Publications

Population assessments of fish species often rely on data from surveys with different objectives, such as measuring biodiversity or community dynamics. These surveys often contain spatial–temporal dependencies that can greatly influence conclusions drawn from analyses. Pygmy whitefish (PWF, Prosopium coulterii) populations in Lake Superior were recently assessed as Threatened by the Committee on t

Walleye (Sander vitreus) is an economically and culturally important species in Lake Erie that has experienced large interannual variability in recruitment. We examined the importance of prey biomass during the larval period to walleye recruitment while also considering the importance of temperature. Using nine years of field data over a 22-year period (1994–2016) for larval walleye and zooplankto

The Lake Ontario April bottom trawl survey and Alewife, Alosa psuedoharengus population assessment are conducted annually to track prey fish community status and aid management decisions related to predator-prey balance. No survey was conducted in 2020 due to the Covid-19 pandemic. The 2021 survey included 248 bottom trawls in both U.S. and Canadian waters, from March 30 - May 7 in the main lake a

A U.S. Geological Survey-led assessment of data gaps and science needs across the Great Lakes ecosystem indicated the following:• Expanded data collection or monitoring would provide basic ecosystem, social, and public health data to manage the Great Lakes system and to develop and test models and decision support tools.• New science and advanced technologies (for example, sensors and high-perform

No abstract available.

No abstract available.

Changes in winter conditions, such as decreased ice coverage and duration, have been observed in the Laurentian Great Lakes for more than 20 years. Such changes have been hypothesized to be linked to low Coregonus spp. survival to age-1 as most cisco (Coregonus artedi) populations are autumn spawners whose embryos incubate under ice throughout the winter. The quantity of light during winter is reg

In 2014, 94 paired neuston net samples (0.5 mm mesh) were collected from the surface waters of Lake Superior. These samples comprise the most comprehensive surface water survey for microplastics of any of the Great Lakes to date, and the first to employ double net trawls. Microplastic abundance estimates showed wide variability, ranging between 4000 to more than 100,000 particles/km2 with most loc

Estimates of the number of successfully breeding adults (NS) in a population can predict levels of recruitment. However, assessments of NS are often difficult to obtain because encounters with adults are limited due to life-history characteristics, low abundance or other constraints associated with access to critical habitats. Alternatively, efforts to sample individuals at earlier ontogenetic sta

To determine if a survival bottleneck occurs in Lake Erie's lake whitefish (Coregonus clupeaformis) population and explore possible mechanisms responsible, we examined contemporary and historical dynamics of lake whitefish eggs, larvae and juveniles. Widespread spawning and low overwinter egg retention were observed in 2016–2018, however subsequent larval CPUE remained consistent with historical o

Sea lamprey (SL; Petromyzon marinus), one of the oldest living vertebrates, have a complex metamorphic life cycle. Following hatching, SL transition into a microphagous, sediment burrowing larval stage, and after 2–10+ years, the larvae undergo a dramatic metamorphosis, transforming into parasitic juveniles that feed on blood and bodily fluids of fishes; adult lamprey cease feeding, spawn, and die

Costs to producing sexual signals can create selective pressures on males to invest signaling effort in particular contexts. When the benefits of signaling vary consistently across time, males can optimize signal investment to specific temporal contexts using biological rhythms. Sea lamprey, Petromyzon marinus, have a semelparous life history, are primarily nocturnal, and rely on pheromone communi