Climate forcing of growth in the bivalve Eurhomalea exalbida from the Beagle Channel, Tierra del Fuego

THOMAS BREY,; BETINA JUDITH LOMOVASKY; LOHMANN, G.; KLÜGEL, A.

Kiel, Alemania

Simposio; 42td European Marine Biology Symposium; 2007

Life is shaped by the interaction between individual capabilities and environmental constraints on both evolutionary and individual time scales. Therefore, understanding the present ecological and ecophysiological status of an organism requires information on its past life history. On the other hand, if we can model environmental effects on an organism’s biology and ecology, we can link organism history to environmental history. This will facilitate the prediction of future environmental change effects on the individual, population and ecosystem level. Enduring hard structures of long-lived organisms can serve as archives of growth history and of environmental conditions during lifetime, which are reflected in morphological, elemental and isotopic parameters in shells and skeletons. Here we present a 72-year chronology of shell growth in the shallow water venerid bivalve Eurhomalea exalbida from the Beagle Channel. Long-term growth patterns in this mollusc are correlated to large-scale climate cycles represented by El Niño Southern Oscillation and by the Interdecadal Pacific Oscillation. We discuss whether this signal is mediated through oceanographical or through meteorological coupling processes. Moreover, the growth chronology indicates an overall increase in annual shell growth during the last 50 years that may be indicative of local effects of global warming.