The Impact of a Changing Climate on Whales, Dolphins and Porpoises: A Call For Action

This Report summarises knowledge on the potential consequences of climate changes for cetacean species (whales, dolphins and porpoises) and briefly discusses potential adaptation measures. The impacts of climate change on cetaceans are expected to be diverse and mediated in various ways. Some impacts may be direct: for example, as temperatures change some cetacean species may respond by shifting their distributions to remain within optimal habitat. However, in some cases such range shifts will not be possible. For example, the northern Indian Ocean is fringed by land, limiting the ability of species to move northwards into cooler habitat as waters warm.

Climate change will also have indirect impacts on cetaceans, such as a probable increase in susceptibility to disease and contaminants and changes in the availability and abundance of food resources, particularly for whales which have specialised feeding habitats. The prey species of many cetaceans concentrate in particular areas under specific environmental conditions. Cetaceans depend on finding these high prey concentrations at specific times and locations. If climate change affects the geographic distribution and timing of these oceanographic conditions, this can be expected to ultimately have serious consequences for marine mammal reproduction and survival.