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Quagga Mussel Induced Phosphorus Cycling Changes In Lake Michigan, Rae-Ann Maclellan-Hurd Aug 2020

Quagga Mussel Induced Phosphorus Cycling Changes In Lake Michigan, Rae-Ann Maclellan-Hurd

Theses and Dissertations

Quagga mussels (Dreissena rostriformis bugensis) are an invasive ecosystem engineer that have successfully colonized both profundal and nearshore regions in Southern Lake Michigan. Quagga mussels directly altered the flow of nutrients by filtering particles, excretion of soluble forms of nutrients in the benthos, and through the production of biodeposits. Mussel excretion, egestion, and capture rates of P were compared between a 25 meter and a 55 meter deep site near Milwaukee Harbor to determine the retention of nutrients in these regions. The capture rate of particulate phosphorus at the 25m site (278 ± 388 μmol m-2) was similar to that …


An Investigation Into The Trophic Magnification Of Polychlorinated Biphenyls In The Lake Michigan Food Web, Philip Hurst May 2020

An Investigation Into The Trophic Magnification Of Polychlorinated Biphenyls In The Lake Michigan Food Web, Philip Hurst

Theses and Dissertations

Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants known to contribute to several adverse health conditions in humans including cancers and a suite of liver diseases. While there exist 209 unique PCB congeners, the World Health Organization has identified 12 that pose the greatest health risk to humans due to these congeners’ functional similarity to dioxins, another notoriously toxic class of contaminants. Along with methylmercury, PCBs are the primary drivers behind fish consumption advisories in the Great Lakes. These guidelines are informed primarily by surveys of contaminants in freshwater biota. However, the proliferation of invasive species, such as …


Senior Project: An Investigative Study Into The Bacterial Contamination Of Little Black Creek, Margaret I. Brenneman Apr 2020

Senior Project: An Investigative Study Into The Bacterial Contamination Of Little Black Creek, Margaret I. Brenneman

Honors Projects

An investigation of Escherichia coli concentrations in a west Michigan stream was conducted to determine sources of fecal contamination that impact water quality. Little Black Creek (LBC) is located in Muskegon County and discharges into Lake Michigan at the P.J. Hoffmaster Campground Beach. Often referred to as an “indicator bacteria,” water contaminated with E. coli has a high probability to contain other enteric pathogens as well. Beach water testing in 2020 using Colilert-18 methods revealed E. coli levels of 579 cfu/100mL in the creek discharge area that exceeded total body contact criteria of 300 cfu/100mL. A follow-up study of the …


Survival, Fidelity, And Dispersal Of Double-Crested Cormorants On Two Lake Michigan Islands, Christopher R. Ayers, Katie C. Hanson-Dorr, Ken Stromborg, Todd W. Arnold, Jacob S. Ivan, Brian S. Dorr Jun 2019

Survival, Fidelity, And Dispersal Of Double-Crested Cormorants On Two Lake Michigan Islands, Christopher R. Ayers, Katie C. Hanson-Dorr, Ken Stromborg, Todd W. Arnold, Jacob S. Ivan, Brian S. Dorr

USDA Wildlife Services: Staff Publications

Colony fidelity and dispersal can have important consequences on the population dynamics of colonial-nesting birds. We studied survival and inter-colony movements of Double-crested Cormorants (Phalacrocorax auritus; cormorants) nesting at Spider and Pilot islands, located 9 km apart in western Lake Michigan, during 2008–2014. We used live resighting and dead recovery data from both colonies, plus dead recoveries from throughout North America, in a multistate live and dead encounter model to estimate annual survival, inter-colony movements, plus temporary and permanent emigration to unmonitored sites. Annual survival averaged 0.37 (annual process variation, ˆ = 0.07) for hatch-year, 0.78 (ˆ= 0.08) for secondyear, …


Comparison Of An Electron Transport System (Ets) Enzyme-Mediated Reduction Assay And Respiration Rate Of The Invasive Copepod Eurytemora Carolleeae In Green Bay, Wi, Usa, Alexander Timpe May 2019

Comparison Of An Electron Transport System (Ets) Enzyme-Mediated Reduction Assay And Respiration Rate Of The Invasive Copepod Eurytemora Carolleeae In Green Bay, Wi, Usa, Alexander Timpe

Lawrence University Honors Projects

The use of aquatic resources for agriculture, trade, and recreation adds stress to water-dwelling organisms. Rapid changes in abiotic conditions, such as warming due to climate change and nutrient loading from agricultural runoff and urban areas, threaten to induce profound alterations to aquatic environments. These changes affect interspecific community interactions and may cause an aquatic resource to lose its functionality that is valuable to humans. Studying organisms such as plankton that form an ecosystem’s foundation is an important step towards understanding the entire food web and predicting how it may or may not be able to respond to a changing …


Pseudomonas Diversity Within Urban Freshwaters, Mary Batrich, Laura Maskeri, Ryan Schubert, Brian Ho, Melanie Kohout, Malik Abdeljaber, Ahmed Abuhasna, Mutah Kholoki, Penelope Psihogios, Tahir Razzaq, Samrita Sawhney, Salah Siddiqui, Eyad Xoubi, Alexandria Cooper, Thomas Hatzopoulos, Catherine Putonti Feb 2019

Pseudomonas Diversity Within Urban Freshwaters, Mary Batrich, Laura Maskeri, Ryan Schubert, Brian Ho, Melanie Kohout, Malik Abdeljaber, Ahmed Abuhasna, Mutah Kholoki, Penelope Psihogios, Tahir Razzaq, Samrita Sawhney, Salah Siddiqui, Eyad Xoubi, Alexandria Cooper, Thomas Hatzopoulos, Catherine Putonti

Bioinformatics Faculty Publications

Freshwater lakes are home to bacterial communities with 1000s of interdependent species. Numerous high-throughput 16S rRNA gene sequence surveys have provided insight into the microbial taxa found within these waters. Prior surveys of Lake Michigan waters have identified bacterial species common to freshwater lakes as well as species likely introduced from the urban environment. We cultured bacterial isolates from samples taken from the Chicago nearshore waters of Lake Michigan in an effort to look more closely at the genetic diversity of species found there within. The most abundant genus detected was Pseudomonas, whose presence in freshwaters is often attributed …


Survey Of Microbial Populations Within Lake Michigan Nearshore Waters At Two Chicago Public Beaches, Kema Malki, Katherine Bruder, Catherine Putonti Sep 2017

Survey Of Microbial Populations Within Lake Michigan Nearshore Waters At Two Chicago Public Beaches, Kema Malki, Katherine Bruder, Catherine Putonti

Catherine Putonti

Lake Michigan is a critical resource for the residents of Chicago, providing drinking water to its 9+ million area residents. Along Chicago׳s 26 miles of public beaches the populous urban environment and this freshwater environment meet. While city-led monitoring initiatives investigate pathogenic bacteria in these nearshore waters, very little is known about other microbial species present. We collected surface water samples from two Chicago public beaches – Montrose Beach and 57th Street Beach – every ten days from June 5 through August 4, 2013 as well as once in early Fall (October 4, 2013). Sixteen bacterial communities in total were …


Survey Of Viral Populations Within Lake Michigan Nearshore Waters At Four Chicago Area Beaches, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Siobhan C. Watkins, Yuriy Fofanov, Catherine Putonti Sep 2017

Survey Of Viral Populations Within Lake Michigan Nearshore Waters At Four Chicago Area Beaches, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Siobhan C. Watkins, Yuriy Fofanov, Catherine Putonti

Catherine Putonti

In comparison to the oceans, freshwater environments represent a more diverse community of microorganisms, exhibiting comparatively high levels of variability both temporally and spatially Maranger and Bird, Microb. Ecol. 31 (1996) 141–151. This level of variability is likely to extend to the world of viruses as well, in particular bacteria-infecting viruses (bacteriophages). Phages are known to influence bacterial diversity, and therefore key processes, in environmental niches across the globe Clokie et al., Bacteriophage 1 (2011) 31–45; Jacquet et al., Adv. Ocean Limn. 1 (2010) 97–141; Wilhelm and Suttle, Bioscience 49 (1999) 781–788; Bratback et al., Microb. Ecol. 28 (1994) 209–221. …


18s Rdna Dataset Profiling Microeukaryotic Populations Within Chicago Area Nearshore Waters, Daniel Searle, Emily Sible, Alexandria Cooper, Catherine Putonti Sep 2017

18s Rdna Dataset Profiling Microeukaryotic Populations Within Chicago Area Nearshore Waters, Daniel Searle, Emily Sible, Alexandria Cooper, Catherine Putonti

Catherine Putonti

Despite their critical role in the aquatic food web and nutrient cycling, microeukaryotes within freshwater environments are under-studied. Herein we present the first high-throughput molecular survey of microeukaryotes within Lake Michigan. Every two weeks from May 13 to August 5, 2014, we collected surface water samples from the nearshore waters of four Chicago area beaches: Gillson Park, Montrose Beach, 57th Street Beach, and Calumet Beach. Four biological replicates were collected for each sampling date and location, resulting in 112 samples. Eighty-nine of these samples were surveyed through targeted sequencing of the V7 and V8 regions of the 18S rDNA gene. …


Assessment Of Microbial Populations Within Chicago Area Nearshore Waters And Interfaces With River Systems, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Thomas Hatzopoulos, Siobhan C. Watkins, Catherine Putonti Sep 2017

Assessment Of Microbial Populations Within Chicago Area Nearshore Waters And Interfaces With River Systems, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Thomas Hatzopoulos, Siobhan C. Watkins, Catherine Putonti

Catherine Putonti

The Chicago area locks separate and control water flow between the freshwaters of Lake Michigan and the network of Illinois waterways. Under extreme storm conditions, however, the locks are opened and storm waters, untreated waste, and runoff are released directly into the lake. These combined sewer overflow (CSO) events introduce microbes, viruses, and nutrients such as nitrogen and phosphorous into nearshore waters which likely affect the native species. We collected surface water samples from four Chicago area beaches – Gillson Park, Montrose Beach, 57th Street Beach, and Calumet Beach – every two weeks from May 13 through August 5, 2014. …


Yellow Perch Genetic Stock Structure In Eastern Lake Michigan: What Is The Importance Of Drowned River Mouth Lakes?, Gregory M. Chorak Aug 2017

Yellow Perch Genetic Stock Structure In Eastern Lake Michigan: What Is The Importance Of Drowned River Mouth Lakes?, Gregory M. Chorak

Masters Theses

Habitat heterogeneity has the possibility of structuring populations. Even in connected landscapes, there can be cryptic structuring of populations that coincides with landscape features that limit gene flow or select for different phenotypes within a species. Yellow perch (Perca flavescens) is an economically and ecologically prominent fish in the Laurentian Great Lakes. In the Lake Michigan basin, yellow perch reside in nearshore Lake Michigan, including drowned river mouths (DRMs, lake-like habitats that link tributaries to Lake Michigan). The goal of this study was to understand whether yellow perch populations are structured in eastern Lake Michigan by the connected …


A Spiny Water Flea Invasion And Effects On The Zooplankton Community In Southern Green Bay, Lake Michigan, Casey Ann Merkle May 2017

A Spiny Water Flea Invasion And Effects On The Zooplankton Community In Southern Green Bay, Lake Michigan, Casey Ann Merkle

Lawrence University Honors Projects

The spiny water flea (Bythotrephes longimanus) is an invertebrate aquatic invasive species (AIS) in the Great Lakes that competes with native fish species for zooplankton, perhaps contributing to a decline of fish populations or changes in zooplankton communities in Lake Michigan. Bythotrephes produce two types of eggs, immediately hatching versus resting eggs which are tolerant to harsh conditions and allow for rapid dispersal. We determined Bythotrephes population density and population dynamics in Green Bay during the summer months of 2015 and 2016. Population dynamics were similar at both sites in Green Bay in each year, with peak population …


Population Genetics And Distribution Of The Oriental Weatherfish, Misgurnus Anguillicaudatus, In Chicago Area Waterways, John Belcik Jan 2017

Population Genetics And Distribution Of The Oriental Weatherfish, Misgurnus Anguillicaudatus, In Chicago Area Waterways, John Belcik

Master's Theses

Oriental Weatherfish (Misgurnus anguillicaudatus), native to Southeast Asia, are freshwater fish belonging to the family Cobitidae (loaches). They are benthic fish with the ability to breathe atmospheric air, and exhibit an unusual behavior of swimming vertically in the water column in response to changes in barometric pressure. Oriental Weatherfish appear to be successful invaders to North American waterways. Within the last century they have been sighted in freshwater systems throughout the United States, yet the distribution and source of this invasion are largely unknown. This study investigates the distribution patterns, surveying methods, and population genetics of the Oriental Weatherfish within …


From Land To Lake: Contrasting Microbial Processes Across A Great Lakes Gradient Of Organic Carbon And Inorganic Nutrient Inventories, Deborah K. Dila Aug 2016

From Land To Lake: Contrasting Microbial Processes Across A Great Lakes Gradient Of Organic Carbon And Inorganic Nutrient Inventories, Deborah K. Dila

Masters Theses

Freshwater ecosystems have strong linkages to the terrestrial landscapes that surround them, and contributions of carbon and inorganic nutrients from soil, vegetation and anthropogenic sources subsidize autochthonous water body productivity to varying degrees. Abundant freshwater phytoplankton and bacterioplankton are key to linking the planet's geosphere and atmosphere to the food webs in the hydrosphere through their growth and respiration. Rich resources that move through land margin waterways make them active sites for cycling organic carbon and thus important, but understudied, contributors to global climate. During 2010-2011, we examined seasonal changes in carbon and nutrient inventories, plankton community composition and metabolism …


18s Rdna Dataset Profiling Microeukaryotic Populations Within Chicago Area Nearshore Waters, Daniel Searle, Emily Sible, Alexandria Cooper, Catherine Putonti Jan 2016

18s Rdna Dataset Profiling Microeukaryotic Populations Within Chicago Area Nearshore Waters, Daniel Searle, Emily Sible, Alexandria Cooper, Catherine Putonti

Bioinformatics Faculty Publications

Despite their critical role in the aquatic food web and nutrient cycling, microeukaryotes within freshwater environments are under-studied. Herein we present the first high-throughput molecular survey of microeukaryotes within Lake Michigan. Every two weeks from May 13 to August 5, 2014, we collected surface water samples from the nearshore waters of four Chicago area beaches: Gillson Park, Montrose Beach, 57th Street Beach, and Calumet Beach. Four biological replicates were collected for each sampling date and location, resulting in 112 samples. Eighty-nine of these samples were surveyed through targeted sequencing of the V7 and V8 regions of the 18S rDNA gene. …


Diel Vertical Migration Of An Invasive Calanoid Copepod, Eurytemora Affinis, In Little Sturgeon Bay, Wisconsin, Alexandra N. Poli Jun 2015

Diel Vertical Migration Of An Invasive Calanoid Copepod, Eurytemora Affinis, In Little Sturgeon Bay, Wisconsin, Alexandra N. Poli

Lawrence University Honors Projects

Eurytemora affinis, a calanoid copepod, is known to be a versatile, prolific invader of freshwater ecosystems across the globe. It has recently been documented in the Laurentian Great Lakes, including in Little Sturgeon Bay, an embayment of Lake Michigan. One survival mechanism that could make E. affinis a successful invader is diel vertical migration (DVM), a behavior in which animals move to different lakes depths at different times of day in order to avoid predation. Much is known about DVM of E. affinis, but primarily from studies in marine and brackish systems. Our goal was to investigate how …


Round Goby-Induced Changes In Young-Of-Year Yellow Perch Diet And Habitat Selection, Christopher John Houghton May 2015

Round Goby-Induced Changes In Young-Of-Year Yellow Perch Diet And Habitat Selection, Christopher John Houghton

Theses and Dissertations

A critical step in the recruitment of age-0 yellow perch (Perca flavescens) to the

adult population occurs during their transition to the demersal stage. If larval age-0

yellow perch survive recruitment bottlenecks imposed by alewife (Alosa

pseudoharengus) and dreissenid mussels, they transition to demersal feeding in late

August and early September. In Lake Michigan, demersal age-0 yellow perch seek

rock substrate where they begin feeding on benthic invertebrates in late summer.

That research preceded the invasion of the round goby (Neogobius melanostomus), a

species that can have negative impacts on benthic forage. The current study used

the spread of round …


Assessment Of Microbial Populations Within Chicago Area Nearshore Waters And Interfaces With River Systems, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Thomas Hatzopoulos, Siobhan C. Watkins, Catherine Putonti Jan 2015

Assessment Of Microbial Populations Within Chicago Area Nearshore Waters And Interfaces With River Systems, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Thomas Hatzopoulos, Siobhan C. Watkins, Catherine Putonti

Bioinformatics Faculty Publications

The Chicago area locks separate and control water flow between the freshwaters of Lake Michigan and the network of Illinois waterways. Under extreme storm conditions, however, the locks are opened and storm waters, untreated waste, and runoff are released directly into the lake. These combined sewer overflow (CSO) events introduce microbes, viruses, and nutrients such as nitrogen and phosphorous into nearshore waters which likely affect the native species. We collected surface water samples from four Chicago area beaches – Gillson Park, Montrose Beach, 57th Street Beach, and Calumet Beach – every two weeks from May 13 through August 5, 2014. …


Survey Of Viral Populations Within Lake Michigan Nearshore Waters At Four Chicago Area Beaches, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Siobhan C. Watkins, Yuriy Fofanov, Catherine Putonti Jan 2015

Survey Of Viral Populations Within Lake Michigan Nearshore Waters At Four Chicago Area Beaches, Emily Sible, Alexandria Cooper, Kema Malki, Katherine Bruder, Siobhan C. Watkins, Yuriy Fofanov, Catherine Putonti

Bioinformatics Faculty Publications

In comparison to the oceans, freshwater environments represent a more diverse community of microorganisms, exhibiting comparatively high levels of variability both temporally and spatially Maranger and Bird, Microb. Ecol. 31 (1996) 141–151. This level of variability is likely to extend to the world of viruses as well, in particular bacteria-infecting viruses (bacteriophages). Phages are known to influence bacterial diversity, and therefore key processes, in environmental niches across the globe Clokie et al., Bacteriophage 1 (2011) 31–45; Jacquet et al., Adv. Ocean Limn. 1 (2010) 97–141; Wilhelm and Suttle, Bioscience 49 (1999) 781–788; Bratback et al., Microb. Ecol. 28 (1994) 209–221. …


Survey Of Microbial Populations Within Lake Michigan Nearshore Waters At Two Chicago Public Beaches, Kema Malki, Katherine Bruder, Catherine Putonti Jan 2015

Survey Of Microbial Populations Within Lake Michigan Nearshore Waters At Two Chicago Public Beaches, Kema Malki, Katherine Bruder, Catherine Putonti

Bioinformatics Faculty Publications

Lake Michigan is a critical resource for the residents of Chicago, providing drinking water to its 9+ million area residents. Along Chicago׳s 26 miles of public beaches the populous urban environment and this freshwater environment meet. While city-led monitoring initiatives investigate pathogenic bacteria in these nearshore waters, very little is known about other microbial species present. We collected surface water samples from two Chicago public beaches – Montrose Beach and 57th Street Beach – every ten days from June 5 through August 4, 2013 as well as once in early Fall (October 4, 2013). Sixteen bacterial communities in total were …


Genetic Structure Of Yellow Perch Populations In Coastal Areas Of Eastern Lake Michigan, Jessica N. Wesolek Dec 2014

Genetic Structure Of Yellow Perch Populations In Coastal Areas Of Eastern Lake Michigan, Jessica N. Wesolek

Masters Theses

Genetic population substructure is often overlooked because of discontinuities between management and actual population structure as in the case of yellow perch, an ecologically and economically important indigenous fish species in the Laurentian Great Lakes. A knowledge gaps pertaining to the natural history of yellow perch relates to the biological connectivity between nearshore Lake Michigan and drowned river mouth (DRM) lakes, where it remains unclear whether resident yellow perch from Lake Michigan use DRM lakes for spawning or whether DRM lakes contribute to nearshore yellow perch populations in Lake Michigan. I used DNA fingerprinting (genotyping) to explore biological connectivity between …


Phosphorus Recycling By Profunda Quagga Mussels In Lake Michigan, Caroline Mosley Dec 2014

Phosphorus Recycling By Profunda Quagga Mussels In Lake Michigan, Caroline Mosley

Theses and Dissertations

Quagga mussels (Dreissena rostiformis bugensis) act as ecosystem engineers in the southern basin of Lake Michigan, altering physical habitats and biogeochemical processes. Adapted to cold and oligotrophic conditions, profunda quagga mussels thrive on the soft substrate of deeper depths. At a 55 m site (10,000 mussels m-2) offshore from Milwaukee, WI, profunda mussel biomass (g m-2) was 1/3 of biomass (g m-2) measured at a 10 m comparison site (5,000 mussels m-2). Higher densities but less biomass is due to profunda mussels having less tissue for a given length and the population per m2 comprising of mostly small mussels ( …


Variation In Round Goby Feeding Interactions In Near-Shore Lake Michigan Based On Three Trophic Indicators, Michael Lee Henebry Jul 2014

Variation In Round Goby Feeding Interactions In Near-Shore Lake Michigan Based On Three Trophic Indicators, Michael Lee Henebry

Open Access Theses

Understanding trophic interactions of non-native species is key to elucidating their potential ecological role in newly-invaded ecosystems. The Great Lakes region has long been characterized by a high rate of invasive species establishment. Round Goby (Neogobius melanostomus ) were first detected in Lake Michigan in 1994, and have since increased dramatically in abundance. While past studies of Round Goby in Lake Michigan have primarily focused on specific regions and habitats, Lake Michigan is a large, diverse system and Round Goby trophic interactions may vary across regions and over time. During May, July, and September 2010-2011, we collected Round Goby …


Plankton Trophic Structure Within Lake Michigan As Revealed By Stable Carbon And Nitrogen Isotopes, Zachery G. Driscoll May 2014

Plankton Trophic Structure Within Lake Michigan As Revealed By Stable Carbon And Nitrogen Isotopes, Zachery G. Driscoll

Theses and Dissertations

Zooplankton represent a critical component of aquatic food webs in that they transfer energy from primary producers to higher trophic positions. However, their small size makes the application of traditional trophic ecology techniques difficult. Fortunately, novel techniques have been developed that can be used to elucidate feeding information between zooplankton species. I used the analysis of stable carbon and nitrogen isotope ratios to estimate the trophic structure of Lake Michigan's zooplankton community. The major zooplankton species, three size classes of seston, and seston from specific water column depths were collected in 2011 and 2012 for stable isotope analysis. Trophic position …


Diet Analysis Of Burbot From Eastern Lake Michigan: 1999-2012, Casey J. Hares May 2014

Diet Analysis Of Burbot From Eastern Lake Michigan: 1999-2012, Casey J. Hares

All NMU Master's Theses

The Lake Michigan fish community has undergone many changes due to introduction of non-native species, climate shifts, and management actions. Managers need to understand the time course of these alterations, including the time-frame of impact on the food web in the lake. I used a collection (1999-2012) of diet samples from burbot from eastern Lake Michigan to evaluate temporal alterations in burbot diet with particular attention to non-native vs. native forage. Catch per unit effort (burbot/net · day) decreased from a high of 5.82 burbot/net · day (± 2.19) in 2001 to a low of 0.750 burbot/net · day (± …


Distribution And Dynamics Of Nitrogen And Microbial Plankton In Southern Lake Michigan During Spring Transition 1999-2000, Wayne S. Gardner, Peter J. Lavrentyev, Joann F. Cavaletto, Mark J. Mccarthy, B. J. Eadie, Thomas Johengen, James Cotner Apr 2014

Distribution And Dynamics Of Nitrogen And Microbial Plankton In Southern Lake Michigan During Spring Transition 1999-2000, Wayne S. Gardner, Peter J. Lavrentyev, Joann F. Cavaletto, Mark J. Mccarthy, B. J. Eadie, Thomas Johengen, James Cotner

Peter J. Lavrentyev

[ 1] Ammonium and amino acid fluxes were examined as indicators of N and microbial food web dynamics in southern Lake Michigan during spring. Either (NH4+)-N-15 or a mixture of N-15-labelled amino acids (both at 4 muM N final concentration) was added to Lake Michigan water. Net fluxes were measured over 24 h under natural light and dark conditions using deck-top incubators and compared to microbial food web characteristics. Isotope dilution experiments showed similar light and dark NH4+ regeneration rates at lake ( 6 versus 5 nM N h(-1)) and river-influenced ( 20 versus 24 nM N h(-1)) sites. Ammonium …


Effects Of Toxic Cyanobacteria (Microcystis Aeruginosa) On The Feeding And Reproduction Ecology Of The Copepod Eurytemora Affinis From Green Bay, Lake Michigan, Nicholas J. Barrett Jan 2014

Effects Of Toxic Cyanobacteria (Microcystis Aeruginosa) On The Feeding And Reproduction Ecology Of The Copepod Eurytemora Affinis From Green Bay, Lake Michigan, Nicholas J. Barrett

Lawrence University Honors Projects

Toxic Cyanobacteria is known to be a bad food source to consumers as well as a main contributor to harmful algal blooms. This study investigates the feeding relationship between an invasive copepod in the Great Lakes system, Eurytemora affinis, and a toxic strain of cyanobacteria, Microcystis aeruginosa. E.affinis has been shown to feed on toxic cyanobacteria. By measuring the filtering rate, ingestion rate, egg production and offspring size between three different food conditions, we hope to gain insight into the effects of toxic cyanobacteria on the feeding and reproduction of this copepod. Food sources include a good green algal …


Lake Michigan Hydrodynamics: Mysis And Larval Fish Interactions, Yutta Wang Dec 2013

Lake Michigan Hydrodynamics: Mysis And Larval Fish Interactions, Yutta Wang

Theses and Dissertations

I studied the interactions between Lake Michigan hydrodynamics (the spring thermal bar) and Mysis, deepwater sculpin, and burbot larvae. The thermal bar is a zone of sinking 4º С water that separates warmer inshore water from colder offshore water. Mysis was a major bycatch of sampling for larval fishes. The density of Mysis did not differ statistically between inshore (about 6º С) and offshore of the thermal bar, but the percentage of Mysis that were newborns was significantly higher inshore (P = 0.007). These "early start" coastal Mysis may have an advantage in growth and survival, but with the risk …


The Effects Of Habitat Use On The Round Goby, Neogobius Melanostomus, In The Lower Fox River And Lake Michigan., Matthew E. Larsen May 2013

The Effects Of Habitat Use On The Round Goby, Neogobius Melanostomus, In The Lower Fox River And Lake Michigan., Matthew E. Larsen

Lawrence University Honors Projects

The invasive round goby was introduced to Lake Michigan in 1998 (DeStasio, 2012). Since the species was introduced they have increased their range to include tributaries of the Lake Michigan watershed; such as the Lower Fox River. The presence of the round goby in the Lower Fox River was first documented in the Lower Fox River in 2006 (Kornis, 2008). We compared the size and age differences between round goby populations at these habitats to see if there was a variance between the two habitats. Round goby from Lake Michigan were statistically longer and heavier than those from the Lower …


Nearshore Benthic Oxygen Dynamics In Lake Michigan, Emily H. Tyner May 2013

Nearshore Benthic Oxygen Dynamics In Lake Michigan, Emily H. Tyner

Theses and Dissertations

The intense colonization of the Laurentian Great Lakes by dreissenid mussels has profoundly changed ecosystem processes, particularly benthic oxygen dynamics. Dissolved oxygen concentrations in mussel beds, sloughed Cladophora mats, and sediment indicate that hypoxia forms and disappears in some substrata (ephemeral Cladophora mats), while occurring consistently in others (depositional areas of sloughed Cladophora). Dissolved organic carbon concentrations are high (mean: 143 ± ± 28 ppm) in depositional Cladophora mats but lower (˂ 10 ppm) in most other environments. Field sampling and laboratory experiments suggest that under conditions of low water velocity and thick Cladophora cover, hypoxia may develop atop …