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Whales Eating Plastic | Earth Wise

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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

Return Of The Fin Whale | Earth Wise

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The fin whale is the second largest whale species and therefore the second largest creature on Earth.  They can grow to more than 80 feet in length.  From 1904 to 1976, there was massive industrial whaling in the Southern Ocean surrounding Antarctica.  During that period, whalers killed about 700,000 fin whales, reducing their population by 99%.  The species was nearly extinct.

In 1982, the International Whaling Commission voted to ban commercial whaling.  Since that time, fin whales started to make a comeback in their historical feeding grounds.

During a nine-week expedition in the waters around the Antarctic Peninsula, researchers encountered the largest gathering of fin whales ever documented.  About 150 fin whales were seen diving and lunging against the water’s surface.  It was a feeding frenzy triggered by large amounts of krill in the water.  The actions of the whales are known as a “whale pump” that drives the krill to the surface.  Not only does it provide huge amounts of food for the whales but also for other animals, including seabirds and seals.

Forty years after the commercial whaling ban, the number of fin whales has been increasing.  Large groups were observed in a 2013 survey.  Aerial surveys in 2018 and 2019 recorded 100 groups of fin whales, usually composed of a just a handful of individuals.  They did document eight large groups of up to 150 individuals.

Not all species of whales have rebounded so successfully since the whaling ban.  The rebound in fin whale population is not only good for the whales, but for the entire ecosystem in the Southern Ocean.  It is a glimmer of good news in a time of great challenges for global biodiversity and for marine life in particular.

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Once Facing Extinction, Massive Fin Whales Have Returned to Antarctic Waters

Photo, posted November 15, 2007, courtesy of Gregory Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Whales As Ecosystem Engineers | Earth Wise

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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.

A Powerful Case For Protecting Whales

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Efforts to mitigate climate change typically face two major challenges.  One is to find effective ways to reduce the amount of atmospheric carbon dioxide.  The other is how to raise enough money to implement climate mitigation strategies. 

Many proposed solutions to climate change, like carbon capture and storage, are complex, expensive, and in some cases, untested.  What if there was a low-tech solution that was effective and economical?

Well, it turns out there is one, and it comes from a surprisingly simple, “no-tech” strategy to capture CO2: increase global whale populations. 

According to a recent analysis by economists with the International Monetary Fund, whales help fight climate change by sequestering CO2 in the ocean. 

Whales sequester carbon in a few ways.  They hoard it in their fat and protein-rich bodies, stockpiling tons of carbon apiece.  When whales die, they turn into literal carbon sinks on the ocean floor.  While alive, whales dive to feed on tiny marine organisms like krill and plankton before surfacing to breathe and excrete. Those latter activities release an enormous plume of nutrients, including nitrogen, iron, and phosphorous, into the water.  These so-called “poo-namis” stimulate the growth of phytoplankton, microscopic marine algae that pull CO2 out of the air and return oxygen to the air via photosynthesis.  Phytoplankton are responsible for every other breath we take, contributing at least 50% of all oxygen to the atmosphere and capturing approximately 40% of all CO2 produced. 

With other economic benefits like ecotourism factored in, economists estimate that each whale is worth $2 million over its lifetime, making the entire global population possibly a one trillion dollar asset to humanity.

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How much is a whale worth?

Photo, posted June 12, 2013, courtesy of Gregory Smith via Flickr.

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Why Do Animals Eat Ocean Plastic?

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It’s no secret that there is a lot of plastic debris in our oceans.  In fact, scientists estimate that there is more than 165 million tons of plastic trash swirling about in our oceans today, with an additional 8.8 million tons flowing in every year.  And as the oceans swell with plastic litter, hundreds of marine species are ingesting the stuff – often with dire consequences.

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