Responses of plankton and fish from temperate zones to UVR and temperature in a context of global change

GONCALVES, R.; SOUZA, M.S.; AIGO; MODENUTTI, B.E.; BALSEIRO, E.G; VILLAFAÑE, V.; CUSSAC, V.; HELBLING, E.W.

ECOLOGÍA AUSTRAL

ASOCIACIÓN ARGENTINA DE ECOLOGÍA

Año: 2010 vol. 20 p. 129 - 153

0327-5477

In the last decades, both temperature and UVB (280-315 nm) radiation on the surface ofthe Earth increased at growing rates as a result of human activities. Many studies had evaluatedthe effects of temperature on aquatic ecosystems, but now the field broadens as the combinationand variations of temperature and radiation gains especial importance. In this work we attempt torevisit some of our knowledge about the effects of UVR and temperature on marine and freshwaterplankton and fish from temperate regions (defined here as latitudes between 30-60º), especiallyfrom the Patagonia area, due to the special characteristics found in these sites. UVR affects (oftennegatively) almost all processes, from carbon fixation to behavior; and certainly all trophic levelsin plankton, from virus to fish larvae. The most prominent UVR danger is probably the mutagenicaction of UVB, which will affect a number of processes such as photosynthesis, growth and celldivision, among many others. In metazoans, UVR may cause stress upon survival or show sublethaleffects such as those in behavior and feeding. It is difficult to extract a general pattern, even in agroup of organisms, as responses to UVR appear to be species-specific and strongly influencedby local conditions (e.g., UVR penetration, PAR/UVR ratios, and acclimation). While in manycases significant effects have been determined, a number of mechanisms are available to avoidand / or minimize the damage produced by UVR. However, this may not hold true for globaltemperature changes. In the case of fishes for example, temperature appears as the main factordriving habitat distributions, so the biogeography must be taken into account to consider thepotential outcomes of UVR and temperature changes. Even in the different scenarios predictedby climatic models (including ozone layer recovery and temperature rise over the next decades)more research combining UVR and temperature as factors