POPULATION-DYNAMICS OF THE BIVALVE LATERNULA-ELLIPTICA FROM POTTER COVE, KING-GEORGE ISLAND, SOUTH SHETLAND ISLANDS

Body size, geographical distribution and biomass make Laternula ellipt ica one of the most important bivalve species of the Antarctic. A comp lete study on the population dynamics (reproduction cycle, growth, mor tality and productivity) of this species from King George Island gave growth parameters for the von-Bertalanffy-growth-function of: L-infini ty= 112.2mm, K=0. 160yr(-1),t(0)=0.000yr. Total mortality was estimate d as Z = 0.392 yr(-1). Somatic production and mean biomass of two dist inct sub-populations were 8.7 and 67.3 g AFDW m(-2) yr(-1) at Beach & Glacier and 20.0 and 88.6 g AFDW m(-2) yr(-1) at Punta Elefante. The f ollowing P/(B) over bar values were calculated; Beach & Glacier = 0.12 9, Punta Elefante = 0.226. It is suggested that these differences are linked to mortality caused by icebergs which is expected to be higher at the shallower Punta Elefante site.