Record Details
Using Oregon trawl logbooks to study spatial and temporal characteristics of commercial groundfish species associations
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Using Oregon trawl logbooks to study spatial and temporal characteristics of commercial groundfish species associations |
| Names |
Lee, Yong Woo
(creator) Sampson, David B. (advisor) |
| Date Issued | 1997-08-29 (iso8601) |
| Note | Graduation date: 1998 |
| Abstract | Species associations of fifteen major commercial groundfish species in the northeastern Pacific ocean and their spatial and temporal characteristics were studied using Oregon bottom trawl logbook data, 1987 to 1993. Screening procedures were used to remove questionable data from the original logbook files, which resulted in the exclusion of information from 46% of the total available tows. Two multivariate methods, detrended correspondence analysis (DCA) and Ward's method of hierarchical cluster analysis were used to derive the association patterns of species and species groups. A general linear model that was developed for the primary DCA axis suggested that the species associations are strongly correlated with depth, but minimally correlated with the other environmental variables that were examined (latitude, season, and year). The weak correlations between DCA axis 1 and the temporal variables indicate that species associations in the study region are fairly persistent over time. The same multivariate techniques were used to examine possible sampling effects due to changes in the participating trawl vessels that contributed logbook information. Depth and latitudinal distributions of species occurrence in the logbook were similar to distributions derived from National Marine Fishery Service triennial bottom trawl survey. However, the analysis also showed that the depth coverage by the survey is not broad enough to accurately characterize associations among species that are currently subject to commercial fishing activity. |
| Genre | Thesis/Dissertation |
| Topic | Trawls and trawling -- Catch effort -- Oregon |
| Identifier | http://hdl.handle.net/1957/33901 |
