Joint Meetings of Ichthyologists and Herpetologists, Providence, Rhode Island, July 7-11, 2010
The assemblage structure and ecology of meso- and bathypelagic fishes are poorly known in general, particularly over mid-ocean ridges. In June 2004, the month-long MAR-ECO (Census of Marine Life) research expedition aboard the R/V G.O. Sars sampled the deep-pelagic fauna over the northern Mid-Atlantic Ridge with the objective of quantitatively assessing the nekton associated with the ridge from Iceland to the Azores. A total of 115 discrete-depth trawl samples were taken from the surface to depths of 3000+ meters using two different double-warp midwater trawls, one of commercial fishing size (a large ‘Akra' trawl) and one of oceanographic research size (‘Macroplankton' or ‘Krill' trawl). Catch data revealed the deep-sea smelt Bathylagus euryops to be the biomass dominant species, accounting for over 28% of total biomass, as well as being the 3rd most abundant species along the MAR. Further distributional analyses elucidated a trend in decreasing biomass from north to south with a biomass maximum around 1500-2000 meters. Understanding the food-web structure and organic cycling of deep-pelagic ecosystems is critical for increasing our knowledge of the distributional patterns of deep-sea fishes. Preliminary results indicate that gelatinous zooplankton represents a significant component of the diet of B. euryops. Molecular probes are currently being developed to identify these prey items in this, and other fishes that consume gelatinous zooplankton.
Sweetman, Christopher J. and Sutton, Tracey, "Distribution and Trophic Ecology of Bathylagus euryops (Teleostei: Microstomatidae) Along the Northern Mid-Atlantic Ridge" (2010). Oceanography Faculty Proceedings, Presentations, Speeches, Lectures. 257.