Loss of world's seagrass beds seen accelerating

By Jim Loney

MIAMI (Reuters) - The world's seagrass meadows, a critical habitat for marine life and profit-maker for the fishing industry, are in decline due to coastal development and the losses are accelerating, according to a new study.

Billed as the first comprehensive global assessment of seagrass losses, the study found 58 percent of seagrass meadows are declining and the rate of annual loss has accelerated from about 1 percent per year before 1940 to 7 percent per year since 1990.

Published this week in the Proceedings of the National Academy of Sciences, the study, based on more than 200 surveys and 1,800 observations dating back to 1879, found that seagrasses are disappearing at rates similar to coral reefs and tropical rainforests.

"Seagrasses are disappearing because they live in the same kind of environments that attract people," James Fourqurean, a professor at Florida International University and a co-author of the study, said in an e-mailed response to questions.

"They live in shallow areas protected from large storm waves, and they are especially prevalent in bays and around river mouths."

Scientists say seagrass processes waste dumped into the sea, helps stabilize ocean-bottom sediments in coastal areas to reduce erosion, provide nurseries for fish and shellfish and feeding grounds for larger marine creatures, including those that live in coral reefs.

But the grasses can be damaged by polluted water from coastal development, decreasing water clarity, and by dredging and filling of meadows.

The scientists also said global climate change "is predicted to have deleterious effects on seagrasses." Many scientists believe greenhouse gases are causing the world to warm, leading to a host of environmental effects including warming and rising oceans.