Zonation of demersal fishes off Anvers Island, western Antarctic Peninsula

• Published in: Antarctic Science
• Main Authors: Amsler, Margaret O., Eastman, Joseph T., Smith, Kathryn E., Mcclintock, James B., Singh, Hanumant, Thatje, Sven, Aronson, Richard B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2015
• Subjects: Antarc*; Antarctic; Antarctic Peninsula; Antarctic Science; Anvers Island; Palmer Archipelago
• Online Access: http://dx.doi.org/10.1017/s0954102015000462; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102015000462

Abstract The Antarctic fish fauna from outer continental shelf/upper slope depths is under-sampled compared to that of the inner shelf, and there are limited quantitative data available on absolute abundance and taxonomic change with depth. A photographic survey of demersal fishes was conducted along a depth-gradient of 400–2099 m on the outer shelf and upper slope west of Anvers Island, Palmer Archipelago. A total of 1490 fishes were identified at least to the family level. Notothenioids composed 52.7% of absolute abundance and non-notothenioids 47.3%. The most abundant families were Nototheniidae (39.4%), followed by Macrouridae (28.9%), Zoarcidae (16.9%), and Channichthyidae (12.1%). The most abundant species were the notothenioids Lepidonotothen squamifrons (30.5%) and Chionobathyscus dewitti (11.7%), and the non-notothenioid Macrourus spp. (29.5%). The absolute abundance of all fishes peaked at 400–599 m. Depths of maximum abundance were 400–599 m for L. squamifrons , 700–1499 m for Macrourus spp., and 900–1499 for C. dewitti . At 700–999 m the abundance shifted from primarily notothenioids to the non-notothenioids Macrourus spp. and zoarcids. Fishes of the outer shelf and upper slope are not provincialized like those of the inner shelf and are circum-Antarctic.