Antarctic Science
- Antarctic Science / Volume 23 / Issue 02 / February 2011, pp 127-138
- Copyright © Antarctic Science Ltd 2011
- DOI: http://dx.doi.org/10.1017/S0954102010000970 (About DOI), Published online: 26 January 2011
Biological Sciences
The impact of sediment deposition and iceberg scour on the Antarctic soft shell clam Laternula elliptica at King George Island, Antarctica
Eva E.R. Philippa1 c1, Gunnar Husmanna1 and Doris Abelea2
a1 Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
a2 Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven, 27570 Bremerhaven, Germany
Abstract
Recent rapid changes of air temperature on the western side of the Antarctic Peninsula results in increased sediment discharge and ice scouring frequencies in coastal regions. These changes are bound to especially affect slow growing, sessile filter feeders such as the Antarctic bivalve, Laternula elliptica, a long-lived and abundant key species with circumpolar distribution. We investigated the effect of sedimentation and ice scouring on small/young and large/old individuals at two closely located stations, distinctly influenced by both types of disturbance. Small individuals dealt better with disturbance in terms of their respiratory response to sediment exposure, reburrowing ability, and survival after injury, compared to larger animals. At the more disturbed station L. elliptica population density was lower, but larger animals reburrowed faster after iceberg disturbance and reduced their metabolic rate under strong sediment coverage, compared to larger animals of the less disturbed station, indicating that an adaptation or learning response to both types of disturbance may be possible. Smaller individuals were not influenced. Laternula elliptica seems capable of coping with the rapidly changing environmental conditions. Due to a decrease in population density and mean population lifespan, L. elliptica could however lose its key role in the bentho-pelagic carbon flux in areas of high sediment deposition.
(Received June 08 2010)
(Accepted October 18 2010)
(Online publication January 26 2011)
Correspondence:
