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Jeremy P. Holden

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Deepwater sculpin are important in oligotrophic lakes as one of the few fishes that use deep profundal habitats and link invertebrates in those habitats to piscivores. In Lake Ontario the species was once abundant, however drastic declines in the mid-1900s led some to suggest the species had been extirpated and ultimately led Canadian and U.S. agencies to elevate the species' conservation status. Following two decades of surveys with no captures, deepwater sculpin were first caught in low numbers in 1996 and by the early 2000s there were indications of population recovery. We updated the status of Lake Ontario deepwater sculpin through 2016 to inform resource management and conservation. Our data set was comprised...
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Benthic prey fishes are a critical component of the Lake Ontario food web, serving as energy vectors from benthic invertebrates to native and introduced piscivores. Beginning in 1978, Lake Ontario benthic prey fishes were assessed using bottom trawls collected from the lake’s south shore (depth range: 8 – 150 m). Historically, the survey targeted the then dominant species, Slimy Sculpin, however in 2015, the Benthic Prey Fish Survey was cooperatively expanded to a whole-lake survey, to address resource management information needs related to Round Goby, Deepwater Sculpin, and nearshore native fishes. In 2016, 142 trawls were collected at 18 transects, and spanned depths from 6 – 225 m. Trawl catches indicated the...
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Managing Lake Ontario fisheries in an ecosystem-context, requires reliable data on the status and trends of prey fishes that support predator populations. We report on the community and population dynamics of Lake Ontario pelagic prey fishes, based on bottom trawl surveys. We emphasize information that supports the international Lake Ontario Committee’s Fish Community Objectives. In 2016, 142 bottom trawls were collected in U.S. waters, and for the first time 46 trawls were conducted in Canadian waters. A total of 420,386 fish from 24 species were captured. Alewife were 89% of the total fish catch and 93% of the pelagic prey fish catch. The Rainbow Smelt abundance index in U.S. waters increased slightly in 2016...
Categories: Publication; Types: Citation
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In 2015 the joint USGS and NYSDEC surveys for Alewife and Rainbow Smelt were combined for the first time into a comprehensive spring pelagic prey fish survey. The adult Alewife abundance and weight indices in 2015 increased slightly from 2014 levels, and adult Alewife abundance has remained relatively stable for the past five years. Adult Alewife condition in both spring and fall increased from 2014 values and was above long-term means. Yearling Alewife abundance was the lowest observed in the 38-year time series. Alewife year class strength at age 1 is related to the number of spawning adults and summer temperatures and winter duration in the first year after hatching. Moderate year classes were produced during...
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Alewife (Alosa pseudoharengus) and Rainbow Smelt (Osmerus mordax) are the most abundant pelagic planktivores in Lake Ontario (Weidel et al 2017), and the most important prey for salmon and trout, making up greater than 90% of the diet of the top predator, Chinook salmon (Lantry 2001, Brandt 1986), and supporting a multimillion dollar sportfishery. Alewife are also important prey for warm water predators, notably Walleye (Sander vitreus). Abundance of Alewife and smelt has declined since the 1980s, likely due to reduced nutrient loading, proliferation of invasive dreissenid mussels, and predation by stocked salmon and trout. Cisco (Coregonus artedi), a native planktivore, historically dominated the offshore pelagic...
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