Most Important Coral Reefs Likely Gone by 2100
UNESCO has issued a report that finds that all 29 coral reefs designated as World Heritage sites would likely die by the end of the century unless severe cuts in greenhouse gas emissions are made.
“Nearly half (13) of the 29 World Heritage Listed reef properties were exposed to levels of heat stress that cause coral bleaching, on average, more than twice per decade during the 1985-2013 period,” the report’s authors wrote. “Coral communities typically take at least 15 to 25 years to recover from mass mortality events such as destructive cyclones and mass bleaching events. If the frequency of mass mortality events increases to a point where the return time of mortality events is less than the time it takes to recover, the abundance of corals on reefs will decline.”
World Heritage coral reefs are “recognized for their unique and global importance and for being part of the common heritage of humanity.” They include the Phoenix Islands Protected Area in Kiribati, the Great Barrier Reef in Australia, Papahānaumokuākea in United States, the Belize Barrier Reef Reserve System in Belize and Tubbataha Reefs Natural Park in the Philippines.
Coral reefs worldwide suffered back-to-back bleaching events from 2015 to 2017. A report released last week by the United States National Oceanic and Atmospheric Administration found that the bleaching is subsiding with cooler waters. That could give some corals time to recover, provided ocean temperatures don’t spike again.
Failed Orca Pregnancies Tied to Lack of Fish
A new study links pregnancy failures in endangered killer whales to a dearth of Chinook salmon, which is the primary food source for orcas that frequent the inland waters of Washington State.
In a paper to be published in the journal PLOS ONE, researchers from the University of Washington analyzed hormone levels in 350 samples of excrement of Southern resident killer whales. They found that in 24 failed pregnancies, the orcas were suffering from nutritional stress. Successful pregnancies are crucial to the survival of the Southern resident killer whales, whose numbers have dwindled to 78 individuals. The marine mammals also face threats from boat collisions and water pollution.
The researchers found that the pregnancy failures mirrored the decline in salmon runs.
“Pregnancy failure, likely brought on by poor nutrition, is the major constraining force on population growth,” Sam Wasser, the study’s lead author and a biology professor at the University of Washington, told the Seattle Times.
Scotland’s Coastal Waters Awash in Plastic Trash
A two-month Greenpeace expedition around the coastline of Scotland found plastic trash on every beach of the 30 surveyed, as well as the presence of microplastics in the feeding grounds of basking sharks.
Plastic bottles, bags, packaging and debris was also collected from the habitats of a range of wildlife, including whales, seas and seabirds.
“It cannot be right that our beaches, seas and the stunning wildlife they are home to should become the final dumping ground for throwaway plastic bottles and other plastic trash,” Trish Brown, an oceans campaigner at Greenpeace U.K., said in a statement. “With a truckload of plastic entering the ocean every minute, we need urgent action from governments and from major soft drinks companies which produce billions of single-use plastic bottles every year, like Coca-Cola, to stop the flow of plastic into the sea.”