Research Document - 2008/019
Preliminary Results from the September 2007 Bottom-trawl Survey of the Southern Gulf of St. Lawrence
By T. Hurlbut, T. Surette, D.P. Swain, R. Morin, G. Chouinard, H.P. Benoît and C. LeBlanc
Each September since 1971, a standardized research vessel bottom-trawl survey has been conducted in the southern Gulf of St. Lawrence (NAFO Division 4T). The primary objective of this survey is to obtain abundance indices for the major demersal fish resources in the area. This report presents the preliminary results of the survey conducted from 4-29 September 2007. In 2007, the abundance and biomass indices for southern Gulf of St. Lawrence cod were lower than in 2006 and near the record-low catch rates observed in 2005, and indicate that the abundance remains very low compared to that observed in the late 1970s and during the 1980s. The abundance of American plaice continues to be near the lowest level observed in the history of this survey. The indices of abundance and biomass for white hake from the 2007 survey increased to the highest levels observed since 2000 but are still low compared to the 1980s. The abundance and biomass of witch flounder declined below the high values observed in the late 1990s and early 2000s; the index for yellowtail flounder remained at a relatively high level; and, for winter flounder, it was largely unchanged relative to previous years. Bottom temperatures were relatively warm in 2007. For the third consecutive year, no sub-zero bottom water occurred over the Magdalen Shallows in September. The area covered by waters below 1°C increased slightly relative to 2006, but remained below the high values seen during the 1989-1998 cold period.
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