foraging

Disappearing snow crabs

November 21, 2023 By EarthWise Leave a Comment

Alaska snow crabs are a cold-water species found off the coast of Alaska in the Bering, Beaufort, and Chukchi Seas. They are one of ten commercially-fished species in Alaskan waters. The perils of crab fishing in this region have been well documented for many years in the reality TV series Deadliest Catch.

Last year, officials in Alaska canceled the winter snow crab season for the first time ever due to a sharp population decline. While the number of juvenile snow crabs was at record highs just a few years earlier, approximately 90% of snow crabs mysteriously disappeared ahead of the 2021 season.

This year, officials in Alaska have once again canceled the snow crab harvest season for the second year in a row, citing the overwhelming numbers of crabs – in the billions – missing from Alaskan waters.

Scientists have suspected that the warming ocean temperatures triggered this snow crab population collapse. But did the crabs move someplace else or die off? According to a new study recently published by scientists at the National Oceanic and Atmospheric Administration, warmer ocean temperatures likely caused the snow crabs to starve to death. The research team found a significant link between recent marine heat waves in the eastern Bering Sea and the sudden disappearance of the snow crabs that began showing up in surveys in 2021.

According to the study, warmer ocean water dramatically increases snow crabs’ caloric needs. But with the warmer water also disrupting much of the region’s food web, snow crabs had a hard time foraging for food and weren’t able to keep up.

Researchers expect the population may eventually find refuge in colder waters further north.

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Climate Change And Crabs

Billions of crabs went missing around Alaska

Photo, posted August 28, 2013, courtesy of Boris Kasimov via Flickr.

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Return Of The Blue Whales | Earth Wise

December 21, 2020 By EarthWise Leave a Comment

An international research team has revealed that critically endangered Antarctic blue whales have returned to the sub-Antarctic island of South Georgia, 50 years after whaling just about wiped them out. Other recent research has found that humpback whales are also returning to the region.

Blue whales were commonplace off South Georgia before 20th century industrial whaling taking place between 1904 and 1971 killed over 42,000 of them there. Most of that number were killed before the mid-1930s. As a result, blue whales essentially vanished from the region. Whale survey ships sighted only a single blue whale between 1998 and 2018.

But things have changed in recent years. A survey this past February resulted in 58 blue whale sightings and numerous acoustic detections. Although commercial whaling was banned in the area in the 1960s, it has taken a long time for the whales to make a comeback.

Researchers are not sure why blue whales have taken so long to return to the area. It may be that so many were killed over the years that the remaining population had little or no cultural memory of South Georgia Island as a foraging ground, and that it is only now being rediscovered.

In total, 41 individual blue whales have been photo-identified from South Georgia over the past 10 years, although none of those matched the 517 whales in the current Antarctic blue whale photographic catalogue. Dedicated whale surveys are difficult in a region known for its harsh weather and inaccessibility but are crucial to the future management of South Georgia’s seas. In any case, researchers see the recent sightings as a very positive step forward for conservation of the Antarctic blue whale.

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Blue whales return to South Georgia after near extinction

Photo, posted September 7, 2007, courtesy of the NOAA Office of National Marine Sanctuaries via Flickr. Photo credit: NOAA.

Earth Wise is a production of WAMC Northeast Public Radio.

Bees Threatening Bees | Earth Wise

October 16, 2020 By EarthWise Leave a Comment

Domesticated honeybees are an essential part of our agricultural system, being responsible for one in every three bites of food Americans consume and contributing $15 billion a year to the value of the nation’s crop production. Millions of bee colonies are trucked across the country every year to pollinate cranberries, melons, broccoli, blueberries, and cherries, and also to produce honey.

After the growing seasons, honeybees are trucked to various locations to rest and rebuild their population and to replenish bees lost to disease and pesticides. Some of these locations are in national forests. Thousands of hives belonging to 112 apiaries are currently permitted in national forests by the Department of Agriculture. This presents a problem because these hives are being permitted on public lands with virtually no environmental review and with little consideration of the impact these colonies can have on local wild bee populations.

The 4,000 wild bee species in the U.S. consume up to 95% of local available pollen. Nearly 40 federally listed threatened or endangered species of bees, butterflies, and flower flies depend on national forest land for their survival. And now the pollinators in these places, which were once refuges for these species and others, increasingly face competition from millions of domesticated honeybees.

Honeybees are super-foraging machines and are literally taking the pollen out of the mouths of other bees and pollinators. Honeybees themselves have been facing numerous problems from habitat loss, pesticides, and other stress factors. So, what is happening is essentially a pollinator habitat crunch that carries long-term implications for the U.S. food supply. We need to find some answers and the sooner the better.

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Will Putting Honey Bees on Public Lands Threaten Native Bees?

Photo, posted August 9, 2015, courtesy of Tak H. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cities Can Help Bees

December 14, 2017 By EarthWise Leave a Comment

Global bee populations have been drastically declining as a result of habitat loss, pesticides and climate change. But studies are showing that planting flower patches in urban gardens and green spaces can make a real difference in restoring natural pollinators. There are already positive results in cities from Chicago to London to Melbourne.

[Read more…] about Cities Can Help Bees