i
An analysis of some factors affecting survey catches of squids, Loligo pealei and Illex illecebrosus, in the northwest Atlantic
-
1997
Details:
-
Personal Author:
-
Corporate Authors:
-
NOAA Program & Office:
-
Description:"In this paper, we examine how research survey catches of two commercially important squid species, Loligo pealei and Illex illecebrosus, are affected by environmental factors. In particular, the univariate habitat association test of Perry and Smith (1994) is applied to evaluate whether squid catch rates during the NEFSC autumn bottom trawl surveys are associated with depth, time of day, bottom temperature, and surface temperature. Consistent associations of squid catches with environmental factors indicate some characteristics of preferred habitat. Previous research has suggested that diurnal effects on bottom trawl catch rates of Loligo and Illex are important (Sissenwine and Bowman 1978; Shepherd and Forrester 1987) with greater catch rates occurring during the day. In this study, we also investigate size-specific differences in squid catches, by time of day, and compute adjustment factors to standardize catch numbers by time of day. Adjustment factors for catch weight per tow by time of day are also evaluated. Potential effects of depth and temperature on squid catch rates are also explored"--Introduction.
-
Keywords:
-
Series:
-
Format:
-
Document Type:
-
Place as Subject:
-
License:
-
Rights Information:CC0 Public Domain
-
Compliance:Library
-
Main Document Checksum:
-
Download URL:
-
File Type: