Great Lakes Fishery Commission

Updated 2021-09-14 17:50:37

Lake Erie -> 1.0 Intensively Managed Species -> Whitefish

Maintain an adult lake whitefish population with a diverse age structure and sustainable levels of adult biomass

Lake whitefish (Coregonus clupeaformis) are native to Lake Erie and were an important commercial species during the 19^th and early 20^th century. By the 1950s the population and fishery had declined drastically due to over exploitation, habitat degradation, and invasive species introductions (Oldenburg et al. 2007). A limited recovery of lake whitefish began in the 1980s due to reduced exploitation, sea lamprey control, and other ecosystem changes including nutrient reductions (Oldenburg et al. 2007), however the population remains relatively small. Estimates of adult lake whitefish abundance declined steadily after 2007 due to below average hatching success from 2004-2013, resulting in a record low adult abundance from 2014-2017. Fortunately, several successful lake whitefish hatches since 2014, especially the 2015, 2018, and 2019 cohorts, have resulted in a modest reversal of this trend. Harvest remains well below historic levels.

Lake whitefish are assessed using population models that incorporate fishery and agency data to estimate population size and sustainable harvest levels. If the adult population falls below a level known as the limit reference point, management interventions in the form of harvest reductions are considered. The Lake Erie Committee has identified the 2014-2017 period of low abundance, from which the stock subsequently rebounded, as the limit reference point for the population (2.1 million kg). The population is considered sustainable if there are enough adults to support stable recruitment and long-term fisheries.

During the 2016-2020 reporting period, the average adult lake whitefish biomass was 4.4 million kg; annual estimates of adult biomass exceeded the limit reference point in 3 of the 5 years and exhibited an increasing trend (Figure 1). Average harvest during this period was 40,500 kg, which was well below the long-term average of 258,386 kg (Figure 2). Reduced harvest during this period were reflective of low population abundance and reduced quotas for the Ontario gillnet fishery that limited harvest opportunities dramatically.

Lake Erie index trawl and gill net surveys documented gradually improving population status in recent years fueled by the entry of young lake whitefish into the population combined with increased survival of older fish. Nineteen year classes aging from 0 – 23 are currently represented in the population, indicating multiple years of hatching success. Responsible and conservative harvest practices including annual quotas and seasonal and spatial restrictions on fisheries promote continued improvement of the lake whitefish population. 

Figure 1. Estimated lake whitefish adult biomass in Lake Erie relative to the limit reference point, 1994-2020. The limit reference point is the average adult biomass from 2014-2017, a period of low abundance. The population is considered sustainable if the adult biomass is above the limit reference point.

Figure 2. Annual and average commercial harvest (kg) of lake whitefish in Lake Erie, 1987-2020.