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Categories: Biology: Marine, Engineering: Biometric
Published Climate change shrinking fish
(via sciencedaily.com) Original source Fish weight in the western North Pacific Ocean dipped in the 2010s due to warmer water limiting food supplies, according to a new study. Researchers analyzed the individual weight and overall biomass of 13 species of fish. In the 1980s and 2010s, the fish were lighter. They attributed the first period of weight loss to greater numbers of Japanese sardine, which increased competition with other species for food. During the 2010s, while the number of Japanese sardine and chub mackerel moderately increased, the effect of climate change warming the ocean appears to have resulted in more competition for food, as cooler, nutrient-dense water could not easily rise to the surface. These results have implications for fisheries and policymakers trying to manage ocean resources under future climate change scenarios.
Published Researchers are first to see at-risk bat flying over open ocean
(via sciencedaily.com) Original source On a research cruise focused on marine mammals and seabirds, scientists earned an unexpected bonus: The first-ever documented sighting of a hoary bat flying over the open ocean.
Published Walleye struggle with changes to timing of spring thaw
(via sciencedaily.com) Original source Walleye are one of the most sought-after species in freshwater sportfishing, a delicacy on Midwestern menus and a critically important part of the culture of many Indigenous communities. They are also struggling to survive in the warming waters of the Midwestern United States and Canada. According to a new study, part of the problem is that walleye are creatures of habit, and the seasons -- especially winter -- are changing so fast that this iconic species of freshwater fish can't keep up.
Published Extinctions could result as fish change foraging behavior in response to rising temperatures
(via sciencedaily.com) Original source Fish species respond to temperature increases by going after more readily available prey. Models suggest this behavior could lead to more extinctions.
Published 'Janitors' of the Sea: Overharvested sea cucumbers play crucial role in protecting coral
(via sciencedaily.com) Original source Researchers discovered that sea cucumbers -- sediment-eating organisms that function like autonomous vacuum cleaners of the ocean floor -- play an enormous role in protecting coral from disease.
Published Snakes do it faster, better: How a group of scaly, legless lizards hit the evolutionary jackpot
(via sciencedaily.com) Original source More than 100 million years ago, the ancestors of the first snakes were small lizards that lived alongside other small, nondescript lizards in the shadow of the dinosaurs.
Published Climate change could push bowhead whales to cross paths with shipping traffic
(via sciencedaily.com) Original source The population of bowhead whales that migrates between the Bering and Beaufort Seas each year is a conservation success story, with today's population nearing -- if not exceeding -- pre-commercial whaling numbers. But climate change is shifting the whales' feeding grounds and migration patterns, potentially pushing them to spend more time in the paths of oncoming ships, according to a new study.
Published Why are fish getting smaller as waters warm? It's not their gills
(via sciencedaily.com) Original source A collaborative team of scientists recently found that there is no physiological evidence supporting a leading theory -- which involves the surface area of fish gills -- as to why many fish species are 'shrinking' as waters grow warmer due to climate change. Known as the Gill Oxygen Limitation (GOL) theory, it has been proposed as the universal mechanism explaining fish size and has been used in some predictions of future global fisheries yields. However, the researchers conducted a series of long-term experiments on brook trout and found that, though increased temperatures do lead to significantly decreased body size, gill surface area did not explain the change.
Published Citizen science to mitigate the environmental crisis in the marine environment
(via sciencedaily.com) Original source Citizen science can help to improve conservation and management strategies for Mediterranean marine ecosystems, and to mitigate the impact of the environmental crisis.
Published An awkward family reunion: Sea monsters are our cousins
(via sciencedaily.com) Original source The sea lamprey, a 500-million-year-old animal with a sharp-toothed suction cup for a mouth, is the thing of nightmares. A new study discovered that the hindbrain -- the part of the brain controlling vital functions like blood pressure and heart rate -- of both sea lampreys and humans is built using an extraordinarily similar molecular and genetic toolkit.
Published Mercury levels in tuna remain nearly unchanged since 1971
(via sciencedaily.com) Original source Tuna is one of the most popular seafoods worldwide. But this protein-rich fish can build up high levels of methylmercury from feeding on contaminated prey, like smaller fish or crustaceans. Despite efforts to reduce mercury emissions into the environment, researchers report that levels in tuna appear to be unchanged since 1971. They warn that more aggressive emission reduction targets are needed to start nudging down tuna mercury levels.
Published Toxic elements found in stranded whales, dolphins over 15 years
(via sciencedaily.com) Original source Researchers evaluated the prevalence, concentration and tissue distribution of essential and non-essential trace elements, including heavy metal toxicants in tissue (blubber, kidney, liver, skeletal muscle, skin) and fecal samples collected from 90 whales and dolphins stranded in Georgia and Florida from 2007 to 2021.
Published Baleen whales evolved a unique larynx to communicate but cannot escape human noise
(via sciencedaily.com) Original source The iconic baleen whales, such as the blue, gray and humpback whale, depend on sound for communication in the vast marine environment where they live. Now researchers have for the first time found that baleen whales evolved novel structures in their larynx to make their vast array of underwater songs.
Published Gulf corals still suffering more than a decade after Deepwater Horizon oil spill, scientists report
(via sciencedaily.com) Original source Deep-water corals in the Gulf of Mexico are still struggling to recover from the devastating Deepwater Horizon oil spill in 2010, scientists report at the Ocean Science Meeting in New Orleans. Comparing images of more than 300 corals over 13 years -- the longest time series of deep-sea corals to date -- reveals that in some areas, coral health continues to decline to this day.
Published Unlocking the energetic secrets of collective animal movement: How group behavior reduces energy costs in fish
(via sciencedaily.com) Original source Researchers questioned if coordinated group movements by animals moving through a fluid could reduce the energy cost of locomotion. By combining biomechanics and bioenergetics the researchers found not only a significant amount of energy conservation, but also identified the reduced energy use per tail beat.
Published Even very low levels of pesticide exposure can affect fish for generations
(via sciencedaily.com) Original source Fish exposed to some pesticides at extremely low concentrations for a brief period of time can demonstrate lasting behavioral changes, with the impact extending to offspring that were never exposed firsthand, a recent study found.
Published Artificial reefs help preserve coral reefs by shifting divers away from the natural ones, according to new long-term study of one in Eilat
(via sciencedaily.com) Original source Divers are essentially tourists who love coral reefs and invest a lot of time and effort to watch them. Unfortunately, divers also cause damage to corals, often unintentionally, through disturbing and resuspending sand, touching them, hitting them with their equipment, and scaring fish away. Artificial reefs have been proposed as a means of diverting diving pressure from the natural reef to alternative sites, thus preserving both dive tourism and the coral reef.
Published Nature's checkup: Surveying biodiversity with environmental DNA sequencing
(via sciencedaily.com) Original source A thousand kilometers south of Tokyo, far into the largest ocean on Earth, lies a chain of small, volcanic islands -- the Ogasawara Islands. Nature has been able to develop on its own terms here, far from both humans and the warm Kuroshio current, which acts like a shuttle, moving marine species from Taiwan, over the Ryukyu Islands, and up the Pacific coast of mainland Japan. With upwards of 70 % of trees and many animal species being endemic to the archipelago, the islands have been dubbed 'the Galapagos of the East', as they are valuable as both a biodiversity hotspot and a cradle of scientific discovery.
Published Decline in microbial genetic richness in the western Arctic Ocean
(via sciencedaily.com) Original source Researchers analyzed archival samples of bacteria and archaea populations taken from the Beaufort Sea, bordering northwest Canada and Alaska. The samples were collected between 2004 and 2012, a period that included two years -- 2007 and 2012 -- in which the sea ice coverage was historically low. The researchers looked at samples taken from three levels of water: the summer mixed layer, the upper Arctic water below it and the Pacific-origin water at the deepest level. The study examined the microbes' genetic composition using bioinformatics and statistical analysis across the nine-year time span. Using this data, the researchers were able to see how changing environmental conditions were influencing the organisms' structure and function.
Published Viruses that can help 'dial up' carbon capture in the sea
(via sciencedaily.com) Original source Armed with a catalog of hundreds of thousands of DNA and RNA virus species in the world's oceans, scientists are now zeroing in on the viruses most likely to combat climate change by helping trap carbon dioxide in seawater or, using similar techniques, different viruses that may prevent methane's escape from thawing Arctic soil.