Tag Archives: ocean ecosystems

Along the North Coast, mixed news about the health of the undersea kelp forest 

Mary Callahan, THE PRESS DEMOCRAT

Aerial surveys conducted each year to gauge abundance in the iconic kelp forests off the North Coast showed a slight improvement last fall, offering a glimmer of hope for the recovery of the coastal marine habitat, the California Department of Fish and Wildlife has reported.

But conditions for the “bull kelp,” an annual type of seaweed — especially off Sonoma County — have become so bleak in recent years that even a reported doubling of the forest canopy during last year’s growing season has done little to bring the underwater habitat back to full strength, scientists said.

Despite patches that resemble the historic ecosystem in some ways, large swaths of ocean floor off the North Coast remain devoid of bull kelp and other fleshy algal species, prompting continued starvation among common marine herbivores like red abalone and urchins, they said.

Even with growth in the overall canopy last year, data indicates the kelp off Sonoma and Mendocino counties covered at least 95 percent less surface area in 2016 than it did in the banner year of 2008, said Cynthia Catton, an environmental scientist with the state wildlife agency.

The apparent expansion of the kelp canopy “is deceptive,” said Sonke Mastrup, environmental program manager for the agency’s invertebrate program, “because 2016 is still way below anything we would consider normal.”

Read more at: Along the North Coast, mixed news about the health of the undersea kelp forest | The Press Democrat

Filed under Habitats, Sonoma Coast

Widespread loss of ocean oxygen to become noticeable in 2030s

Earth Sciences, PHYS.ORG

A reduction in the amount of oxygen dissolved in the oceans due to climate change is already discernible in some parts of the world and should be evident across large regions of the oceans between 2030 and 2040, according to a new study led by the National Center for Atmospheric Research (NCAR).

Scientists know that a warming climate can be expected to gradually sap oceans of oxygen, leaving fish, crabs, squid, sea stars, and other marine life struggling to breathe. But it’s been difficult to determine whether this anticipated oxygen drain is already having a noticeable impact.

“Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life,” said NCAR scientist Matthew Long, lead author of the study. “Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it’s been challenging to attribute any deoxygenation to . This new study tells us when we can expect the impact from climate change to overwhelm the natural variability.”

The study is published in the journal Global Biogeochemical Cycles, a publication of the American Geophysical Union. The research was funded by the National Science Foundation, NCAR’s sponsor.

Read more at: Widespread loss of ocean oxygen to become noticeable in 2030s

Filed under Climate Change & Energy, Wildlife