Assessment of 2J3KL capelin in 2020

Abstract

Due to COVID-19 limitations, the spring acoustic survey was not conducted in 2020. However, Capelin larval indices, fall bottom trawl survey data, the Capelin forecast model, commercial landings and samples, and other ecosystem and environmental variables were used in the assessment. Based on all available evidence, Capelin abundance remains very low and this stock is experiencing reduced productivity. Under current ecosystem conditions and exploitation levels, no sustained growth has been observed for 30 years, and prospects remain poor. Capelin is an integral component of the ecosystem on the Newfoundland and Labrador Shelf. Continued low abundance is inhibiting the production and/or recovery potential of other finfish (e.g., Northern cod). The Newfoundland and Labrador climate experiences important fluctuations at decadal time scales, with potential impacts on ecosystem productivity. The Capelin collapse in 1990-91 and the recent declines (2015-17) were associated with cold periods, while the modest increases between the mid-2000s to mid-2010s were observed in generally warm periods. A modest increase in Capelin was observed (2013-15) in the warmer-than-average 2000s. This increase, however, was short-lived and followed by a colder period and return to low levels of Capelin. Since 2018, a warming trend has been observed. Higher nitrate inventories since approximately 2015 have resulted in improved primary (chlorophyll) and secondary (zooplankton biomass) production indices over the past four to five years. Ongoing changes in zooplankton seasonality and community structure (fewer large, energy-rich calanoids and more small copepods) may impact Capelin recovery. Increased summer and fall zooplankton biomass since 2016 may have contributed to the recent improvement of the fall adult Capelin condition index. However, Capelin larval productivity has remained low since 2014 despite an increase in abundance of a preferred prey (Pseudocalanus) over the same period. Ecosystem conditions in the Newfoundland Shelf and Northern Grand Bank (Northwest Atlantic Fisheries Organization [NAFO] Divs. 2J3KL) remain indicative of overall limited productivity of the fish community, with the total Research Vessel (RV) biomass index still much lower than prior to the collapse in the early-1990s. While there has been some recovery since this collapse, declines were observed after the mid-2010s. The current total RV biomass index remains below the early-2010s level, but with some positive signals in 2020. The increase in groundfish biomass observed from the mid-2000s to the mid-2010s appears stalled. These increases have been associated with bottom-up processes, including an improved prey field. Groundfish declines observed in recent years are associated with simultaneous reductions in Capelin and shrimp availability. Estimates of consumption by fishes and the occurrence of Capelin in cod and Greenland Halibut stomachs indicate low Capelin availability in 2020, with levels comparable to the 2017-19 period. The estimate of the spring acoustic biomass index from the forecast model for 2021 is near the average of the post-collapse period. The projection for 2021 is approximately 24% of the post-collapse high (forecast model estimate for 2015) and approximately 6% of the spring acoustic biomass index values observed in the late-1980s (1985-90). There is a 65% probability that the spring 2021 index will be about the same as 2020, and a 32% probability of an increase. The preliminary 2022 projection suggests a decline in the biomass index from 2021. There have been seven consecutive low larval abundance years (2014-20) including all of the year-classes available to the fishery in 2021. The commercial fishery landed 89% of the Total Allowable Catch (TAC) for Divs. 2J3KL in 2020 (16,114 tonnes). Overall, current removals from all predation are large compared to the fishery. Delays in beach spawning have persisted since 1991 and are associated with low larval productivity and smaller year classes. The large size of age-1 Capelin during the fall of 2020 suggests a high proportion of age-2 fish will be maturing in 2021. Due to the high rate of post-spawning mortality, this is expected to result in low numbers of age-3 Capelin in 2022. Low larval production has resulted in impaired recruitment for this stock. Late spawning, early maturation, and changes in feeding conditions for Capelin in Divs. 2J3KL are associated with low Capelin productivity during the last five years and poor prospects for 2021 and 2022. Given this stock’s continued low levels, significant ecological role, and poor prospects – including record low larval production in four of the last five years – it is advised that removals from all sources be kept at the lowest possible level.