Impacts of climate variation and potential effects of climate change on South American seabirds - a review

The coastal and oceanic waters around the South American coasts provide rich foraging grounds for breeding and wintering seabirds, but there is growing concern that climate change will provide additional pressures to the seabirds around South America. As in many other coastal ecosystems, seabirds around South America are already faced with threats to their breeding habitats such as human disturbance and introduced predators, and threats at sea such as persistent pollutants and pesticides and direct mortality risks due to fisheries and oil spills. The sensitivity of South American marine ecosystems to ocean climate anomalies is well known from the dramatic population collapses caused by El Nino Southern Oscillation (ENSO) events. However, longer-term climate change effects have been explored less often and few long-term data sets exist for South American seabirds. Seven Large Marine Ecosystems (LME) border South America. While all LMEs experienced warming during the last 50 years, their climate dynamics have differed in recent decades. Climate models suggest that potential climate change effects may be important, especially due to changes in ENSO intensity and frequency and associated changes in the ocean climate of Atlantic and Pacific marine ecosystems. In this review, we found that the best studied seabird communities are those of the Patagonian Shelf and the Humboldt Current, but overall, our knowledge on climate effects on South American seabirds is scarce.