Climate change will likely have a profound impact on resources in Pacific Ocean national parks. Changes are predicted to occur in sea-level rise, food webs, community structure of marine organisms, and oceanographic processes. Nevertheless, predicting the nature or extent of these changes and their impacts is highly uncertain (Stephenson et al. 2010). For example, sea temperature, salinity, and ocean circulation are expected to change, but because they are interrelated and vary spatially and seasonally, scientists expect “unexpected” responses by organisms (NRC 2002). Most scientists, though, agree that ocean and coastal conditions, including those in Pacific Ocean parks, will be altered over the coming decades as a result of climate change (Largier et al. 2011; Learmonth et al. 2006; see http://www.nature.nps.gov/climatechange/effects.cfm). Ocean parks of the National Park System have common oceanographic and biological settings and related vulnerabilities to changes in climate, and staffs are seeking ways to coordinate response strategies. Here we consider the potential impacts of climate change on pinnipeds (seals and sea lions) that occur in some 18 national parks around the Pacific Ocean from Hawaii to Alaska, and the role that the National Park Service can play in conserving this group of marine mammals.
Pinnipeds occur throughout the Pacific Ocean and range from critically endangered monk seals (Monachus schauinslandi) that use select sites in several Hawaiian Island parks to the more cosmopolitan harbor seals (Phoca vitulina) that use a diversity of habitats in parks from Alaska to California (table 1; fig. 1 and fig. 2, below). This group of marine mammals faces unusual challenges because they rest and pup (“haul out”) on land and ice but forage at sea, sometimes in close proximity to haul-outs, but often traveling great distances to feed. Although the National Park Service manages only a fraction of the total area needed for effective conservation of these species, it manages some key habitats for pinnipeds, which affords them extra protection for reproduction and survival. To this end, a specific management strategy for pinnipeds within parks in collaboration with other management agencies is needed. We first describe linkages between climate change and pinniped abundance and distribution in national parks, and then highlight four specific roles that parks can play that will aid in conserving these animals and their habitats.
Figure 2. A pinniped colony enjoys a remote beach at Channel Islands National Park.