marine animals

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

Lighted Nets Protect Marine Wildlife | Earth Wise

March 16, 2022 By EarthWise Leave a Comment

Gillnets are walls or curtains of netting that hang in the water to trap fish. They are one of the most extensively used fishing gear in coastal regions throughout the world’s oceans. While they are very effective at catching targeted fish species, they are not discriminating. As a result, they carry significant risk of bycatch – the accidental capture of unwanted species as well as other interactions with various marine animals.

Researchers from The Wildlife Conservation Society, NOAA Fisheries, Arizona State University, and the National Fisheries and Aquaculture Institute of Mexico have recently published a study showing that using lighted gillnets reduced overall bycatch by 63%, including a 95% reduction in sharks, skates, and rays, and an 81% reduction in Humboldt squid.

Gillnets often catch endangered, threatened, and protected species such as sharks, sea turtles, marine mammals, and seabirds, as well as unwanted species and non-marketable juvenile target fish species. The bycatch animals are often dead or injured and are generally dumped overboard.

Illuminating gillnets with LED lights has emerged over the past decade as an effective tool to reduce bycatch of endangered sea turtles. The new study is the first detailed examination of the effectiveness of illumination for other vulnerable species.

Gillnets are ubiquitous because they are inexpensive and catch everything that passes them. Global populations of sharks, skates, and rays have declined as a result of bycatch and illegal fishing. The results of this study are encouraging because they provide a practical solution for increasing the selectivity of gillnets and avoiding bycatch.

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Lighted Nets Dramatically Reduce Bycatch of Sharks and Other Wildlife While Making Fishing More Efficient

Photo, posted September 19, 2015, courtesy of Jim Bahn via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plastic Pollution And The Galapagos Islands | Earth Wise

July 12, 2021 By EarthWise 1 Comment

The proliferation of plastics remains one of the world’s most challenging environmental problems. Plastic pollution can be found in some of the most remote regions of the planet, including atop the world’s tallest mountains and in the deepest depths of the ocean. Even the Galapagos Islands, a volcanic archipelago in the Pacific Ocean, are no exception.

According to a new study by researchers from the University of Exeter, the Galapagos Conservation Trust, and the Galapagos Science Center, plastic pollution has been found in seawater, on beaches, and inside marine animals at the Galapagos Islands.

In the most polluted hotspots, more than 400 plastic particles were found per square metre of beach. The researchers found that only 2% of macroplastic pollution – plastic fragments larger than five millimeters – was identified as coming from the Galapagos islands. All seven of the marine invertebrate species examined – 52% of individuals tested – were found to contain microplastics.

Significant accumulations of plastic were also found in key habitats, including rocky lava shores and mangroves. In fact, plastics were found in all marine habitats at the island of San Cristobal, which is where Charles Darwin first landed in Galapagos.

Most of the plastic pollution in the Galapagos appears to arrive via ocean currents. According to the research team, the highest levels of plastic pollution were found on east-facing beaches, which are exposed to pollution carried across the ocean on the Humboldt Current.

The pristine images of the Galapagos, a world-famous biodiversity haven, might give the impression that the region is protected from plastic pollution. But clearly that is not the case.

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Plastic in Galapagos seawater, beaches and animals

Photo, posted April 12, 2012, courtesy of Ben Tavener via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Edible Six-Pack Rings

June 4, 2019 By EarthWise Leave a Comment

There has much talk about plastic straws and their harmful effects on the environment. But much like the straws, plastic six-pack rings are also enemies of the ocean. While straws and six-pack rings account for only a tiny fraction of all the plastic trash in the ocean, images of marine animals tangled up in the rings have sparked public backlash against these common items. The soft but tough plastic rings are transparent which means that in the water animals don’t even see them. They end up tangled in the loops, which can cut into their skin and constrict parts of their bodies, leading to serious injury or death. Birds, turtles, and otters are among the frequent victims of six-pack rings.

Plastic straws have readily available alternatives such as paper straws and reusable straws. But the plastic rings that have been available for more than 40 years are not as easy to replace. By law, six-pack rings are photo-degradable, so they do gradually disintegrate when exposed to direct sunlight. But even then, they remain quite dangerous at least for a while.

The Saltwater Brewery in Delray Beach, Florida, recently has released edible six-pack rings, representing a brand-new approach to sustainable beer packaging. The rings are 100% biodegradable and edible. They are actually made from barley and wheat ribbons from the brewing process. This packaging can be safely eaten by animals that may come into contact with them in the wild.

Producing the edible rings represents a big investment for a small brewery but the company hopes to influence larger brewers and inspire them to get on board with the safer packaging.

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Saltwater Brewery Creates Edible Six-Pack Rings

Photo courtesy of Saltwater Brewery.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving Beaches With Seagrass

February 22, 2019 By EarthWise Leave a Comment

Almost a quarter of the Gross Domestic Product of places around the Caribbean Sea is earned from tourism. Preserving the beaches in the region is an economic imperative. With increasing coastal development, the natural flow of water and sand is disrupted, natural ecosystems are damaged, and many tropical beaches simply disappear into the sea.

With such high stakes, expensive coastal engineering efforts such as repeated replenishing of sand and the construction of concrete protective walls are common strategies. Rising sea levels and increasingly powerful storms only increase the threat to tropical beaches.

Researchers from The Netherlands and Mexico recently published a study in the journal BioScience on the effectiveness of seagrass in holding onto sand and sediment along shorelines.

Seagrasses are so-named because most species have long green, grass-like leaves. They are often confused with seaweeds but are actually more closely related to flowering plants seen on land. Seagrasses have roots, stems and leaves, and produce flowers and seeds. Seagrasses can form dense underwater meadows and are one of the most productive ecosystems in the world. Seagrasses provide shelter and food to an incredibly diverse community of animals, from tiny invertebrates to large fish, crabs, turtles, marine mammals and birds.

The researchers performed measurements of the ability of seagrass along Mexico’s Yucatan Peninsula coastline to keep sand in place and prevent erosion. They found that the amount of erosion was strongly linked to the amount of vegetation. Quite often, seagrass beds have been regarded as a nuisance, rather than a valuable asset for preserving valuable coastlines. The study opens opportunities for developing new tropical beach protection schemes in which ecology is integrated into engineering solutions.

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