Updated 2023-11-21 16:10:05
Lake Ontario -> 3.0 Deep Pelagic And Offshore Benthic Zone Goal -> Deep Pelagic and Offshore Benthic Prey Fish Community
Reporting Interval
2014 - 2019
Area
Meeting Target?
Meets
Indicator Trend
Upward trend
Confidence?
High
Increasing populations of native prey fish (e.g. Slimy Sculpin, Deepwater Sculpin)
During the 2014-2019 reporting period, slimy sculpin biomass has been low compared to historical values whereas deepwater sculpin biomass has increased. In 2019, slimy sculpin biomass reached a record all-time low in U.S. waters over the entire time series back to 1978. Between 1978-1995, Deepwater Sculpin were absent from bottom trawl catches before first reappearing in catches beginning in 1996 (Lantry et al. 2007; Weidel et al., 2020a). Deepwater Sculpin became common in offshore trawls starting around 2009, and since then has shown increasing trend in biomass per area including over the 2014-2019 reporting period (Weidel et al., 2017; Weidel et al., 2020b).
Figure 1. Deepwater sculpin biomass index from the October bottom trawl survey 1978-2019 in Lake Ontario. Values represent the depth-stratified (20m strata), area- weighted mean biomass expressed as pounds (lbs) per hectare in either U.S. waters, or Canadian waters.
Figure 2. Slimy sculpin biomass index from the October bottom trawl survey 1978-2019 in Lake Ontario. Values represent the depth-stratified (20m strata), area-weighted mean biomass expressed as pounds (lbs) per hectare in either U.S. waters, or the whole-lake
Methodology
Estimates of benthic preyfish biomass were calculated using bottom trawl data from the collaborative Lake Ontario October benthic preyfish survey, previously known as the slimy sculpin survey. This survey has been conducted annually since 1978 (except for in 1983 when no sampling occurred), and historically covered 6 to 10 transects along the southern shore of Lake Ontario. Beginning in 2015, the survey expanded with collaboration from OMNRF and NYSDEC research vessels to increase the number of sites sampled across Canadian waters and in shallow water habitats. The survey typically occurs during late September-early October and uses a Yankee bottom trawl. Catches are separated to species, counted, and weighed in aggregate then subsampled for individual length and weight measurements. For more details on methodology of the survey see Weidel et al. (2020b).
Other Resources
Lantry, B.F., R. O’Gorman, M.G. Walsh, J.M. Casselman, J.A. Hoyle, M.J. Keir, and J.R. Lantry. 2007. Reappearance of deepwater sculpin in Lake Ontario: resurgence or last gasp of a doomed population? Journal of Great Lakes Research 33:34-45.
Weidel, B.C., M.G. Walsh, M.J. Connerton, B.F. Lantry, J.R. Lantry, J.P. Holden, M.J. Yuille, and J.A. Hoyle. 2017. Deepwater sculpin status and recovery in Lake Ontario. Journal of Great Lakes Research 43:854-862.
Weidel, B.C., M.J. Connerton, M. Walsh, J. Holden, K. Holeck, and B.F. Lantry. 2020a. Lake Ontario deepwater sculpin recovery: An unexpected outcome of ecosystem change. Pages 467-482, In: From catastrophe to recovery: Stories of fish management success. American Fisheries Society.
Weidel, B.C., B.P. O’Malley, M.J. Connerton, J.P. Holden, C.A. Osborne. 2020b. Bottom trawl assessment of Lake Ontario prey fishes, 2019. Section 12, In: 2019 Annual Report, Bureau of Fisheries Lake Ontario Unit and St. Lawrence River Unit to the Great Lakes Fishery Commission’s Lake Ontario Committee, Ann Arbor, MI.
Contributing Author(s)
- Brian P. O’Malley - USGS
- Brian C. Weidel - USGS
- Jeremy P. Holden - OMNRF
- Jessica A. Goretzke - NYDEC