Lawler et al., 2007:

"The major vulnerabilities of marine mammals under climate change are related to effects on their food resources. There is considerable uncertainty over what these will be, but they may include reduced quantity or quality and greater spatial and temporal variability, affecting the ability of marine mammals to adequately utilise the resource. These effects are exacerbated by the reduced population sizes of many marine species, particularly coastal species such as the Australian snubfin dolphin, Indo-Pacific humpback dolphin and the dugong.

Climate change is only one of the many threats faced by marine mammals in the GBR. While assessment of the likely effects of climate change remains tentative, there are a number of other threats for which the evidence is more direct and more current. Some marine mammal species in the GBR are already under threat from incidental entanglement in gill nets and shark nets, pollution, overfishing of prey resources, and habitat degradation.

A large and stable population size is probably the most fundamental aspect of resilience to additional impacts. If several of the marine mammal species in the GBR have reduced population size, then there is the prospect that the cumulative effect of these threats and climate change may result in the loss of those species, particularly those restricted to certain types of habitats and those with small geographic ranges (e.g. Australian snubfin dolphin, Indo-Pacific humpback dolphins, dugongs)."

Table 16.1: Marine mammal species known or suspected to occur in the GBR