On the midwater fish faunas of Gulf Stream rings with respect to habitat differences between slope water and northern Sargasso Sea
Jahn, Andrew E.
MetadataShow full item record
Northern Sargasso Sea
KeywordFishes; Atlantis II (Ship : 1963-) Cruise AII71; Atlantis II (Ship : 1963-) Cruise AII85; Chain (Ship : 1958-) Cruise CH110; Chain (Ship : 1958-) Cruise CH111; Knorr (Ship : 1970-) Cruise KN35; Knorr (Ship : 1970-) Cruise KN38
Forty-three 1000-in oblique Isaacs-Kidd midwater trawl collections were made on six cruises. In most cases, these were accompanied by 1500-m hydrocasts and plankton tows to 800 m. The fish collections comprise 19,400 specimens in 129 species, from Slope Water, Gulf Stream, Northern Sargasso Sea, and four cold-core rings. Temperature, salininty, oxygen, phosphate, and zooplankton biomass information accompany the collections. A model predicts that expatriate populations of Caribbean species can be maintained in the Slope Water and Northern Sargasso Sea in excess of 15 per cent of their Caribbean population density. With Caribbean contamination accounted for, the relative abundances of species in Slope Water and Northern Sargasso Sea are used to assign habitat preferences. Species clusters derived from an ordination using correspondence ana1ysis agree well with the habitat preference groups. The assemblage of species in the rings occupies the middle of a gradient in faunal composition from winter conditions in Slope Water to fall conditions in the Northern Sargasso Sea. The midwater habitat is modeled as two layers, and the ring environment as a hybrid habitat consisting of a surface layer of Northern Sargasso Sea habitat and a deep layer of Slope Water habitat. This model is consistent with patterns of species abundance. It is argued that the dramatic change in the depth of the main thermocline on crossing the Gulf Stream is the major physical factor affecting fish distributions with respect to this boundary.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Woods Hole Oceanographic Institution Apri, 1976.Appendix C, Biographical notes, not included.
Showing items related by title, author, creator and subject.
The ecology of colonial radiolarians : their colony morphology, trophic interactions and associations, behavior, distribution, and the photosynthesis of their symbionts Swanberg, Neil Ralph (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1979-08)Colonial radiolarians (Spumellaria) are among the most common and abundant large zooplankton, but they have been little studied by modern biologists. Colonies were found on 98% of epipelagic diving stations in the period ...
Limits of Nematoscelis megalops in the northwestern Atlantic in relation to Gulf Stream cold core rings. I, Horizontal and vertical distributions Wiebe, Peter H.; Boyd, Steven H. (Woods Hole Oceanographic Institution, 1979-01)The hydrographic limit of the distribution of Nematoscelis megalops in the Northwestern Atlantic Ocean is usually marked by the abrupt changes in water properties across the Gulf Stream. There are, however, isolated but ...
Nutritional ecology of Agalma okeni and other siphonophores from the epipelagic western North Atlantic Ocean Biggs, Douglas C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1976-05)The feeding and fishing behavior of siphonophores in their natural environment: was observed by SCUBA diving at 171 stations in warm-water areas of the Western North Atlantic Ocean. Calycophorae and Physonectae showed ...