Respiratory responses of three Antarctic ascidians and a sea pen to increased sediment concentrations


Contact
Doris.Abele [ at ] awi.de

Abstract

Glacial retreat and subglacial bedrock erosion are consequences of rapid regional warming on the West Antarctic peninsula. Sedimentation of fine grained eroded particles can impact the physiology of filter feeding benthic organisms. We investigated the effect of increasing concentrations of sediment on the oxygen consumption of suspension feeding species, the ascidians Molgula pedunculata, Cnemidocarpa verrucosa, Ascidia challengeri, and the pennatulid Malacobelemnon daytoni in Potter Cove (South Shetland Islands, Antarctica). In A. challengeri and C. verrucosa oxygen consumption increased gradually up to a critical sediment concentration (Ccrit) where species oxygen consumption was maximal (Omax in mg O2 g-1 dm d-1) and further addition of sediments decreased respiration. Ccrit was 200 mg L-1 for A. challengeri (Omax of 0.651 ± 0.238) and between 100 and 200 mg L-1 for C. verrucosa (Omax of 0.898 ± 0.582). Oxygen consumption of M. pedunculata increased significantly even at low sediment concentrations (15-50 mg sediment L-1). Contrary to the ascidians, sediment exposure did not affect oxygen consumption of the sea pen. The tiered response to sedimentation in the four species corroborates recent field observations that detected a reduction in abundance of the sensitive ascidian Molgula pedunculata from areas strongly affected by glacial sediment discharge, whereas sea pens are increasing in abundance. Our investigation relates consequences (population shifts in filter feeder communities) to causes (glacial retreat) and is of importance for modelling of climate change effects in Antarctic shallow coastal areas.



Item Type
Article
Authors
Divisions
Programs
Peer revision
ISI/Scopus peer-reviewed
Publication Status
Published
Eprint ID
30425
DOI 10.1007/s00300-012-1208-1

Cite as
Torre, L. , Servetto, N. , Eöry, M. , Momo, F. , Tatián, M. , Abele, D. and Sahade, R. (2012): Respiratory responses of three Antarctic ascidians and a sea pen to increased sediment concentrations , Polar Biology, 35 (11), pp. 1743-1748 . doi: 10.1007/s00300-012-1208-1


Share


Citation

Research Platforms

Campaigns


Actions
Edit Item Edit Item