Global threats to pinnipeds

Abstract

The 2008 IUCN (International Union for Conservation of Nature) review of the status of the world’s mammals identified marine mammals (IUCN 2008) as disproportionally threatened and data poor compared to their terrestrial counterparts, and their status was noted as a particular concern (IUCN 2008, Mace et al. 2008, Schipper et al. 2008). The threats faced by marine mammals were identified as being different, with accidental mortality and pollution being dominant threats that superseded habitat loss, which was identified as the principal concern for land mammals. It was suggested that harvesting remained a major threat for half of the marine mammal species in the world. The distribution of marine mammals was described as being concentrated in tropical and temperate coastal platforms and associated with high levels of primary productivity. Threat levels were highest for marine mammals living in the North Atlantic, North Pacific and Southeast Asia. Range size was described as generally declining toward both poles. Although these generalities are of course correct for all marine mammals, it must be recognized that the larger number of species of cetaceans compared to other marine mammal groups (85 cetaceans, the polar bear Ursus maritimus, 4 extant sirenians and 36 pinniped species) biases the conclusions in the assessment for marine mammals to such a degree that a separate summary for the pinnipeds of the world is warranted. Additionally, a species-level assessment masks some important conservation concerns for pinnipeds with species classified as Least Concern actually containing threatened subspecies (e.g., ringed seals). Finally, and perhaps most importantly, climate change issues were not specifically addressed in the vast majority of marine mammal assessments done for the 2008 IUCN review (IUCN 2008). We present here a complete assessment of the status and threats facing pinnipeds at the subspecies level, integrating the expected impacts of changing patterns of threat due to global climate change.