Continued illegal gill net fishing cited in push for ban on Mexican seafood
In what could be a last-ditch effort to save imperiled vaquita in the Gulf of California, conservation advocates are urging the Obama administration to launch economic sanctions against Mexico to halt that country’s trade in totoaba. According to the Center for Biological Diversity, the sanctions would be justified because Mexico is violating the Convention on International Trade in Endangered Species (CITES) by not enforcing the ban on totoaba trade.
There, the die-off had a clear ecological trickle-down effect, called a trophic cascade by biologists. After the sea stars died, populations of their favorite prey, green sea urchins, quadrupled. The urchins quickly gobbled up kelp, reducing by 80 percent. Undersea kelp forests are critical to near-shore ocean ecosystems, providing cover and food for many marine species.
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”→
New survey results show as few as 60 remaining vaquita porpoises in the Gulf of California
The population of vaquita porpoises in the Gulf of California may be down to just 60 individuals, according to conservation advocates, who released the results of recent surveys in a press release last week.