Global change: challenges facing amphibians

This chapter was written by Blaustein et al. They talk about global changes, like increase UV-B radiation (ozone depletion), pollution (CO2, CFCs, organofluorocarbons) global warming, and the effects that these have on amphibians. Some amphibians might be affected by global warming, for example, some are breeding earlier due to the increase in temperatures, and some have lost their habitat, like some amphibians in the cloud forest of Costa Rica. Drier weather makes breeding ponds shallower, so amphibians are more exposed to UV radiation, which can cause mutations and affect the immune system. Some amphibians respond negatively to increase UVB radiation, but some don’t: this can be explained by different capacities to repair UVB damage. UVB caused DNA damage is repaired by a photolyase enzyme (CDP-cyclobutane pyrimidine dimer) that has been found in higher levels in amphibians that are not affected by UVB. They talk about the research of Merila et al, which combines climate change, UV and amphibian breeding. They say that if amphibians are breeding earlier, then they are less exposed to UV radiation. The solution to all these global problems will come the day that pollution levels decrease. Some international treaties have the intention to decrease or end these problems, but, without the signature of the Kyoto Protocol by the US, it is less likely that CO2 levels will decrease soon. Also CFCs are very stable: estimates suggest that those in use today will continue to deplete the ozone layer for 50 to 150 years.