The 36 samples collected with a 22-foot semi-balloon shrimp
trawl at depths from 40 to 1,829 meters off the central coast of
Oregon between July 1961 and June 1962 provided preliminary data
on the distribution, species composition, and associations of benthic
fishes with respect to depth and sediment type.
Sixty-seven species of bottom fishes representing 21 families
were collected; 86 percent of the total number of fishes was composed
of specimens from the families Pleuronectidae, Scorpaenidae,
and Bothidae.
Four communities of benthic fishes were found off the central
Oregon coast within the depth interval from 40 to 1 ,829 meters.
They were characterized by two or three dominant species, depth,
and average sediment type. Ninety-seven percent of the species
occurring in the communities showed high abundance in only one
community. Some species also demonstrated size segregation by
communities.
The total number of species collected in progressively deeper
communities was 26 (42 to 73 meters), 31 (119 to 199 meters), 20
(594 to 1,143 meters), and 9 (1,383 to 1,829 meters). Therefore
the highest number of speciesoccurred in the community on the outer
continental shelf and upper slope, while the lowest number of species
occurred at the extreme depths on the continental slope. The number
of species found on the continental shelf and slope were similar.
Species inhabiting the continental slope, however, usually occurred
over greater depth ranges.
A comparison of the catches of the 22-foot shrimp trawl and a
94-foot fish trawl indicated that the small trawl used in this study
retained comparatively few large fishes or semi-pelagic species.
Fishes of the genus Sebastodes were grossly undersampled and probably
comprised a major portion of the fish population, especially
between the depths of 183 to 547 meters. / Graduation date: 1968
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28214 |
| Date | 07 July 1967 |
| Creators | Day, Donald Stewart |
| Contributors | Pearcy, William G. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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