Coupling of Pelagic and Benthic Communities over a Seamount in the Eastern North Pacific
Abstract
Recent studies indicate that seamounts can be sites of enriched biological activity with enhanced biomass of pelagic and benthic organisms relative to the surrounding water. We undertook a study to examine the interaction of micronekton/nekton and benthopelagic animals/epibenthic megafauna over a deep oceanic seamount, Fieberling Guyot, located in the eastern North Pacific. We monitored the number and movements of acoustically detectable targets within the bottom 100 m of the water column over the summit using a vertically-profiling acoustic array developed for this study. A large multiple opening-closing net system (10 m2) and free-vehicle baited traps were used to collect the pelagic fauna for identification, sizing and gut content analysis. A total of 26 acoustic targets were detected, dispersed non-randomly with a skewed distribution between 65 and 85 m above bottom. Temporal distribution of targets was random but revealed higher numbers in the morning than in the evening. The micronekton/nekton consisted of 114 species which were gravimetrically dominated by fish, especially the macrourid, Malacocephalus laevis. Four species of benthopelagic animals/epibenthic megafauna were collected including a new macrourid species, Nezumia n.sp. There are no strong trends in the diel distribution of the micronekton/nekton and the limited data on acoustic targets shows a random temporal distribution. Alternative explanations of trophic coupling over Fieberling Guyot are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1994
- Accession Number
- ADA274750
Entities
People
- Kenneth L. Smith Jr
Organizations
- Scripps Institution of Oceanography