Dungeness Crabs’ Shells Are Dissolving From the Severity of Pacific Ocean Acidification
As the Pacific Ocean becomes more acidic, Dungeness crabs, which live in coastal areas, are seeing their shells eaten away, according to a new study commissioned by the National Oceanic and Atmospheric Administration (NOAA).
The study authors looked at ocean acidification levels from 2016. They found that the lowered pH is dissolving the shells of young Dungeness crabs in Oregon, Washington and British Columbia. Without strong shells, the young crabs suffer damage to their sensory organs, as CNN reported.
The findings contribute to growing concerns about the viability of the Dungeness crab as atmospheric carbon dioxide, which continues to rise, is absorbed by the Pacific Ocean and increases acidification, as The Seattle Times reported.
"If the crabs are affected already, we really need to make sure we pay much more attention to various components of the food chain before it is too late," said study lead author Nina Bednarsek, a senior scientist with the Southern California Coastal Water Research Project, as CNN reported.
The study was published last week in the journal Science of the Total Environment.
Dungeness crabs are vital to the West Coast fishing industry — netting around $200 million annually. They are also important to tribal and recreational crabbers. The crabs have thrived in coastal waters that have recently become hotspots for ocean acidification, according to The Seattle Times.
Ocean acidification happens when the pH of ocean water drops. The primary cause is an increase in absorption of atmospheric CO2 over a long period. When CO2 is absorbed by seawater, a chain of chemical reactions is set in motion. That causes the sea water to increase its acidity as an increase in hydrogen ions tamps down carbonate ions, which would balance out the water's pH level, as NOAA explained in a statement.
Crustaceans and corals need carbonate ions to help them build strong shells. In their absence, it becomes difficult for crabs, oysters and clams to build shells. It also stops corals from building strong skeletons and it weakens plankton, as CNN reported.
"Decreases in carbonate ions can make building and maintaining shells and other calcium carbonate structures difficult for calcifying organisms," explains NOAA.
Previous research had shown that ocean acidification was causing harm to West Coast pteropods, small free-swimming snails that are food for Dungeness crab, according to The Seattle Times. Direct damage to Dungeness crabs was not expected for many years to come, so the findings have alarmed NOAA scientists.
"We found dissolution impacts to the crab larvae that were not expected to occur until much later in this century," Richard Feely, study co-author and NOAA senior scientist, said as CNN reported.
The research boat that took samples in 2016 did not just find damage to the crab's shell, but also to tiny hair-like structures crabs use to navigate their environments, which is something scientists had never seen before. Crabs without these tiny mechanoreceptors could move slowly and have trouble swimming and finding food, according to CNN.
As for shell damage, the shells showed signs of scarring and abnormal ridging, which may impair a crab's ability to swim, stay buoyant and escape from predators. The damaged crabs were also smaller, which suggests developmental delays, as the Sustainability Times reported.
"We were really surprised to see this level of dissolution happening," Bednarsek said, as The Seattle Times reported.
The authors say their findings mean more research is needed to make new predictions about the future of the Dungeness crab as the Pacific coastal waters continue to absorb more carbon dioxide, according to The Seattle Times.
- Ocean Acidification Causing Coral Reefs to Be Less Resilient to ... ›
- Study: Plastic Pollution Increases Ocean Acidification - EcoWatch ›
At first glance, you wouldn't think avocados and almonds could harm bees; but a closer look at how these popular crops are produced reveals their potentially detrimental effect on pollinators.
Migratory beekeeping involves trucking millions of bees across the U.S. to pollinate different crops, including avocados and almonds. Timothy Paule II / Pexels / CC0<p>According to <a href="https://www.fromthegrapevine.com/israeli-kitchen/beekeeping-how-to-keep-bees" target="_blank">From the Grapevine</a>, American avocados also fully depend on bees' pollination to produce fruit, so farmers have turned to migratory beekeeping as well to fill the void left by wild populations.</p><p>U.S. farmers have become reliant upon the practice, but migratory beekeeping has been called exploitative and harmful to bees. <a href="https://www.cnn.com/2019/05/10/health/avocado-almond-vegan-partner/index.html" target="_blank">CNN</a> reported that commercial beekeeping may injure or kill bees and that transporting them to pollinate crops appears to negatively affect their health and lifespan. Because the honeybees are forced to gather pollen and nectar from a single, monoculture crop — the one they've been brought in to pollinate — they are deprived of their normal diet, which is more diverse and nourishing as it's comprised of a variety of pollens and nectars, Scientific American reported.</p><p>Scientific American added how getting shuttled from crop to crop and field to field across the country boomerangs the bees between feast and famine, especially once the blooms they were brought in to fertilize end.</p><p>Plus, the artificial mass influx of bees guarantees spreading viruses, mites and fungi between the insects as they collide in midair and crawl over each other in their hives, Scientific American reported. According to CNN, some researchers argue that this explains why so many bees die each winter, and even why entire hives suddenly die off in a phenomenon called colony collapse disorder.</p>
Avocado and almond crops depend on bees for proper pollination. FRANK MERIÑO / Pexels / CC0<p>Salazar and other Columbian beekeepers described "scooping up piles of dead bees" year after year since the avocado and citrus booms began, according to Phys.org. Many have opted to salvage what partial colonies survive and move away from agricultural areas.</p><p>The future of pollinators and the crops they help create is uncertain. According to the United Nations, nearly half of insect pollinators, particularly bees and butterflies, risk global extinction, Phys.org reported. Their decline already has cascading consequences for the economy and beyond. Roughly 1.4 billion jobs and three-quarters of all crops around the world depend on bees and other pollinators for free fertilization services worth billions of dollars, Phys.org noted. Losing wild and native bees could <a href="https://www.ecowatch.com/wild-bees-crop-shortage-2646849232.html" target="_self">trigger food security issues</a>.</p><p>Salazar, the beekeeper, warned Phys.org, "The bee is a bioindicator. If bees are dying, what other insects beneficial to the environment... are dying?"</p>
EcoWatch Daily Newsletter
Australia is one of the most biodiverse countries in the world. It is home to more than 7% of all the world's plant and animal species, many of which are endemic. One such species, the Pharohylaeus lactiferus bee, was recently rediscovered after spending nearly 100 years out of sight from humans.
Scientists have newly photographed three species of shark that can glow in the dark, according to a study published in Frontiers in Marine Science last month.
- 10 Little-Known Shark Facts - EcoWatch ›
- 4 New Walking Shark Species Discovered - EcoWatch ›
- 5 Incredible Species That Glow in the Dark - EcoWatch ›
FedEx's entire parcel pickup and delivery fleet will become 100 percent electric by 2040, according to a statement released Wednesday. The ambitious plan includes checkpoints, such as aiming for 50 percent electric vehicles by 2025.
- Which Is Worse for the Planet: Beef or Cars? - EcoWatch ›
- Greenhouse Gas Levels Hit Record High Despite Lockdowns, UN ... ›
- 1.8 Billion Tons More Greenhouse Gases Will Be Released, Thanks ... ›