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.
New study helps explain how carbon flux changes over time
The shells of tiny ocean organisms called foraminifera have once again given climate researchers huge clues about the long-term carbon cycle in the world’s oceans. The information helps show the buildup of heat-trapping greenhouse gases will affect the climate.
Study identifies bleaching and mortality thresholds for imperiled coral reefs
The steady rise in ocean temperatures projected for the next few decades will put more and more corals at risk of bleaching, as the warm water simply overwhelms their thermal tolerance mechanisms.
Recent research along the Great Barrier Reef shows that corals have been able to survive past bleaching events because they were acclimated to warmer temperatures by being exposed to a pattern of gradually warming waters in the lead up to each episode. But global warming is likely to change that, the scientists said.
Before long, temperature increases of as little as 0.5 degrees Celsius may push many corals over the edge as the warm water causes them to expel the algae-like dinoflagellates that help keep them alive and give them their color.
Lead author Dr. Tracy Ainsworth from Coral CoE said bleaching is like a marathon for corals.
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.
The bluefin tuna population in the Pacific Ocean has dropped so low that a coalition of conservation groups have petitioned the National Marine Fisheries Service to protect the species under the Endangered Species Act.
According to the petition, the population has declined more than 97 percent since fishing began, largely because countries have failed to reduce fishing enough to protect the iconic species, a luxury item on sushi menus.
“Without help, we may see the last Pacific bluefin tuna sold off and lost to extinction,” said Catherine Kilduff of the Center for Biological Diversity. “New tagging research has shed light on the mysteries of where majestic bluefin tuna reproduce and migrate, so we can help save this important species. Protecting this incredible fish under the Endangered Species Act is the last hope, because fisheries management has failed to keep them off the path toward extinction.” Continue reading “Endangered species status sought for bluefin tuna”→
Australian scientists have closely tracked the status of reefs along their coastline for the past few months as it became evident that this year’s strong El Niño would raise ocean temperatures above the limit of what most corals species can survive, and the latest survey results confirm their worst fears. In a press release, the researchers said the impacts are still unfolding along the 2,300-long reef, with the worst damage to the central and northern sections. Continue reading “Global warming kills a third of Great Barrier Reef’s corals”→