But as rising ocean temperatures threaten to make fishery closures routine, it will be even harder to count on crab for holiday meals—or livelihoods. Over the past decade, warming sea waters have produced harmful algal blooms that contaminate crab meat with domoic acid, a neurotoxin that can cause seizures, memory loss and other serious symptoms and has been blamed for poisoning and stranding scores of sea lions in California every year. State officials delayed three out of the last six crab seasons to protect public health after an unprecedented multiyear marine heat wave, dubbed “the blob,” hit the north Pacific Ocean in 2013.
The ocean absorbs carbon dioxide from the atmosphere, which reduces pH levels and concentrations of calcium carbonate, a mineral used by shellfish to calcify their shells. As more carbon is released into the atmosphere, concentrations of calcium carbonate decrease and the shells of organisms like foraminifera get thinner, a trend Osborne saw clearly in the sediment cores she examined.
“The shell thickness record instantly showed a long-term declining trend,” she said. “It was really obvious across entire record.”
The commercial Dungeness crab fishery will open north of Sonoma County on Monday after several delays needed to allow the crustaceans to mature before the harvest begins. The northern season, which usually starts Dec. 1, is opening two months after… Read More ›
As the Pacific Ocean acidifies—a consequence of carbon emissions—oyster farms off California, Washington State, and British Columbia have struggled to get larvae to grow into seed, the stage when young oysters’ shells have formed. Though scientists are not quite sure why, the water off Southeast Alaska hasn’t seen the same deleterious effects. Now, entrepreneurs and investors are eyeing the state, looking to turn a profit off the short-lived gains of climate change.
It’s a calamity that threatens Washington state’s $270-million-a-year shellfish industry. And it has the Taylors — after a century-plus producing shellfish in the Evergreen State — exploring every potential angle to steel their mollusks against the corrosive effects of ocean acidification.
The Gulf of Maine stretches from Cape Cod to Canada and is a key marine environment and important to commercial fishing. Blue mussels are used in seafood dishes and worth millions to the economy of some New England states, but are also important in moving bacteria and toxins out of the water.
… as climate change alters the chemistry of the world’s oceans, scientists and fishermen are just beginning to understand how this economically, culturally, and ecologically important species will be impacted.
The researchers then observed the oysters’ physiological responses to ingesting the microplastics. The most obvious effect was on reproduction. Oysters that were exposed to microplastics produced fewer and smaller egg cells and slower sperm. Exposed oysters also produced fewer larvae and their offspring tended to grow more slowly.