humpback whales

Whales Eating Plastic | Earth Wise

December 1, 2022 By EarthWise Leave a Comment

Plastic waste has been accumulating in the world’s oceans in greater and greater quantities and much of it is in the form of microplastic particles. Many kinds of whales – the largest creatures on Earth – feed by gulping up mouthfuls of krill and other tiny creatures and then straining the seawater through bristly filter structures called baleens. As they do this, they are likely to be swallowing large amounts of plastic.

Scientists at Stanford University recently estimated just how much plastic whales are ingesting by tracking the foraging behavior of 65 humpback whales, 29 fin whales, and 126 blue whales in the Pacific Ocean. Each of the whales was tagged with a camera, microphone, and GPS device suction-cupped to their back.

After accounting for the concentration of microplastics in parts of the Pacific Ocean, the researchers were able to estimate the amount of plastic the whales were consuming. Humpback whales likely consume 4 million microplastic pieces each day, adding up to about 38 pounds of plastic waste. Fin whales swallow an estimated 6 million pieces each – amounting to 57 pounds of plastic. Blue whales, which are the largest creatures on Earth, eat an estimated 10 million microplastic pieces, or as much as 95 pounds of plastic waste each day.

Despite their enormous size, whales actually eat rather low on the food chain, which puts them close to where the plastic is in the water. Krill eats plastic and whales eat the krill. Many marine animals are at risk of eating microplastics, but whales are unique in that they can consume so much of it. It is just one more way in which the ocean plastic situation is a global crisis.

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Blue Whales Swallowing 95 Pounds of Plastic Daily, Scientists Estimate

Photo, posted October 21, 2005, courtesy of Tobias Begemann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Snail Darter Is Safe | Earth Wise

November 14, 2022 By EarthWise Leave a Comment

The snail darter is a three-inch-long snail-eating fish that was once only found in the Little Tennessee River. When that river was going to be dammed by the Tellico Dam under construction in the 1970s, the snail darter was listed on the endangered species list and the little fish subsequently became the subject of a legal battle that made it all the way up to the U.S. Supreme Court. With the dam project 95% complete in 1978, the Supreme Court blocked further construction, citing the Endangered Species Act. A year later, Congress exempted the project from the requirements of the Act, thereby clearing the way for the completion of the dam.

In order to save the snail darter, biologists transplanted the fish into several other nearby rivers and waterways. In addition, the Tennessee Valley Authority modified the operation of the Tellico Dam to release more oxygen-rich water downstream. Beyond those measures, the river cleanup under the Clean Water Act further aided the fish’s recovery.

In 1984, the snail darter was removed from the endangered species list and was listed as threatened or vulnerable. Recently, the U.S. Department of the Interior officially removed the snail darter from the federal list of threatened and endangered wildlife.

The snail darter is the fifth fish species to be delisted because its population has recovered. It is the first in the eastern United States. With better management of water releases at dams, many other imperiled aquatic species could be recovered.

Overall, more than 50 plants and animals have recovered under federal protection, including American alligators, humpback whales, peregrine falcons, and bald eagles.

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Once at Center of Controversial Case, the Snail Darter Fish Is No Longer Threatened

Photo, posted July 22, 2015, courtesy of The U.S. Fish and Wildlife Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Whales As Ecosystem Engineers | Earth Wise

December 14, 2021 By EarthWise Leave a Comment

Researchers from Stanford University have been studying the role of large whales on ocean ecosystems with some surprising results.

From 1910 to 1970, people killed about 1.5 million baleen whales in the waters surrounding Antarctica. The whales were hunted for their blubber, baleen, and meat. Baleen is the filtering fringe that certain whales use instead of teeth to capture food from the ocean. A primary food source for these whales is krill, small shrimp-like creatures. One would assume that the decimation of the baleen whale population in the Southern Ocean would have led to a surge in krill populations. But the new research has found that the opposite is the case.

The precipitous decline of large marine mammals has negatively impacted the health and productivity of ocean ecosystems.

New high-tech tagging devices that attach to whales for brief periods allow researchers to record their movements and activities. For the first time, it has been possible to accurately determine how much krill whales actually consume, and the answer is that they eat two to three times as much as previously thought. Interestingly, the same technology shows that fish-eating whales like humpbacks eat somewhat less than previously thought.

Baleen whales are essentially mobile krill processing plants. They eat the krill, digest it, and produce iron-laden excretions that are needed by phytoplankton, which comprise the bottom of the food chain that nourish krill and other small creatures. With fewer whales, there is less nourishment for the krill. In fact, based on the new data, estimates are that the historic abundance of krill in the Southern Ocean had to be about five times what it is today.

Whales are important ecosystem engineers.

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Stanford researchers find whales are more important ecosystems engineers than previously thought

Photo, posted November 18, 2010, courtesy of Dr. Brandon Southall, NMFS/OPR via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recovering Marine Life By 2050 | Earth Wise

May 27, 2020 By EarthWise Leave a Comment

Marine life has faced challenges for a long time. There have been centuries of overfishing in many places and pollution of various types has been especially harmful in recent decades. But despite all of this, a new scientific review published in the journal Nature contends that marine life in the world’s oceans could be fully restored in as little as 30 years provided that aggressive conservation policies are adopted.

The research spotlights the strong resiliency of ocean animals and cites the successful recovery of a number of marine species, including humpback whales.

The study indicates that nations around the world must agree to designate 20 to 30 percent of the oceans as marine protected areas, institute sustainable fishing guidelines, and regulate pollution. These measures would not come cheaply. The estimated cost would be around $20 billion a year.

However, the report also estimates that the economic return on this investment would be tenfold and would create millions of new jobs. Rebuilding fish stocks and maintaining sustainable fishing policies could increase global profits of the seafood industry by over $50 billion a year. Conserving coastal wetlands could save the insurance industry more than $50 billion a year as well by reducing storm damage.

A major sticking point, however, is climate change. Climate change is increasing ocean temperatures and driving acidification. Unless these changes are brought under control, the restoration of marine life is not going to be successful. We have reached the point where it is within our power to choose between a future with a resilient and vibrant ocean or an irreversibly disrupted ocean. Whether we embrace that challenge remains to be seen.

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Marine Life Could Recover By 2050 With the Right Policies, Study Finds

Photo, posted April 20, 2012, courtesy of Matthias Hiltner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alien Waters Invade The Arctic

June 18, 2018 By EarthWise Leave a Comment

The Arctic is heating up faster than any other region of the planet. As a result, once-distinct boundaries between the frigid polar ocean and the warmer, neighboring Atlantic and Pacific Oceans are blurring, opening the way for the southern waters to enter the polar regions. The volume of Pacific Ocean water flowing into the Arctic Ocean through the Bering Strait has increased by 70% over the past decade. The Arctic Ocean’s cold layering system that blocks Atlantic inflows is breaking down.