Potential effects of climate change on marine mammals

Predicted impacts of climate change on the marine environment include an increase in temperature, a rise in sea levels and a decrease in sea-ice cover. These impacts will occur at local, regional and larger scales. The potential impacts of climate change on marine mammals can be direct, such as the effects of reduced sea ice and rising sea levels on seal haul-out sites, or species tracking a specific range of water temperatures in which they can physically survive. Indirect effects of climate change include changes in prey availability affecting distribution, abundance and migration patterns, community structure, susceptibility to disease and contaminants. Ultimately, these will impact on the reproductive success and survival of marine mammals and, hence, have consequences for populations. Marine mammal species, which have restricted geographical distributions with little or no opportunity for range expansion in response to climate change, may be particularly vulnerable to the effects of climate change. The potential effects of climate change on marine mammals have a number of implications for their conservation and highlight several areas requiring further research.