Study shows how changing ocean chemistry slows life cycle
Ocean acidification could take a bite out of the economically important Dungeness crab fishery along the Pacific Northwest coast. As the oceans absorb more CO2 from the atmosphere, the increasingly corrosive water is likely slow development and reduce survival of the crab’s larval stages, according to new research by the NOAA Fisheries Northwest Fisheries Science Center in Seattle.
Ocean acidification is one of the most serious effects of increasing CO2 emissions from fossil fuel combustion. Based on what we know about emissions trends, the average pH of surface waters off the Pacific Northwest Coast is expected to drop to about 7.8, and even more when periodic upwelling carries deep water to the surface. Acidification has already been found to slow coral growth, impair shark feeding, and speed the spread of invasive species, among other impacts.
The study, recently published in the journal Marine Biology, shows that the crab larvae hatched at the same rate regardless of pH, but those that hatched at lower levels showed signs of slowed development. The researchers suggested that the lower pH may reduce the metabolic rate of embryos. That could extend their vulnerable larval period, or could jeopardize the timing of their development in relation to key food sources, the scientists said. Continue reading “Ocean acidification puts Dungeness crab fishery at risk”→
Warm ocean temperatures in the Pacific led to what researchers now are calling an unprecedented bloom of toxic algae along the west coast of North America in 2015. The algal toxin domoic acid was found in samples from a wide range of marine organisms — and for the first time, in the muscle tissue of several commercial fish species.
Scientists from the University of California, Santa Cruz led the investigations into the spread of the toxin through the marine food web, finding that it persisted in Dungeness crab months after the algal bloom disappeared from coastal waters.
Domoic acid is a potent neurotoxin produced by a type of microscopic algae called Pseudo-nitzschia that occurs naturally in coastal waters. Blooms of the toxic algae along the California coast typically occur in the spring and fall and last just a few weeks. This year, however, unusual oceanographic conditions (unrelated to El Niño) led to the largest and longest-lasting bloom ever recorded. Continue reading “Algae toxin found in West Coast fish for first time”→
Climate change may bolster spotted owl survival in the future
Northern spotted owl populations continue to decline across the Pacific Northwest, researchers said in a new study showing that competition from barred owls, along with habitat destruction and climate change are all factors in population trends.
‘More years like 2015 do not bode well for the frogs …’
LINZ — This year’s fierce drought in the Pacific Northwest has given researchers a chance to see how climate change may affect the region long-term, and the outlook is not good for amphibians.
The low winter snowpack and long, hot summer have left some frogs high and dry as their mountain ponds dry up and disappear. Those conditions could be the norm in another 50 years, said Se-Yeun Lee, research scientist at University of Washington’s Climate Impacts Group and one of the lead authors of the study published last week in PLOS ONE.
FRISCO — With water temperatures approaching lethal levels for salmon, the National Park Service is enacted an emergency closure of recreational fishing on most rivers and streams in Olympic National Park.