Benthic infaunal communitites across the Weddell Sea Basin and South Sandwich Slope, Antarctica
The present study represents the first quantitative investigation of deep-sea benthic infauna in Antarctica. Box cores and multicores were used to collect sediment from 12 stations across the slope and abyssal basin of the Weddell Sea and the slope off the South Sandwich Islands, including sites in...
| Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2004
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| Subjects: | |
| Online Access: | https://pure.uhi.ac.uk/en/publications/6afe46c7-459e-4346-afd6-c994892fb0a5 https://doi.org/10.1016/j.dsr2.2004.07.014 |
| Summary: | The present study represents the first quantitative investigation of deep-sea benthic infauna in Antarctica. Box cores and multicores were used to collect sediment from 12 stations across the slope and abyssal basin of the Weddell Sea and the slope off the South Sandwich Islands, including sites in the South Sandwich Trench (6300 m). The multicore was a more efficient sampler than the box core. Nine phyla of invertebrates were found, dominated by annelids (67%), crustaceans (20%); other phyla (13%). A total of 117 taxa were identified to the species level: 72 were polychaetes; 45 were crustaceans. Many taxa are new to science. Highest densities were at the 1000 in depth on the western slope of the Weddell Sea (260 individuals per 0.1 m(-2)) and at ca. 2200 m on the South Sandwich Slope (132 individuals per 0. 1 m(-2)); lowest densities were in the central Weddell Sea Basin (39 individuals per 0.1 m(-2)). Species richness and rarefaction analysis suggest that the fauna is undersampled. The 117 species identified in this study were represented by only 237 specimens, indicating that species were being added at a rate of one species for every two specimens collected. Rarefaction curves do not begin to reach an asymptote supporting high estimates of diversity. Some species appear to be limited to distinct zones in upper and middle slope depths, other species extend from the slope to the abyssal basin, and at least two species appear to be restricted to the abyssal basin. In general, the densities of infauna on the slopes surrounding the Weddell Sea Basin have lower densities than well studied areas off North America. However, abyssal populations in Antarctica appear to have denser infaunal populations than those from off New England and the North Pacific Gyre. Productive surface waters of the Weddell Sea and subsequent sinking of phytoplankton to the seabed are probable reasons for the higher benthic productivity in Antarctic abyssal sediments. Similarity analyses were not informative because so few species were ... |
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