Kelp Forests And Invasive Urchins

Purple sea urchins have boomed off Northern California, destroying kelp forests that provide a crucial ecosystem. Steve Lonhart / NOAA MBNMS

Kelp is being farmed now, but where it is a naturally occurring forest it needs help. Thanks to National Public Radio (USA) for this:

In Hotter Climate, ‘Zombie’ Urchins Are Winning And Kelp Forests Are Losing

They’re purple, spiky and voracious, and just off the West Coast, there are more of them than you can count.

Purple sea urchins have exploded in recent years off California, covering the ocean floor in what divers describe as a “purple carpet.” Continue reading

Kelp Forest Versus Kelp Farm

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Kelp forest commentary is not new to our pages, but much more frequently the generic category seaweed has been highlighted for its farming potential. We have apparently not give sufficient attention to the specific value of natural kelp forests. Thanks to Yale 360 and science writer Alastair Bland for this story:

As Oceans Warm, the World’s Kelp Forests Begin to Disappear

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The progression of the destruction of a kelp forest in Tasmania by urchins, photo 1/3.

Kelp forests — luxuriant coastal ecosystems that are home to a wide variety of marine biodiversity — are being wiped out from Tasmania to California, replaced by sea urchin barrens that are nearly devoid of life.

A steady increase in ocean temperatures — nearly 3 degrees Fahrenheit in recent decades — was all it took to doom the once-luxuriant giant kelp forests of eastern Australia and Tasmania: Thick canopies that once covered much of the region’s coastal sea surface have wilted in intolerably warm and nutrient-poor water.

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The progression of the destruction of a kelp forest in Tasmania by urchins, photo 2/3.

Then, a warm-water sea urchin species moved in. Voracious grazers, the invaders have mowed down much of the remaining vegetation and, over vast areas, have formed what scientists call urchin barrens, bleak marine environments largely devoid of life.

Today, more than 95 percent of eastern Tasmania’s kelp forests — luxuriant marine environments that provide food and shelter for species at all levels of the food web — are gone. With the water still warming rapidly and the long-spine urchin spreading southward in the favorable conditions, researchers see little hope of saving the vanishing ecosystem.

Diver_surveying_overgrazed_reef_web The progression of the destruction of a kelp forest in Tasmania by urchins, photo 3/3. The Australian island state has lost more than 95 percent its kelp forests in recent decades. COURTESY OF SCOTT LING Continue reading

Kelp Farming, Whether For Food Or Fuel, Is In Our Future

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Kelp plants grow on a 30-foot-long, white PVC pole suspended in the water. If this is successful, instead of just one row, there would be a whole platform, hundreds of meters across and hundreds of meters deep, full of kelp plants. Courtesy of David Ginsburg/Wrigley Institute

Farming seaweed, using the power of the sun and the vast resources of the oceans, is a topic we expect to be featuring more of in these pages, and whether considering it as food or fuel we know the folks at the salt will be one of our primary sources delivering the goods:

The push for renewable energy in the U.S. often focuses on well-established sources of electricity: solar, wind and hydropower. Off the coast of California, a team of researchers is working on what they hope will become an energy source of the future — macroalgae, otherwise known as kelp.

The Pacific Coast is known for its vast kelp forests. It’s one of the fastest-growing plants on Earth, and farming it requires no fertilizer, fresh water, pesticides, or arable land. “It can grow 2 to 3 feet per day,” says Diane Kim, one of the scientists running the kelp research project at the University of Southern California. Continue reading