Nys Dec Lake Erie 2020 Annual Report
NYS DEC LAKE ERIE 2020 ANNUAL REPORT
to the Lake Erie Committee and the Great Lakes Fishery Commission
March 2021
New York State Department of Environmental Conservation 625 Broadway, Albany, New York 12233-4753
Andrew M. Cuomo, Governor
MOST OF THE WORK REPORTED IN THIS DOCUMENT IS SUPPORTED BY THE FEDERAL AID IN SPORT FISH RESTORATION PROGRAM
Full Report Citation:
NYSDEC 2021. Lake Erie 2020 Annual Report. New York State Department of Environmental Conservation, Albany, New York, USA.
Example Report Section Citation:
Markham, J.L. 2021. Coldwater gill net assessment. Section F in NYSDEC 2021, Lake Erie 2020 Annual Report. New York State Department of Environmental Conservation, Albany, New York, USA.
NYS DEC LAKE ERIE 2020 ANNUAL REPORT to the Great Lakes Fishery Commission’s Lake Erie Committee
NYSDEC Lake Erie Fisheries Research Unit e-mail: [email protected]
Jason Robinson, Lake Erie Fisheries Research Unit Leader James Markham, Aquatic Biologist Pascal Wilkins, Aquatic Biologist Michael Cochrane, Research Vessel Captain Richard Zimar, Fisheries Technician MariEllen (Ginger) Szwejbka, Secretary
Steven LaPan, Great Lakes Fisheries Section Head (Retired) Steven Hurst, Chief, Bureau of Fisheries
Acknowledgements
The Lake Erie Fisheries Research Unit recognizes the contributions of seasonal staff essential to completing an ambitious field schedule. During the 2020 field year these individuals included Fish and Wildlife Technicians Kevin Smith, Trista Daley, and Benjamin Szczygiel. We also acknowledge contributions of DEC’s Region 9 Fisheries Office, Buffalo State College’s Great Lakes Center, SUNY Fredonia, Cornell University, the USGS Great Lakes Science Center, and the USFWS Northeast Fisheries Center in support of various Lake Erie field activities.
The Unit would also like to recognize the contributions of our Great Lakes Fisheries Section Head Steve LaPan, retired in 2020, to the Unit and to management of the fishery resources in both Lake Erie and Lake Ontario.
March 2021
New York State Department of Environmental Conservation 625 Broadway, Albany, New York 12233-4753
Preface
The Lake Erie Annual Report is prepared by New York State Department of Environmental Conservation as a compilation of ongoing Lake Erie investigations mostly supported by Federal Aid in Sportfish Restoration. This annual report is intended as a resource document for other member agencies of the Great Lakes Fishery Commission’s Lake Erie Committee, as well as information for Lake Erie’s angling community and other interested stakeholders. Many initiatives reported under this cover are long term monitoring efforts which are updated each year. Other efforts may not always be updated annually if there were no new activities since the previous report. In 2020, the Lower Trophic Level Monitoring Program was not completed due to Covid-19 issues and will not be included in this report. However, protocols were able to be developed and all other long-term monitoring programs were able to be completed in a safe manner following New York State and NYS DEC policies.
The summaries contained in this report are provisional although every effort has been made to ensure their accuracy. We strongly encourage researchers to contact NYS DEC Lake Erie Fisheries Research Unit before using or citing any specific data summary contained in this report.
TABLE OF CONTENTS
Lake Erie 2020 Annual Report New York State Department of Environmental Conservation
Presented at the Lake Erie Committee Meeting March 26, 2021
SECTION TITLE
A PROGRAM HIGHLIGHTS
B RESEARCH PARTNERSHIPS AND WRITTEN CONTRIBUTIONS (J.M. Robinson)
C FORAGE AND JUVENILE YELLOW PERCH SURVEY (J.L. Markham and P.D. Wilkins)
D WARMWATER GILL NET ASSESSMENT (P.D. Wilkins)
E COMMERCIAL FISHERY ASSESSMENT (P.D. Wilkins)
F COLDWATER GILL NET ASSESSMENT (J.L. Markham)
G SEA LAMPREY ASSESSMENT (J.L. Markham)
H SALMONINE STOCKING SUMMARY (J.L. Markham and M.T. Todd)
I OPEN LAKE SPORT FISHING SURVEY (P.D. Wilkins)
APPENDIX I COMMON AND SCIENTIFIC NAMES OF FISH
NYSDEC Lake Erie Fisheries Research Unit 2020 Program Highlights
The New York State Smallmouth Bass Department of Environmental Lake Erie supports New York’s, and perhaps the country’s, finest Conservation’s Lake Erie smallmouth bass fishery. Bass fishing quality in 2020 was below Fisheries Research Unit average for the 33-year survey. Generally stable spawning success (LEFRU) is responsible for coupled with very high growth rates produce relatively high angler research, assessment and catch rates and frequent encounters with trophy-sized fish. Over the fisheries management past 33 years increasing preference for catch-and-release angling activities for one of New has drastically reduced harvest of smallmouth to only 2% of the York’s largest and most overall catch. Since 2000 overall abundance has declined. Recent diverse freshwater fishery data indicate relatively stable adult abundance (age 3+) over the last resources. Our annual monitoring programs are designed to improve decade with an increase in older bass over the last five years. our understanding of the Lake Erie fish community, guide fisheries Juvenile abundance measures from 2020 suggest 2018 was a below management, and safeguard this valuable resource for current and average bass year class. future generations. This document shares just a few of the highlights from the 2020 program year. Our complete annual report is available Gill Net Catches of Smallmouth Bass on DEC’s website at http://www.dec.ny.gov/outdoor/32286.html, or by 50 contacting DEC’s LEFRU office (contact information below). Age 8 + 40 Age 3 to 7 Tributary Angler Survey Age 1 & 2 New York’s Lake Erie tributaries consistently produce some of the highest quality fishing for steelhead in the nation. The tributary angler 30 survey is conducted on a three-year cycle to monitor fishery performance and determine progress towards goals stated in the 20
Steelhead Management Plan. The average steelhead catch rate from Catch per Net the most recent 2017-18 survey indicated excellent fishing quality (0.56 fish/hr.) and represented a significant improvement compared 10 to the 2011-12 and 2014-15 surveys.
0 Walleye 1981 1985 1989 1993 1997 2001 2005 2009 2013 2017 Lake Erie’s eastern basin walleye resource is comprised of adult walleye from local spawning stocks and substantial contributions of adult migrants from west basin spawning stocks. Walleye fishing Yellow Perch quality in New York waters has been at record levels for the past four Lake Erie yellow perch populations have experienced wide years with 2018 representing the highest catch rate in the 33-year oscillations in abundance over the last 30 years, from extreme lows survey. Recent increases in fishing quality are largely attributable to in the mid-1990’s to an extended recovery that has now lasted almost east basin spawning success over the past decade, and the recent two decades. Poor recruitment in 2011-2013 resulted in a declining western basin walleye spawning success. Juvenile walleye surveys adult population and angler catch rates with a 12-year low occurring indicate exceptional local spawning success in 2016 and 2017 and a in 2016. Perch fishing quality began to increase in 2017 and 2018 due potentially unprecedented level of west basin spawning success in to the strong 2015 cohort but returned to the long-term average in 2018 and 2019. Overall good recruitment through recent years 2020. Weak to moderate recruitment in 2017 and 2018, coupled with suggests adult walleye abundance and fishing quality in the east an aging 2015 year class, should support average to slightly below basin will remain high for the several years. average fishing quality in 2021. Juvenile abundance measures from 2020 suggest 2019 was an above average yellow perch year class. Age-1 Walleye Index 25 Gill Net Catches of Yellow Perch 350
20 300
250 15
200 10 150 Catch per Net 5 Catch per Net 100
0 50 1980 1985 1990 1995 2000 2005 2010 2015 0 Year Class 1993 1997 2001 2005 2009 2013 2017
Lake Erie Fisheries Research Unit 178 Point Drive North Dunkirk, NY 14048-1031 (716) 366-0228
Lake Trout Restoration Salmonid Management Re-establishing a self-sustaining lake trout population in Lake Erie New York annually stocks approximately 127,500 steelhead and continues to be a major goal of Lake Erie’s coldwater program. Lake 50,000 domestic rainbow trout into Lake Erie and its tributaries to trout have been stocked since 1978 and annual assessments monitor provide recreational angling opportunities. Wild reproduction of progress towards lake trout rehabilitation plan restoration objectives. steelhead also occurs in some tributaries but remains a minor The overall index of abundance of lake trout in the New York waters contributor to the fishery. Steelhead stocking was slightly above target of Lake Erie has remained relatively stable for the past five years but in 2020 while domestic rainbow stocking was slightly below target. It below the plan objective of 8.0 fish/lift. Adult lake trout (age 5+) should be noted that stocking targets for steelhead declined 50% in abundance increased in 2020 and remains high relative to the entire 2020 to accommodate an experimental approach at New York’s time series; older fish (age 10+) are increasing in abundance. Natural Salmon River Hatchery to improve overall size of stocked steelhead. reproduction has not yet been detected in Lake Erie. Significant Initial results indicated significant increases in both size and weight, stocking and sea lamprey control efforts must be continued to build and resulted in a more consistent stocking product. Further and maintain the adult population necessary to support natural experimentation and evaluation are expected over the next two years. reproduction. An acoustic telemetry study that began in 2016 is A year-round angler survey was completed in the Upper Cattaraugus providing valuable information on movements and spawning locations Creek system in 2020, providing baseline estimates of effort, catch, used by stocked lake trout during the fall and will guide future and harvest for this area following fish passage at the Springville restoration efforts. Dam.
Gill Net Catches of Lake Trout NYSDEC Trout & Salmon Stocking 12 Steelhead Dom. Rainbow Trout Brown Trout Chinook Coho Age 7+ 500 10 Age 5 & 6 Age 1 to 4 400 8
6 300
4 200 Catch per Net
2 Number(thousands) 100
0 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 0 1990 1993 1996 1999 2002 2005 2008 2011 2014 2017 2020 Sea Lamprey Sea lamprey invaded Lake Erie and the upper Great Lakes in the Prey Fish The LEFRU conducts several surveys focused on understanding 1920s and have played an integral role in the demise of many native factors that influence fish community structure. These include trawling coldwater fish populations. Great Lakes Fishery Commission (GLFC) to assess prey fish abundance, predator diet studies, and lower food coordinated sea lamprey control in Lake Erie began in 1986 in support web monitoring. Since the onset of our trawl survey, rainbow smelt of lake trout rehabilitation efforts, and regular treatments are have been the dominant component of the open lake forage fish conducted to reduce sea lamprey populations. Annual monitoring community. Round goby became a prominent component of the undertaken by LEFRU includes observations of sea lamprey wounds forage fish community following their introduction in the late 1990’s. on lake trout and other fish species. Wounding rates on lake trout Goby abundance increased rapidly initially but has since stabilized at have been relatively stable over the past 20 years but remain above a lower level. In recent years overall prey fish biomass has been targets. Inspections of sportfish documented sea lamprey wounding generally lower due in large part to reductions in adult smelt on warmwater species as well. GLFC surveys conducted in recent abundance and variability in emerald shiner recruitment. Overall years indicate the largest source of Lake Erie’s sea lamprey biomass of soft-rayed forage fishes increased in 2020 and was above production may be the St. Clair River rather than traditionally average, mainly due to a high abundance of age-1 and older rainbow monitored and treated eastern basin Lake Erie streams. smelt. Smelt also dominated both walleye and lake trout diets in 2020. However, other fish species, including goby and yellow perch, have Sea Lamprey Wounding Rate on Lake Trout been more prominent in diets over the past five years. Lower trophic 70 monitoring was not conducted in 2020 due to Covid-related issues. Target = 5 wounds/100 fish 60 Forage Fish Biomass Trends 25,000 50 Smelt
40 20,000 Emerald Shiner
30 Round Goby
15,000 20
Wounds per per 100 Fish Wounds 10 10,000 0 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020 5,000
Biomass (grams per hectare) 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
Lake Erie Fisheries Research Unit 178 Point Drive North Dunkirk, NY 14048-1031 (716) 366-0228
NYSDEC Lake Erie Annual Report 2020
B. RESEARCH PARTNERSHIPS AND WRITTEN CONTRIBUTIONS
Jason M. Robinson
NYSDEC as signatory to the Great Lakes Fishery The LEFRU also collaborates with investigators from Commission's (GLFC) "Strategic Plan for Management various government and academic institutions in pursuit of Great Lakes" is obliged to participate in joint of a broad array of initiatives. Table B.1 lists active management of shared fishery resources. The Lake Erie collaborations in 2020. Pages two and three of this Fisheries Research Unit’s (LEFRU) routine fishery section list written contributions by LEFRU staff in management and research collaborators include the 2020. New York’s LEFRU remains willing to pursue Pennsylvania Fish and Boat Commission, the Ohio additional partnerships to the extent such collaborations Division of Wildlife, the Michigan Department of are consistent with our mission, and practical for Natural Resources, the Ontario Ministry of Natural integrating with our ongoing programs. Resources and Forestry, the United States Geological Survey and the United States Fish and Wildlife Service.
TABLE B.1. 2020 list of active research partnerships on Lake Erie with NYSDEC. Principal Collaborator Project Description
GLATOS Multiple Lake Erie GLATOS Projects, and acoustic telemetry infrastructure
Buffalo State College Eastern Lake Erie lower trophic monitoring program
USFWS Long term pathogen surveillance of Lake Erie fishes
DFO - Canada Long term contaminant monitoring of Lake Erie lake trout
USGS Grass carp demographics in Lake Erie Identify contribution of west and east basin walleye to NY gillnet indices using otolith Ohio State University microchemistry Identify contribution of west and east basin walleye to recreational and commercial Ohio State University fisheries in Lake Erie using genetics Quantify walleye spawning phenology, skip spawning and site fidelity in Lake Erie using Ohio State University acoustic telemetry Validating the use of oxygen isotope ratios in walleye otoliths to reconstruct the lifetime University of Guelph thermal histories Determine how changes in fish biomass across space and time relate to changes in Lake DFO - Canada Erie productivity U. Windsor, OMNRF Trophic position and diet composition of Lake Erie fishes
EPA US EPA GLNPO Great Lakes Fish Monitoring Program
Section B Page 1
NYSDEC Lake Erie Annual Report 2020
Written Contributions by Lake Erie Fisheries Research Unit Staff in 2020
Below is a list of written and/or published products that are either completed or near completion, on which Lake Erie Fisheries Research Unit Staff have made substantive contributions in 2020. These may include contributions to the peer reviewed literature, management plans, technical reports, and other contributions.
Peer Reviewed Literature: Matley, J. K., M. D. Faust, G. D. Raby, Y. Zhao, J. M. Robinson, T. MacDougall, T. A. Hayden, A. T. Fisk, C. S Vandergoot, and C. C Krueger. 2020. Seasonal habitat-use differences among Lake Erie’s walleye stocks. Journal of Great Lakes Research. Journal of Great Lakes Research. 46:609–621. Euclide, P. T., T. MacDougall, J. M. Robinson, M. D. Faust, C. C. Wilson, K. Chen, E. A. Marschall, W. A. Larson, and S. A. Ludsin. 2021. Mixed-stock analysis in the age of genomics: Rapture genotyping enables evaluation of stock-specific exploitation in a freshwater fish population with shallow genetic structure. Evolutionary applications. In Press. Markham, J. L., and J. M. Robinson. 2021. Evaluation of Steelhead stocking size and location on emigration and adult returns. North American Journal of Fisheries Management. Accepted. Grunder, S., J. L. Markham, W. P. Sullivan. C. Eilers, K. Tallon, and D. McGarry. A review of sea lamprey control in Lake Erie, 2000-2019. Journal of Great Lakes Research. Accepted. Lennox, R. J., F. G. Whoriskey, P. Verhelst, C. Vandergoot, J. Reubens, E. L. Rechisky, M. Power, I. Mulder, J. Markham, S. K. Lowerre-Barbieri, S. T. Lindley, N. A. Knott, S. Kessel, S. Iverson, C. Huveneers, L. C. Fetterplace, L. P. Griffin, C. Friess, A. Filous, R. Harcourt, A. J. Danylchuk, S. J. Cooke, E. J. Chávez, K. Whoriskey. Globally coordinated acoustic aquatic animal tracking reveals unexpected, ecologically important movements across oceans, lakes, and rivers. Zoological Journal of the Linnean Society. In Preparation.
Book Chapters: Euclide, P. T., J. M. Robinson, T. MacDougall, M. D. Faust, M. Bootsma, K. Chen, W. A. Larson, S. Ludsin, E. A. Marschall, K. T. Scribner, W. Stott, and C. C. Wilson. (In Review). Using Genomic Data to Guide Walleye Management in the Great Lakes. in Bruner, J. C., and R. L. DeBruyne, editors. Ecology, Management, and Culture of Sauger, Walleye, and Yellow Perch.
Management Plans: Weimer, E., R. Drouin, J. Markham, C. Murray, and T. Wills. 2020. Lake Erie Yellow Perch Management Plan. Lake Erie Committee, Great Lakes Fishery Commission. Ann Arbor, MI. A Strategic Plan for the Rehabilitation of Lake Trout in Lake Erie, 2021-2026. Great Lakes Fishery Commission. Ann Arbor, MI. In Preparation.
Technical Briefs: Markham, J. L., T. E. Kielbasinski, J. Hentges, and P. Kinney. 2020. Experimental Fish Culture Techniques at the Salmon River Hatchery to Improve Steelhead Stocking Size. Bureau of Fisheries Technical Brief, New York State Department of Environmental Conservation, Albany, New York, USA. Markham, J. L., and S. Cornett. 2020. Evaluation of the upper Cattaraugus Creek trout fishery. Bureau of Fisheries Technical Brief, New York State Department of Environmental Conservation, Albany, New York, USA.
Section B Page 2
NYSDEC Lake Erie Annual Report 2020 Technical Reports: NYSDEC 2020. Lake Erie 2019 Annual Report. New York State Department of Environmental Conservation, Albany, New York, USA. YPTG 2020. 2019 Report of the Lake Erie Yellow Perch Task Group. Presented to the Standing Technical Committee, Lake Erie Committee, and Great Lakes Fishery Commission. HTG 2020. 2019 Report of the Lake Erie Habitat Task Group. Presented to the Standing Technical Committee, Lake Erie Committee, and Great Lakes Fishery Commission. WTG 2020. 2019 Report of the Lake Erie Walleye Task Group. Presented to the Standing Technical Committee, Lake Erie Committee, and Great Lakes Fishery Commission. CWTG 2020. 2019 Report of the Lake Erie Cold Water Task Group. Presented to the Standing Technical Committee, Lake Erie Committee, and Great Lakes Fishery Commission. FTG 2020. 2019 Report of the Lake Erie Forage Task Group. Presented to the Standing Technical Committee, Lake Erie Committee, and Great Lakes Fishery Commission.
Other Contributions: Francis, J., T. Hartman, K. Kuhn, B. Locke, and J. Robinson. 2020. Fish community objectives for the Lake Erie basin. Great Lakes Fishery Commission Special Publication. Ann Arbor, MI. Wills, T. C., and J. Kerns. 2021. The State of Lake Erie in 2015. Great Lakes Fish. Commission Special Publication. Ann Arbor, MI.
Section B Page 3
NYSDEC Lake Erie Annual Report 2020
C. FORAGE AND JUVENILE YELLOW PERCH SURVEY
James L. Markham and Pascal D. Wilkins
Introduction Trawl webbing: 2.0 inch stretch Twine diameter: 21 thread The Lake Erie Unit’s annual bottom trawling program Cod-end webbing: 0.4 inch stretch has been conducted since 1992 and replaced the Juvenile Percid Assessment conducted from 1986 to Species density is calculated from known trawl fishing 1991 (Culligan et al. 1992). The principal objectives of dimensions obtained using trawl mensuration the program are to assess trends in abundance of equipment (NETMIND) between 2004-2016 and juvenile yellow perch and monitor forage fish individual tow distances estimated from vessel community status. Data from this program are merged navigation electronics. An analysis completed in 2016 with those from other jurisdictions to generate lake- revealed a trawl wingspread (13.8 ft) that was slightly wide estimates of juvenile yellow perch and forage fish different than the previous value (14.2 ft) estimated populations and are reported by the Lake Erie from a more limited trawl calibration exercise Committee’s inter-agency Forage Task Group (Forage conducted in the late 1990’s. Density estimates for the Task Group 2021) and Yellow Perch Task Group entire time series were updated to reflect the new (Yellow Perch Task Group 2021). wingspread measurements. In 2019, a new trawl mensuration system from SIMRAD was purchased and Methods installed. This gear was very similar in size and weight to the NETMIND equipment and produced net This annual trawling program is conducted during configuration measurements (wing spread, net height) October–November at selected locations with trawlable that allowed us to determine if the net was fishing substrate between the 50- and 100-ft depth contours in correctly and consistently compared to the previous New York’s portion of Lake Erie. Standard tow tows and years. duration is 10 minutes. Survey procedures generally follow those performed for an inter-agency, western An analysis was conducted in 2015 using a generalized basin Lake Erie assessment that is reported annually in linear modeling approach quantifying the effect of Lake Erie’s Forage Task Group Report (Forage Task bottom temperature – as a proxy for fall turnover – on Group 2021). All agencies report measures of species trawl catches of seven commonly encountered species density as mean number per hectare and biomass as and life stages (Markham and Robinson 2016). The grams per hectare (Forage Task Group 1998); a hectare results of this analysis indicated that the effect of fall is 2.471 acres. Species defined as forage include all life turnover (bottom temperature) on catches of warm- and stages of rainbow smelt, emerald shiner, spottail shiner, cool-water benthic species and life stages, including round goby, trout-perch, log perch, and darters, and yellow perch, round goby, and young-of-the-year young-of-the-year (YOY) life stage of yellow perch, (YOY) rainbow smelt, is relatively modest compared to white perch, lake whitefish, white bass, smallmouth the effect of temperature on catches of pelagic species bass, alewife, and gizzard shad. such as emerald shiner, and species with cooler temperature preferences such as yearling-and-older The standard gear for this trawling program is a 4-seam (YAO) rainbow smelt. Varying bottom temperatures bottom trawl with the following characteristics: over the course of the survey period do not seem to be a significant impediment to characterizing relative year Headrope length: 26.3 ft class strength for benthic warm water species. As such, Footrope length: 33.3 ft this trawl survey likely provides a better annual Ground wire to doors: 50.0 ft abundance index for benthic warm water species and life stages compared to cool water (e.g. YAO rainbow ______Section C Page 1
NYSDEC Lake Erie Annual Report 2020
smelt) and pelagic species (e.g. emerald shiner), Forage Fish Biomass especially for temperatures at which the survey usually 30,000 operates (57.2–64.4 °F (14–18°C)) and in years in which soft-rayed 25,000 clupeids part or all of the survey is completed prior to fall spiny-rayed turnover. As a result of this analysis, beginning in 2017 20,000
the fall trawling survey was conducted following fall 15,000 turnover to provide more consistent estimates of all forage fishes, especially cool water and pelagic species. 10,000 5,000 Results and Discussion Biomass (Grams Per Hectare) 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
A total of 34 valid trawl tows were completed in the New York waters of Lake Erie in 2020 (Figure C.1). FIGURE C.2. Biomass (grams-per-hectare) of functional groups of Sampling was completed after fall turnover on four forage fishes collected with a bottom trawl in the New York waters of Lake Erie, October–November, 1992–2020. days between October 22 – November 6, 2020 with standard daytime trawling effort totaling 340 minutes. o increase in 2020, Clupeids (YOY gizzard shad, YOY Survey sampling temperatures (53.1–58.5 F (11.7– alewife) remain a relatively minor contributor to this 14.7oC)) remained within the long-term temperature o o forage fish assessment. range of the program (>50 F or 10 C). Rainbow smelt (all life stages) were the dominant Status of Forage Fish species by weight (87%) sampled in 2020 (Figure C.3). The estimated biomass of forage-sized fish was 15,413 The majority of the rainbow smelt biomass was grams/ha in 2020 (Figure C.2). This was a marked comprised of age 1 and older fish (93%). Other species increase compared to 2019 and above the time series that made a significant biomass contribution in 2020 average (12,655 grams/ha), ranking as the 11th highest included Clupeids (6%) and YOY yellow perch (4%). total biomass (62nd percentile) in the 29-year time series. Much of the increase compared to 2019 was due Time series trends of relative biomass (g/ha) for to an abundance of rainbow smelt (soft-rayed), selected species of interest are presented in Figure C.4. specifically the age-1 and older lifestage. Despite an Rainbow smelt often comprise the highest biomass of any individual species in this trawl survey. Until this year, rainbow smelt catches over the past decade have Forage Biomass by Species
Yellow perch - YOY
White perch - YOY
Rainbow Smelt - ALL
Clupeids
Trout Perch - ALL
Emerald shiner - ALL
Round goby - ALL FIGURE C.1. Locations of 34 individual 10 minute trawls between the 50 to 100 ft. depth contours used to assess the abundance of age-0 yellow perch and forage fish species in the New York waters of Lake FIGURE C.3. Biomass (grams-per-hectare) of forage fishes by life Erie, October, 2020. stage collected with a bottom trawl in the New York waters of Lake Erie, October–November, 2020.
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NYSDEC Lake Erie Annual Report 2020
Rainbow Smelt: Age-1 and older Emerald Shiner: All life stages
20,000 12,500
16,000 10,000
12,000 7,500
8,000 5,000 Biomass (g/ha)Biomass 4,000 (g/ha)Biomass 2,500
0 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
Rainbow Smelt: YOY Round Goby: All life stages
5,000 4,000
4,000 3,000 3,000 2,000 2,000 Biomass (g/ha)Biomass Biomass (g/ha)Biomass 1,000 1,000
0 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
White Perch: YOY Alewife: YOY
2,500 4,000
2,000 3,000 1,500 2,000 1,000 Biomass (g/ha)Biomass 500 (g/ha)Biomass 1,000
0 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
Trout-Perch: All life stages Gizzard Shad: YOY
12,500 800
10,000 600 7,500 400 5,000 Biomass (g/ha)Biomass
Biomass (g/ha)Biomass 200 2,500
0 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
FIGURE C.4. Biomass (grams per hectare) of selected species collected with a bottom trawl in the New York waters of Lake Erie, October– November, 1992–2020.
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NYSDEC Lake Erie Annual Report 2020
Yellow Perch: YOY Walleye: YOY
20,000 400
16,000 300 12,000 200 8,000 Biomass (g/ha)Biomass Biomass (g/ha)Biomass 100 4,000
0 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
Yellow Perch: Age 1 Lake Whitefish: YOY
6,000 160 5,000 120 4,000 3,000 80 2,000 Biomass (g/ha)Biomass
Biomass (g/ha)Biomass 40 1,000 0 0 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
FIGURE C.4 (Continued). Biomass (grams per hectare) of selected species collected with a bottom trawl in the New York waters of Lake Erie, October–November, 1992–2020. YOY yellow perch, and trout perch (all life stages), been dominated by the YOY life stage; YAO smelt had were below average. It is also notable that YOY walleye been generally low since 2012 (Figure C.4). Three of were encountered again in 2020 trawl samples, which the largest year classes of YOY rainbow smelt have usually only occurs when large year classes are occurred since 2014, but these have not translated into produced. YOY walleye have been caught in high high adult (YAO) smelt abundance. However, the relative abundance for five consecutive years. moderate 2019 year class of smelt translated into the second highest YAO biomass in this time series in Soft-rayed forage fishes (rainbow smelt, emerald 2020. Despite a high abundance of top predators shiners, spottail shiners, trout-perch and round goby) (walleye, lake trout), rainbow smelt continue to thrive typically comprise the majority of the overall biomass and play a major role in the predator-prey dynamics of in trawl catches in the New York waters of Lake Erie the Lake Erie food web. (Figure C.5). From 2011-2019, a variable but generally declining trend was observed this group, and biomass Emerald shiner biomass remained low in 2020 for the in 3 of the previous 4 years was in the lower quartile second consecutive year. Since 2001 emerald shiners (<25th percentile) of the time series. However, a large have often contributed measurably to total forage increase in the biomass of this group was evident in biomass, but annual abundance is highly variable. Peaks 2020 and ranked as the 4th highest in the time series. in abundance have been evident in 2003, 2006, 2011,
2014, and 2018 with each followed by several years of low abundance.
Biomass indices for YOY gizzard shad (3rd highest in time series) were above average in 2020 while most other species, including round goby, YOY white perch, ______Section C Page 4
NYSDEC Lake Erie Annual Report 2020
Soft-Rayed Fish Biomass Trends trout in recent years. A more thorough accounting of 24,000 overall predator growth and condition will be necessary Smelt to evaluate the effects of a changing forage fish 20,000 Emerald Shiner community. Round Goby 16,000
12,000 Juvenile Yellow Perch Assessment
8,000 The 2020 mean density estimate for age-0 (YOY) yellow perch (91.6/ha) was well below average 4,000 th th
Biomass (Grams Per Biomass (Grams Per Hectare) (244.7/ha) and ranked as moderate (15 ; 49 percentile) 0 for the time series (Table C.1; Figure C.4). Two of the 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 highest YOY yellow perch abundance indices have occurred in the past five years with moderate levels of FIGURE C.5. Catch-per-hectare of common soft-rayed forage fishes (all ages combined) collected with a bottom trawl in the New York abundance in the other three years. The age-1 yellow waters of Lake Erie, October–November, 1992–2020. perch (2019 year class) density estimate was 56.2/ha in 2020, ranking it as 5th (83rd percentile) highest in the A complex interdependent relationship exists between time series and well above average (Table C.1; Figure prey fish and predator populations in Lake Erie. C.4). The high age-1 abundance of the 2019 year class Predator abundance can influence prey fish abundance, was unexpected given the low abundance of these fish which can in turn impact predator growth, condition, as YOY in 2019. Abundance at age-1 is a good indicator and feeding behavior. Management agencies often have of year class strength, and age-1 indices have been high limited options available to influence these predator- in four of the previous six years. Adult (age 2+) yellow prey dynamics. However, monitoring metrics perch relative abundance increased to 22.0/ha in 2019, associated with predator-prey interactions is essential ranking it as 19th (34th percentile) in the time series and for making informed management decisions. The Lake below average (Table C.1). The majority of the adult Erie Fisheries Research Unit monitors several predator yellow perch trawl catches in 2020 were comprised of growth and diet indices that are directly influenced by the very strong age-4 (2016 year class) cohort. The prey fish population abundance and composition. dominance of the age-4 cohort was consistent across all surveys in 2020. Overall, this trawling program Growth and condition of smallmouth bass and adult continues to indicate a period of sustained but variable lake trout continue to be generally high and stable (see yellow perch recruitment success and overall elevated Sections D and F). However, declines in juvenile abundance since 2003. Average or better age-1 yellow walleye growth (currently lowest in time series) and perch indices have been recorded in ten of the last 17 condition indices of adult, angler-caught walleye have years, including 2015, 2016, 2017, and 2020. been observed over the past decade. This trend was especially evident in the condition of large walleye (28 Trends in juvenile yellow perch length-at-age indicate inches) in 2018 and 2019 (see Section J). Predator diets relative stability for both age-0 and age-1 groups over between 2015-2019 also indicated that rainbow smelt the past decade (Figure C.6). The average total length were not the prominent prey species for east basin for age-0 yellow perch was 3.3 inches and age-1 yellow walleye as they were historically (see Section J). In perch averaged 6.0 inches in 2020, which were both contrast, smelt were the prominent forage item for adult higher than the time series average (3.1 and 5.4 inches, walleye in 2020, and condition improved. This may respectively). indicate that high predatory demand combined with low forage biomass, especially adult rainbow smelt, can impact adult predator growth. Greater diet diversity has also been generally observed in both walleye and lake
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NYSDEC Lake Erie Annual Report 2020
TABLE C.1. Density (number per hectare) of yellow perch collected with a bottom trawl in the New York waters of Lake Erie, October– Juvenile Yellow Perch Growth 8.0 November, 1992–2020. Age-0 Age-1 7.0
Density (yellow perch per ha) 6.0 Year Age-0 Age-1 Age-2+ 5.0 1992 10.7 2.4 9.5 4.0 1993 113.0 3.1 6.1 3.0 1994 49.0 8.6 1.0 2.0
1995 5.9 13.6 14.6 Mean Length (inchesTL) 1.0 1996 105.8 0.3 7.0 0.0 1997 0.2 5.7 2.7 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 1998 1.3 0.4 0.3 FIGURE C.6. Mean total length of age-0 and age-1 yellow perch 1999 35.9 33.3 11.1 collected by bottom trawl in New York waters of Lake Erie, October– 2000 23.9 7.0 28.4 November, 1992–2020. Years in which sample sizes were less than 2001 100.4 11.7 23.5 4 were excluded. Error bars are 95% confidence intervals. 2002 9.5 16.0 37.9 2003 484.8 2.0 22.0 References 2004 1.5 29.4 62.2 2005 59.3 5.6 34.5 Culligan, W. J., F. C. Cornelius, D. W. Einhouse, D. L. 2006 290.6 40.9 29.8 Zeller, and R. C. Zimar. 1992. 1992 Annual Report 2007 412.0 42.3 87.2 to the Lake Erie Committee. New York State 2008 1116.7 45.5 56.4 Department of Environmental Conservation, 2009 11.9 64.1 44.1 Albany, USA. 2010 197.7 4.2 39.9 Forage Task Group 1998. Report of the Lake Erie 2011 89.5 141.8 25.7 Forage Task Group, March 1999. Presented to the 2012 280.0 16.7 62.6 Standing Technical Committee, Lake Erie 2013 4.4 24.4 40.6 Committee of the Great Lakes Fishery Commission. 2014 274.2 2.9 105.4 Ann Arbor, Michigan, USA. 2015 68.6 57.3 79.5 2016 2178.2 53.0 45.5 Forage Task Group 2021. 2020 Report of the Lake Erie Forage Task Group, March 2021. Presented to the 2017 247.0 129.5 28.6 Standing Technical Committee, Lake Erie 2018 662.4 11.4 112.2 Committee of the Great Lakes Fishery Commission. 2019 169.1 2.5 14.3 Ann Arbor, Michigan, USA. 2020 91.6 56.2 22.0
Average 244.7 28.7 36.4 Markham, J. L. and J. M. Robinson. 2016. Forage and juvenile yellow perch survey. Section C in NYSDEC 2016, Lake Erie 2015 Annual Report. New York State Department of Environmental Conservation, Albany, USA. Yellow Perch Task Group 2021. 2020 Report of the Lake Erie Yellow Perch Task Group, March 2021. Presented to the Standing Technical Committee, Lake Erie Committee of the Great Lakes Fishery Commission. Ann Arbor, Michigan, USA.
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NYSDEC Lake Erie Annual Report 2020
D. WARMWATER GILL NET ASSESSMENT
Pascal D. Wilkins
Introduction system. Both bottom and limnetic warmwater habitats were sampled with 700 ft. monofilament gill nets from The annual warmwater fish community gill net 1993 through 1995. Beginning in 1996, only bottom assessment has been performed by New York’s Lake habitat has been sampled and all measures reported for Erie Fisheries Research Unit since 1981. The principal this survey are from bottom-set gill nets. Each net was objective of this September assessment is to produce made up of 14 individual gill net panels (50 ft long x 6 standardized indices of relative abundance, age ft high) with stretch mesh sizes ranging from 1.25 to 6 composition, and growth of walleye, smallmouth bass inches. An examination of gill net catches from 1993 to and yellow perch in New York’s portion of Lake Erie. 2004 found the 6-inch panel contributed miniscule Walleye and yellow perch relative abundance and age catches for commonly encountered species, but composition data are also contributed to the Lake Erie experienced excessive net damage because interagency Committee’s (LEC) interagency Walleye and Yellow standard monofilament twine diameter is often too Perch Task Groups for annual lake wide assessment weak to retain species large enough to be entangled. (Walleye Task Group 2021, Yellow Perch Task Group Beginning in 2005, New York’s new standard gill net 2021). Secondary objectives include monitoring became a 650 ft gang consisting of 13 panels ranging abundance trends for other commonly encountered from 1.25 to 5.5 inches. Previous summary statistics warmwater fish species and detecting rare or invasive were not re-analyzed with the deletion of 6.0-inch panel species. Long-term index netting remains invaluable as catches because separate evaluations confirmed the a tool to quantify and understand the relationships presence/absence of the 6.0-inch panel did not between fishing mortality, age structure, and year class measurably change overall catch rates for all commonly strength. This information is imperative for informed encountered species. management to ensure the continued sustainability of Lake Erie sport fish populations. The warmwater gill net sampling period extends from September 1 until the target number of net sets is Methods achieved or the bottom water temperature in the sampling area reaches 59°F (15°C). Targeted sampling This annual assessment began in 1981, and methods effort is 40 overnight gill net sets, with three to six nets were significantly altered in 1993 to adopt a standard set each sample day. Effort is distributed between 25 interagency approach to fish community assessment. A nearshore and 15 offshore sites (Figure D.1). Nets are detailed description of current survey methods can be ideally set between 12:00 PM and sunset and retrieved found in Ryan et al. (1993). Several fixed sampling between sunrise and 12:00PM the following day. Data stations from New York’s former (pre-1993) gill netting from gill nets that sampled for more than 24 hours, assessment on Lake Erie were retained to maintain experience prolonged exposure to water temperatures continuity of a long-term data series for nearshore (<50 <59°F (15°C), or that became badly damaged, tangled, ft) waters. Long-term catch rates presented in this report or fouled by filamentous algae or other debris are focus principally on the nearshore stratum, where a omitted. standard sampling strategy has been performed since 1981. All nearshore catch rates obtained by the former Catches from overnight sets are completely enumerated (pre-1993) standard gill net were calibrated to the by species. Walleye, yellow perch, and smallmouth current standard as described by Culligan et al. (1994). bass are measured, weighed, sexed, and scales, spines An offshore stratum (>50 ft) was added in 1993, or otoliths are removed for age determination. Large primarily to assess yellow perch status. catches of walleye, smallmouth bass, and yellow perch are sub-sampled as needed to process samples in a This assessment utilizes a stratified, random approach timely manner. with stations selected from a 2.5-minute lat/long grid ______Section D Page 1 NYSDEC Lake Erie Annual Report 2020
2021) should contribute to excellent walleye fishing for several years (see Section N).
Age-1 and age-2 walleye were 1.6 and 1.2 inches below the long-term average length, respectively, in 2020 and ranked at or near the lowest observed lengths since the survey began (Figure D.5). Evidence of reduced forage biomass coupled with increasing walleye abundance in recent years (Section C) is likely influencing walleye growth even at early ages. A more thorough investigation of the impact of forage biomass and predator density on growth and condition may be warranted in the coming years if these trends continue.
Walleye Abundance Index
40 Age 1 & 2 Age 3 to 7 Age 8 + 35
FIGURE D.1. Warmwater gill net sampling sites for 2020. Red 30 markers represent nearshore sites (<50 ft) and white markers 25 represent offshore sites (>50 ft). 20 Results and Discussion 15 10 Number Net per Walleye 5 0 The relative walleye abundance index in 2020 was 19.1 fish per net, the 13th highest index in the 40-year survey (Figure D.2). Juvenile walleye are not captured Sampling Year consistently at offshore sites so only nearshore sites are FIGURE D.2. Walleye catch by age category per gill net set from nearshore stations (< 50 ft) in New York waters of Lake Erie, included in the walleye abundance index. Eighteen September–October, 1981–2020. walleye age groups were represented in the 2020 sample (nearshore and offshore). Age-1 walleye dominated the nearshore catch (2019 year class; 30%) 2020 Walleye Gill Net Age Distribution followed by age-4 fish (2016 year class; 24%) and age- 8 2 fish (2018 year class; 23%; Figure D.3). Nearshore (< 50 ft) Offshore (> 50 ft) 6 Yearling walleye catch rates in 2020 ranked the 2019 th year class as the 12 largest (6.0 age-1 walleye per net), 4 falling within our established threshold for a “strong” year class (Figure D.4). Five of the six exceptional year classes observed during the 40-year survey have Number Net per 2 occurred in the last 18 years and are still represented in the current walleye population. Consecutive weak 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 walleye year classes have not been observed since the Age early 1990’s and only a single weak year class has been FIGURE D.3. Age composition of walleye caught in nearshore and observed in the last 15 years. Four exceptional local offshore gill nets from the New York waters of Lake Erie, September– walleye year classes (2010, 2012, 2016, 2017) have October, 2020. occurred since 2010. Exceptional local walleye recruitment, especially the 2016 and 2017 cohorts, coupled with strong western basin recruitment (WTG ______Section D Page 2 NYSDEC Lake Erie Annual Report 2020______
Yearling Walleye Abundance Index Smallmouth Bass Abundance Index 30 50 Age 8 + 25 40 Age 3 to 7
20 Age 1 & 2 30 15 20 10 Number Net per
Number Net per 10 5
0 0
Year Class Sampling Year FIGURE D.4. Relative abundance of age-1 walleye collected from FIGURE D.6. Smallmouth bass catch rates by age category from nearshore stations (< 50 ft) in New York waters of Lake Erie, nearshore stations (< 50 ft) in New York waters of Lake Erie, September–October, 1981–2020. Error bars represent 95% September–October, 1981–2020. confidence limits.
2020 Smallmouth Gill Net Age Distribution Length of Age-1 and Age-2 Walleye 3 20 Nearshore (< 50 ft) Age-1 Age-2 Size Limit Offshore (> 50 ft) 18 2 16
14 1 Number Net per 12 Total (inches) Length Total 10 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Age Sampling Year FIGURE D.7. Age composition of smallmouth bass caught in nearshore and offshore gill nets from the New York waters of Lake FIGURE D.5. Mean total length of age-1 & age-2 walleye collected Erie, September–October, 2020. from variable mesh gill nets in the New York waters of Lake Erie, September–October, 1981–2020. Years in which sample sizes were less than 6 were excluded. Error bars are 2 standard errors. The relative abundance index for age-2 smallmouth bass (“recruitment index”) in 2020 (1.6 fish per net) was Smallmouth Bass well below the time series average of 4.3 fish per net The smallmouth bass gill net index of relative (Figure D.8). abundance has declined substantially since its peak in the early 2000’s, with the smallmouth bass relative Age-2 and age-3 smallmouth bass averaged 11.3 inches abundance in 2020 (10.1 fish per night) approximately and 13.6 inches total length, respectively (Figure D.9), half of the time series average (19.5 fish per net; Figure slightly above the respective long-term averages of 10.9 D.6). Age-4 smallmouth bass dominated the 2020 and 12.9 inches. Beginning in the late-1990’s, nearshore sample (21%), which included 16 age groups smallmouth bass showed significantly elevated growth from age-0 to age-15 (Figure D.7). Offshore gill nets rates that roughly correspond to the invasion of eastern caught fewer sub-adult smallmouth bass and fewer Lake Erie by round goby (see Section C). Increased smallmouth bass overall than companion nearshore gill bass growth following the invasion of round goby has nets, which is typical. persisted to the present day and has recently been more rigorously examined using this data series by Crane and Einhouse (2016). They found that bass diet composition
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shifted from crayfish and a diversity of prey fish species smallmouth bass in the New York waters of Lake Erie. to predominantly goby after the invasion. Increases in Ages 3-10 were used to calculate annual survival size at age and overall growth rate were attributed to a estimates for each year class from 1978-2009 using shift to goby as the major bass prey item. Presently, the catch curve analysis. Year classes that lived their entire observed mean length of Lake Erie smallmouth bass life without goby, those that lived a portion of their life exceeds measures for New York’s other fast-growing with goby, and those that lived their entire life with bass populations (Green et al. 1986). Reasons for the goby are separated in the figure to examine the potential continued increases in bass growth are not understood role that goby introduction played in the observed but may be related to declining bass abundance. changes in survival. Age-2 Smallmouth Bass Abundance Index Smallmouth Bass Gill Net Index (old bass, 8+) 25 8 7 20 6 15 5 4 10 3 Number Net per 5 2 Number Net per 1 0 0
Sampling Year Sampling Year FIGURE D.8. Relative abundance of age-2 smallmouth bass collected from nearshore stations (< 50 ft) in New York waters of Lake FIGURE D.10. Age-8 and older smallmouth bass catch rates from Erie, September–October, 1981–2020. nearshore stations (< 50 ft) in New York waters of Lake Erie, September–October, 1981–2020. The aging structure for large bass (>17 in) was changed from scales to otoliths in 1993. Length of Age-2 and Age-3 Bass 15 Age-3 Bass Survival By Year Class 100 14 Age-2 90 13 80 12 70 11 60
10 50 Total (inches) Length Total 40 Goby not present 9 Goby partially present
Annual Percent Survival Percent Annual 30 Goby present for whole life 20 Sampling Year
FIGURE D.9. Mean total length of age-2 and age-3 smallmouth bass Year Class collected from variable mesh gill nets in the New York waters of Lake Erie, September–October, 1981–2020. Error bars are 95% FIGURE D.11. Estimated survival of age 3-10 smallmouth bass from confidence limits. nearshore stations (< 50 ft) in the New York waters of Lake Erie. Each point represents the survival rate estimate of smallmouth bass by year class, 1978–2009. From 2007–2014 older smallmouth bass (Age-8+) were less abundant than they were in the early to mid-2000’s From the 1970’s to the early 2000’s there was a (Figure D.10), which was a source of concern for bass substantial decrease in annual bass survival rates from anglers. In response to these concerns we examined approximately 84% for late 1970’s cohorts to trends in bass survival to better understand the possible approximately 64% for early 2000’s cohorts. Bass reasons for the reduction in older bass. Figure D.11 survival reached its lowest point in cohorts born in the illustrates the annual estimated survival rate of adult ______Section D Page 4 NYSDEC Lake Erie Annual Report 2020______
late 1990’s and early 2000’s which coincides with the and is the result of two years of weak to moderate onset and peak of the goby invasion and the relative recruitment in 2017 and 2018 (see Section C) coupled absence of older bass from those year classes. Cohorts with the 2015 year class beginning to age out of the born more recently (late 2000’s) appear to be population. Further declines in the perch population are experiencing higher survival rates, as evidence by expected in upcoming years without an improvement in increased abundances of older (age-8+) bass in the juvenile recruitment. population in recent years (Figure D.10). Bass survival Yellow Perch Abundance Index rates over time correlate well with numbers of older 350 Ages 1 and 2 bass in the population indicating that decreased 300 survival, not recruitment issues, likely caused the Ages 3 to 7 250 paucity of older individuals in the population. This is Ages 8 + further supported by overall stability in our age-2 index 200 of recruitment (Figure D.8). It is possible that goby have 150 been a driver of bass mortality as a vector for disease 100 (Clostridium botulinum) or via decreases in age at Net per Number 50 maturity. However, goby have persisted even during the more recent period of increased bass survival, which 0 may indicate that they are not the only driver of recent bass dynamics or that mechanisms driving survival Sampling Year have changed over time. Smallmouth bass dynamics as FIGURE D.12. Yellow perch gill net catch rates by age category from they relate to goby introduction and abundance, disease, offshore stations (> 50 ft). in New York waters of Lake Erie, angling pressure, recruitment and other factors are still September–October, 1993–2020. relatively poorly understood in the New York waters of Lake Erie. 2020 Yellow Perch Gill Net Age Distribution 80 Yellow Perch 70 Yellow perch are not typically encountered in high 60 densities in the shallower, nearshore (0 to 50 ft.) gill net 50 locations. Therefore, the offshore gill net sets (Figure 40 D.1, 50 to 100 ft.) are used to index yellow perch 30 abundance. This deeper stratum has been sampled since
Number Net per 20 the interagency index fishing protocol was 10 implemented in New York starting in 1993. 0 1 2 3 4 5 6 7 8 9 10 11 12 Yellow perch relative abundance was 125.9 fish per net Age in 2020, near the time series average of 126.2, and the FIGURE D.13. Age composition of yellow perch collected in offshore, fifteenth highest index observed (Figure D.12). Age-4 gill nets from the New York waters of Lake Erie, September–October, yellow perch (2016 year class) dominated the catch in 2020.
2020, accounting for 55% of the yellow perch captured Other Fish Species (Figure D.13). Yellow perch abundance has remained relatively high since a period of low abundance during Relative abundance (catch per net) for the 14 species the 1990’s. Relatively consistent juvenile recruitment, most commonly encountered in the 40-year gill net coupled with a conservative harvest strategy by eastern series are reported in Figure D.14. All species were basin management jurisdictions (YPTG 2021) seem to encountered within observed historic abundance have fostered improved status of yellow perch in Lake ranges. Erie’s eastern basin, the lake’s least biologically productive zone. While yellow perch abundance remains high relative to the time series, reductions in relative abundance are evident over the past two years ______Section D Page 5 NYSDEC Lake Erie Annual Report 2020
FIGURE D14. Bar plots represent gill net catch rates for selected fish species collected in the nearshore (< 50 ft) stations in New York waters of Lake Erie, September–October, 1981–2020. The solid line represents gill net catch rates in the offshore (> 50 ft) stations from September– October, 1993–2020.
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FIGURE D.14 (Continued). Bar plots represent gill net catch rates for selected fish species collected in the nearshore (< 50 ft) stations in New York waters of Lake Erie, September-October, 1981-2020. The solid line represents gill net catch rates in the offshore (> 50 ft) stations from September–October, 1993–2020.
References
Crane, D. P., and D. W. Einhouse. 2016. Changes in Ryan, P., S. Orsatti, D. Einhouse, D. Davies, R. growth and diet of smallmouth bass following Knight, M. Rawson, M. Turner, J. Murphy, and S. invasion of Lake Erie by the round goby. Journal Nepszy. 1993. Interagency Protocol for Index of Great Lakes Research 42(2):405-412. Fishing with Gill Nets in Lake Erie. Report to the Standing Technical Committee and the Great Culligan, W. J., F. C. Cornelius, D. W. Einhouse, D. Lakes Fishery Commission. September, 1993. L. Zeller, R. C. Zimar, B. J. Beckwith, and M. A. Wilkinson. 1994. Annual Report of the Lake Erie Walleye Task Group, 2021. Report of the Lake Erie Unit to the Lake Erie Committee and the Great Walleye Task Group. Presented to the Standing Lakes Fishery Commission. New York State Technical Committee, Lake Erie Committee, and Department of Environmental Conservation, Great Lakes Fishery Commission.
Bureau of Fisheries report. April, 1994. Yellow Perch Task Group, 2021. Report of the Lake Einhouse, D. W., W. J. Culligan, and J. Prey. 2002. Erie Yellow Perch Task Group. Presented to the Changes in the smallmouth bass fishery of New Standing Technical Committee, Lake Erie York’s portion of Lake Erie with Initiation of a Committee, and Great Lakes Fishery Commission. spring black bass season. American Fisheries Society Symposium. 31:603-614.
Green, D. M., B. L. Schonhoff, and W. D. Youngs.
1986. The New York State Bass Study 1977-1980,
Use of angler Collected Data to Determine
Population Dynamics. New York State
Department of Environmental Conservation, Bureau of Fisheries report. April, 1986.
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E. COMMERCIAL FISHERY ASSESSMENT
Pascal D. Wilkins
Introduction Licensed Commercial Fishermen and Nets 10 80 Licensed Fishermen 9 Following 1986 legislation that prohibited the use of 70 Licensed nets gill nets in the New York waters of Lake Erie, a small 8 60 commercial trap net fishery targeting yellow perch near 7 50 Barcelona Harbor emerged and has remained for the 6
last 35 years. 5 40
4 30 Methods 3 Nets Licensed Licensed Fishermen Licensed 20 2 Commercial fishermen are required to submit monthly 10 1 reports summarizing daily fishing effort and catches. 0 0 The standard unit of effort is the number of net lifts that occurred during a day, irrespective of the amount of time the gear may have fished. Catches are reported as Year Figure E.1. Number of licensed commercial fishermen and combined pounds harvested. Non-target species returned to the licensed fyke and trap nets in the New York waters of Lake Erie, lake are not always reported. Due to increased fishing 1986–2020. Missing license and net data in 1998 and 2007 were activity, collections of yellow perch ageing structures interpolated.
(anal spines) resumed in 2005 to assess the age Table E.1. Monthly effort and catch of the five most reported species distribution of the commercial harvest. These data, in New York’s 2020 Lake Erie commercial fishery. Not all species along with harvest and effort totals, are reported to the were harvested. Commercial catch of prominent species (lbs) Effort Yellow Perch Task Group (YPTG) of the Great Lakes Month Y. Perch Burbot W. Perch Suckers W. Bass (# of lifts) Fishery Commission’s Lake Erie Committee to produce Mar 236 20 1 1 2 a yellow perch status summary for Lake Erie’s eastern Apr 3,457 381 3 4 28 basin (Yellow Perch Task Group 2021). May 7,091 120 24 1 52 Jun 3,350 110 4 7 2 42 Jul 34 2 Results and Discussion Aug 0 Sep 0 Oct 669 123 10 Four fishermen were issued licenses and two reported Nov commercial fishing activity in 2020. The four fishermen Dec licensed a combined total of 70 fyke nets and trap nets Total 14,837 754 32 13 2 136 (Figure E.1). The number of licensed fishermen has remained relatively constant recently while the amount A total of 136 net lifts were reported in 2020, which was of gear licensed has increased. Increases in reported the 8th lowest (21st percentile) trap netting effort in the effort have not kept pace with increases in the amount time series (Table E.1; Figure E.2). Reported of gear licensed, indicating fishermen are only fishing a commercial yellow perch harvest in 2020 totaled portion of their licensed gear. 14,837 lbs. (~32,089 fish), which was the 9th highest (76th percentile) in the history of the 35-year trap net Seasonal fishing activity extended from March through fishery (Table E.1, Figure E.2). All yellow perch caught November, with the greatest yellow perch harvest in 2020 were sold; burbot were the only other captured occurring in May (Table E.1). Commercial fishing species sold (59%; 444 lbs.). activity has been somewhat elevated during the most recent 15-year period (2006–2020), generally corresponding to a period of increased yellow perch abundance in Lake Erie’s eastern basin (See section D). ______Section E Page 1 NYSDEC Lake Erie Annual Report 2020
Commercial Yellow Perch Harvest and Effort 25 2,000 Harvest Effort 20 1,600
15 1,200 Net lifts 10 800
Poundsof perch (thousands) 5 400
- 0
Ye ar Figure E.2. Total commercial yield of yellow perch and trap net lifts Figure E.3. Percent frequency age distribution of 150 yellow perch reported by commercial fisherman operating in New York’s portion of sampled from the commercial harvest in New York’s portion of Lake Lake Erie, 1986-2020. Erie, May and June 2020.
We sampled commercially harvested yellow perch on two occasions during periods of high commercial References fishing activity in April and June to characterize the age and size distribution of the 2020 commercial harvest. Yellow Perch Task Group. 2021. Report of the Lake Age determination from 150 yellow perch anal fin Erie Yellow Perch Task Group, March 2021. samples identified 9 cohorts that ranged from age-2 to Presented to the Standing Technical Committee, age-10. Age-4 was the dominant cohort, comprising Lake Erie Committee of the Great Lakes Fishery 67% of the sample (Figure E.3). The mean length and Commission. Ann Arbor, Michigan, USA. weight of yellow perch from this sample was 10.0 inches and 0.46 lbs, respectively. Sex ratio was skewed towards mature females; 69% of the yellow perch examined were females expressing gametes.
In 2020, the commercial fishery harvest accounted for an estimated 48% of the total measured harvest by number of fish (41% by weight). The proportion of total harvest associated with the commercial fishery was relatively high in 2020 due to declines in recreational effort rather than increases in commercial fishing activity. The commercial and recreational yellow perch fisheries remain spatially segregated; very little targeted recreational yellow perch effort is expended near Barcelona Harbor. Nevertheless, significant expansion of the commercial fishery is not recommended as it could become difficult to maintain New York’s long- term yellow perch harvest within annually established total allowable harvest recommendations.
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F. COLDWATER GILL NET ASSESSMENT
James L. Markham
The annual coldwater fish community gill net assessment program has been performed by New Lake Erie York’s Lake Erie Fisheries Research Unit since 1986. The principal objective of this August survey is to Area 1 produce standardized indices of relative abundance and ON Area 2 sea lamprey wounding rates (see Section G) for NY coldwater fish species in the New York waters of Lake Erie. In addition, the survey produces age and strain PA composition data for lake trout. Data from this survey are also contributed to the Lake Erie Committee’s (LEC) interagency Coldwater Task Group for annual lake wide assessments (Coldwater Task Group 2021). Long-term index netting remains invaluable as a tool for assessing the health of the coldwater fish
community, assessing progress towards sea lamprey FIGURE F.1. Standard gill net locations (white dots) by area for control, and measuring the success of lake trout assessment of coldwater species in the New York waters of Lake Erie, restoration efforts. August, 2015-2019.
Rehabilitation of a self-sustaining lake trout population decrease the number of required samples, and maintain in the eastern basin of Lake Erie continues to be a major comparable metrics between survey methodologies. objective of New York’s Great Lakes coldwater fisheries management program. This objective is Previous Survey Design pursued in cooperation with member agencies of the The original coldwater gill net survey design employed Great Lakes Fishery Commission’s LEC, the U.S. Fish from 1986-2019 used a standardized random transect and Wildlife Service (USFWS), and the US Geological approach during the month of August. Detailed Survey’s Lake Erie Biological Station at Sandusky, methods for this survey can be found in Markham Ohio. A lake trout management plan (Markham et al. (2020). LORAN-C lines of position having a relative 2008) was approved by the LEC in 2008 and serves as North/South orientation were used to establish a guide for ongoing rehabilitation efforts. equidistant candidate transects from Dunkirk west to the New York/Pennsylvania boundary. This sampling Methods area was divided into two equal sections (Area 1 and Area 2, Figure F.1); the entire area bounds the A new survey design to assess lake trout and other approximate summertime coldwater habitat in the New coldwater species was implemented in 2020 following York waters of Lake Erie. Five randomly selected five years of sampling which identified substantial transects in each area (10 total) were sampled annually. differences in species abundance between standard Five lifts were fished per sampling night on each survey sites (net locations adjacent to the thermocline) transect, yielding 50 lifts annually. and experimental sites in offshore waters (Markham 2020). The previous survey design resulted in over Although there were some modifications to the survey sampling of the area directly adjacent to the 50oF design and gear over time, in general the standard isotherm and a complete lack of sampling in offshore survey net consisted of a gang of 10 randomly ordered, waters (Figure F.1). The new survey was designed to 8 ft deep by 50 ft long monofilament gill net panels (500 provide better coverage of the entire coldwater habitat, ft total length per net gang), ranging from 1.5 to 6.0 inch by 0.5 inch increments, set overnight on bottom. On any
Section F Page 1 NYSDEC Lake Erie Annual Report 2020
given transect, the first net gang (net #1) was fished The new survey is divided into two groups – standard parallel with shore (on contour), at a depth of 8-10 ft. assessment nets and offshore assessment nets. The below the 50oF isotherm. Each of the next three standard assessment nets are set in grids located in successive net gangs (nets #2-4) were set on contours similar areas to the previous assessment survey. Two along the transect in a northerly (deeper) direction at net gangs in each of eight randomly chosen grids (16 increments of 5.0 feet greater depth or 0.5 miles net gangs total) are set following the standard distance from the previous gang, whichever occurred procedures for net #1 (i.e. 8-10 ft. deeper than the 50oF first. The placement of the fifth gang (net #5) was 50 isotherm) and net #3 (10 ft deeper than net #1). If the feet deeper than the shallowest gang (net #1) or 1.0 mile depth and temperature criteria were to fall outside of the distant from the fourth net gang, whichever occurred standard assessment grid (i.e. shallower or deeper), then first. nets would be moved to the adjacent grid to the north or south following the protocols. These nets are set parallel New Survey Design to the shoreline but otherwise can be placed anywhere within the grid following the traditional protocol for The new survey continues to occur during August each temperature and depth. An additional sixteen net gangs year following stratification, covers a similar sampling (offshore assessment nets) are set in randomly selected area, and employs the same gill net configuration offshore grids. Nets in these areas are set in any location described above. A 2.5 minute grid system is used for within the selected grid but in a direction consistent random selection of netting locations as opposed to the with the bottom contour. Altogether, a total of 32 net transect approach (Figure F.2). gangs are targeted for a complete survey each year.
Standard Assessment Grids (Yellow Boxes: Pick 8) 1627 1623 1618 1613 1607 1602 1597 1592 1586 1580
Offshore Assessment Grids (Black Boxes: Pick 16) 1625 1626 807 1621 1622 1616 1617 795 1611 1612 788 1605 1606 1599 1600 1601 774 1594 1595 1596 1588 1589 1590 1591 1582 1583 1584 1585 751 1576 1577 1578 1579
FIGURE F.2. 2.5 minute grid system used to randomly select standard (yellow boxes) and offshore (black boxes) assessment netting locations during the coldwater gill net survey in the New York waters of Lake Erie. Each grid is assigned a unique number ID.
Section F Page 2 NYSDEC Lake Erie Annual Report 2020
Previous and New Survey Comparability catches for this species in this survey, and higher catches of lake whitefish occurring in nets closer to the Prior to the re-design of the survey, an analysis thermocline. As a result of this analysis, abundance comparing catch-per-effort (CPE) trends for lake trout, indices for all three species will only use data from burbot, and lake whitefish from all standard assessment standard assessment nets (nets #1 and #3) for nets versus just nets #1 and #3 between 1985 and 2018 comparison to the long-term data series; a new was performed. The goal of this analysis was to abundance index was developed utilizing all netting determine the feasibility of using these two nets for locations (i.e. both standard and offshore assessment comparison to the long term data series. The results of netting). Unless indicated, all other data metrics use the analysis indicated a strong relationship for both lake data from all collected fish regardless of sampling trout and burbot, and a comparable but slightly weaker location. Biased sets due to temperature shifts or other relationship for lake whitefish (Figure F.3). The weaker issues were deleted from abundance index calculations relationship for lake whitefish was not unexpected but are otherwise used for age, growth, diet, and given the patchy distribution and high variability in wounding statistics.
FIGURE F.3. Comparison of lake trout, lake whitefish, and burbot CPE using all standard assessment nets and only nets #1 and #3 including confidence limits (2 SE’s), 1985-2018 (left side graphs), and plot of CPE for all nets versus nets #1 and #3 by year (right side).
Section F Page 3 NYSDEC Lake Erie Annual Report 2020
Total length, weight, sex, maturity, stomach contents, 185 feet. Target coldwater species caught during the fin clips, and sea lamprey wounding are recorded for survey (all nets) included 201 lake trout, 36 lake every lake trout. Secondary targets (i.e. burbot, whitefish, 9 burbot, and 1 steelhead. Other non-target whitefish, and other salmonids) are examined using the species included 4 white bass and 26 walleye. same protocol. Snouts are retained from all tagged lake trout for coded-wire tag (CWT) retrieval. Otoliths and Natural Reproduction of Lake Trout a fin-clip sample are also collected from any lake trout There were no potentially wild lake trout (missing fin without a clip and CWT for future determination of clips and CWT) sampled in 2020 (Table F.1). origin. Otoliths and/or scales are collected from Altogether, 65 potentially wild fish have been caught secondary targets as needed. since 2000, representing 2.2% or less of the annual lake Klondike strain lake trout are an offshore form from trout sample. This rate is similar to rates of Lake Superior and are thought to behave differently clipping/tagging error in the hatchery, casting doubt on than commonly stocked “Lean” strain lake trout. the wild origin of these fish. Otoliths, and more recently Klondike strain lake trout have not been stocked in Lake fin clip samples, from any potentially wild lake trout are Erie since 2010, and due to low abundances (only 2 removed and saved and will be used in future otolith caught in 2020) are no longer separately reported unless chemistry and/or genetic analyses to determine if these noted (Markham 2018). Lean strain lake trout comprise fish were of wild or hatchery origin. all other stocked strains, including Finger Lakes, Lake TABLE F.1. Number and percentage of potentially wild lake trout, and Champlain, and Slate Island. total sample size of lake trout caught in coldwater assessment gill nets in the New York waters of Lake Erie, 2000–2020. A potentially wild Results and Discussion fish has no fin clips and no coded-wire tag (CWT). Number of Fish Number of Lake Percent without Year A total of 32 lifts were completed during the August without Tags/Clips Trout Sampled Tags/Clips 2020 assessment (Figure F.4). Half of these lifts (16) 2000 3 134 2.2 sampled the standard assessment stratum at depths 2001 5 249 2.0 between 80 and 120 feet while the remaining 16 nets 2002 2 226 0.9 2003 11 550 2.0 sampled the offshore stratum at depths between 97 and 2004 2 248 0.8 2005 1 281 0.4 2006 1 353 0.3 Lake Erie 2007 1 355 0.3 2008 5 603 0.8 2009 3 466 0.6 ON 2010 6 365 1.6 2011 5 659 0.8 NY 2012 3 498 0.6 PA 2013 2 528 0.4 2014 2 837 0.2 2015 5 782 0.6 2016 0 363 0.0 2017 2 361 0.6 2018 1 356 0.3 2019 5 359 1.4 2020 0 201 0.0
FIGURE F.4. Gill net locations for assessment of coldwater species in the NY waters of Lake Erie, August, 2020. White circles represent standard assessment net locations; blue circles indicate offshore net locations randomly selected from a 2.5 minute grid system.
Section F Page 4 NYSDEC Lake Erie Annual Report 2020
Lake Trout Age Structure 1.5 FL LC KL SI In 2020, 14 age classes ranging from age-4 to 35 were represented in the sample of 165 known-age fish as determined by CWT or fin clip examination (Table 1.0 F.2). Ages 5 and 10 were the most abundant cohorts; no lake trout younger than age-4 were caught (Figure F.5). Abundance of lake trout older than age-10 has increased in recent years and now represents a significant portion 0.5 of the population. The 35-year old male sampled in per Lift) (Number CPE 2020 was the oldest lake trout ever encountered in this survey. 0.0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20+ TABLE F.2. Number, mean total length (inches TL), mean weight Age
(lbs.), and percent maturity of known age and sex lake trout (Lean FIGURE F.5. Relative abundance by age and strain of lake trout strain) by age class collected in gill nets (all mesh sizes) from New collected from standard assessment gill nets fished in New York York waters of Lake Erie, August, 2020. waters of Lake Erie, August, 2020. Stocking strain codes: FL = Finger Lakes, LC = Lake Champlain, KL = Klondike, and SI = Slate Island. MEAN MEAN PERCENT AGE SEX NUMBER LENGTH WEIGHT MATURE (inches TL) (pounds) Lake Trout Strains Male 0 ------1 Female 0 ------Four lake trout strains were detected among the 165 fish Male 0 ------caught with hatchery-implanted CWT’s or fin-clips 2 Female 0 ------(Figure F.5). Lake Champlain, Finger Lakes, and Slate Male 0 ------3 Island have been the most commonly stocked lake trout Female 0 ------Male 15 24.3 6.3 100 strains in Lake Erie over the past ten years (see Section 4 Female 1 24.4 6.2 100 H, Figure H.2). Lake Champlain and Finger Lakes Male 22 26.7 8.5 100 strains were the most numerous strains caught in Lake 5 Female 14 26.9 8.6 100 Erie in 2020, comprising over 97% of the catch. Catches Male 3 27.4 10.2 100 6 of the Klondike strain have declined to the point that Female 1 27.2 8.6 100 Male 7 28.7 10.9 100 they were scarcely detected (2 fish) in our most recent 7 Female 1 28.9 11.7 100 survey. Despite being stocked in the Ontario waters of Male 12 29.1 11.2 100 8 Lake Erie since 2005, Slate Island strain fish are not Female 5 29.8 12.6 100 commonly sampled in the New York assessment Male 25 31.8 14.8 100 10 survey. Female 7 30.0 13.1 100 Male 9 30.7 13.6 100 11 Female 7 30.6 13.9 100 Lake Trout Growth and Maturity Male 11 32.3 15.0 100 12 Female 6 31.7 15.6 100 Mean length-at-age and weight-at-age of age-5 lake Male 2 30.8 12.1 100 trout have remained relatively consistent for the past 15 13 Female 5 31.0 13.7 100 years (Figures F.6 and F.7). A decline in length and Male 1 30.5 12.8 100 14 especially weight was evident in 2019 and consistent Female 3 32.7 17.2 100 with recent changes in the forage community, Male 3 35.0 20.4 100 17 Female 0 ------especially rainbow smelt abundance (see Section C). Male 1 38.1 22.4 100 However, both metrics increased in 2020 to values more 18 Female 2 33.6 18.7 100 typical in recent years. Lean strain male lake trout are Male 1 32.6 13.4 100 19 typically 100% mature by age-4, and females 100% Female 0 ------Male 1 35.9 20.5 100 mature by age-5 (Table F.2). Maturity schedules are 35 Female 0 ------consistent with previous surveys and remain unchanged throughout the time series.
Section F Page 5 NYSDEC Lake Erie Annual Report 2020
30 14 Mature Females Mature Males 12 ) 28
s Immature Total
10
(inche 26 8 24 6
Mean Length 22 4 CPE (Number per Lift) (Number CPE
20 2 1986 1990 1994 1998 2002 2006 2010 2014 2018 0 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 FIGURE F.6. Mean length-at-age with 95% confidence limits (approximated as 2 SE’s) for age-5 Lean strain lake trout collected in FIGURE F.8. Catch per lift of immature, mature (by sex), and total gill nets from New York waters of Lake Erie, August, 1986-2020. lake trout (all strains) caught in standard assessment gill nets from NY waters of Lake Erie, August, 1986–2020.
12 trout are typically less abundant in offshore nets 10 compared to standard netting locations (Markham ) 2020). lbs
( 8
6 Lake Trout Survival 4 Point estimates of annual survival (S) for individual Mean Weight 2 cohorts were calculated by strain and year class using a catch curve approach which employed a 3-year running 0 1986 1990 1994 1998 2002 2006 2010 2014 2018 average of catch per unit effort at ages 4 through 11. A running average was used due to the high year-to-year FIGURE F.7. Mean weight-at-age with 95% confidence limits variability in catches, particularly of the Finger Lakes (approximated as 2 SE’s) for age-5 Lean strain lake trout collected in gill nets from New York waters of Lake Erie, August, 1986-2020. strain fish. The Superior and Finger Lakes strains have been the most consistently stocked lake trout strains in Lake Trout Abundance Lake Erie (see Section H) and provide the best timeline of changes in lake trout survival across a range of Relative abundance of lake trout sampled in standard conditions. Prior to 1986, combined survival estimates assessment nets (all ages combined) in 2020 was 8.8 for both strains were near or below the 60% target lake trout/lift (Figure F.8). This represents an increase survival rate (Lake Trout Task Group 1985; Markham compared to the past four years and is above both the et al. 2008) due to excessive mortality from a large, time-series average (5.5 fish/lift) and the target of 8.0 untreated sea lamprey population (Table F.4). fish/lift listed in the Lake Erie lake trout management
plan (Markham et al. 2008). No immature lake trout Substantial increases in survival occurred following the (generally < age 4) were sampled in 2020, continuing a initial sea lamprey treatments in Lake Erie in 1986. declining trend in their relative abundance (Figure F.8). While survival estimates have generally remained However, lake trout are not fully recruited to the gill above targets for the Finger Lakes strain since 1986, the nets until at least age-4, so relative abundance measures Superior strain experienced very low survival for the of cohorts less than age-4 typically increase at older 1997–2001 cohorts, presumably due to increased sea ages. This was only the second time that immature lake lamprey predation (see Section G). Estimated Klondike trout were not caught in the survey. Relative abundance strain survival was very low and was comparable to the of mature adult lake trout (generally > age 5) increased Superior strain for the 1997–2001 year classes. in 2020 to the second highest level in the time series,
mainly due to recruitment of the 2015 (age-5) year class
to this metric (Figure F.8). The abundance of lake trout
in all nets (standard and offshore) was 6.3 fish/lift. Lake
Section F Page 6 NYSDEC Lake Erie Annual Report 2020
TABLE F.4. Catch curve analysis estimates of annual survival (S) by Lake Trout Diet strain and year class for lake trout caught in standard assessment nets in the New York waters of Lake Erie, 1985–2020. Three-year Stomach analysis of lake trout revealed a diet entirely running averages of CPE from ages 4–11 were used due to year-to- year variability in catches. Cells in red indicate survival estimates that comprised of fish in 2020 (Figure F.9). Rainbow smelt fall below the 0.60 target rate. Asterisk (*) indicates years where only were the dominant prey item, occurring in 94% of the partial age ranges were available. non-empty stomachs, followed by round goby (6.4%) ST R AIN and yellow perch (6.4%). Rainbow smelt have been the Year Class LC SUP FL KL ALL long-term main prey item for lake trout, but round 1983 0.687 0.454 1984 0.619 0.502 0.533 gobies have become a more common prey item, 1985 0.543 0.594 0.578 especially in years with lower smelt abundance. 1986 0.678 0.634 1987 0.712 0.928 0.655 1988 0.726 0.818 0.679 Rainbow smelt were more numerically abundant in lake 1989 0.914 0.945 0.766 trout diets compared to other fish species, averaging just 1990 0.789 0.634 0.709 over six per stomach (Figure F.10). These results also 1991 0.615 coincided with observed higher abundances of yearling 1992 0.599 1993 0.850 0.646 and older rainbow smelt in our fall trawling survey 1994 0.649 compared to recent years (see Section C). Despite the 1995 0.489 high affinity for rainbow smelt, it is worth noting the 1996 0.780 0.667 increased presence of other fish species in lake trout 1997 0.404 0.850 0.549 1998 0.414 0.364 diets for the third consecutive year. Fish other than 1999 0.323 0.760 0.431 rainbow smelt or round goby occurred in 10.3% of the 2000 0.438 0.769 0.655 non-empty lake trout in 2020, the second highest 2001 0.225 0.696 0.522 occurrence in the time series (highest in 2018). The 2002 0.693 0.633 2003 0.667 0.242 0.585 majority of fish in this category were yellow perch 2004 0.485 0.420 (6.4%); other species included gizzard shad (2.6%) and 2005 0.450 0.629 white perch (1.3%). 2006 0.827 0.58 0.770 2007 0.835 0.619 0.791 2008 0.850 0.807 0.579 0.728 Lake Trout 2009 0.782 0.763 100 2010* 0.925 0.894 2011* 80 2012* 0.984 0.906 0.953 Smelt M EAN 0.885 0.575 0.753 0.501 0.633 60 Goby Other Fish Estimates of survival were calculated for Lake Inverts Champlain strain (predominately Finger Lakes origin) 40 to determine if their survival was comparable to Finger 20
Lakes or Superior strains. Results indicate above target Percent Occurrencein Diet survival rates for the 2008–2010 and 2012 cohorts, 0 similar to Finger Lakes strain survival estimates. Given 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019
Lake Erie’s continuing sea lamprey control issues, FIGURE F.9. Percent occurrence in diet of rainbow smelt, round goby, stocking lake trout strains that survive sea lamprey all other fish species, and invertebrates from non-empty stomachs of attack and consistently have above target survival rates lake trout (all strains) collected in gill nets from New York waters of Lake Erie, August, 1999–2020. (i.e. Finger Lakes and Lake Champlain strains) will produce a more stable adult population and provide the best opportunity for restoration.
Section F Page 7 NYSDEC Lake Erie Annual Report 2020
Lake Trout Lake Whitefish Abundance 10 Smelt Lake whitefish have exhibited highly variable catches Goby 8 in this survey (as depicted by large confidence limits), Yellow Perch both within and among years. A total of 34 lake Other
6 whitefish were caught in 16 standard assessment nets in 2020, resulting in a CPE of 2.1 fish/lift (Figure F.12). This was slightly below the time series average of 2.6 4 fish/lift. The Lake whitefish abundance index has increased since 2015 due to several above average year Average per Average Stomach 2 classes produced since 2014 (see Section C).
0 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019 15 Whitefish Average FIGURE F.10. Average number per stomach of rainbow smelt, round goby, yellow perch, and all other fish species, from non-empty 12 stomachs of lake trout (all strains) collected in gill nets from New York waters of Lake Erie, August, 2001–2020. 9 Burbot Abundance The burbot abundance index in the 2020 standard 6 assessment nets was 0.19 fish/lift, the lowest estimate CPE (Number per Lift) (Number CPE observed in the time-series (Figure F.11). Burbot 3 abundance has declined over 95% from a peak in 2004 and at the present time shows no signs of recovery. The 0 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 abundance of burbot in all nets (standard and offshore) FIGURE F.12. Catch per effort (number fish/lift) and confidence limits was 0.28 fish/lift. Previous surveys indicated similar (approximated as 2 SE’s) of lake whitefish caught in standard abundances of burbot in both standard and offshore assessment gill nets from New York waters of Lake Erie, August, netting locations (Markham 2020). While the exact 1986–2020. Dashed line indicates time series average. reasons for the decline of burbot in Lake Erie are unclear, it is likely related to a combination of recruitment failure (Stapanian et al. 2010; Coldwater Task Group 2016), sea lamprey predation, and competition with adult lake trout (Coldwater Task Group 2016).
6 Burbot 5 Average
4
3
2 CPE (Number per Lift) (Number CPE
1
0 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
FIGURE F.11. Catch per effort (number fish/lift) and confidence limits (approximated as 2 SE’s) of burbot caught in standard assessment gill nets from New York waters of Lake Erie, August, 1986–2020. Dashed line indicates time series average.
Section F Page 8 NYSDEC Lake Erie Annual Report 2020
References Markham, J., A. Cook, T. MacDougall, L. Witzel, K. Kayle, C. Murray, M. Fodale, E. Trometer, F. Neave, J. Fitzsimons, J. Francis, and M. Stapanian. Coldwater Task Group. 2016. 2015 Report of the Lake 2008. A strategic plan for the rehabilitation of lake Erie Coldwater Task Group, March 2016. Presented trout in Lake Erie, 2008-2020. Lake Erie to the Standing Technical Committee, Lake Erie Committee, Great Lakes Fisheries Commission, Committee of the Great Lakes Fishery Commission, Ann Arbor, MI. Available at Ann Arbor, Michigan, USA. http://www.glfc.org/lakecom/lec/LEC_docs/other_ Coldwater Task Group. 2021. 2020 Report of the Lake docs/manplan2008.pdf [accessed 14 January 2008] Erie Coldwater Task Group, March 2021. Presented Stapanian, M. A., L. D. Witzel, and A. Cook. 2010. to the Standing Technical Committee, Lake Erie Recruitment of burbot Lota lota in Lake Erie: an Committee of the Great Lakes Fishery Commission, empirical modeling approach. Ecology of Ann Arbor, Michigan, USA. Freshwater Fish 19:326-337. Lake Trout Task Group. 1985. A Strategic Plan for the
Rehabilitation of Lake Trout in Eastern Lake Erie. Report to the Great Lakes Fishery Commission’s Lake Erie Committee, Ann Arbor, Michigan, USA.
Markham, J. L. 2017. Coldwater gill net assessment.
Section F in NYSDEC 2017, Lake Erie 2016 Annual Report. New York State Department of Environmental Conservation, Albany, New York, USA.
Markham, J. L. 2018. Coldwater gill net assessment.
Section F in NYSDEC 2018, Lake Erie 2017 Annual
Report. New York State Department of
Environmental Conservation, Albany, New York,
USA.
Markham, J. L. 2020. Coldwater gill net assessment. Section F in NYSDEC 2020, Lake Erie 2019 Annual Report. New York State Department of Environmental Conservation, Albany, New York, USA.
Section F Page 9 NYSDEC Lake Erie Annual Report 2020
G. SEA LAMPREY ASSESSMENT
James L. Markham
Sea lamprey invaded Lake Erie and the upper Great concern over observed population declines (Coldwater Lakes in the 1920's with the opening of the Welland Task Group 2021). However, this was discontinued in Canal connecting lakes Erie and Ontario. While not the 2020 due to the low number of burbot caught in the exclusive cause, sea lamprey predation played an coldwater survey (N=9 in 2020). Fish are examined for integral part in the eventual demise of Lake Erie’s lake wounds during August gill net assessments targeting trout population. The initial Strategic Plan for Lake lake trout, burbot and other coldwater species in New Trout Restoration in Eastern Lake Erie (Lake Trout York’s portion of Lake Erie (see Section F). Task Group 1985) pointed to the lack of lamprey control as a bottleneck for re-establishing lake trout. Sea lamprey wounds on lake trout are classified as A1- The Sea Lamprey Management Plan for Lake Erie A4 for evidence of active feeding, and as B1-B4 (Lake Trout Task Group 1985a) followed with a set of wounds for non-active feeding, according to King and goals to achieve sea lamprey control. Since 1986, Great Edsall (1979). Standard wounding rates on lake trout Lakes Fishery Commission (GLFC) agents have are reported as the number of fresh (A1-A3) wounds per conducted regular lampricide treatments of key Lake 100 fish > 21 inches. A1 and A4 wounds, specifically, Erie tributaries to control sea lamprey populations and are also reported as evidence of the current and previous mitigate the damage they inflict on the lake’s coldwater year’s wounding, respectively. Data are tabulated using fish community. lake trout total length (TL) categories: 17-21 inches, 21- 25 inches, 25-29 inches, and >29 inches. This report updates long-term sea lamprey wounding rate indices on lake trout and other species through data Beginning in 2013, angler survey technicians began collected by the New York State Department of recording wounds (fresh or healed) observed on Environmental Conservation’s (DEC) Lake Erie harvested fish examined during the Open Lake Sport Fisheries Research Unit during the annual coldwater Fishing Survey (see Section J). These observations assessment survey (see Section F). Previous monitoring identify the broader list of sport fish species attacked by of adult sea lamprey populations also included nest sea lamprey, and perhaps over time will also generate counts on standard stream sections; this survey was useful information to establish a wounding index for discontinued in 2019 because it was not routinely other species in the fish community. incorporated in management decisions. Other lake wide adult and larval sea lamprey assessments, and all Lake Results and Discussion Erie sea lamprey control efforts, are performed by the United States Fish and Wildlife Service (Service) and Lake Trout Wounding Rate Assessment the Department of Fisheries and Oceans Canada (DFO) Lake trout collected in coldwater assessment netting as agents of the GLFC. A summary of these activities had a total of 36 A1–A3 wounds observed on 201 lake can be found in the Lake Erie Coldwater Task Group trout greater than 21 inches in 2020, resulting in a Report (Coldwater Task Group 2021). wounding rate of 17.9 wounds per 100 fish (Figure G.1;
Table G.1). This represents an increase from the Methods previous two years and is similar to wounding rates
during the 2013-2017 time period. Annual measures of Wounding Rate Assessment A1–A3 wounding have been above the target rate of 5.0 Lake trout are the only Lake Erie fish species used for wounds per 100 fish since 2002 (Lake Trout Task sea lamprey wounding assessments due to their Group 1985a, Markham et al. 2008). availability throughout the Great Lakes and vulnerability to sea lamprey attacks. Sea lamprey Sea lamprey will typically target larger lake trout (>24 wounds on burbot have also been reported due to inches) when available (Swink 2003). In 2020, the
Section G Page 1 NYSDEC Lake Erie Annual Report 2020
A1-A3 Wounds on Lake Trout >21 Inches A1 Wounds on Lake Trout >21 Inches 70 18 A1-A3 Target A1 Average 16 60 14 50 12
40 10
30 8
6 20 Wounds per 100 Fish Wounds per 100 Fish 4 10 2
0 0 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020
FIGURE G.1. Number of fresh (A1-A3) sea lamprey wounds per 100 FIGURE G.2. Number of A1 sea lamprey wounds per 100 adult lake adult lake trout >21 inches sampled in gill nets from New York waters trout >21 inches sampled in gill nets from New York waters of Lake of Lake Erie, August, 1980–2020. The target wounding rate is < 5 Erie, August, 1980–2020. The post-treatment average includes wounds per 100 lake trout (solid black line). Patterned bars indicate 1987–2019 (dashed blue line). Patterned bars indicate the pre- the pre-treatment period. treatment period.
TABLE G.1. Frequency of sea lamprey wounds and wounding rates Cumulative attacks from previous years are indicated observed on standard length groups of lake trout collected from gill by A4 wounds (healed). Altogether 187 A4 wounds nets in New York waters of Lake Erie, August, 2020. were found on 201 lake trout >21 inches in 2020, Size Class Wound No. A1-A3 No. A4 Total Length Sample Classification Wounds Per Wounds Per resulting in an A4 wounding rate of 93.0 wounds/100 (inches) Size A1 A2 A3 A4 100 Fish 100 Fish fish (Table G.1). This was the highest A4 wounding rate 17-21 0 0 0 0 0 0.0 0.0 in the time series and well above the series average 21-25 17 0 1 1 5 11.8 29.4 (40.0 wounds/100 fish) for the 14th time in the past 16 25-29 68 0 0 8 37 11.8 54.4 years (Figure G.3). The majority of A4 wounds were >29 116 0 8 18 145 22.4 125.0 found on lake trout greater than 25 inches (Table G.1). >21 201 0 9 27 187 17.9 93.0 A4 wounding rates on lake trout >29 inches remain very high (125.0 wounds/100 fish) with many fish having highest A1-A3 wounding rates occurred on lake trout multiple healed wounds. >29 inches (22.4 wounds/100 fish; Table G.1). Wounding rates in the 21-25 and 25-29 inch categories A4 Wounds on Lake Trout >21 Inches were identical (11.8 wounds/100 fish). Lake trout <21 100 A4 Average inches were not captured during the 2020 survey, but 90 rarely show signs of sea lamprey attacks. 80
70 Fresh A1 wounds are considered indicators of the attack 60 rate for the current year at the time of sampling 50 (August). No A1 wounds were found on lake trout in 2020, marking the second consecutive year and only the 40 30
third time in the past 26 years this has occurred (Table Wounds per 100 Fish G.1; Figure G.2). A1 wounding rates have been below 20 the post-treatment series average of 1.9 wounds/100 10 fish for the past seven years. 0 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012 2015 2018
FIGURE G.3. Number of healed (A4) sea lamprey wounds observed per 100 adult lake trout >21 inches sampled in gill nets from New York
waters of Lake Erie, August, 1985–2020. The post-treatment average (dashed blue line) includes 1987–2019. Patterned bars indicate the pre-treatment period.
Section G Page 2 NYSDEC Lake Erie Annual Report 2020
Lake Champlain (LC) and Finger Lakes (FL) were the of healed wounds without concomitant increases in most prevalent lake trout strains sampled in 2020 (Table fresh wounds. G.2). Consistent with results from the previous two years, both A1–A3 and A4 wounding rates were similar Despite continued efforts and improvements in recent between these strains. The FL and LC strains are years, sea lamprey control in Lake Erie continues to fall genetically very similar to each other (T. Copeland, short of the benchmarks recommended in the Lake Erie USFWS, personal communication) and appear to Lake Trout Rehabilitation Plan (Markham et al. 2008). possess similar levels of sea lamprey survival. Sample Strains better able to survive sea lamprey attacks, such sizes on both the Klondike and Slate Island strains were as the Lake Champlain and Finger Lakes strains, should too low (N=2) to provide meaningful measures of be used exclusively to achieve rehabilitation goals. wounding. However, previous survey results have These strains are also well suited to take advantage of shown that, in general, Superior lake trout strains such the nearshore spawning habitat historically available in as Klondike, Slate Island and Traverse Island have Lake Erie. higher wounding rates compared to the Finger Lakes strain (Markham 2011; Markham 2014; Rogers et al. Open Lake Sport Fishing Survey 2019). No sea lamprey wounds were observed by creel survey
technicians examining 596 angler kept sport fish during Over the past decade numbers of observed healed the 2020 Open Lake Sport Fishing Survey (Table G.3). wounds (A4) on lake trout have increased without an The majority of the examined fish were walleye. It observed increase in fresh wounds (A1-A3). Reasons should be noted that angler contact and handling of kept for the decoupling of the fresh and healed wounding fish was minimized during the survey due to Covid-19 trends are not well understood. Changes in the areas safety protocols, thus potentially compromising the where sea lamprey are mainly produced in Lake Erie detection of wounds during this survey. Observations (from east basin streams to the St. Clair River in the from this survey over the past eight years have shown west basin) may be a contributing factor. Increased sea that sea lamprey attack warm and cool-water species lamprey production in western Lake Erie may delay such as smallmouth bass, walleye, and northern pike, predation on eastern basin lake trout until after our and confirm that sea lamprey have the potential to affect August survey. A delay in timing of predation could Lake Erie’s entire fish community. cause an increase in healed wounding without observed increases in fresh wounds. Another possible TABLE G.3. Number of recorded wounds (fresh or healed) on fish explanation is the change in lake trout strain examined during the Open Lake Sport Fishing Survey, May–October, composition. Since 2002 there has been a gradual 2020. transition away from stocking Lake Superior strain lake Wounds Observed Number of Fish trout, which are highly susceptible to sea lamprey Species Fresh Healed Examined induced mortality, towards lake trout strains that are Lake Trout 0 0 1 better able to survive sea lamprey attacks (i.e. Finger Yellow Perch 0 0 91 Walleye 0 0 504 Lakes, Lake Champlain strains; Schneider et al. 1996; see Section F). A decrease in mortality due to sea lamprey attacks could cause increases in the prevalence Future Control Efforts Sea lamprey control continues to be an integral part of TABLE G.2. Frequency of sea lamprey wounds observed on lake the management and restoration goals for coldwater fish trout >21 inches, by strain, in New York waters of Lake Erie, August, 2020. species in the Lake Erie Fish Community Goals and
Wound No. A1-A3 No. A4 Objectives (Francis et al. 2020). Although lake trout Sample Classification Wounds Per Wounds Per wounding rates remain above target levels, continued Lake Trout Strain Size A1 A2 A3 A4 100 Fish 100 Fish Finger Lakes 80 0 3 12 74 15.2 78.8 suppression of sea lamprey is essential for lake trout Klondike 2 0 0 2 1 ------restoration and for maintaining the coldwater fish Lake Champlain 82 0 4 10 85 17.1 103.7 community as a functioning part of the Lake Erie food Slate Island 2 0 0 0 0 ------web.
Section G Page 3 NYSDEC Lake Erie Annual Report 2020
References
Coldwater Task Group. 2021. 2020 Report of the Lake Rogers, M. W., J. L. Markham. T. MacDougall. C. Erie Coldwater Task Group, March 2021. Presented Murray, and C. S. Vandergoot. 2019. Life history to the Standing Technical Committee, Lake Erie and ecological characteristics of humper and lean Committee of the Great Lakes Fishery Commission. ecotypes of lake trout stocked in Lake Erie. Ann Arbor, MI. Hydrobiologia. [online]. Available from: https://doi.org/10.1007/s10750-019-03986-4. Francis, J., T. Hartman, K. Kuhn, B. Locke, and J. [accessed 1 July 2019]. Robinson. 2020. Fish community objectives for the Lake Erie basin. Great Lakes Fishery Commission, Schneider, C. P., R. W. Owens, R. A. Bergstedt, and R. Special Publication 2020-01, Ann Arbor, MI. O’Gorman. 1996. Predation by sea lamprey [online]. Available from: (Petromyzon marinus) on lake trout (Salvelinus www.glfc.org/pubs/FisheryMgmtDocs/Fmd20- namaycush) in southern Lake Ontario, 1982-1992. 01.pdf [accessed 11 June 2020]. Canadian Journal of Fisheries and Aquatic Sciences 53(9):1921-1932. King, L. E., Jr. and T. A. Edsall. 1979. Illustrated Field Guide for the Classification of Sea Lamprey Attack Swink, W. D. 2003. Host selection and lethality of Marks on Great Lakes Lake Trout. Great Lakes attacks by sea lampreys (Petromyzon marinus) in Fishery Commission, Special Publication 79-1, Ann laboratory studies. Journal of Great Lakes Research Arbor, MI. 29 (Supplement):307-319. Lake Trout Task Group. 1985. A Strategic Plan for the Rehabilitation of Lake Trout in Eastern Lake Erie. Report to the Great Lakes Fishery Commission’s Lake Erie Committee, Ann Arbor, MI. Lake Trout Task Group. 1985a. A Sea Lamprey Management Plan for Lake Erie. Report to the Great Lakes Fishery Commission’s Lake Erie Committee, Ann Arbor, MI. Markham, J. L. 2011. Sea lamprey assessment. Section G in NYSDEC 2011, Lake Erie 2010 Annual Report. New York State Department of Environmental Conservation, Albany. Markham, J. L. 2014. Sea lamprey assessment. Section G in NYSDEC 2014, Lake Erie 2013 Annual Report. New York State Department of Environmental Conservation, Albany. Markham, J., A. Cook, T. MacDougall, L. Witzel, K. Kayle, C. Murray, M. Fodale, E. Trometer, F. Neave, J. Fitzsimons, J. Francis, and M. Stapanian. 2008. A strategic plan for the rehabilitation of lake trout in Lake Erie, 2008-2020. Lake Erie Committee, Great Lakes Fisheries Commission, Ann Arbor, MI. Available at http://www.glfc.org/lakecom/lec/LEC_docs/other_ docs/manplan2008.pdf [accessed 14 January 2013].
Section G Page 4 NYSDEC Lake Erie Annual Report 2020
H. SALMONINE STOCKING SUMMARY
James L. Markham and Michael T. Todd
New York has maintained a robust annual stocking 138,530 yearling steelhead were stocked into the Lake program for salmonines (trout and salmon) into Lake Erie tributaries from the Salmon River State Fish Erie and its tributaries at least since 1968 when the first Hatchery (SRSFH). This was slightly above the coho salmon were introduced. Initial introductions were stocking target of 127,500 yearlings. It should be noted made to create a recreational fishery and to utilize the that the stocking target for steelhead declined from lake’s sparsely inhabited hypolimnion (below the 255,000 to 127,500 (50%) yearlings in 2020. The thermocline). One exception is lake trout, which have reduction was necessary to accommodate an been stocked by the US Fish and Wildlife Service experimental approach initiated by SRSFH staff with (USFWS) since the mid-1970's to re-establish this guidance from Vermont’s Ed Weed Fish Culture native species. Coho and Chinook salmon are no longer Station to determine if improvements in average length stocked into Lake Erie by any jurisdiction and most of and overall length distribution of spring yearling the lake wide stocking effort focuses on steelhead and steelhead could be achieved (Markham et al. 2020). lake trout. This experimental approach was a recommendation from a study conducted on stocked yearling steelhead The number of fish stocked is expressed as yearling in Chautauqua Creek, with the goal of improving adult equivalents; the majority of the salmonines stocked in returns and providing stability to New York’s tributary Lake Erie are stocked at the yearling (one year old) life steelhead fishery (Markham and Robinson 2019). The stage. However, in some years surplus fish become results from the first year using the experimental rearing available and are typically stocked as fall fingerlings (~ techniques indicated that significant increases in both 6 months old). In this instance, fall fingerlings are average length (~1 inch greater) and weight (2 times converted to yearling equivalents based on a lake wide greater) of yearling stocked fish was achieved, and standard of 0.03527 yearlings per fall fingerling for resulted in a more consistent (i.e. less variation in size) steelhead and brown trout (unpublished data), and 0.41 stocking product (Markham et al. 2020). Further yearlings per fall fingerling for lake trout (B. Lantry, hatchery experimentation and evaluation of the juvenile USGS, unpublished data). steelhead is expected to continue for two more years to determine annual size variation using these techniques. Results and Discussion A total of 45,000 fall fingerling domestic rainbow trout A total of 347,485 salmonines were stocked into the raised at the Bath State Fish Hatchery were stocked in New York waters of Lake Erie in 2020 (Table H.1). The 2020, which equaled the stocking target (Table H.1; majority (261,455; 75%) were stocked as yearlings with Figure H.1). This was the third year of stocking fall the remainder being fall fingerlings. Stocking was at or fingerling domestic rainbow trout into the Lake Erie close to target for all species in 2020. The overall tributaries as replacements for yearling brown trout. combined stocking of salmonines in yearling Brown trout stocking was terminated because the most equivalents in 2020 was below average compared to the recent 16-year brown trout stocking effort failed to previous 31 years of the time-series and the lowest produce a reliable lake, harbor, or tributary fishery number of salmonines stocked in New York’s portion based on angler surveys (Markham and Todd 2018). of Lake Erie since 1981 (Figure H.1). The domestic rainbow trout were stocked into New York’s four largest streams (Cattaraugus, Eighteen Steelhead Mile, Canadaway, and Chautauqua Creeks) near the end of October. Due to their large size at stocking (average Steelhead/rainbow trout were the most numerous = 7.5 inches), the fall fingerling domestic rainbow trout salmonine species stocked in NY’s portion of Lake Erie were considered yearlings in Figure. H.1. In addition to in 2020 (Tables H.1 and H.2; Figure H.1). A total of
Section H Page 1 NYSDEC Lake Erie Annual Report 2020
the fall fingerlings, 3,750 yearling domestic rainbow Cooperative Net Pen Project trout were stocked into Eighteen Mile Creek in late An annual cooperative pen-rearing project pursued in March (Table H.1). partnership with the Bison City Rod and Gun Club in
the lower Buffalo River did not occur in 2020 due to Lake Trout construction and Covid-19 related issues. This project A total of 119,175 Lake Champlain (LC) and Finger is scheduled to resume in 2021. Lakes (FL) strain yearling lake trout were stocked in New York’s portion of Lake Erie on April 6-8, 2020 References (Table H.1). The lake trout were shore stocked in Barcelona Harbor; transportation offshore of Dunkirk Markham, J., A. Cook, T. MacDougall, L. Witzel, K. via the R/V Argo was not possible due to Covid-19 Kayle, C. Murray, M. Fodale, E. Trometer, F. restrictions. Additional yearling lake trout were also Neave, J. Fitzsimons, J. Francis, and M. Stapanian. stocked into the Pennsylvania waters of Lake Erie in 2008. A strategic plan for the rehabilitation of lake 2020 (79,450 FL strain); no lake trout were stocked into trout in Lake Erie, 2008-2020. Lake Erie Ohio or Ontario waters in 2020. The combined total of Committee, Great Lakes Fisheries Commission, 198,625 yearlings was near Lake Erie’s Lake Trout Ann Arbor, MI. Available at Management Plan (Markham et al. 2008) annual http://www.glfc.org/lakecom/lec/LEC_docs/other_ stocking target of 200,000 yearlings (Figure H.2). Lake docs/manplan2008.pdf [accessed 14 January 2008] trout stocking targets on Lake Erie have been met or Markham, J. L., and J. M. Robinson. 2019. Evaluation exceeded in 12 of the past 14 years. of steelhead stocking size and location on
emigration and adult returns in Chautauqua Creek, In addition to the yearlings, 41,030 fall fingerling lake NY. New York State Department of Environmental trout (FL strain) were stocked into Cattaraugus Creek in Conservation, Albany. mid-October 2020. This was the final year of a three- year pilot stocking initiative to determine if stream Markham, J. L., T. E. Kielbasinski, J. Hentges, and P. stocked lake trout can survive and return to the stream Kinney. 2020. Experimental Fish Culture in the fall; the goal is to establish a successful adult Techniques at the Salmon River Hatchery to spawning population. Evaluation of this pilot stocking Improve Steelhead Stocking Size. Bureau of program will begin in fall 2021 through electrofishing Fisheries Technical Brief, New York State surveys and an ongoing tributary angler survey. Thus Department of Environmental Conservation, far no lake trout stocked into Cattaraugus Creek have Albany. been caught during the annual Coldwater gill net survey Markham, J. L. and M. T. Todd. 2018. Salmonine (see Section F). stocking summary. Section H in NYSDEC 2018, Lake Erie 2017 Annual Report. New York State Department of Environmental Conservation,
Albany.
Section H Page 2 NYSDEC Lake Erie Annual Report 2020
Steelhead Dom. Rainbow trout Brown trout Chinook Coho 500 450 400 350 300 250 200 150 100 50 Yearlings StockedYearlings (thousands) 0 1968 1972 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020
FIGURE H.1. Number (in yearling equivalents) of coho and Chinook salmon, brown trout, and rainbow trout (domestic and steelhead) stocked in New York waters of Lake Erie, 1968-2020. 1 fall fingerling = 0.035 yearling equivalents. Fall fingerling domestic rainbow trout stocked in 2018– 20 were considered yearlings due to their relatively large size at stocking.
SUPERIOR FINGER LAKES LEWIS LAKE KLONDIKE LAKE CHAMPLAIN OTHERS 400
350
300
250
200
150
100
50
Yearlings StockedYearlings (thousands) 0 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019
FIGURE H.2. Number (in yearling equivalents) of lake trout stocked by all jurisdictions in Lake Erie, 1980–2020, by strain. Stocking targets through time are shown by black lines; the current annual stocking target is 200,000 yearlings. “Superior” includes Superior, Apostle Island, Traverse Island, Michipicoten, and Slate Island strains; “Others” include Clearwater Lake, Lake Ontario, Lake Erie, Lake Manitou, and Huron- Perry strains. 1 fall fingerling = 0.41 yearling equivalents.
Section H Page 3 NYSDEC Lake Erie Annual Report 2020
TABLE H.1. Summary of trout stocking in New York waters of Lake Erie in 2020. Months indicates the number of months fish spent in the hatchery prior to stocking.
Species Location Date Year Class Hatchery Strain Months Stage #/lb. Clip/Mark Number Target Lake Trout Barcelona 4/6/2020 2019 ANFH Finger Lakes 16 Ylg 14.2 640856 39,817 40,000 Lake Trout Barcelona 4/7/2020 2019 ANFH Lake Champlain 16 Ylg 14.2 640855 39,604 40,000 Lake Trout Barcelona 4/8/2020 2019 ANFH Lake Champlain 16 Ylg 16.2 640852 39,754 40,000 Lake Trout Cattaraugus Creek 10/15/2020 2020 ANFH Finger Lakes 10 FF 63 640986 41,030 40,000 Lake Trout Totals Lake Trout Yearlings 119,175 120,000 Lake Trout Fall Fingerlings 41,030 40,000
Rainbow Trout Canadaway Creek 3/18/2020 2019 SRSFH Washington 12 Ylg 13.6 None 10,000 10,000 Rainbow Trout Chautauqua Creek 3/18/2020 2019 SRSFH Washington 12 Ylg 13.6 None 25,000 25,000 Rainbow Trout Silver Creek 3/18/2020 2019 SRSFH Washington 12 Ylg 13.6 None 5,000 5,000 Rainbow Trout Walnut Creek 3/18/2020 2019 SRSFH Washington 12 Ylg 13.6 None 5,000 5,000 Rainbow Trout Cattaraugus Creek 3/19/2020 2019 SRSFH Washington 12 Ylg 13.7 None 56,030 45,000 Rainbow Trout Eighteen Mile Creek 3/19/2020 2019 SRSFH Washington 12 Ylg 13.7 None 20,000 20,000 Rainbow Trout Buffalo Creek 3/20/2020 2019 SRSFH Washington 12 Ylg 13.7 None 10,000 7,500 Rainbow Trout Cayuga Creek 3/20/2020 2019 SRSFH Washington 12 Ylg 13.7 None 7,500 5,000 Rainbow Trout Buffalo River Net Pens ----- SRSFH Washington Ylg None 0 5,000 Rainbow Trout Eighteen Mile Creek 3/31/2020 2019 CSFH Domestic 16 Ylg 4.9 None 3,750 5,000 Rainbow Trout Canadaway Creek 10/28/2020 2020 BSFH Domestic 10 FF 6.5 None 10,000 10,000 Rainbow Trout Chautauqua Creek 10/28/2020 2020 BSFH Domestic 10 FF 6.5 None 10,000 10,000 Rainbow Trout Cattaraugus Creek 10/29/2020 2020 BSFH Domestic 10 FF 6.5 None 15,000 15,000 Rainbow Trout Eighteen Mile Creek 10/29/2020 2020 BSFH Domestic 10 FF 6.5 None 10,000 10,000
Rainbow Trout Totals Steelhead Yearlings (Washington Strain) 138,530 127,500 Domestic Rainbow Trout Fall Fingerlings (Randolph Strain) 45,000 45,000 Domestic Rainbow Trout Spring Yearlings (Randolph Strain) 3,750 5,000
TOTAL ALL SPECIES Yearlings 261,455 252,500 Fall Fingerlings 86,030 85,000
Hatchery Codes: RSFH - Randolph State Fish Hatchery; CSFH - Caledonia State Fish Hatchery; SRSFH - Salmon River State Fish Hatchery ANFH - Allegheny National Fishery Hatchery; BSFH - Bath State Fish Hatchery
Section H Page 4 NYSDEC Lake Erie Annual Report 2020
TABLE H.2. Approximate numbers (in thousands of fish) of salmon and trout planted in New York waters of Lake Erie,1970-2020. Lake trout numbers include those stocked in Pennsylvania, Ontario, and Ohio waters. Totals do not include spring fingerling or fry stockings.
YEAR Species/
Type 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 Coho Y 64 96 50 30 29 100 87 149 144 50 81 0 139 181 169 200 102 200 169 148 0 0 0 0 0 0 Coho F 0 0 0 0 0 0 390 50 0 50 0 0 0 0 0 0 0 0 38 180 163 161 76 0 0 0 Coho f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 80 0 0 0 200 0 0 0 Chin f 0 0 0 125 125 85 65 362 206 0 0 71 280 550 478 547 529 500 520 620 574 525 565 497 500 500 Lake Y 0 0 0 0 0 0 0 0 236 201 41 41 196 205 176 154 199 205 203 213 195 206 225 217 200 160 Lake F 0 0 0 0 0 150 186 125 0 508 474 0 39 17 0 0 0 0 0 60 0 127 0 42 0 82 Lake fry 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 150 0 0 150 200 0 Lake adt 0 0 0 0 0 0 0 0 0.1 0 0 0 0 0 0.1 0 0 0 0 0 0 0 0 0 0 2.7 Brown Y 0 0 0 0 28 0 42 42 0 26 50 34 53 50 38 42 40 0 38 53 47 44 47 47 0 0 Brown F 0 0 0 0 60 26 25 81 0 0 0 0 85 50 0 0 50 0 22 42 37 0 0 0 0 0 Brown f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 20 0 0 0 0 0 0 0 Rbow Y 0 0 0 0 15 0 0 12 19 29 43 46 0 61 39 34 32 41 34 38 37 39 43 43 42 2.5 Rbow F 0 0 0 0 0 0 25 0 0 0 0 40 0 50 28 32 49 0 22 25 38 0 0 0 0 21 Rbow f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 110 120 148 0 0 0 0 0 0 0 0 0 Rbow adt 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 Sthd Y 0 0 0 0 28 0 0 0 0 0 0 0 0 15 81 100 118 270 107 103 121 143 105 214 208 218 Sthd F 0 0 0 0 0 0 0 0 0 0 0 0 37 0 38 0 0 0 0 13 48 0 130 0 0 0 TOTAL 64 96 50 155 285 361 820 821 605.1 864 689 232 829 1179 1157 1229 1267 1216 1253 1495 1260 1245 1391 1060 951 986.2
YEAR Species/
Type 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Coho Y 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Coho F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Coho f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Chin f 500 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lake Y 82.9 120 107 158 128 120 120 120 111.6 54.2 88 137.6 202.8 223.3 277.7 234.3 55.3 260 230.1 246.6 218.7 126.7 247.3 251.5 198.6 Lake F 0 0 0 40.5 7 0 0 0 0 58.4 0 0 0 0 0 0 123.7 0 99.1 81.7 26.9 17 40 40 41 Lake fry 0 301 81 0 262.7 130.2 283.5 109.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lake adt 1 0 0 1 0.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Brown Y 0 0 0 0 0 0 38.7 43.4 36 37.4 37.5 37.9 36 37.6 37.5 38.1 35.5 32.6 38.5 37.8 38.1 36.5 0 0 0 Brown F 0 0 0 0 0 0 33.6 39.5 0 0 0 0 0 25 0 7.4 0 0 5 0 0 0 0 0 0 Brown f 0 0 0 0 0 35 0 0 0 0 0 0 0 0 40 0 0 0 0 0 0 0 0 0 0 Rbow Y 42.5 46.9 47 55.3 47.5 21.3 2.2 2.5 2.4 5 5 4.5 5 4.7 4.9 1 5 5 4 5 5 5 4.4 5 3.8 Rbow F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 46 15 0 0 0 0 0 0 49.8 61 45 Rbow f 90.6 84 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Rbow adt 0 0.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Sthd Y 274.8 228 253 255 250.8 255 255 251.3 255 270 270 268 265 272 303.7 304.3 255 255 255 147.5 401.2 255 255 146.8 138.5 Sthd F 20 40 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 30 25 203 76.3 0 0 TOTAL 1012 1019 407 509.8 433.5 431.3 449.5 456.7 405 425 400.5 448 508.8 562.6 709.8 600.1 474.5 552.6 631.7 548.6 714.9 643.2 672.8 504.3 426.9 Legend: Y=Standard stocked yearling; F=Fall fingerling; f=Spring fingerling; fry=Advanced yolk- sac/swim-up fry; adt=Surplus broodstock
Section H Page 5 NYSDEC Lake Erie Annual Report 2020
I. OPEN LAKE SPORT FISHING SURVEY
Pascal D. Wilkins
Introduction
Since 1988, a direct contact sport fishing survey has interviews of boat anglers who had just completed their been conducted to monitor boat fishing activity. This fishing trip. Angler interviews were conducted between has been a standard, annual program that extends from 0900 EDT and 1 hour after sunset. May through October along the entire New York portion of Lake Erie. The principal objective of this During 1991, and for all surveys after 2001, fishing survey is to estimate angler effort, catch, and harvest for effort has been estimated using an “access approach” all fish species in the open water sport fishery in the using boat counts obtained at the five major harbors New York waters of Lake Erie. Walleye and yellow bordering New York’s portion of Lake Erie (Pollock et perch effort and harvest-at-age data are also contributed al. 1994). The specific application of this method to the to the Lake Erie Committee’s (LEC) interagency New York waters of Lake Erie is described in Einhouse Walleye and Yellow Perch Task Groups for annual lake (2005). A limited number of aerial boat counts were wide assessment, quota setting, and compliance (WTG conducted from 2002 to 2004 to evaluate whether the 2021, YPTG 2021). change in survey methodology affected absolute measures of fishing effort and harvest. This Methods investigation found that previous and current survey procedures produced very similar results, but the Assessment of the daytime open lake sport fishery current methodology was more administratively occurs from May 1 through October 31 each year. Our efficient and remained statistically robust (Einhouse current methodology employs stratification by day type 2005). (weekday/weekend day), harbor, and month. Although survey procedures changed in 2002, some independent From 1993 to 1997 this survey was augmented by a measures of fishing and boating activity (annual paid spring angler survey of the nighttime walleye fishery, launch totals at municipal ramps) suggest our results and those results were reported annually in earlier remain directly comparable for the entire 1988 to 2020 editions of this report (Einhouse 2005). This nighttime time series (Einhouse 2005). Daytime angler survey survey component was suspended from 1998 to 2005, estimates for fishing effort, harvest, and catch rates, and then resumed during 2006 to update the status of with associated precision measures (standard error or this fishery. Nighttime surveys may be conducted SE), were calculated for each stratum using the intermittently in future years as determined by available formulae described in Einhouse (2005) based on resources and program needs. methods described in Pollock et al. (1994). Results and Discussion From 1988 to 2001, standard angler survey methodology included an aerial boat count to measure Estimated overall 2020 open water sport fishing effort fishing effort. Standard survey methods from 1988 to in New York waters of Lake Erie was 364,708 angler- 2001 were patterned after a study by Schmidt (1975), hours, down slightly (-10%) from 2019 (Table I.1). collecting effort and catch information as independent Peak fishing activity occurred in June, but fishing samples with two collection schedules of stratified activity remained high from June through August. The random sampling. Aerial counts of fishing boats were most frequently used site was Buffalo Harbor (Safe conducted to measure daytime fishing effort. Catch and Harbor Marina, formerly Buffalo Small Boat Harbor), harvest data were obtained by roving between five to which accounted for 40% of estimated boat fishing six representative fishing access sites to conduct effort in 2020 (Table I.1). Sturgeon Point Marina was closed in May and October due to a sandbar blocking
Section I Page 1
NYSDEC Lake Erie Annual Report 2020 lake access. Walleye was the most targeted sport fish, Total Open Water Boat Fishing Effort accounting for 77% of the overall angling effort (Figure 1.0 I.1). Smallmouth bass and yellow perch angling Walleye Black Bass accounted for 11% and 5% of the total effort, Hours - 0.8 Yellow Perch respectively. All Others
A major declining trend in boat fishing effort extended 0.5 through the 1990’s and 2000’s to a low point in 2009. Since 2009 effort has generally increased (Figure I.2). 0.3 This increase is almost totally attributable to MillionsAngler of improvements in the status of walleye stocks and 0.0 increases in targeted walleye effort. Lake Erie’s major decline in boat fishing effort from the late 1980’s Sampling Year through the 1990’s is consistent with broad trends FIGURE I.2. Open water sport fishing angler effort in New York waters observed in other waters and is likely attributable to of Lake Erie for walleye, bass, yellow perch and all other species, factors independent of fishing quality such as high fuel May–October, 1988-2020. prices, aging of the boat angler population, and regional TABLE I.2. Harvest, catch, and two standard errors (2SE) of selected population decline. species by boat anglers fishing on the New York waters of Lake Erie, May-October, 2020. A total of 20 species were encountered by boat anglers Species Harvested 2SE Caught 2SE in 2020, resulting in a total catch of 247,734 fish (Table Walleye 84,615 13,322 103,850 15,733 I.2). Eleven species were harvested resulting in a total Yellow Perch 34,407 14,139 38,877 14,910 harvest of 121,219 fish. Walleye and yellow perch Smallmouth Bass 865 475 39,694 13,733 accounted for 98% of the harvest and 58% of the catch. Lake Trout 447 261 1,556 777 Steelhead 316 215 580 331 TABLE I.1. The distribution of 2020 open water boat fishing effort White Bass 246 166 8,194 1,854 (angler-hours) in New York’s portion of Lake Erie. *14 other species 323 233 54,982 8,208 Harbor May Jun Jul Aug Sep Oct Total Total 121,219 19,438 247,734 27,018 Barcelona 2,762 16,617 14,235 16,532 5,457 356 55,959 *72% of catch of other species were freshwater drum Dunkirk 8,239 10,006 20,946 23,283 3,641 799 66,914 Cattaraugus 2,227 22,021 8,434 20,059 17,585 3,112 73,437 Walleye Sturgeon Pt. - 4,126 8,607 9,625 1,884 - 24,242 Buffalo 22,337 59,615 34,433 12,458 11,379 3,932 144,155 Estimated 2020 targeted walleye fishing effort was 278,930 angler-hours, a 6% decrease from 2019 and the Grand Total 35,566 112,384 86,654 81,957 39,947 8,199 364,708 second highest annual effort measured since 1998 (Figure I.3). Estimated 2020 total daytime walleye Distribution of Open Water Boat Fishing Effort harvest was 84,615 fish, a 52% decrease from 2019 All Others (Table I.2). 7% Yellow Perch 5% Walleye was the most frequently caught species in 2020 (Table I.2). Walleye catch and harvest peaked in June, and the June–September period accounted for 94% of Black Bass 11% total catch and harvest (Table I.3). All five harbors were significant contributors to walleye catch and harvest in 2020. Walleye catch rates have been relatively high Walleye over the past decade and at record levels from 2017– 77% 2020. The 2020 targeted walleye catch rate was 0.34 fish per hour, the fourth highest measured in the 33-year time series and well above the long-term average FIGURE I.1. Distribution of directed sport fishing effort by boat anglers in New York waters of Lake Erie, May-October, 2020. (Figure I.4).
______Section I Page 2 NYSDEC Lake Erie Annual Report 2020
Walleye Harvest and Effort 600 250,000 Effort 500 Harvest 200,000
400 150,000 300 100,000
200 Number Harvested Number 50,000
100 Thousands of Angler Hours Angler of Thousands
0 -
1988 1990 1996 1998 2000 2008 2010 2012 2020 1992 1994 2002 2004 2006 2014 2016 2018 Year
FIGURE I.3. Annual trends in walleye sport fishing effort (angler-hours) and number harvested from May-October, 1988–2020.
Measures of walleye angler success can also be year classes in the east and west basins and is an expressed as frequency of boat limit catches and zero indicator of excellent fishing quality now and a forecast catches for targeted walleye trips. Table I.4 shows that for the coming years. limit catches of walleye are generally uncommon across all years, while complete lack of success (zero harvest) Walleye angling quality occurs more frequently. In 2020, 7% of walleye fishing 0.90 26 CPE boats achieved a party limit while 31% failed to harvest 0.80 Length walleye. 25 0.70 24 TABLE I.3. Distribution of daytime walleye catch and harvest totals in 0.60 the New York waters of Lake Erie during 2020. 0.50 23 May Jun Jul Aug Sep Oct Total Barcelona Catch 294 5,215 8,253 6,561 569 30 20,922 0.40 22 Harvest 176 4,862 6,729 5,572 479 30 17,849 0.30
Dunkirk Catch 1,788 2,938 8,578 5,525 833 - 19,663 (in) length Mean 21
Harvest 1,614 2,709 8,158 5,307 701 - 18,488 (fish/hr) cpeDirected 0.20 Cattaraugus Catch 20 3,103 1,807 9,378 4,366 8 18,682 20 Harvest 20 2,620 1,583 9,027 4,231 - 17,481 0.10 Sturgeon Catch - 1,144 1,603 3,582 510 - 6,838 0.00 19 Harvest - 1,079 1,330 3,252 385 - 6,047 Buffalo Catch 3,404 20,627 12,004 622 1,021 68 37,746 Harvest 3,161 14,299 6,054 438 740 58 24,750 Sampling Year Total Catch 5,506 33,027 32,245 25,668 7,299 106 103,850 FIGURE I.4. Annual trends in walleye sport fishing quality as Harvest 4,971 25,570 23,854 23,596 6,536 88 84,615 measured by mean length harvested (inches) and catch rate (number per hour or CPE), 1988 - 2020. CPE calculations are weighted by the In the past, large decreases in the average size of amount of walleye effort estimated at each harbor. harvested walleye have been a precursor to excellent The age distribution of the walleye harvest was fishing, as they are an indication of large pulses of determined from otolith samples taken at fish cleaning young walleye entering the fishery. In the last five years stations and was expanded to estimate number the average size of harvested walleye decreased by 1.5 harvested by age (Figure I.5). Walleye harvest was inches to 20.7 inches in 2020 (Figure I.4), one of the dominated by the 2016 (age-4) and 2015 (age-5) year lowest observations in survey history. This decrease is classes, comprising approximately 35% and 30% of the a result of recent production of exceptionally strong total harvest, respectively (Figure I.5). It is likely that
______Section I Page 3 NYSDEC Lake Erie Annual Report 2020 most age-5 fish are the result of exceptional west basin and 2019 east and west basin year classes (See Section recruitment in 2015 and that most age-4 fish are the D). Overall strong walleye recruitment throughout Lake result of the exceptional east basin recruitment in 2016. Erie in recent years should continue to result in excellent fishing quality in New York waters for years In general, walleye weight at length has been trending to come. down over the last decade. In 2020 the estimated weight of a 20-, 24- and 28-inch harvested walleye was 2.6, 4.5 and 7.3 lbs., respectively, compared to long-term averages of 2.7, 4.7 and 7.6 lbs. (Figure I.6). In 2020, rainbow smelt dominated angler-caught walleye diets (Figure I.7) which may indicate an increase in suitable forage (See section C). Smelt have consistently dominated the walleye diets until recently, when goby became a more prominent diet item. 2020 was the first time in six years that smelt comprised the majority (>50% by volume) of the diet. FIGURE I.5. Age distribution of the 2020 walleye harvest estimated TABLE I.4. Walleye boat fishing quality metrics, including harvest by expanding the age distribution of samples at fish cleaning stations (HPE) and catch rates, harvest and catch per boat, percentage of by the 2020 walleye harvest estimate. boats achieving their daily limit, and percentage of boats that harvested no walleyes, 1988–2020. Walleye/ang-hr Walleye/boat trip Walleye boat trips Daily limit Estimated Walleye Weight at Length Year HPE CPE harvest catch % Limit % Zero regulation 9 1988 0.19 0.22 2.6 3.0 4 41 5 8 1989 0.21 0.23 3.2 3.5 5 39 5 7 1990 0.13 0.15 2.0 2.3 1 42 5 1991 0.08 0.08 1.1 1.2 1 59 5 6 1992 0.06 0.06 0.8 0.9 1 71 5 5 1993 0.12 0.12 1.7 1.8 2 48 5 1994 0.15 0.16 2.1 2.2 3 45 5 4 1995 0.10 0.10 1.3 1.4 1 55 5 Weight(lbs.) 3 1996 0.14 0.15 1.8 2.0 3 47 5 1997 0.11 0.11 1.5 1.5 1 50 5 2 28 Inches 1998 0.12 0.13 1.7 1.8 1 47 5 1 24 Inches 1999 0.13 0.13 1.8 1.9 3 52 5 20 Inches 0 2000 0.14 0.15 2.1 2.2 5 49 5 2001 0.08 0.09 1.2 1.3 1 60 5 2002 0.11 0.12 1.4 1.6 2 52 5 Sampling Year 2003 0.14 0.15 2.1 2.3 4 39 4 2004 0.06 0.06 0.7 0.8 0 65 4 FIGURE I.6. Estimated body weight (lbs.) of angler-caught walleye in 2005 0.17 0.27 2.2 3.6 8 44 4 the New York waters of Lake Erie at 20,24, and 28 inches, 1995– 2006 0.24 0.29 3.1 3.8 12 32 4 2020. Error bars represent 95% confidence intervals. 2007 0.19 0.21 2.6 2.9 4 36 5 2008 0.16 0.17 2.1 2.3 2 42 5 2009 0.12 0.13 1.5 1.7 2 50 5 Targeted walleye angling effort increased in response to 2010 0.21 0.24 2.9 3.3 5 36 5 excellent fishing quality over the last decade. However, 2011 0.18 0.21 2.7 3.1 5 37 5 though the quality of walleye fishing in the New York 2012 0.18 0.24 2.8 3.6 5 37 5 2013 0.19 0.21 2.7 3.1 3 39 6 waters of Lake Erie is at record levels, walleye effort is 2014 0.27 0.32 3.7 4.4 6 28 6 nowhere near the highs recorded in the late 1980’s and 2015 0.24 0.25 3.3 3.4 4 30 6 2016 0.21 0.24 2.7 3.1 4 36 6 early 1990’s (Figure I.3). This may indicate limited 2017 0.31 0.52 3.9 6.5 10 32 6 capacity for increased walleye effort in the NY waters 2018 0.50 0.73 6.4 9.4 23 20 6 2019 0.57 0.71 6.6 8.3 24 18 6 of Lake Erie by the current angling population. 2020 0.29 0.34 3.6 4.2 7 31 6 Ave* 0.18 0.22 2.5 3.0 5 43 Walleye exploitation in New York’s portion of Lake Erie is relatively modest compared to other The exceptional east basin 2016 and west basin 2015 jurisdictions, indicating that efforts to further publicize walleye year classes supported above-average fishing the current, unprecedented walleye fishing quality are quality in 2020. There is also evidence of an exceptional justified. 2017 east basin year class and strong 2018 west basin ______Section I Page 4 NYSDEC Lake Erie Annual Report 2020
NY Angler Caught Walleye Diets Smallmouth Bass 100% 90% Estimated targeted fishing effort for smallmouth bass in 80% 2020 was 39,845 angler hours (Figure I.8). Though 70% targeted smallmouth bass effort has been very stable 60% over the past decade, 2020 effort decreased to levels not 50% observed since the late 1980’s, prior to the 40% implementation of New York’s spring bass season Smelt 30% Goby (1994). The decline in bass angler effort was most likely Yellow Perch Percent by Percentby Volume due to COVID-19 and travel restrictions on out-of-state 20% Other Fishes 10% Unidentifiable Fish bass anglers. Smallmouth bass angling quality has been Invertebrates quite variable over the last decade, ranging from 1.37 to 0% 0.80 fish per hour. The amount of trip-to-trip variability has also increased. Overall catch rate by bass anglers Sampling Year was 0.82 bass per hour in 2020 (Figure I.9), the twelfth FIGURE I.7. Diet composition (percent by volume) of angler caught walleye from the New York waters of Lake Erie, collected at fish lowest in the time series. Smallmouth bass harvest was cleaning stations,1993–2020. estimated at 865 fish in 2020, only 2.2% of the total bass catch (39,694) and the second lowest in the time series The most important factor contributing to walleye (Table I.5; Figure I.8). Approximately 72% of the catch fishing quality in the east basin of Lake Erie is the and 83% of the harvest was reported from the Buffalo summertime movements of walleye from the west basin Harbor survey location in 2020. of Lake Erie into the central and east basins. The magnitude of this migration varies between years and A long-term decline in smallmouth bass harvest rates the contribution of west basin walleye becomes less has been underway since this survey began in the prominent as the distance from the west basin increases 1980’s. This notable trend of increasing catch-and- (Matley et al. 2020; Raby et al. 2018; Euclide et al. in release fishing has caused catch rates by anglers review). The east basin walleye stocks, which are targeting smallmouth bass to diverge from overall significantly smaller than the west basin stock, typically harvest totals. In recent years, smallmouth bass harvest remain in the east basin year-round, making them more totals have been the lowest observed in the time series. susceptible to harvest in the spring, near Buffalo (i.e. far Anglers targeting species other than smallmouth bass east), and in years when the magnitude of migration is can account for as much as 70% of the total smallmouth reduced (Dippold et al. 2020; Zhao et al. 2011; Euclide et al. in review).
Smallmouth Bass Harvest and Effort 250 45,000
Effort 40,000 Harvest 200 35,000
30,000 150 25,000
20,000 100
15,000 Number Harvested Number
50 10,000
5,000 Thousands of Angler Hours Angler of Thousands
0 -
1992 1994 1996 2004 2006 2008 2016 2018 2020 1988 1990 1998 2000 2002 2010 2012 2014 Year
FIGURE I.8. Annual trends in smallmouth bass sport fishing effort (angler-hours) and number harvested from May through October, 1988–2020. ______Section I Page 5 NYSDEC Lake Erie Annual Report 2020 bass harvest in a given year. The excellent quality TABLE I.6. Bass boat fishing quality metrics, including harvest and catch rates, harvest and catch per boat, and percentage of boats that percid fishing observed recently may also provide a caught no bass, 1988–2020. *Averages only include data from 1994– more appealing alternative for catch-and-consume present following the implementation of a spring season with a single anglers. fish 20” minimum size. Bass/ang-hr Bass/boat trip Year Boat trips Measures of bass angler success can also be expressed HPE CPE harvest catch % Zero as catch per boat and frequency of zero catches for 1988 0.22 0.59 2.7 7.1 23 targeted bass fishing trips. Table I.6 indicates that the 1989 0.18 0.59 2.0 6.5 22 2020 catch per boat was 8.8 (average 12.6) and the 1990 0.18 0.69 2.1 7.9 12 percentage of boats that caught no bass was 14% 1991 0.17 0.54 2.1 6.7 22 (average 16.1%). Lake Erie’s bass angling quality can 1992 0.14 0.61 1.8 7.7 26 still be characterized as excellent, especially relative to 1993 0.09 0.54 1.0 5.8 23 1994 0.09 1.05 1.1 12.8 14 other bass populations. 1995 0.11 1.27 1.3 14.6 11 1996 0.08 1.12 0.9 13.7 12 Smallmouth Bass angling quality 1997 0.09 1.12 1.1 14.3 12 2.50 18 CPE 1998 0.09 1.05 1.1 12.8 14 Length 1999 0.06 0.91 0.8 10.6 17 2.00 2000 0.07 0.65 0.9 8.1 17 17 2001 0.07 0.87 0.9 11.7 13 1.50 2002 0.06 0.79 0.7 9.2 20
16 2003 0.06 1.03 0.7 11.5 17
1.00 2004 0.06 0.98 0.6 10.9 17
2005 0.04 0.82 0.4 9.9 23 Mean length (in) length Mean
Directed cpe (fish/hr) cpeDirected 15 2006 0.05 0.79 0.5 8.7 22 0.50 2007 0.05 1.01 0.6 12.7 16 2008 0.05 0.94 0.6 10.5 21 0.00 14 2009 0.06 1.06 0.7 12.4 19 2010 0.07 1.04 0.8 11.4 20 Sampling Year 2011 0.05 1.19 0.6 13.8 18 FIGURE I.9. Annual trends in smallmouth bass sport fishing quality 2012 0.03 1.44 0.4 18.1 14 as measured by mean length harvested (inches) and catch rate (number per hour or CPE), 1988– 2020. A spring bass season was 2013 0.04 1.50 0.6 18.5 15 implemented in 1994 which significantly increased catch rates. 2014 0.05 1.40 0.6 16.9 15 Numbers of harvested smallmouth bass have not been sufficient to estimate average length in the last three years. 2015 0.04 1.40 0.5 17.5 14 2016 0.03 0.97 0.3 11.8 17 TABLE I.5. Distribution of smallmouth bass catch and harvest totals 2017 0.02 0.83 0.2 9.4 23 in the New York waters of Lake Erie during 2020. May Jun Jul Aug Sep Oct Total 2018 0.02 1.41 0.3 17.5 9 Barcelona Catch 341 1,346 139 13 - - 1,838 2019 0.01 1.05 0.1 11.4 12 Harvest - 39 - - - - 39 2020 0.02 0.88 0.2 8.8 14 Dunkirk Catch 3,924 2,977 126 - - 185 7,211 Ave* 0.05 1.06 0.6 12.6 16 Harvest - 19 - - - - 19 Cattaraugus Catch 141 634 150 35 193 30 1,184 Harvest - 55 - - - - 55 Yellow Perch Sturgeon Catch - 195 157 478 112 - 942 Harvest - - 10 23 - - 33 Yellow Perch was the second most harvested species by Buffalo Catch 12,341 6,756 3,311 2,510 2,427 1,173 28,519 Harvest - 71 52 230 326 39 718 boat anglers in 2020 (Table I.2). Estimated 2020 Total Catch 16,747 11,909 3,883 3,035 2,732 1,389 39,694 targeted yellow perch effort was 18,677 angler-hours, a Harvest - 185 62 253 326 39 865 38% decrease from 2019 and well below average (34,491 angler-hours) for the 33-year time series (Figure I.10). Estimated 2020 yellow perch harvest (34,407 fish) was below average (Figure I.10). Boats
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Yellow Perch Harvest and Effort 90 300,000 Effort 80 Harvest 250,000 70
60 200,000
50 150,000 40
30 100,000
20 Harvested Number 50,000
10 Thousands of Angler Hours Angler of Thousands
0 -
1988 1994 2000 2006 2012 2018 1990 1992 1996 1998 2002 2004 2008 2010 2014 2016 2020 Year FIGURE I.10. Annual trends in yellow perch sport fishing effort (angler-hours) and number harvested from May through October, 1988–2020. launching out of Cattaraugus Creek accounted for 73% Yellow Perch angling quality of the catch and 78% of the harvest of yellow perch in 5.00 CPE 2020 (Table I.7). The highest monthly yellow perch 4.50 Length 12 harvest occurred in September (39% of total). 4.00
3.50 The overall 2020 yellow perch catch rate was 1.68 11 perch per hour (Figure I.11), well above the time-series 3.00 2.50 average of 1.47 fish per hour. The mean length of 10 harvested yellow perch was 11.0 inches in 2020 (Figure 2.00
I.11). The age distribution of the yellow perch harvest 1.50 (in) length Mean Directed cpe (fish/hr) cpeDirected 9 was determined from anal spine samples and was 1.00 expanded to estimate harvest at age. Yellow perch 0.50 harvest in 2020 was dominated by the 2016 and 2015 0.00 8 year classes (ages 4 and 5, respectively) making up approximately 91% of the total harvest (Figure I.12). Sampling Year FIGURE I.11. Annual trends in yellow perch sport fishing quality as TABLE I.7. Distribution of yellow perch catch and harvest totals in the measured by mean length harvested (inches) and catch rate (number New York waters of Lake Erie during 2020. per hour or cpe), 1988–2020. May Jun Jul Aug Sep Oct Total Barcelona Catch 47 379 35 77 30 - 568 Measures of yellow perch angler success can also be Harvest 47 209 23 77 30 - 386 Dunkirk Catch 151 248 364 802 - - 1,566 expressed as frequency of boat limit catches and Harvest 151 181 308 766 - - 1,406 frequency of zero catches for targeted yellow perch Cattaraugus Catch 959 9,585 87 947 12,036 4,894 28,507 fishing trips. Table I.8 shows that boat limit catches of Harvest 939 8,909 62 894 11,495 4,528 26,827 Sturgeon Catch - 65 147 193 1,305 - 1,710 yellow perch remain a rare occurrence across all years, Harvest - 52 115 114 1,305 - 1,586 while complete lack of success (zero harvest) occurs Buffalo Catch 2,827 1,144 1,319 553 577 107 6,527 more commonly. During 2020, only 3% (average 1.4%) Harvest 2,341 643 647 23 548 - 4,201 Total Catch 3,984 11,421 1,952 2,572 13,948 5,000 38,877 of yellow perch fishing boats achieved a party limit, Harvest 3,477 9,995 1,156 1,874 13,378 4,528 34,407 while 27% (average 40%) failed to harvest any perch.
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efforts are conveying this message to the angling community with recommendations to harvest all perch with barotrauma or count them towards your limit.
TABLE I.8. Yellow perch boat fishing quality metrics, including harvest and catch rates, harvest and catch per boat, percentage of boats achieving their daily limit, and percentage of boats that harvested no yellow perch, 1988–2020. Perch/ang-hr Perch/boat trip Perch boat trips Daily limit Year HPE CPE harvest catch % Limit % Zero regulation 1988 1.65 1.67 17.4 17.7 0 40 none 1989 2.04 2.17 24.2 25.7 0 36 none 1990 0.66 0.70 7.3 7.7 0 43 none 1991 0.56 0.59 6.0 6.3 0 46 none FIGURE I.12. Age distribution of the 2020 yellow perch harvest 1992 0.34 0.36 3.5 3.7 0 58 none estimated by expanding the age distribution of samples collected 1993 0.31 0.37 3.2 3.8 0 68 none during the angler survey by the 2020 harvest estimate. 1994 0.33 0.42 3.9 5.0 0 45 none 1995 0.53 0.76 4.4 6.4 0 38 none 1996 0.30 0.51 3.3 5.5 0 63 none Beginning in 2001, excellent yellow perch fishing 1997 0.27 0.35 2.2 2.9 0 71 50 quality returned after a full decade of poor fishing. 1998 0.46 0.67 4.4 6.4 0 75 50 Improvements in yellow perch fishing quality were 1999 0.44 0.78 5.7 10.2 0 70 50 2000 0.20 0.20 2.1 2.1 0 56 50 consistent with other population metrics (Sections C 2001 1.64 1.75 18.4 19.7 2 24 50 and D) indicating improved status relative to the 1990's. 2002 1.03 1.17 8.9 10.1 1 39 50 2003 0.79 0.97 8.2 10.1 0 45 50 Yellow perch fishing effort and harvest peaked in 2014, 2004 1.17 1.38 13.0 15.3 0 38 50 supported by the two strongest year classes observed to 2005 1.11 1.36 11.9 14.7 0 40 50 that point (2008 & 2010). These two strong year classes 2006 1.35 1.46 14.1 15.2 2 31 50 2007 0.99 1.08 9.7 10.6 0 43 50 were followed by three consecutive years of weak 2008 1.79 2.18 18.3 22.2 3 28 50 recruitment in 2011–2013. As the 2008 and 2010 year 2009 1.72 2.23 18.4 23.9 3 24 50 2010 1.43 1.98 15.3 21.2 1 35 50 classes aged and exited the population, fishing quality 2011 2.00 2.59 23.1 30.0 3 27 50 declined as evidenced by the relatively low observed 2012 2.24 3.40 26.8 40.5 5 20 50 catch rates in 2016 and 2017. Strong year classes of 2013 2.64 3.56 30.2 40.7 6 18 50 2014 2.73 3.45 33.3 42.0 7 14 50 yellow perch in 2014, 2015, and 2016 led to somewhat 2015 2.15 2.67 26.1 32.3 3 27 50 improved fishing quality from 2018 to 2020. The 2016 2016 0.95 1.15 10.7 12.9 1 39 50 2017 1.50 1.78 17.2 20.3 2 26 50 cohort is likely to be the only cohort with a significant 2018 1.47 1.74 15.1 18.0 1 27 50 fishery contribution in 2021 as the 2014 and 2015 2019 1.82 1.96 21.5 23.2 4 26 50 cohorts decline. Reliance on a single large cohort is 2020 1.64 1.75 16.2 17.2 3 27 50 likely to reduce catch rates in 2021. Ave* 1.22 1.49 13.5 16.5 1 40
Other Species In recent years, trends in perch catch and harvest have decoupled from catch-per-effort and abundance, i.e. Sport catch and harvest estimates for other prominent increases in perch abundance have not resulted in species are presented in Table I.2. Freshwater drum increased effort, catch, and harvest as they have in the (39,361; 16%) and white bass (8,194; 3%) were past. We hypothesize that the reason for this decoupling routinely caught by anglers in 2020. Round goby is that exceptional walleye fishing has caused some (8,793) also remained a commonly encountered perch anglers to shift their effort to walleye. nuisance species. Lake trout (1,556), steelhead (580), lake whitefish (195), and brown trout (27) were the Perch fisheries in New York’s portion of Lake Erie salmonids identified in the 2020 angler catch. Lake typically operate in deeper water (> 40 ft) and some trout (447) and steelhead (316) were the most anglers tend to release smaller, but otherwise commonly harvested of the salmonid species. harvestable-sized yellow perch. Yellow perch that are retrieved from depths greater than 30 ft. are known to experience barotrauma resulting in high mortality for released fish (Knight et al. 2019). Ongoing outreach ______Section I Page 8 NYSDEC Lake Erie Annual Report 2020
References
Walleye Task Group, 2021. Report of the Lake Erie Dippold, D. A., G. D. Adams, and S. A. Ludsin. 2020. Walleye Task Group. Presented to the Standing Spatial patterning of walleye recreational harvest in Technical Committee, Lake Erie Committee, and Lake Erie: Role of demographic and environmental Great Lakes Fishery Commission. factors. Fisheries Research 230:105676. Yellow Perch Task Group, 2021. Report of the Lake Einhouse, D. W. 2005. Angler Survey Methods for Erie Yellow Perch Task Group. Presented to the Lake Erie’s Open Water Sport Fishery. New York Standing Technical Committee, Lake Erie State Department of Environmental Conservation, Committee, and Great Lakes Fishery Commission. Albany, New York. Zhao, Y., D. W. Einhouse, and T. M. MacDougall. Euclide, P. T., T. MacDougall, J. M. Robinson, M. D. 2011. Resolving some of the complexity of a Faust, C. C. Wilson, K. Y. Chen, E. A. Marschall, mixed-origin walleye population in the east basin W. A. Larson, and S. A. Ludsin. In Review. Mixed- of Lake Erie using a mark–recapture study. North stock analysis in the age of genomics: Rapture American Journal of Fisheries Management. 31: genotyping enables evaluation of stock-specific 371–381. exploitation in a freshwater fish population with weak genetic structure. Evolutionary Applications. Knight, C. T., R. T. Kraus, D. A. Panos, A. M. Gorman, B. S. Leonhardt, J. M. Robinson, and M. Thomas. 2019. Is barotrauma an important factor in the discard mortality of yellow perch? Journal of Fish and Wildlife Management 10(1):69-78. Matley, J. K., M. D. Faust, G. D. Raby, Y. Zhao, J. Robinson, T. MacDougall, T. A. Hayden, A. T. Fisk, C. S. Vandergoot, and C. C. Krueger. 2020. Seasonal habitat-use differences among Lake Erie’s walleye stocks. Journal of Great Lakes Research 46(3):609-621. Pollock, K. H. 1994. Angler survey methods and their application in fisheries management. American Fisheries Society, Special Publication 25, Bethesda, Maryland. Raby, G. D., C. S. Vandergoot, T. A. Hayden, M. D. Faust, R. T. Kraus, J. M. Dettmers, S. J. Cooke, Y. Zhao, A. T. Fisk, and C. C. Krueger. 2018. Does behavioural thermoregulation underlie seasonal movements in Lake Erie walleye? Canadian Journal of Fisheries and Aquatic Sciences 75(3):1-9. Schmidt, B. R. 1975. Results and Evaluation of an Aerial Creel Survey Technique on Lake Sharpe, South Dakota. Master’s Thesis, South Dakota State University, Brookings, South Dakota.
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APPENDIX I
Common and scientific names of fish potentially mentioned in text, tables, and/or figures.
Common Name Scientific name Alewife Alosa pseudoharengus Banded Killifish Fundulus diapphanus Blacknose Shiner Notropis heterolepis Bluntnose Minnow Pimephalesnotatus Bridle Shiner Notropis bifrenatus Brook Silverside Labidesthes sicculus Brown Trout Salmo trutta Bullheads Ictaluridae spp. Burbot Lota lota Carp Cyprinus carpio Channel Cat Ictalurus punctatus Chinook Salmon Oncorhynchus tshawytscha Coho Salmon Oncorhynchus kisutch Darter spp. Percidae spp. Emerald Shiner Notropis atherinoides Freshwater Drum Aplodinotus grunniens Gizzard Shad Dorosoma cepedianum Goldfish Carassius auratus Lake Sturgeon Acipenser fulvescens Lake Trout Salvelinus namaycush Lake Whitefish Coregonus clupeaformis Largemouth Bass Micropterus salmoides Muskellunge Esox masquinongy Northern Hog Sucker Hypentelium nigricans Northern Pike Esox lucius Quillback Carpiodes cyprinus Rainbow Smelt Osmerus mordax Rainbow Trout/Steelhead Oncorhynchus mykiss Redhorse Sucker spp. Moxostoma spp. Rock Bass Ambloplites rupestris Round Goby Neogobius melanostomus Rudd Scardinius crythrophthalmus Sea Lamprey Petromyzon marinus Smallmouth Bass Micropterus dolomieui Spottail Shiner Notropis hudsonius Sticklebacks Gasterosteidae spp. Stonecat Noturus flavus Trout-perch Percopsis omiscomaycus Walleye Sander vitreus White Bass Morone chrysops White Perch Morone americana White Sucker Catastomus commersoni Yellow Perch Perca flavescens ______Appendix I Page 1