Sea otter return boosts ailing seagrass in California

[xchrom]

http://www.bbc.co.uk/news/science-environment-23814524


A sea otter enjoys a crab in California, and helps seagrass in the process

The return of sea otters to an estuary on the central Californian coast has significantly improved the health of seagrass, new research has found.

Seagrass was deemed to be heading for extinction in this region before the otters returned.

But scientists found that the animals triggered a chain reaction of events that boosted the water-dwelling plants.

The research is published in the journal, PNAS.

[madrchsod]

1. they better start moving again...

maybe the atlantic will be safe,

i don't think radioactive seaweed is healthy

[OKIsItJustMe]

2. Sea otters promote recovery of seagrass beds

http://news.ucsc.edu/2013/08/sea-otters-seagrass.html

[font face=Serif][font size=5]Sea otters promote recovery of seagrass beds[/font]

[font size=4]Recolonization of Elkhorn Slough by sea otters led to recovery and expansion of seagrass beds due to cascading effects on the food web, study finds[/font]

August 26, 2013
By Tim Stephens

[font size=3]Scientists studying the decline and recovery of seagrass beds in one of California's largest estuaries have found that recolonization of the estuary by sea otters was a crucial factor in the seagrass comeback. Led by researchers at the University of California, Santa Cruz, the study will be published in the Proceedings of the National Academy of Sciences the week of August 26.

Seagrass meadows, which provide coastal protection and important habitat for fish, are declining worldwide, partly because of excessive nutrients entering coastal waters in runoff from farms and urban areas. The nutrients spur the growth of algae on seagrass leaves, which then don't get enough sunlight. In Elkhorn Slough, a major estuary on California's central coast, algal blooms caused by high nutrient levels are a recurring problem. Yet the seagrass beds there have been expanding in recent years.

"When we see seagrass beds recovering, especially in a degraded environment like Elkhorn Slough, people want to know why," said Brent Hughes, a Ph.D. candidate in ecology and evolutionary biology at UC Santa Cruz and first author of the PNAS study. His coauthors include Tim Tinker, a wildlife biologist with the U.S. Geological Survey, and Kerstin Wasson, research coordinator for the Elkhorn Slough National Estuarine Research Reserve, who are both adjunct professors of ecology and evolutionary biology at UCSC.

Hughes and his colleagues documented a remarkable chain reaction that began when sea otters started moving back into Elkhorn Slough in 1984. The sea otters don't directly affect the seagrass, but they do eat enormous amounts of crabs, dramatically reducing the number and size of crabs in the slough. With fewer crabs to prey on them, grazing invertebrates like sea slugs become more abundant and larger. Sea slugs feed on the algae growing on the seagrass leaves, keeping the leaves clean and healthy.

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http://dx.doi.org/10.1073/pnas.1302805110