Synergetic effects of UV radiation and temperature in cold-adapted calanoid copepods from Patagonia (Argentina): bioaccumulation of photoprotective compounds and mortality trends.

DIÉGUEZ MARIA DEL CARMEN; GARCÍA, PATRCIA E.; PÉREZ A. PATRICIA; ZAGARESE HORACIO E.

Lake Tahoe, USA

Conferencia; AGU Chapman Conference: Lakes and Reservoirs as Sentinels, Integrators, and Regulators of Climate Change; 2008

Climate change is likely to impact aquatic ecosystems in the Patagonia region ofSouthern South America through different mechanisms: (i) direct increase in UV due toozone depletion, (ii) direct effect on water temperature and (iii) indirect effects oftemperature on tolerance of organisms to UV and changes in the radiation environmentmediated by changes in DOC levels. The identification of biological processesinfluenced by UV exposure and temperature in predictable ways will improve ourappreciation of their combined effects on freshwaters. In the copepod Boeckellaantiqua, the accumulation of photoprotective compounds (MAAs and carotenoids)could be dissected out into uptake and elimination processes, both of which are stronglyand predictably influenced by UV and temperature. However, Boeckella antiqua isrestricted to a few sites in Northwestern Patagonia. Here, we extend the results to B.gracilis, which occurs along a broad latitudinal gradient from 6º N to 49º S. Analysesof mortality trends suggest that increases in temperature will translate into additionalphoto-toxicity stress in Boeckella species, even under a stable UV scenario.