Characteristics of macrobenthic assemblage from sub-littoral sediment off the Lazarev Sea, East Antarctica

Abstract

Comparative account of the occurrence and abundance of benthic macro-organisms collected from the Lazarev Sea in Queen Maud Land, (east Antarctica), during austral summer of 1984-85 and 1992-93 (fourth and twelfth Indian Antarctic expeditions) is presented and discussed. Total 42 seabed samples were taken from 15 locations in the depth ranged of 150 to 700 m. Sediment of the Lazarev Sea ranged from silty clay to sandy clay. The fraction of silt-clay and sand varied between 60.5 to 75.5 and 24.3 to 39.5 %, respectively. Organic carbon content of shelf sediment ranged from 1.29 to 6.95mg. g sup(-1) (mean = 4.16 plus or minus 1.97 sd; n = 42). Faunal density ranged from 1882 to 9643 ind.m sup(-2) (mean = 4895.2 plus or minus 28S2.5 sd; n = 15). The total macrobenthic standing crop varied from 2.928 to 20.833 g. m sup(-2) (mean=8.91 plus or minus 5.69 sd, n = 15) on dry weight basis. A total of 69 macroinvertebrate species inhabiting the benthic environment of Polynia region is presented with ecological information about collection site. Most of the benthic species appear to have circumpolar distribution. The significant positive correlation of surface chlorophyll-a with sediment organic content and benthic biomass propose a strong bentho-pelagic coupling in a seasonally locked environment