Large predators shift due to climate change in the Pacific Ocean

1 October 2012

To manage marine ecosystems proactively, it is important to identify species at risk and habitats critical for conservation. Climate change scenarios have predicted an average sea surface temperature rise of 1–6 °C by 2100, which could affect dramatically the distribution and habitat of many marine species. A new study recently published in Nature Climate Change examined top predator distribution and diversity in the light of climate change.

The scientific team used a database of 4,300 electronic tags deployed on 23 marine species from the Tagging of Pacific Predators project, and output from a global climate model to 2100.

The study predicts up to a 35% change in core habitat for some species and a substantial northward displacement of biodiversity across the North Pacific.

For already stressed species, increased migration times and loss of pelagic habitat could exacerbate population declines or inhibit recovery. Many top predators in marine ecosystems are in decline globally resulting from overfishing, bycatch and other indirect anthropogenic threats including habitat destruction. When large predators are removed or displaced, resulting trophic cascades can alter the stability of marine ecosystems.

The difference from one species to another is their ability to adapt to temperatures and to use multiple ocean areas and/or sources of food. Among the Pacific's top predators, turtles, sharks and marine mammals such as whales appear to be most at risk from habitat shifts associated with Pacific warming. But animals such as seabirds and tunas may benefit from climate-change-related shifts that could actually increase their potential habitat for foraging due to their broader tolerances to temperature.

More in Nature Climate Change >>