Assessment of Newfoundland East and South Coast Atlantic Herring (Clupea harengus) stock complexes to 2018

Abstract

The assessment of Newfoundland east and south coast Atlantic herring (Clupea harengus) stock complexes considered data to the spring of 2018. Stock status index updates were provided for the Bonavista Bay-Trinity Bay (BBTB), St. Mary’s Bay-Placentia Bay (SMBPB), and Fortune Bay (FB) stock complexes; biological updates were provided for White Bay-Notre Dame Bay (WBNDB) and Conception Bay-Southern Shore (CBSS) stock complexes. All Newfoundland stock complexes are comprised of a mix of spring and fall spawning herring. Spring spawners historically dominated in all areas, but with increased fall spawner recruitment in the late 1990s and through the early 2000s, stock composition in most areas shifted to largely fall spawners by the 2010s. However, a decline in fall spawner recruitment and the presence of several strong spring spawner year classes entering the fishery at the time of this assessment led to an increase in the percentage of spring spawners in recent years relative to the last decade. Stock status is assessed using the spring research gillnet program, which provides the only fishery-independent index of abundance for the BBTB and FB stock areas. Since 2018, a similar program has also been run in Placentia Bay (PB) through DFO’s Coastal Environmental Baseline Program, the results of which were used to update stock status for this assessment. The stock status index in BBTB decreased in 2017, largely due to below average catch rates; however, there are indications of positive future prospects with strong recruitment of incoming spring spawner year classes. Given these diverging trends, the stock status evaluation for BBTB is uncertain. In FB, the stock status index declined throughout the 2000s as spring recruitment was poor and fall recruitment did not increase in this stock area as it did in others. The index improved slightly in 2017 due to the strong recruitment of the 2012 year class, however at the time of this assessment there were no indications of subsequent strong recruitment. Based on these indices the stock status of FB is negative. In PB, catch rates from the 2018 gillnet program were above average, but the catch was dominated by a single year class, giving an uncertain stock status.