Tributaries support spawning habitats for three of the four major sub-stocks of Lake Erie walleye (Sander vitreus). Despite a history of anthropogenic degradation and the extirpation of other potamodromous species, the Maumee River, OH continues to support one of the largest fish migrations in the Laurentian Great Lakes. To determine if spawning habitat availability and quality could limit production of Maumee River walleye, a habitat suitability model based on river bottom substrates and water depth was created for the lower 51 km of the Maumee River, and the distribution and relative abundance of walleye eggs deposited in a 25-km stretch of river were assessed. Walleye eggs were collected using a diaphragm pump at 7-10 sites two to three times per week from 1 April–7 May 2014 and from 24 March–5 May 2015, beginning shortly after ice out and continuing until early May when spawning ceased. To quantify spawning habitat within the Maumee River, a side-scan sonar unit and a bow-mounted transducer were used to identify river bottom substrate types. Substrate composition was visually delineated by drawing polygons around substrate patches and assigning the dominant substrate classification to each polygon in GIS software. Visual substrate surveys were conducted throughout the study area during June and September 2014–2016 and were used to inform the substrate classifications made by the side-scan sonar. Water depth and water velocity were modeled in the hydraulic modeling program HEC-RAS based on topographic data and water level gage data. Known walleye spawning habitat preferences from peer-reviewed literature were used to assign habitat suitability index (HSI) values from two different HSI models to substrate, modeled water depth, and modeled water velocity for spawning adult walleye, and habitat suitability maps were generated.

Lake Erie walleye (Stizostedion vitreum) recruitment fluctuates annually and depends partially on their diet and growth during their first year of life. To determine how age-0 walleye have responded to changes in prey species and abundance, larval and young of year walleye were collected from western Lake Erie in 2019 and 2014. Larval and young of year fish stomachs were extracted and dissected, with prey contents removed for later identification. All prey contents were identified to the lowest possible taxonomic level using a dissecting microscope and counted, with up to 20 prey items from each taxa per fish measured (0.01 mm) using a digital computer image analysis system. Zooplankton prey items were identified to order, family, or genus and measured for body length, excluding the spine. Invertebrate prey items were identified to order, family, or genus and measured for body length and/or head capsule width. Fish prey items were measured for total length, standard length, backbone length, or otolith length depending on their degree of digestion.

Lake Erie walleye (Stizostedion vitreum) recruitment fluctuates annually and depends partially on their diet and growth during their first year of life. To determine how age-0 walleye have responded to changes in prey species and abundance, larval and young of year walleye were collected from western Lake Erie in 2019 and 2014. Larval and young of year fish stomachs were extracted and dissected, with prey contents removed for later identification. All prey contents were identified to the lowest possible taxonomic level using a dissecting microscope and counted, with up to 20 prey items from each taxa per fish measured (0.01 mm) using a digital computer image analysis system. Zooplankton prey items were identified to order, family, or genus and measured for body length, excluding the spine. Invertebrate prey items were identified to order, family, or genus and measured for body length and/or head capsule width. Fish prey items were measured for total length, standard length, backbone length, or otolith length depending on their degree of digestion.

Defining a realized niche using key habitat components like temperature, water clarity, and dissolved oxygen (DO) is important to understanding how distributions and demographics of freshwater fish populations may respond to environmental changes. However, habitat preferences are often defined in a laboratory setting and may not accurately reflect preferred habitat in nature. To define a realized niche for walleye, temperature and depth sensors were implanted into 176 fish in three northern Wisconsin lakes while temperature, light intensity, and dissolved oxygen (DO) profiles were monitored within each lake. These data include: 1) sensor temperature and depth observations collected by acoustic telemetry and archival tags between June – October 2022, 2) information on walleye tagged in this study, 3) sensor information from HOBO loggers that recorded lake light intensity and temperature, and 4) dissolved oxygen profiles recorded during the study period.

These data include a field study of the sediment hardness and fish egg density (walleye [Sander vitreus] and lake whitefish [Coregonus clupeaformis]) after sediment cleaning treatments (propulsion sled or hydro-jet sled) conducted at two reef locations in Saginaw Bay, Lake Huron, during 2018 and 2019. The data includes the year, species, reef, treatment type (jet, fan, control), number of eggs, and egg density in the treatment area. Relative sediment hardness for the treatment areas assessed before and after sediment cleaning experiments is provided. Additionally, walleye eggs were collected from Brookville Reservoir, Indiana, and incubated at the aquaculture research laboratory at Purdue University (West Lafayette, Indiana) to determine the effect of sediment cover on egg hatching success rate. The incubated eggs were exposed to different sediment types and levels of sediment coverage intensity. The data contains the year, treatment, parental female length (2019 only), number of walleye hatched, and egg diameter (2019 only) collected in the laboratory study.

These data include a field study of the sediment hardness and fish egg density (walleye [Sander vitreus] and lake whitefish [Coregonus clupeaformis]) after sediment cleaning treatments (propulsion sled or hydro-jet sled) conducted at two reef locations in Saginaw Bay, Lake Huron, during 2018 and 2019. The data includes the year, species, reef, treatment type (jet, fan, control), number of eggs, and egg density in the treatment area. Relative sediment hardness for the treatment areas assessed before and after sediment cleaning experiments is provided. Additionally, walleye eggs were collected from Brookville Reservoir, Indiana, and incubated at the aquaculture research laboratory at Purdue University (West Lafayette, Indiana) to determine the effect of sediment cover on egg hatching success rate. The incubated eggs were exposed to different sediment types and levels of sediment coverage intensity. The data contains the year, treatment, parental female length (2019 only), number of walleye hatched, and egg diameter (2019 only) collected in the laboratory study.

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eDNA-based spatiotemporal distribution data (occupancy model format) for rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus) within the Bruneau-Jarbidge Rivers Wilderness in southern Idaho and northern Nevada, USA. Data also include stream discharge and stream temperature data for each site. All data were collected between October 2015 and September 2016.

eDNA-based spatiotemporal distribution data (occupancy model format) for rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus) within the Bruneau-Jarbidge Rivers Wilderness in southern Idaho and northern Nevada, USA. Data also include stream discharge and stream temperature data for each site. All data were collected between October 2015 and September 2016.

Data are from biological and physical environmental assessments conducted during 2019 in the Maumee River, Ohio. Sites were located from river kilometer 24 to 11. Water quality parameters, fishes, invertebrates, and river channel characteristics were assessed during 2019 from May-September. Previously established standardized sampling methods were used during all assessments.