entanglements

Marine Heat Waves | Earth Wise

August 17, 2023 By EarthWise Leave a Comment

In late July, the ocean temperature measured in Florida Bay, between the southern end of the Florida mainland and the Florida Keys, was 101.1 degrees Fahrenheit, a possible world record for sea surface temperature. There is no official record keeping for ocean temperatures, but the highest previous reading ever reported was 99.7 degrees in the middle of Kuwait Bay in 2020.

What is going on is a marine heat wave and marine heat waves can last for weeks, months, or even years. The current Gulf of Mexico marine heat wave has been present for several months, beginning in February or March. Experimental forecasts by the National Oceanic and Atmospheric Administration say the extreme ocean temperatures in the area may persist through at least October.

The ocean absorbs 90% of the excess heat associated with global warming. Therefore, marine heat waves all over the planet are becoming warmer over time. The current marine heat wave would likely have occurred even without climate change, but because of it, the event is extraordinarily warm.

Marine heat waves cause stress to corals and other marine ecosystems. Exposure to extreme temperatures for long periods of time causes corals to eject the algae that live inside of them, resulting in white or pale coral. This coral bleaching leaves the coral without food and will ultimately kill it.

In general, extreme heat can be destructive and deadly for marine ecosystems. A massive marine heat wave known as “the Blob” took hold in 2013-2016 in the northeastern Pacific Ocean and led to an ecological cascade of fishery collapses, toxic algal blooms, and record numbers of humpback whale entanglements.

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The ongoing marine heat waves in U.S. waters, explained

Photo, posted December 25, 2016, courtesy of Paul Asman and Jill Lenoble via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Right Whales And The Warming Atlantic | Earth Wise

October 25, 2021 By EarthWise Leave a Comment

The warming of the Atlantic Ocean has driven the critically endangered North Atlantic right whale population from its traditional and protected habitat. This has exposed the whales to more lethal ship collisions, increased entanglements with commercial fishing gear, and greatly reduced calving rates.

Since 2010, the calving rate has declined, and the right whale population has dropped by an estimated 26%. Ten years ago, there were about 500 North Atlantic right whales; now there are an estimated 356.

These are some of the best studied whales in the oceans; scientists basically recognize each individual whale and when they are the victims of ship collisions or fishing entanglements, it is easy to identify which animal was killed.

Because of the warming climate, the Atlantic Meridian Overturning Circulation – an important system of surface and deep currents – has slowed down, causing the Gulf Stream to move north. This has injected warmer and saltier water into the Gulf of Maine. The warming Gulf of Maine has reduced the abundance of copepods, tiny crustations that are the favorite snack of right whales. This has reduced whale calving rates and forced the whales to move north to the cooler waters of the Gulf of St. Lawrence.

For the past 6 years, more and more right whales have been observed feeding in the Gulf of St. Lawrence, where there were no protections in place to prevent ship strikes and fishing gear entanglement. In 2017 alone, 17 right whale deaths were confirmed.

According to a recent report from Cornell University and the University of South Carolina, unless its management is improved, right whale populations will decline and potentially become extinct in the coming decades.

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Warming Atlantic forces whales into new habitats, danger

Photo, posted December 8, 2016, courtesy of Sea to Shore Alliance/NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

North Atlantic Right Whales

January 12, 2018 By EarthWise Leave a Comment

North Atlantic right whales are one of the rarest marine mammals in the world. In fact, according to the National Oceanic and Atmospheric Administration, there are only about 450 of the whales left. Measuring approximately 50 feet long and weighing close to 100,000 pounds, North Atlantic right whales are now more critically endangered than mountain gorillas, black rhinos, and giant pandas.