Research Document - 2012/084

Summary of 2010 Herring Acoustic Surveys in NAFO Divisions 4VWX

By M.J. Power, G.D. Melvin, and A. Clay

Abstract

Automated acoustic recording systems deployed on commercial fishing vessels have been used since 1997 to document the distribution and relative abundance of Atlantic herring from industry vessel surveys and fishing excursions in the Bay of Fundy and coastal Nova Scotia area within Northwest Atlantic Fisheries Organization (NAFO) divisions 4VWX. In 2010, regularly scheduled surveys at approximately 14 day intervals were again conducted on the main spawning components, and the spawning stock biomass for each component estimated by summing these results. Six structured surveys were conducted in Scots Bay, two on Trinity Ledge, three on Spectacle Buoy and eight on German Bank. In most cases, these surveys provided good coverage of the spawning areas consistent with established protocols. Additional data from fishing nights were also examined but were not applied to the overall spawning stock biomass.

In 2010, biomass estimates decreased by almost 40% for survey areas in Scots Bay, Trinity Ledge and German Bank to 312,100t. The 2010 estimate for the overall area combined was below the long term average by about 30% and is cause for concern about the health of the remaining spawning grounds in the 4X stock area.

Biomass estimates from surveys of the coastal Nova Scotia spawning components for the Little Hope/Port Mouton, Halifax/Eastern Shore and Glace Bay areas were also examined. Five surveys were completed for Little Hope, four surveys for Halifax and one for the Glace Bay area. There were substantial decreases in spawning stock biomass recorded for Little Hope and Halifax areas, while Glace Bay again showed virtually no fish in the surveys completed.

The first survey since 2001 was conducted during the spring fishery in June 2010 on the Offshore Banks near ‘The Patch’ and documented 3,579t.

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