One of the highlights of visiting tropical destinations such as the Caribbean and the South Pacific is the profusion of colorful tropical fish that inhabit the warm waters of these places. Climate change is raising water temperatures far from the tropics and tropical fish are migrating to entirely new locations. While this may sound like a good thing, is definitely isn’t.
Many tropical fish species normally feed by browsing or scraping coral reefs of algae and other plants that are otherwise harmful to the reefs. When these herbivores show up in more temperate waters, they encounter bountiful sea grass and kelp forests. They can quickly mow down this undersea bounty, essentially destroying the lush habitats of indigenous species.
Tosa Bay, off the coast of southern Japan, used to have a rich kelp forest but it has now been stripped bare and has been replaced by coral. In the northern Gulf of Mexico, parrot fish populations have increased 20-fold in the past 7 years and they are voracious plant eaters.
Undersea faunas are mixing in an unprecedented way and the ultimate outcome is anybody’s guess. As the arrival of the tropical species drastically alters the undersea vegetation, the community of species living in the area changes completely. Apart from having devastating effects on the native species themselves, the commercial fishing industry is also undergoing dramatic changes as species such as abalone and lobster lose their food sources.
Species on land and sea have always moved around but the changing climate is speeding up this process in a dramatic way.
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Tropical Fish Cause Trouble as Climate Change Drives Them Toward the Poles
Photo, posted October 25, 2009, courtesy of Torsten Mauz via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio.