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Posted May 2009

Increasingly warmer oceans could kickstart a dramatic shift in global marine diversity by fast-tracking the dominance of our seas by invasive alien species and accelerating the loss of biodiversity.

That warning is one of many dire predictions made by the Secretariat of the UN’s Convention on Biological Diversity ahead of this year’s International Day for Biological Diversity, which will be held on May 22 to highlight the damage being done to the world’s ecosystems and human wellbeing by invasive species.

The Secretariat says increasing ocean temperatures, sea levels and a shift in circulation patterns predicted under climate change all affect marine organisms.

It says warming trends in middle to high latitude ocean waters may allow species usually restricted to lower latitudes to expand their range and colonise new sea territory. Species more at home in warmer waters may also increase in abundance.

Warming oceans can cause physiological stress and mass die offs of marine organisms, opening up empty niches to invasion by alien species. They can also cause pathogen range expansions.

Species loss under climate change

The Secretariat says the extinction of native species under climate change has long concerned scientists, governments and institutions but little attention has been paid to which species will replace them.

It warns that under climate change invasive species invasions can occur through:

• Introduction of new species
• Spread of already established new species
• Established non-invasive species becoming invasive under new ecological conditions.

Find out more
> Convention on Biological Diversity’s International Day for Biological Diversity
> Download Invasive Alien Species – A Threat to Biodiversity