prevent tumor metastasis which is the most common cause for cancer death. It is now growing evidence that the environmental pollutants including those found in Great Lakes are involved in this process of carcinogenesis. Our initial effort is to develop small organic molecules which are highly specific in inhibiting matrix metalloproteinase-9 (MMP-9) which appears to be specifically involved in the metastasis of prostate cancer. Our continuing effort is directed to develop synthesis of the potential inhibitors of MMP-9.

Studies directed to understand the mechanism(s) underlying the potentiating effect of cadmium, nickel and other heavy metals designated as environmental pollutants on the genotoxicity of PAHs, and thereby presents the carcinogenic risk to humans. We studied the effect of above metal pollutants on the protective signaling events (p53- dependent or independent cell cycle arrest and apoptosis) induced in response to genotoxic stress by PAHs with a view to determine the biomarker(s) involved in metal toxicity.

We observed that the weakly acidic TSC phenolic fraction is a tumor promoter and increased the number of colonies of cells on soft agar (anchorage-independent cell growth). It possesses hundreds of phenolic components as determined by high pressure liquid chromatography (HPLC). The HPLC separated fractions as well as the crude TSC phenolic fraction are tested individually to examine their effect on anchorage-independent cell growth. We are in the process of determining the particular phenolic fraction(s) responsible for tumor promoting activity.

The Great Lakes Center has made a substantial commitment to the study of the impact of the contributing watersheds on the Great Lakes. We have continued the development of our model watershed in Point Peter Brook watershed in Cattaraugus County, where we have installed weirs with water level gauges and automated samplers along the trunk stream and several tributaries, piezometers, rain gauges, and a meteorological station. The initial goal for this project was to identify Variable Source Area (VSA) controls on the exports of nitrogen (N) and dissolved organic carbon (DOC) during storm events. We have expanded our watershed monitoring program, with funding from the USACE, USEPA, and NYS DEC as part of an effort to identify critical sources of sediment and nutrients to the Cattaraugus Creek, a major contributing watershed to Lake Erie. Part of the goal of the Cattaraugus Creek project is to assess how land use and climate change will affect sediment and nutrient loading, via model predictions. The model can then be used 1) as input to a lake-wide model and 2) for managers and stakeholders to make informed decisions about nutrient management such as developing remediation plans to reduce future excessive loading. The model is currently in finalization stages. The monitoring of the Point Peterbrooke watershed is continuing and this summer will incorporate additional measurement parameters to include the contribution of carbon loads.

This is a multi-institutional, binational effort that is aimed at understanding the dynamics of a lake changing in response to impacts of climate change, non-indigenous species, and anthropogenic factors. This project is in collaboration with SUNY Brockport, SUNY Buffalo, SUNY ESF, Niagara University, and University of Rochester.

This project will determine the biomass and coverage of benthic algae to field-verify satellite imagery on color spectra from nearshore Lake Ontario near the FitzPatrick nuclear power facility.

This project will determine the interaction between water velocity, substrate composition, and streambed slope on round goby swimming performance. Ultimately, these data may assist in barrier design to reduce upstream passage or allow us to predict which streams are most at risk to further invasion.

This project will assess intraguild predation as a mechanism promoting successful invasion of non-native benthic amphipod species.

This project will assess the importance of learning in predator avoidance by native and invasive crayfish.

Long-term experience of studying the exotic species has allowed us to bring together an international team currently working on a project. For 98 freshwater, marine, and brackish species, we collected data on a wide range of biological and ecological parameters. Using this database, we will be able to employ a quantitative approach to address many important problems in invasion biology, and to predict a set of future scenarios that determine invasion success.

Limnoperna fortunei, a bivalve mollusc native to China, is now rapidly spreading in South America. As with Dreissena (the zebra mussels), Limnoperna has rapidly become a major nuisance for many industries and power plants, and its impact on the environment may be even stronger than that of Dreissena. Together with colleagues from Argentina, we conducted the first quantitative survey of Limnoperna in Rio Tercero Reservoir, analyzed mussel coverage on different substrate types, estimated the overall population size, and studied their effect on the benthic community. Our data will help us to predict the potential effect of Limnoperna on aquatic ecosystems in the US.

The objectives of this 3-year study are to: provide pre-invasion information on the community composition, density, biomass and production of benthic habitats in the Madison lakes; predict the effect of zebra mussel invasion on benthic communities in the Madison lakes through comparisons with data to be obtained in southeastern Wisconsin lakes and an extensive long-term database from Eastern European lakes; and to estimate the potential effect of zebra mussels on benthic and pelagic communities and associated fisheries in the Madison Lakes.

Results to date:

Benthic samples collected from Lake Mendota in 2003, 2004, and 2006 were identified during fall 2006 and winter and spring 2007. Eighty macroinvertebrate taxa were identified to the lowest possible taxonomic level in benthic samples from Lake Mendota, including 25 taxa to species level.

Dreissena polymorpha density was sampled in Delavan Lake and Upper Nemahbin Lake. In total, 107 samples were collected from various substrata throughout the lake. The average density of D. polymorpha in Delavan Lake was 21,141 ± 6,785 mussel m-2; biomass: 1,077 ± 268 g m-2. Maximum densities were found on macrophytes and maximum biomass was found on dead shells. These densities are higher than those reported from European lakes (Karatayev et al. 1998). The average density of D. polymorpha in the Upper Nemahbin Lake was much lower: 3,009 ± 971 mussel m-2; biomass: 71 ± 19 g m-2 (n = 38). Maximum density (and biomass) were found on macrophytes.

South American channeled applesnail (Pomacea canaliculata) has been introduced at locations throughout the Indo-Pacific Region where it has become a major threat to rice and taro crops. First reproducing population of channeled-type applesnails was first discovered in Texas in 1989. This invader is of special concern for the Texas coastal ecosystems and Texas rice belt that supports a billion dollar industry annually. The goals of this research are to determine its current distribution and reproductive potential, to define its physiological limits and to predict the potential spread of channeled applesnails in Texas. Thus far the data from this project has been used to produce three M.Sc. theses (by David Hollas and Leah Cartwright, 2006, and Kevin Nichol, 2008) and are currently in preparation for several publications. The first paper will be published in 2008 in Journal of Wetland Restoration.

This snail is of special concern for the USA coastal ecosystems and rice industry. The goals of our research are to determine Pomacea insularum current distribution, and to estimate the rate, patterns and vectors of applesnail spread in Texas. These data will allow prediction of their potential spread in Texas, and the US. With our four years of research experience in the biology and ecology of this invader, we are acting as a resource for information for agencies in other states.

Objectives and Brief Results:

Determine current distribution in southeastern Texas. The distribution surveys are conducted annually; in 2005 and 2006 the presence of Pomacea insularum was confirmed in seven southeast Texas counties (Austin, Brazoria, Chambers, Fort Bend, Harris, Galveston, and Waller). Of 394 total sites surveyed in 13 counties, snails were found in 53. Snails were found in 18 waterways including canals, bayous and streams (Brazos River, Horspen, Sims, Bessie's, Armand, Buffalo, Mustang, Chocolate, Disckinson, New, Whites Bayou, American Canal), and 2 reservoirs (Barker and Addicks). In 2005 snails were first found in four new waterbodies (Sims, Bessie's, Horsepen Bayous, and Bear Creek), all outside of the region of previous distribution.

Determine current densities at selected locations. Population densities in Texas have never been defined before the beginning of our study although these estimates could provide an indication of the potential extent of possible environmental impact and serve a bench marks to determinations of future increases or declines in numbers. 20 infested sites in 13 waterways in 5 counties (Brazoria, Galveston, Harris, Waller, and Ford Bend) were sampled in August 2005. Average densities were from <0.1 to 4 snails/m2. The highest densities found were up to 24 snails /m2; biomass up to >800 g/m2 (Mustang Bayou, Fort Bend). In October 2005 much higher densities (in average 826 snails/m2; 6,689 g/m2) were found in a rice irrigation canal in Brazoria County.

Study monthly population dynamics of snail populations in several permanent lotic and lentic waterbodies. Changes in densities, size structure, growth rate, and reproduction were monitored at permanent sites (3 ponds in Chambers Co Golf Course, and a ditch near Alvin) from November 2004 to January 2005. Snail densities in ponds were up to 44 m-2, biomass: up to >1,700 g m-2 (wet total live mass). Average densities in ponds were from 0.2 ± 0.03 to 2.4 ± 0.3 snails m-2.  In the ditch, densities were lower (average 0.7 ± 0.2 m-2, max 8 m-2, biomass 400 g m-2).

Determine reproduction potential (number of eggs per egg mass; number of egg masses/female/unit of time; reproductive temperature range in Texas). The number of eggs per clutch and annual clutches per female can help predict population growth as it relates to possible future environmental impacts. Reproduction in Texas starts in March and finishes at the end of October – beginning of November. Number of egg masses was proportional to the size of the population and increased through the season from 8 to 426 in August. The average number of eggs per egg clutch was app. 1,000; max: app. 2,500 eggs.

Define selected physiological limits to some abiotic parameters.  Understanding tolerance limits to temperature, pH, salinity, calcium levels and emersion are critical to understanding which areas may be most at risk from applesnail invasions. These studies are currently ongoing in the University of Texas in Arlington (Dr. Robert McMahon and his students).

Determine potential food items in southeastern Texas.  Feeding laboratory trials were conducted in summer 2005 to determine the willingness of snails to consume plant taxa present in and near the Galveston Bay drainage area. Over 15 native and exotic plant species were tested up to date. Nonchoice laboratory feeding experiments revealed that palatability of aquatic plants to the snails varies depend on plant species.

Objectives for 2006-2009:

Determine the rate of applesnail spread in southeastern Texas. Surveys of P. insularum distribution conducted in 2005 and 2006 provided us with a unique opportunity to determine the rate of P. insularum spread in Texas. David Hollas and Leach Cartwright are going to continue the survey in summer 2008. GIS analysis of the current distribution of applesnails. Data on the current distribution and densities of applesnails combined with abiotic data will allow us to determine the speed, vectors and factors affecting snail spread and distribution in Texas.

This organism plays a vital role in the future of lakes that are exposed to acid rain and deforestation and, therefore, have declining calcium levels. Holopedium is an acid tolerant species that has low Ca requirements and, therefore, can potentially replace the common grazer Daphnia in many of the thousands of lakes that are part of the Canadian Granitic Shield, altering permanently the structure of the food webs. We are working with researchers at York University, Ontario, to compare in a highly replicated experiment the competitive and environmental advantages of Holopedium in lakes suffering from decalcifcation and Global Warming.

Recently we studied the metabolism and disposition of PBDEs in trouts under a grant funded by New York Sea Grant. PBDEs are emerging contaminants in Great Lakes Nation's other water ways. There is now increasing evidence that many of these chemicals cause endocrine disruption in aquatic and wildlife species. Our studies indicated that these compounds are bioaccumulated significantly in edible portion of trout muscle. Recently our laboratory is interested in studying the mechanism of by which two widely distributed PBDEs, namely, BDE-47 and BDE-99, induce their biological effects. Our effort was primarily focused on developing a proposal for identifying phenolic metabolites that are potentially involved in the endocrine disruption activities of the parent compounds using fish and mammalian models. A proposal related to these studies was submitted to National Institutes of Health.

Round gobies (Neogobius melanostomus) invaded the Great Lakes via ballast water transfer in the early 1990’s. Since that time they have colonized all of the Great Lakes, with significant impacts on benthic fish and invertebrate communities. Recently, researchers documented the migration of these aggressive benthic fish into tributary streams of some of the lakes. Researchers within the GLC are investigating the impact of goby invasion on stream macroinvertebrate communities.

Most identified stream populations of round gobies are composed of relatively small fish compared to lake populations. Since small gobies tend to consume a diverse array of invertebrates, before switching to a diet high in molluscs when older, there is concern they might reduce the prey base for other stream species. Of particular concern is their possible effects on stream-spawning salmonid species since gobies readily consume fish eggs.

The invasive round goby has had clear documented effects on native benthic fishes and recent studies have shown they could have significant effects on recruitment of nest-guarding species like smallmouth bass via egg consumption. Male round gobies locate and defend nests during reproduction, and then guard the eggs laid by females. Native crayfish make use of similar nest cavities during egg incubation, and egg-brooding dates in the two species overlap. These observations set the stage for potential competition for nest cavities between the invasive goby and resident crayfish. GLC researchers are investigating nest cavity competition between the species to understand the possible effects of this fish invader on the benthic community of the Lakes.

Ampipods are important littoral benthic invertebrates in the Great Lakes, being used as food by almost every fish species at some point in their life cycle. Recently, an amphipod invader, Echinogammarus ischnus, has become numerically dominant in several locations throughout the lakes. The native amphipod has life history characteristics that should enable it to outnumber the invasive species; it reproduces earlier, has larger broods, and grows larger. Yet, in some habitats and locations, the invasive species far outnumbers the native. It is possible that the invasive species simply does better in certain habitat conditions, like mussels beds, than the native. Other researchers have shown that both species prefer mussel bed habitats over other habitat types, and these habitats likely provide excellent refuge from fish predators.

Researchers at the GLC have been investigating amphipod behavioral responses to fish and crayfish predators to determine if differences in predator-avoidance behavior might explain why the invasive species is out competing the native species in mussel beds. Both species seem able to identify fish predators, avoiding fish that prey on invertebrates, but not avoiding fish that do not prey on invertebrates. Both species respond more when more fish are present, but the invasive species responds more to round gobies than the native species. The invasive amphipod is from the PontoCaspian region, just like the round goby is. Thus, these two species share an evolutionary history that is not shared by the native amphipod. Possibly, the high density of round gobies in the Lakes, coupled with the prevalence of mussel beds, is enhancing the success of invasive amphipods. Counteracting this finding is the response of these amphipod species to crayfish predators.

Crayfish are omnivorous, benthic organisms that seem to shift their diet preferences with age; eating more animal matter as juveniles and more plant matter as adults (though there is certainly some controversy on this). Different sized crayfish (and presumable different ages) differ in their ability to capture and consume amphipods and the amphipod species appear to have differences in their ability to avoid crayfish predators. In studies performed at the Field Station, the invasive amphipod was able to avoid large crayfish predators better than the native amphipod, but there was no difference in their ability to avoid small crayfish. Thus, changes in the size distribution, or population age structure of crayfish in the lakes may have implications for amphipod invasion success.

Six species of exotic molluscs known to be established in Texas are: Asian clam (Corbicula fluminea), applesnail (Pomacea insularum), red-rim melania (Melanoides tuberculatus), quilted melania (Tarebia granifera), giant rams-horn snail (Marisa cornuarietis), and Chinese mysterysnail (Cipangopaludina chinensis). Because the current status of C. fluminea, and P. insularum in Texas was recently reviewed (Karatayev et al., 2005; Howells et al., 2006), in this report we concentrated on the analysis of the history of spread, current distribution and potential impact of other exotic gastropods established in Texas. Over 20 waterbodies, most of them known to have populations of exotic gastropods, were sampled in 2006-2007. We found that M. tuberculatus continue to spread in Texas and are already present in at least 27 waterbodies and 18 counties. In contrast to M. tuberculatus, other exotic gastropods are limited to thermally stable spring-fed ponds and streams and did not expand their distribution during the last 30 years. Tarebia granifera was found in the San Antonio River, San Marcos River, and Comal Springs, M. cornuarietis was found only in San Marcos River and Comal Springs. The single well established population of C. chinensis was found in Kidd Springs (spring-fed city park pond) in Dallas, Tarrant County The main vector of spread of exotic gastropods in Texas is aquarium release. In addition, these snails might be spread with scientific equipment that was not adequately disinfected.

The results of the survey are in preparation for publication. 

To better understand the role of crayfish in nutrient dynamics in tributary streams of Lake Erie, researchers at the GLC are studying crayfish populations in Ellicott Creek. Three species of crayfish occur in the stream, and they appear to partition the habitat based on size and morphology. Since different stream sections have different hydraulic patterns (e.g., riffles are fast-flowing whereas pools are slowflowing), they hold different amounts and qualities of organic matter and sediment. The processing characteristics of the different species, coupled with their habitat partitioning, may have implications for nutrient quality and quantity exported form tributary streams.

Crayfishes are an extremely important group of freshwater organisms moving nutrient from the benthic zone to the water column. One of their many roles is processing organic matter; taking coarse organic matter and converting it into fine organic matter which is then available to a large suite of detritusfeeding organisms. This organic matter conversion is important in regulating nutrient cycles and availability as well. When consumed by top aquatic predators, crayfish represent movement of benthicacquired nutrients to the water column. They also have been shown to bioaccumulate mercury in their muscle tissue. Researchers at the GLC have studied the mercury levels in crayfish throughout New England to correlate mercury levels in these important benthic omnivores with mercury levels in other compartments of lakes and rivers.

Mercury is a potent neurotoxin with no physiological function in organisms. Biomagnification (an increase in contaminant concentration observed with increasing trophic level) of mercury has been documented for many systems, and often top piscivores in aquatic systems contain the highest mercury levels. All the Great Lake states have issued fish consumption advisories related to mercury contamination in top predator fish species. Researchers affiliated with the GLC are trying to further understand the dynamics of mercury movement through ecosystems by examining the movement of mercury from aquatic to terrestrial habitats.

Riparian zone spiders (Larinioides sclopetarius) build their webs on structures adjacent to aquatic habitats and feed on emerged aquatic insects. This study examined the mercury content of riparian spiders and their midge prey from areas within the Buffalo River Area of Concern (AOC) and from an upstream area. Spiders contained significantly more mercury than their midge prey, and surprisingly, spiders upstream from the AOC held more mercury than those within the AOC. Researchers are continuing to investigate why the upstream area had higher mercury levels.

Coupled with studies on land use impacts on benthic macroinvertebrate communities and the use of benthic indices for water quality assessment, studies have been conducted to determine how indices vary with season. Big and Little Sister Creeks, tributaries to Lake Erie, were studied in summer and winter to compare the range of variability in benthic indices and macroinvertebrate community composition. If water quality managers seek to identify small changes in surface water quality, they need to have data with low variability. Understanding the seasonal variability in macroinvertebrate community metrics might assist water quality managers in collecting benthic data able to show smaller changes in water quality.

Streams draining into Lake Erie flow through catchments with varied land uses, from forested to agricultural to urban. Water quality condition is affected by the landscape through which a stream flows. Studies have been conducted, and are on-going, as to the effects of various land uses on water quality, and the efficacy of different macroinvertebrate indices in documenting water quality changes.

Dobsonflies are aquatic insects belonging to the Order Megaloptera. They are long-lived insect predators (often a 3-year life cycle), living their larval stages in streams and the adult stage terrestrially. They are dependent on riparian trees or other structures overhanging a stream to complete their life cycle. GLC scientists are investigating whether females show a tree species preference for oviposition. Understanding the role of the riparian corridor tree community composition for these important aquatic insects may provide land-use managers with information on near-stream habitat management. 

Steelhead are an important predator in the lake and the most stocked salmonine with stocking rates of around 2 million fish/year. Previous data on steelhead diet are limited, and do not encompass the entire range of these fish in Lake Erie. The goal of this project is to continue to collect information that is fundamental to understanding the food web dynamics of lake Erie. A better understanding of the role steelhead play in food web dynamics will help fishery managers make effective management decisions.

This project has been examining the freshwater mussel community of Cassadaga Creek in Chautauqua County, NY. Results so far have included evidence of 15 species of mussels in the creek. Among these mussels were the first living specimens of the Rayed Bean (Villosa fabalis), listed as a NYS endangered species, to be found in Cassadaga Creek. In addition, a recently dead specimen of a federally listed species the Clubshell (Pleurobema clava) was collected. This was the first evidence of a recently living Clubshell in NY since 1919. Plans for future work include an extended survey of Cassadaga Creek targeted at identifying areas of high mussel densities. Also, because fishes are essential hosts for the parasitic lifestage of many unionids mussels, we hope to examine the composition of the fish community in creek.

The lower Buffalo River is one of the 47 Areas of Concern in the Great Lakes. The US Army Corps of Engineers is very interested in identifying the amount and chemical character of sediment that enters the Buffalo River and its source areas so that it can control sediment sources and thus reduce costs associated with dredging. We have embarked on a series of projects in partnership with several agencies to provide this information. The first series of projects were aimed at characterizing the spatio-temporal pattern of sediment pollution in the watershed and generating sediment budgets for the Buffalo River watershed and its sub-basins. Critical landscapes and stream reaches contributing sediment to the river have been identified, and hydrologic and sediment data measured in the watersheds been used to calibrate the models. Scenario analyses were then performed on the calibrated models to answer important questions regarding the effectiveness of sediment control practices in the watershed.

The second series of projects involved the composition of the sediments themselves. Sediment cores from the Buffalo River were serially sectioned and analyzed for a variety of organic and inorganic contaminants. From these analyses, a history of contamination at a particular site can be interpreted. The trace metal chemistry of suspended sediments recovered from the major sub-catchments of the river with an in situ centrifuge on loan from the Canadian Centre for Inland Waters was also determined. While the water chemistry in the tributaries is well-known, there was no data on the chemistry of the sediments entering the river. The effectiveness of planned habitat restoration in the river can be estimated from this work.

The Buffalo River is a receiving water for contaminants from a variety of chemical, metallurgical, and petroleum industries that line its shores. Possible pollutant sources to the Buffalo River include industrial discharges, leaching from inactive hazardous waste sites, and upstream point and nonpoint sources. Combined sewer overflows (CSO’s) are also a source of contaminant loading and they undoubtedly impact the linkage between sediment and contaminant transport. There are a total of 39 combined sewer overflows to the Buffalo River AOC that produce discharge high in bacteria and organochlorine compounds, such as polychlorinated biphenyls and polyaromatic hydrocarbons during heavy storm events.

The contaminated bed sediments in the Buffalo River are also likely vectors for contaminant loading to the river. Sediments are an ideal sink for contaminants, and they can be a direct source of contaminants if resuspended, and they can also be a diffusive source of contaminants into the overlying water column. Therefore, it is critical to determine the path sediments take during transport and deposition, as well as their ultimate fate in the system.

The goal of our research was to determine the impact of storms on the water quality of the Buffalo River, Niagara River and Black Rock Canal. We used Seabird CTD oceanographic profilers and EVS-Pro three-dimensional visualization software to collect data and create visual models of parameter responses to storm events and baseflow conditions.

We found that storm events over the Buffalo River watershed produce runoff from the watershed and from CSOs that degrade the water quality in the Buffalo River and the Black Rock Canal. The effects in the Niagara River, however, are minimal. EVS models suggest that suspended sediment settles out quickly and other contaminants are greatly diluted by ambient waters in the Outer Harbor or the Niagara River. Storm events had a more noticeable impact on the Canal than the Buffalo River.

Scajaquada Creek has been identified as one the most polluted tributaries contributing to the Niagara River AOC. Natural resource agencies responsible for the health of the watershed are very keen to identify contaminant sources so that appropriate management measures could be implemented to control these new sources of pollution. We propose to identify these new sediment source areas and quantify their contributions using a combination of monitoring and modeling approaches. Monitoring will be performed using continuously recording hydrolabs and grab sampling for suspended sediment. The GIS based SWAT model will be implemented for the watershed to develop sediment budgets for subbasins and creek reaches. The model will then be calibrated and verified using monitored data. The GIS based model can then be used as a tool by the resource agencies to identify critical source areas of sediment and target appropriate management strategies for these areas.

The Niagara River is the principal outlet for Lake Erie and the Upper Great Lakes Drainage Basin. Its discharge of 200,000 cfs is about the same as the base flow discharge of the Mississippi River at New Orleans. Previous work in the Niagara River by GLC researchers showed that there is a pronounced lateral temperature gradient across the river despite the fact that the water column in the river is thoroughly mixed vertically. The work suggests that the interplay of (1) flow constriction, both laterally and vertically, (2) stratification of the water column in the lake, and especially (3) Coriolus forces, may somehow force lateral flow partitioning. This phenomenon has not previously been described, much less explained. The GLC has undertaken a research program that will provide the preliminary data to choose between the most likely explanations. These two are:

1. The distribution may be the result of “flow stripping” and Coriolus force. Water in Lake Erie is normally stratified in the summer with warmer waters near the surface overlying cooler, denser waters. As this stratified water mass approaches the head of the Niagara River, it encounters the progressively shoaling lake bottom so that the cooler water at depth is prevented from flow into the channel, but the warmer water is allowed to pass. At this point, Coriolus forces could force warmer, buoyant waters to the U.S. shore. A compensatory flow of cooler water toward the surface along the Canadian shore would take place so that the whole mass then becomes laterally partitioned. Preliminary calculations of the Burger number suggests that this scenario is possible.

2. The distribution may be the result of lateral segregation of temperatures in Lake Erie itself due to upwelling. Winds that blow across Lake Erie from the north during a storm pile up warmer waters along the southern shore, producing a superelevation that results in coastal downwelling. A compensatory upwelling of colder bottom waters occurs offshore, again producing a water mass that would enter the Niagara River as a laterally partitioned field.

A third hypothesis, that the segregation is simply due to warm water flowing from the Buffalo River, has already been rejected based on our previous research because (1) we have tracked the flow from the river into the Black Rock Canal, not the Niagara River; and (2) the warm water flow from the Buffalo River is volumetrically insignificant when compared to that of the Niagara.

Four cruises will be made in the summers of 2005 and 2006 to collect data that will help determine the nature of the hydraulic fractionation in the river. Data in Niagara River near its head, and to a distance of 20 km into Lake Erie will be collected. The data will consist of results from (1) CTD profiling which will give us detailed 3-dimensional models of the temperature, turbidity, conductivity, dissolved oxygen, and pH distributions, and (2) current meter observations which will give us vector information on the velocity field.

Like most large cities around the Great Lakes, the waste water and the storm water drainage systems of Buffalo are combined into a single system. Under normal conditions, this poses no problems because the treatment plant is capable of handling the volume of water entering the system. During intense storms, however, the treatment plants are incapable of handling all the water, and overflows of untreated water enter the Buffalo River. The GLC was commissioned by the Buffalo Sewer Authority to monitor the overflows as they entered the river and then flowed out into the lake and down the Niagara River. We used CTD dataloggers deployed from both the R/V Pisces and the R/V Aquarius during the project to develop 3-dimensional models of the plumes. We were most interested in determining the effect of the plumes on the temperature, turbidity, and dissolved oxygen of the receiving waters.

The Buffalo River is a receiving water for contaminants from a variety of chemical, metallurgical, and petroleum industries that line its shores. Contaminant loadings may also come from its upper watershed and from the 39 combined sewer overflows to the Buffalo River, especially during storm events. The goal of our research was to determine the impact of storms on the water quality of the Buffalo River, Niagara River and Black Rock Canal. We used Seabird CTD oceanographic profilers and EVS-Pro three-dimensional visualization software to collect data and create visual models of parameter responses to storm events and baseflow conditions.

We found that storm events over the Buffalo River watershed produce runoff from the watershed and from CSOs that degrade the water quality in the Buffalo River and the Black Rock Canal. The effects in the Niagara River, however, are minimal. EVS models suggest that suspended sediment settles out quickly and other contaminants are greatly diluted by ambient waters in the Outer Harbor or the Niagara River. Storm events had a more noticeable impact on the Canal than the Buffalo River.

Trace analysis of organic compounds of environmental interest in various matrices. These studies include QA/QC for trace analysis of PAHs, PCBs, Polybrominated biphenyl ethers (PBBEs), chlorinated pesticides, and metals by HPLC-UV detector, HPLC-fluorescence detector, GC-FID, GC-ECD, and AA in water, sediments, and fish tissues.

There is considerable evidence indicating that the weakly acidic phenolic fraction of tobacco smoke condensate (TSC), elicits strong tumor-promoting activity in polynuclear aromatic hydrocarbons (PAHs)-initiated animals. Pure phenols by themselves are weak tumor-promoters at very high dose and cannot account for the tumor-promoting activity of the whole phenolic fraction. The mechanism(s) underlying the tumor-promoting activity of the phenolic fraction is not known. We observed that TSC phenolic fraction at non-cytotoxic concentrations attenuates BPDE-induced (i) p53 accumulation and p21 expression in human lung small airway epithelial (SAE) cells and (ii) activation of ERKs and NF-κB in mouse epidermal JB6 (P+) cells. Our ongoing effort in this respect is to understand whether TSC phenolic fraction inhibits p53 function by abrogating (i) DNA binding (in vitro and in vivo) and transcriptional activities of p53, (ii) p21 response, cell-cycle arrest, expression of G1 cyclins, activation of cdks, and phosphorylation of Rb protein, (iii) p53 stability, p53 phosphorylation/acetylation at serine and lysine residues respectively, p53- Mdm2 interaction, and PI3-K/Akt-mediated phosphorylation of Mdm2 which regulates p53-Mdm2 interaction (iv) the activation of DNA damage-induced kinases and their ability to phosphorylate p53 and (v) p53 transcription and NF-kappaB activation. The data from these studies will help in assessing the health risk presented by tobacco smoke constituents.

Polynuclear aromatic hydrocarbons and their heterocyclic analogs are ubiquitous environmental contaminants which are introduced in our environment through incomplete combustion of organic matters such as fossil fuels, tobacco, etc. It has been demonstrated that some of these compounds are potent carcinogens in laboratory animals, and may be responsible for causing majority of human cancers. There is now considerable evidence indicating that these environmental contaminants are metabolically activated to reactive metabolites which binds to DNA thereby inducing carcinogenesis. We are currently investigating various major biochemical pathways that may be involved in the bioactivation of these polynuclear aromatic compounds and their heterocyclic analogs. Our research is currently focused on: 

• Synthesis of the potential metabolites of PAHs and their heterocyclic analogs.
• vivo and in vitro metabolism of PAHs and their heterocyclic analogs, and the characterization of the metabolites produced using modern instrumental techniques (HPLC, GC, GC-MS etc).
• In vitro and in vivo bioassay of carcinogens and their various metabolites. These studies involve (i) cell transformation activity of parent compounds and their metabolites using various bacterial strains, and animal or human cells, and (ii) tumorigenic activity in animal models (mouse skin etc).
• Characterization and evaluation of the potential role of DNA adducts produced by environmental carcinogens and their metabolites using various in vitro and in vivo models in order to understand the structural requirements and the function of these DNA adducts in transforming normal cell to cancerous cells
• Characterization of specific enzymes, especially cytochrome P450s (in animals and humans) involved in the metabolic activation of chemical carcinogens. Cytochrome P450 is an important class of oxidative enzyme which play important role in the metabolic activation of environmental carcinogens. Cytochrome P450s exit in multiple forms and each form (isozyme) may differ significantly from others in its substrate specificity, regioselectivity, and stereoselctivity in the metabolism of carcinogens to their carcinogenic metabolites. Thus the characterization of specific P450s that are involved mainly in the metabolic activation of environmental carcinogens is of significant interest to cancer researchers.
• Potential role of non-carcinogenic metabolites on inhibitory and synergistic effect on the carcinogenicity of carcinogenic metabolites of carcinogens. This study is initiated to understand why certain environmental carcinogens (such as benzo[a]pyrene, dibenz[a,l]pyrene) exhibit high carcinogenic activity compared to their widely accepted ultimate carcinogens, bay-region diol epoxides.

The collective information produced from these and other mechanistic studies will help in assessing the health risk presented by various classes of environmental carcinogens, and in developing various strategies in the prevention of cancer and related diseases caused by these ubiquitous environmental carcinogens/toxicants.

Cadmium is an environmental pollutant and is one of the major metal constituents of tobacco smoke. There is considerable evidence indicating that cadmium elicits synergistic enhancement of cell transformation when combined with benzo[a]pyrene (BP) or other PAHs. Smokers are particularly at a high risk of exposure to mixture of PAHs and cadmium. The mechanism of the synergistic interaction of heavy metals particularly cadmium with PAHs is not established. We observed that cadmium at non-cytotoxic concentrations attenuates PAH-induced (i) p53 accumulation, (ii) NF-κB activation and (iii) DNA fragmentation (indicative of apoptosis) in different cell lines. We also observed that BPDE-induced NF-κB activation and DNA fragmentation are inhibited by inhibitors of p53 and NF-κB respectively. In order to examine whether the synergistic activity of cadmium is due to its interference with BP-induced signaling events which mediate p53 stability, p53 activation and p53 function toward apoptosis, we are investigating the effect of cadmium on (i) NF-κB-mediated p53 transcription, (ii) activation of signaling pathways which regulate NF-κB activation, (iii) the regulation of NF-κB subunits which determines its apoptotic or anti-apoptotic function and (iv) the expression of anti- and pro-apoptotic proteins. The data obtained from these studies will help in assessing the associated health risk presented by tobacco smoke constituents and will be useful for therapeutic strategies in the prevention of cancer.

Polynuclear aromatic hydrocarbon (PAH) are ubiquitous environmental pollutants. There is considerable evidence showing that the prototype PAH bnzo[a] pyrene (BP) induces p53 in human and mouse cells. DNA damage caused by benzo[a]pyrene (BP) or other PAHs induce p53 protein as a protective measure to eliminate the possibility of mutagenic fixation of the DNA damage. 12-O-tetradecanoylphorbol-13-acetate (TPA) inhibits p53 response induced by BP and other DNA-damaging agents and may cause tumor promotion. The molecular mechanism of attenuation of BP-induced p53 response by TPA is not known. We are investigating the interference of TPA with (i) the upstream regulation of p53 and (ii) the downstream signaling pathways which are involved in p53 function. In this regard the role of MAP kinase and NF-kappaB signaling pathways in p53 stabilization and function has been focused.

These studies include (i) developing mechanism-based suicide substartes or inhibitors of cytochrome P450s involved in the metabolic activation of P450s, (ii) developing various synthetic and naturally occurring compounds that potentially interfere with various signaling processes involved in cancer induction and its metastasis.

Lake Erie has recently been the site of botulism type E outbreaks that have affected fish, waterfowl and mudpuppies. These epizootics were caused by a paralytic neurotoxin produced by the bacterium Clostridium botulinum type E. In our previous work, we found genetic evidence of C. botulinum type E in sediment as well as in dreissenid mussels, amphipods, oligochaetes and chironomids collected from Lake Erie. This evidence strongly suggests that aquatic invertebrates are links in the transmission of the toxin from the benthic food web compartment to higher trophic levels such as fish and birds. Continuing research is aimed at gaining a better understanding of the conditions that lead to growth of this bacterium and identification of pathways of bacterial toxin transmission.

Polybrominated diphenyl ethers, PBDEs, are an emerging environmental issue of concern. They are ubiquitous in the environment and levels in humans have increased by a factor of ~100 during the last 30 years. In New York, for example, PBDEs levels of at 135 parts per billion fat were found in breast milk. PBDEs can disrupt thyroid hormone balance, impair neural development, and impair immune response, especially during fetal and neonatal development in both humans, other mammals, and fish. In the Great Lakes, PBDEs have been detected in fish from all trophic levels, and their concentration in Great Lakes fish is doubling every three to four years, even though other toxics like PCBs and mercury are declining. In this experiment, trout were fed corn contaminated with BDE-47, and there tissues were analyzed for amounts of the original material and for any possible contaminants. These analyses showed that there was initial movement of BDE-47 from the stomach to the intestine and muscle tissue, with concentrations peaking at one week. Concentrations in adipose tissue started to increase in four weeks and was still accumulating after 10 weeks. No metabolites were detected in fish tissues during this study. However, consumption of contaminated tissue by higher vertebrates may form the basis for endocrine disruption due to subsequent metabolism by the consumer.

Endocrine-disrupting compounds, ranging from natural estrogens to industrial chemicals (PCBs and PBDEs) enter the Great Lakes and their tributaries through discharge of municipal wastewater treatment plants (WWTPs), industrial wastes, and agricultural drainage. Elevated levels of these compounds in aquatic systems affect fish and other organisms through their effect as endocrine regulators. The presence of estrogens in lakes has been linked to feminization of male fish, reproductive failure, and collapse of the fish population. This on-going project aims to determine the occurrence of estrogens of anthropogenic origin/activities in male fish of selected eastern Lake Erie species.