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Showing posts with the label Oceans

Long-distance movement of microplastics

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Nature Communications Microplastic pollution collected at a Key largo, Florida beach State Park. An Ocean Blue Project photo. Microplastics, detected in southern France, could have been transported over 4,500 km from their source, including over continents and oceans, suggests a study published in Nature Communications. The findings suggest that microplastic pollution can spread globally from its sources to remote regions. Plastic pollution has been documented at high elevations and latitudes, and in regions with little local plastic use. The transportation of microplastics through the atmosphere has been suggested as occurring on regional scales. However, it is unclear how widespread this phenomenon is and, if like mercury and other pollutants, there is free transport of microplastics through the atmosphere that enables trans-continental movement. Steve Allen and colleagues collected atmospheric microplastics at the high-elevation Pic du Midi Observatory in the French Pyrenees, south

Airguns and ship sounds dangerously disrupt the natural behaviour of the "unicorn of the sea." Study

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The Royal Society - Biology Letters A pod of narwhals in the Arctic. Manmade noise is increasing in the Arctic, posing a threat to narwhals. To study this, narwhals were fitted with tags and exposed to ship and airgun noise. The whales showed clear reactions to sound disturbance by first reducing and then ceasing foraging. Reactions could be detected as far as 40 km from the ship, where the signals were embedded in the natural background noise. The reactions of the whales demonstrate their sensitivity and emphasize that - "if healthy narwhal populations are to be maintained,"  humans need to "manage" activities that make such noise. The findings have just been published by the Royal Society. Please also read: RAPIDLY WARMING OCEANS HAVE LEFT MANY NORTHERN MARINE MAMMALS SWIMMING IN TROUBLED WATERS. BUT PERHAPS NONE MORE SO THAN THAT STRANGE AND MYSTERIOUS "UNICORN OF THE SEA," THE NARWHAL .

Baleens - beneficial gluttons of the high seas

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Scientists believe the ravenous appetites of baleen whales - Earth's largest creatures - and their prodigious waste - hold clues to the very health and productivity of our oceans. by Larry Powell A blue whale  (Balaenoptera musculus)  defecates.  Photo credit-Ryan Lavery (Smithsonian) Baleens include humpbacks, fins, minkes and blue whales, the latter being the largest creatures ever to live on Earth. The carnivorous marine mammals catch and consume vast amounts of prey. And they recycle ocean nutrients by excreting undigested food in what have been described as "volcano-like" movements. A minke whale tagged by the research team off the coast of Antarctica in 2019. Credit: Ari Friedlaender under NOAA/NMFS permit 23095. By attaching tags to the backs of 321 whales from seven baleen species, the researchers now reckon that - before the onset of whaling in the twentieth century - and in the Southern Ocean alone - baleens were, amazingly, consuming  more than twice what the w

Australian bushfires triggered prolific phytoplankton blooms vast distances away

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Nature Bushfire East of Lake Dundas, Western Australia. Photo by Pierre Markuse The 2019–2020 Australian wildfires released more than twice as much CO2 as previously reported on the basis of different fire inventories, reports  a Nature paper.   An independent study  also published in Nature ,  suggests that aerosol emissions from these wildfires are likely to have fuelled vast plankton blooms thousands of kilometres away in the Southern Ocean.  The findings highlight the complex links between wildfires, ecosystems and the climate.  Climate-change-driven droughts and warming play a role in increasing the frequency and intensity of wildfires, which release CO2 into the atmosphere, potentially driving further climate change and increasing the risk of wildfires.  In the summer season of 2019–2020, around 74,000 km2 — an area roughly equivalent to 2.5 times the area of Belgium — burned in the eucalyptus forests in the coastal regions of Victoria and New South Wales, Australia. These wildfi

A serious disease of Chinook salmon, originating from fish farms in Norway, has now spread to wild salmon off the coast of BC: Study.

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University of British Columbia The Chinook salmon. Photo by Zureks. The virus known as PRV, is associated with kidney and liver damage in Chinook salmon.  A new study in Science Advances shows -- it's continually being transmitted between open-net salmon farms and wild juvenile Chinook salmon in British Columbia waters. The study traces its origins to Atlantic salmon farms in Norway and finds that the virus is now almost ubiquitous in salmon farms in B.C. It also shows that wild Chinook salmon are more likely to be infected with PRV the closer they are to salmon farms, which suggests farms transfer the virus to wild salmon. Genome sequencing of viruses from farms and wild fish further indicates that transmission occurs between farms and wild salmon. "Both our genomic and epidemiological methods independently came to the same conclusion, that salmon farms act as a source and amplifier of PRV transmission," said Dr. Gideon Mordecai, a viral ecologist and Liber Ero fellow wi

WHAT GOES ON ON THE HIGH SEAS? "SEASPIRACY" PROVIDES AN INSIGHT. AND IT WILL SHOCK Y0U.

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Tough Times for Animal Travellers

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Committee on the Status of Endangered Wildlife in Canada. (COSEWIC) The Blackmouth ( Oncorhynchus tshawytscha) a type of Chinook.  Image by Animal Diversity Web. After maturing at sea, Chinook Salmon on Canada's West Coast swim back to their natal streams to spawn. Twenty-eight populations of Chinook Salmon live in Southern British Columbia, each with different habitats and survival strategies. Chinook Salmon face many threats in both fresh and saltwater, including climate change and detrimental effects from hatchery fish. At the current meeting, COSEWIC considered the 12 populations of Chinook Salmon most impacted by hatcheries: four were designated Endangered, three Threatened, and one Special Concern, while one was deemed Not at Risk. Three remote populations were determined to be Data Deficient, and will require additional research before being re-assessed.   Details here.

As giant ice shelves collapse amid global warming in the Arctic, experts call for more protection for the "Last Ice Area" (LIA). The vast communities of plants and animals living there could be lost, they warn, before we even get to understand them!

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     by Larry Powell                                   The vast Milne Ice Shelf broke up this summer. Animals found  living within its ice cavity (red box),  are shown on the right.  Photo credits: Left: Joseph Mascaro, Planet Labs Inc.  Right: Water and Ice Laboratory, Carleton University. Using tools which included video taken by a robot submarine, a Canadian research team recently discovered an amazing array of plants and animals, living in the hear t of Milne, the very ice shelf which broke apart just this summer north of Ellesmere Island (above), losing almost half of its mass. Dr. Derek Mueller, Professor of Geography and Environment Science at Ottawa's Carleton University, is a team member who's worked in the area for decades. In an email to PinP, he can barely disguise his excitement over what they found. "There are really neat microbial mats (communities of micro-organisms including cyanobacteria, green algae, diatoms, heterotrophic bacteria, and viruses) that li

Recent research shows: More rare, endangered sharks are dying in the worldwide trade in shark fins than earlier feared.

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by Larry Powell   The "Grey Nurse" or "Sand Tiger," shark (  Carcharias taurus ), a coastal species on the ICU's Red List as  critically endangered. A public domain photo by Richard Ling.  Here's how sharks are "finned." After hauling them aboard their vessels, the fishermen cut off their fins, then toss them back into the ocean. Still alive, they sink to the bottom where they're either eaten by other predators or die of suffocation.    About 100 million sharks are believed to be taken by fishers each year, most of them for their fins alone.  It's an industry estimated to be worth US$400 million a year.  The blue shark (Prionaceglauca). Photo by Mark Conlin/NMFS. If one were to believe official trade records over the past twenty years, most fins traded on world markets have come from more abundant "pelagic" species (ones which live in the open ocean) like the blue shark (above).  The leopard shark (Stegostoma fasciatum). An ADV

Arctic ocean moorings shed light on winter sea ice loss

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Science Daily A table iceberg in the Norwegian Arctic. Such icebergs are rare as they calve from shelf ice, which is also rare. They're normally a typical form of iceberg in the Antarctic. This one is about 12m high and about half the size of a soccer field. Photo by Andreas Weith. The eastern Arctic Ocean's winter ice grew less than half as much as normal during the past decade, due to the growing influence of heat from the ocean's interior, researchers have found. Story here.

There is at least 10 times more plastic in the Atlantic than previously thought

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Science News  "Seal trapped in plastic pollution"   by  tedxgp2   Scientists measured 12-21 million tons of three of the most common types of plastic in the top 200 meters of the Atlantic. By assuming the concentration of plastic in the whole Atlantic is the same as that measured at 200 meters deep, the scientists estimated there is around 200 million tons of three of the most common types of plastic alone. Compare this to the previously estimated figure of 17 million.  Details here.

Measuring ecosystem disruption caused by marine heatwaves

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 Nature Above, healthy bull kelp. Below, bull kelp degraded by a marine heatwave. DeWikiMan Marine heatwaves can displace thermal habitats by tens to thousands of kilometres, reports a study in Nature this week. This displacement represents the distance that an organism would have to travel to escape potentially stressful temperatures. The findings open new avenues of research to understand the potential impacts of anomalously warm ocean temperatures on marine species. Marine heatwaves are distinct periods of unusually warm ocean temperatures that can cause dramatic changes to ocean ecosystems, as inhabitants find themselves in waters that are warmer than they are accustomed to. Much of the research into these events focuses on the local impact to species such as corals, but does not take into account mobile organisms (fish, for example) that can travel to find their preferred conditions. To understand how species may have to redistribute under marine heatwave conditio

Rapidly warming oceans have left many northern marine mammals swimming in troubled waters. But perhaps none more so than that strange and mysterious "unicorn of the sea," the narwhal.

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by Larry Powell Narwhals are cetaceans, a family of marine mammals which includes whales and dolphins. Most are found in Canada's Baffin Bay and Davis Strait, in the high Arctic and Atlantic Arctic. Others live off Greenland, Norway and Russia. Many spend several months over winter, beneath the ice-pack, feeding on fish, squid and shrimp and their summers in more open water. It's believed they're capable of diving as deep as 15 hundred meters and holding their breath for an astonishing 25 minutes!  A pod "breaches" through an opening in the sea-ice.  A US Fish &  Wildlife Service photo.   They can weigh up to two thousand kilograms and reach a length of about five meters. They're much larger than some dolphin species, but tiny compared to the mighty blue whale. Many migrate along the ice's edge some 17 hundred kilometres from Canada to Russia. The males grow long, spiral tusks - actually overgrown teeth - that can protrude up t

Toxic Tides - The Tragedy of Fish Farming Everywhere

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One of the biggest challenges facing the aquaculture industry everywhere, is  Lepeophtheirus salmonis , the sea-louse (below). It's a parasite which attacks both farmed and wild salmon, causing lesions and infections which stunt their growth. But the costs of de-lousing are high. And so are the losses suffered by the industry in the marketplace. Many lice can actually kill many fish. Sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, New Brunswick, CA.  Photo by 7Barrym0re   To fight back, the fish-farmers dump pesticides into the waters (below). But, because they’re released directly into the environment, they not only kill the lice, but place beneficial, “non-target” organisms at risk, too. And several of these live in the open ocean, beyond the confines of the farms. This image shows how industry applies pesticides within their operations. The latest (but not the only) cautionary tale about the wisdom of this practise, has just emerged from Norway.  A te