Meeting Abstract

 

P1-205  Friday, Jan. 4 15:30 – 17:30  The Diversity and Distribution of Cephalopods in the Charlie-Gibbs Fracture Zone RICHARDS, JC*; VECCHIONE, M; University of North Carolina at Chapel Hill; Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution jaredunc@live.unc.edu

In the summer of 2009, NOAA surveyed the nekton fauna of the fracture zone on the Mid-Atlantic Ridge halfway between Iceland and the Azores as a small-scale follow-up to a previous large-scale Norwegian expedition. Midwater sampling by NOAA with a Norwegian Krill Trawl resulted in 64 discrete-depth samples from 12 stations at depths from near-surface to 3000 m. An additional seven bottom samples were collected with a large trawl at depths of 2000-3500 m. The expedition collected 471 cephalopods in ca. 24 species. For comparison, over 50 hours of ROV submarine video from the Norwegian expedition was viewed to determine diel migratory patterns of the most common species of cephalopod in the region, Gonatus steenstrupi. We found that trawl stations below the subpolar front were generally most diverse. Cluster analysis showed that bottom trawls were more dissimilar in species composition than midwater trawls. Unlike in the ROV observations, the small Gonatus steenstrupi from trawl samples did not participate in diel vertical migration; suggesting that juveniles in the samples are ecologically distinct from those visible in submersible videos.