Abundance and diversity of deep-sea crustaceans (Decapoda, Lophogastrida, and Euphausiacea) in the micronekton of Bear Seamount, New England Seamount Chain

Bear Seamount (39° 55′ N; 67° 30′ W) is the oldest and westernmost seamount in the New England Seamount Chain. It is located in the Marine National Monument on the continental slope south of Georges Bank and is influenced by unique ecological factors and currents. We enumerated and calculated the diversity, catch per unit effort (CPUE), and distribution of trawl-susceptible crustacean micronekton (2–20 cm) in the vicinity of Bear Seamount. Sixty-six species of pelagic Crustacea (Decapoda, Lophogastrida, and Euphausiacea) were taken with large, double-warp midwater trawls at 33 stations in the spring of 2003 and 2004 and fall of 2014. Oblique trawl sampling occurred from the surface to 2238 m, with most sampling concentrated between 600 and 1700 m depth. In 2003–2004, the assemblage on the south side of the seamount was the most diverse, while the summit assemblage had the greatest CPUE and species richness. In 2014, the summit assemblage was the most diverse and species rich while the assemblage on the west side had the greatest CPUE. Rarefaction curves did not reach an asymptote, suggesting increased sampling effort will yield more species at Bear Seamount. Eusergestes arcticus and Meganyctiphanes norvegica were numerically dominant. Two species Pasiphaea hoplocerca and P. merriami are new records for Northwest Atlantic waters.