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Tropical Invaders Seek a Cool Change

 Moorish idol

Larger-bodied tropical species, such as the Moorish idol, are more likely to show vagrant behaviour into high latitude regions.

By David A. Feary & David Harasti

As oceans warm, a new study has shown that certain measurable traits may help scientists predict which species of tropical fish will successfully shift into cooler temperate waters.

The full text of this article can be purchased from Informit.

Changes in global climate are a substantial threat to bio­diversity. Some species are able to cope with the associated warming by shifting their geographic range. Although there is considerable variation in these responses, average range shifts up to 6.1 km/decade in terrestrial communities and up to 28 km/decade in marine communities have been reported. These shifts are being described as one of the most dramatic results of climate change.

Of all the marine fauna, we can expect that tropical fish may be particularly sensitive to increasing ocean temperatures. These communities exist in a relatively temperature-stable environment, and elevated ocean temperatures may have substantial effects on population distribution.

Australia’s south-east coast is a global hotspot for increasing water temperatures, with rises in excess of 2°C over the past century. While attention has focused on understanding the impacts of changing water temperatures on Australia’s iconic coral reefs, temperate south-eastern Australia is changing more rapidly than almost anywhere in the world. Such changes have been associated with substantial shifts in the bottom marine community structure, from macroalgal-dominated communities to one in which urchin-barren habitats dominate.

One of the strongest signals of climate change within this region is the increasing incursion of...

The full text of this article can be purchased from Informit.