G. Niblock on the L41 TipSUP Noserider. Photo: J. Chandler

Tuesday, August 19, 2008

Cooler Summer and Cold Water Brings More Sealife and Kelp

My speculations that the cooler weather and water has spawned more sea life and more kelp seem to be true. In an article published by online magazine MetroActive this past July, scientists confirmed that the conditions that have made for a cooler summer have been driven by winds and upwelling.

In a nutshell, upwelling is a condition created when strong winds literally blow the warmer, top layer of ocean surface water away, thus allowing the colder water underneath to rise up, or well up. This upwelling brings an enormous food supply that is the start of the food chain. Everything living in the ocean benefits.

The rich supply of nutrients also benefits the kelp beds which many are saying are much larger this year than last. And they are right. Kelp loves cold water and food. The growth has been prolific.

Water temperatures are starting to warm now in the bay, and as we head into Fall, warmer weather will set in. I love nature, but I'm looking forward to the kelp thinning so the surf riding playing field can become a lot less obstructed.

What follows are some excerpts from the article. You can read the whole thing here.

Thanks to James for his very "cool" photo.

"Phytoplankton, microscopic organisms that form the base of the marine food chain, don't put on much of a show, but their abundance this year has drawn huge schools of rockfish, massive flocks of seabirds, hundreds of dolphins and dozens of whales spread out for miles along the bay's famous submarine canyon. Francisco Chavez has been studying these tiny but crucial organisms for the past 20 years at the Monterey Bay Aquarium Research Institute, and this is one of the best years he's seen in quite a while. The main reason for this is the strong winds that drive a process known as coastal upwelling, in which cold and nutrient-rich water lying about 60 meters below the surface is thrown to the top of the water column. Chavez describes this cold deep-sea water as the compost of the sea. Without it, phytoplankton growth is stymied and larger marine life has a hard time finding food. This was the situation from 2004 to 2006, when a lack of upwelling set off a great deal of hand wringing among marine biologists and fishing fleets. This year, however, Chavez has good news. "In the 20-year record, 2008 was the coolest year we've seen in the bay," reports Chavez. "That cooler water is like compost—material has sunk there and degraded. So when you bring that compost to the surface and put it in contact with sun, you stimulate growth that the whales, porpoises and rockfish feed on." A larger marine process known as the California current is also helping funnel nutrients to the Monterey Bay this year. The current is located about 200 kilometers offshore and stretches from the Gulf of Alaska to Baja California. William Sydeman, who holds a Ph.D. in ecology, has been studying the effect of the California current on the marine environment for the past 15 years. He notes that from 2004 to 2006 this current was extremely weak. When the weak current was coupled with a lack of upwelling, there were a number of seabird and salmon deaths. This year, the current seems to have picked up steam, meaning that nutrients stored in cool water off Alaska and Canada are being swept down the coast. As the current makes its way south, nutrients are spread out along California's coastal ecosystems, including the Monterey Bay, further fertilizing areas already seeing robust production due to strong upwelling closer to the shore.
The effect of this year's strong current, however, is already being seen in the kelp forests that hug the coast along the Monterey Bay.
Mark Carr has been surveying rockfish populations in the kelp forest over the past decade. His team sets up fish collectors in four key locations along the coastal kelp every year. During the troubled 2005–2007 period, there were never more than two fish on a collector—sometimes there were none. This year, his team has found 30 to 40 rockfish per collector. Carr explains that the growth of the kelp forests this year bodes well not just for rockfish populations but also for a whole host of invertebrates that inhabit the deep-sea canyon further offshore.

"The upwelled water is nutrient rich and fertilizes the kelp forests along the coasts," explains Carr. "The kelp is going to grow and grow this year. That kelp production of course fuels food webs in the kelp beds, but the kelp is also carried offshore where it gets torn up and falls into the canyon and deep sea reefs. So it's a form of nutrient that abalone, sea urchin and other invertebrates in the canyon feed on."

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