Benthic Faunal Associations on Soft Substrates at Potter Cove, King George Island, South Shetland, Antarctica.

RICARDO SAHADE; MARCOS TATIÁN; JENS KOWALKE; STEPHAN KHÜNE; GRACIELA ESNAL

POLAR BIOLOGY

Springer

Año: 1998 vol. 19 p. 85 - 91

0722-4060

Associations of benthic invertebrates from Potter Cove (Antarctica) were de®ned from photo- transects. Density, percentage cover, species richness S´, diversity index H´, evenness index J´ and mean-size es- timations were studied in relation to water depth down to 30 m. A clear bathymetric pattern was evident, with two different communities at 15 and 30 m, and a tran- sition area between 20 and 25 m. At 15 m we observed a small number of taxa (nine in total), a high percentage of bare substratum (95%), and the dominant species were pennatulids and the bivalve Laternula elliptica. From 20 to 30 m the dominant species was the ascidian Molgula pedunculata and there was a slight increase in S´, H´ and J´, as well as in the mean size of individuals, especially in, diversity index H´, evenness index J´ and mean-size es- timations were studied in relation to water depth down to 30 m. A clear bathymetric pattern was evident, with two different communities at 15 and 30 m, and a tran- sition area between 20 and 25 m. At 15 m we observed a small number of taxa (nine in total), a high percentage of bare substratum (95%), and the dominant species were pennatulids and the bivalve Laternula elliptica. From 20 to 30 m the dominant species was the ascidian Molgula pedunculata and there was a slight increase in S´, H´ and J´, as well as in the mean size of individuals, especially in´, evenness index J´ and mean-size es- timations were studied in relation to water depth down to 30 m. A clear bathymetric pattern was evident, with two different communities at 15 and 30 m, and a tran- sition area between 20 and 25 m. At 15 m we observed a small number of taxa (nine in total), a high percentage of bare substratum (95%), and the dominant species were pennatulids and the bivalve Laternula elliptica. From 20 to 30 m the dominant species was the ascidian Molgula pedunculata and there was a slight increase in S´, H´ and J´, as well as in the mean size of individuals, especially inLaternula elliptica. From 20 to 30 m the dominant species was the ascidian Molgula pedunculata and there was a slight increase in S´, H´ and J´, as well as in the mean size of individuals, especially inMolgula pedunculata and there was a slight increase in S´, H´ and J´, as well as in the mean size of individuals, especially inand there was a slight increase in S´, H´ and J´, as well as in the mean size of individuals, especially in, as well as in the mean size of individuals, especially in M. pedunculata, while the proportion of bare substratum showed a constant decrease with depth. Using multivar- iate analyses, three faunal assemblages related to depth were defined and a strong association of some species, mainly predators and opportunistic necrophages, with, while the proportion of bare substratum showed a constant decrease with depth. Using multivar- iate analyses, three faunal assemblages related to depth were defined and a strong association of some species, mainly predators and opportunistic necrophages, with M. pedunculata was revealed. Ice impact (icebergs and anchor ice) seems to be the major regulating factor of benthic assemblages in shallow waters.was revealed. Ice impact (icebergs and anchor ice) seems to be the major regulating factor of benthic assemblages in shallow waters.