Much attention has been given to the role ballast waters (water used in ships for stability) play in transporting invasive and exotic species around the world, but a potential greater threat, is the commercial trade of aquaria and ornamental plants and animals. So say the authors of "Beyond ballast water: aquarium and ornamental trades as sources of invasive species in aquatic ecosystems," which appears in the April issue of Frontiers in Ecology and the Environment. Dianna Padilla (Stony Brook University) and Susan Williams (Bodega Marine Laboratory, University of California, Davis) highlight the potential risks posed by aquatic plants and pets.
"This largely unregulated industry poses a serious but mostly unrecognized threat to marine and freshwater ecosystems as a source of invasive species" according to the authors.
Water hyacinths, popular ornamental plants, are readily available for purchase from catalogues and on-line. Native to the Amazon basin, they were introduced into Florida in 1884 and by the late 1950's interfered with navigation in Florida's waterways and displaced many native species. It took millions of dollars to clean up the waterways, yet the plant continues to spread across the globe, establishing itself on every continent but Antarctica.
While recognizing the importance of aquaria and ornamental trade, the authors argue that few enforceable regulations have been established. With the increase in popularity of live rock, corals, and tropical and freshwater fish, the potential for a accidental or intentional release into the environment increases.
Unlike many of the organisms transported in ballast waters, aquarium species are usually traded as adults, with only the hardiest fish and plants surviving collection and transport. These conditions set the stage for hardy, sexually mature organisms invading US waters. Fully one-third of aquatic species on the International Union for the Conservation of Nature's list of 100 worst invasive species are from aquarium and ornamental releases.
Padilla and Williams make several suggestions for regulation, including listing native and/or safe alternative aquarium and ornamental species to encourage the trade of less invasive and aggressive species. They also suggest a trade-off using bonds equal to the estimated cost of repairing future damage that could occur in the worst-case scenario of a particular animal or plant escaping into the wild.
Deep Sea Corals
Also in this month's issue of Frontiers in Ecology and the Environment, Santi Roberts and Michael Hirshfield (Oceana) discuss the diversity and biology of deep-sea corals. First observed over 200 years ago, scientific knowledge about these organisms continues to increase as new technologies allow researchers to delve deeper and farther into the ocean than ever before. Deep sea corals, much like their better-known tropical cousins, are found throughout the world, living in darker and colder places, and with equal diversity and reef building capabilities. These corals also provide habitat for economically important species of fish including grouper, bass, jacks, snappers and sharks.
Like all reefs, these corals are susceptible to damage by trawling. Roberts and Hirshfield make several suggestions for better protecting these resources, including protecting untrawled areas, enhancing the enforcement of current regulations, and more research into restoring damaged deep-sea coral communities.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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