Valuable seagrass faces global warming threat

Reuters 24 Jul 08;

GENEVA (Reuters) - Seagrass meadows, which are vital for the survival of much marine life and a source of household materials in Europe and Africa, face a mounting threat from global warming, a report said on Friday.

The report, from the Swiss-based International Union for the Conservation of Nature (IUCN), said the submerged meadows -- many around the Mediterranean -- could be saved through concerted action by governments and scientists.

"Seagrass habitats are already declining due to increasing water temperatures, algae (seaweed) growth and light reduction, which are all effects of global change," said IUCN specialist Mats Bjork, one of the authors of the report.

The report said the grass -- flowering plants found in shallow waters around the globe -- provides food and shelter for prawn and fish populations and is used traditionally as mattress filling, roof covering and for medicines.

If much of it were to disappear, a wide range of species -- including dugongs, sea turtles, sea urchins and seabirds who feed on it -- would also come under increased threat, according to the report.

The report said some of the healthiest seagrass areas known to exist today were off the North African coast of Libya and Tunisia in areas where there had been little industrial or tourism development.

Carl Gustaf Lundin, head of IUCN's Global Marine Program, said the meadows could be saved by making seagrass more resilient to climbing temperatures through mixing genetically more diverse populations.

The report, issued at a conference in Barcelona, said the introduction of protected areas and linking the underwater meadows to nearby mangrove plantations or coral reefs would also give a huge boost to their chances of survival.

Lundin said it was also vital to extend research into how seagrass can be protected -- a effort already promoted by IUCN that would require governments and scientific institutions to devote resources and time.