PURPOSE:

The research survey provides a fisheries-independent source of information about all marine living organisms that are captured by the fishing trawl used to obtain samples in the southern Gulf of St. Lawrence.

DESCRIPTION:

Tow, catch, length frequency, and biological information for fish caught during the annual September research vessel trawl surveys in the southern Gulf of St. Lawrence (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial and non-commercial groundfish.

The catch data that appear in this dataset SHOULD NOT BE USED FOR ECOLOGICAL ANALYSES INVOLVING CATCH RATES. Important factors such as vessel, fishing gear and diurnal periods must be accounted for to use these data in analyses. Please contact the data custodians if you are interested in using this data for any kind of ecological analyses involving catch rates.

PARAMETERS COLLECTED:

abundance estimates (ecological); distribution (ecological); species counts (ecological); gear (fishing); vessel information (fishing); point (spatial)

NOTES ON QUALITY CONTROL:

Scientific names listed in the survey species list have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS) using their online taxon match tool. All sampling locations were plotted on a map to perform a visual check confirming that the latitude and longitude coordinates were within the described sampling area.

In 2003, because of a fire aboard the Alfred Needler, the Wilfred Templeman was used for the survey. However, no comparative fishing experiments have been conducted between the Alfred Needler and the Wilfred Templeman. We are therefore unable to integrate the indices derived for 2003 to the remainder of the survey time-series.

SAMPLING METHODS:

Sampling Method: Consult the "Protocols for research vessel cruises within the Gulf Region (dermersal fish) (1970-1980)" report, link provided in the citations list.

USE LIMITATION:

To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.