"It is significant because it shows that animals can have a big influence on the carbon cycle," said Wilmers, assistant professor of environmental studies. They found that otters 'undoubtedly' have a strong influence on the cycle of CO2 storage." "Comparing kelp density with otters and kelp density without otters, they found that 'sea otters have a positive indirect effect on kelp biomass by preying on sea urchins, a kelp grazer.' But because the researchers also included sea urchins in their tanks, they realized how the two forces interacted: sea urchin grazing increased significantly as warming and acidity increased, pushing the system beyond a critical tipping point, Rasher says. Using data on the rate of kelp growth and its density at sites with and without otters, they found that the presence of sea otters across rocky reef habitat in the study area, covering 51,551 square kilometers (19,900 square miles an area about the same size as Costa Rica), is capable of storing 4.4 to 8.7 million tonnes of carbon compared to if an otter-free condition. The result was less early-winter carrion for the parks many scavengers, such as grizzly bears and ravens, with dead elk bunching up at the end of relatively severe winters. And when older roots die, the carbon becomes locked in the sediments, where it can take hundreds of years or more to convert back to its gaseous form. Wilmers et al., 2012 Sea otters, the "keystone predator" of Aleutian Islands' kelp forests, experienced dramatic population declines in the 1990s. Epub 2014 Nov 22. These include increasing or decreasing prey, changing competitive abilities, shifting feeding rates and altering trophic cascades. Such work is valuable but can miss the big picture if it ignores the community in which a species exists. Accessibility In the case of the Aleutian Islands reefs, for example, if the scientists had simply exposed living reef samples to warmer and more acidic water in the lab, they might have incorrectly concluded the reefs were in no great danger because those impacts alone only slightly softened their skeleton. As a nonprofit news organization, we cannot do it without you. As sea otters have been reintroduced or naturally recovered in other coastal areas of North America, they have substantially disturbed the structure and dynamics of nearshore foodwebs. These leaks account for a higher percentage of muscle cells total respiratory capacity in extremely small mice compared with otters. Science. Now, scientists are studying how these marine mustelids may also be climate superheroes. The events are designed to directly align with the Aquariums mission, to inspire conservation of the marine environment. Similarly, Pace (1981) experimentally removed sea urchins in Barkley Sound (otter-absent region, this study) and found higher kelp population densities and lower depth . Sea otters lack the blubber and large body size that help other marine mammals survive frigid ocean temperatures. The .gov means its official. Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. Invest in quality science journalism by donating today. doi: 10.1126/sciadv.aav1139. MA-043219 to R. 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While the ESA focuses on preventing extinction and promoting species recovery, the MMPA has a more explicitly ecological aim: to maintain marine mammal stocks at levels where they are significant functioning elements of the ecosystems of which they are a part. In other words, marine mammal stocks must be restored to ecological relevance. CO2 concentration in the atmosphere has increased 40 percent since the beginning of the industrial revolution, causing global temperatures to rise, the authors write. Our results provide further evidence of the wide-ranging indirect effects of sea otter predation on nearshore marine communities and another apex predator, the Bald Eagle. are a small mammal in the weasel family. From the moment Berings men returned home to Russia with sea otter pelts, the species was in mortal danger. Fish and Wildlife Service. Epub 2008 Jun 3. R Soc Open Sci. Skeletal muscle thermogenesis enables aquatic life in the smallest marine mammal. They found that otters "undoubtedly have a strong influence" on the cycle of CO2 storage. Our results provide further evidence of the wide-ranging indirect effects of sea otter predation on nearshore marine communities and another apex predator, the Bald Eagle. You will be directed to the following website in 5 seconds: We hope your visit was informative and enjoyable. 2023 Scientific American, a Division of Springer Nature America, Inc. Join one million Future fans by liking us onFacebook, or follow us onTwitterorInstagram. In determining these effects, it's important to recognize that sea otters alter ecosystems via both direct and indirect pathways. Read about our approach to external linking. Sea otters have voracious appetites, eating about a quarter of their body weight every day (Credit: Getty Images). Sea otters recovered modestly during the 20th century; however, their populations remain widely separated. Koel TM, Tronstad LM, Arnold JL, Gunther KA, Smith DW, Syslo JM, White PJ. Sea otters can greatly affect the environment they live in. Medical research advances and health news, The latest engineering, electronics and technology advances, The most comprehensive sci-tech news coverage on the web. Often resting near beds of kelp, where they rely on their buoyant bodies to float on their backs, sea otters can gather in groups of up to 1,000 individuals, grasping one anothers forefeet to create large rafts or pods. Environ Monit Assess. But otters extreme metabolism helps them stay cozy in the waves. The frequency of sea otter pups, rock greenling (Hexagammus lagocephalus), and smooth lumpsuckers (Aptocyclus ventricosus) in the eagle's diet declined with corresponding increases in Rock Ptarmigan (Lagopus mutus), Glaucous-winged Gulls (Larus glaucescens), Atka mackerel (Pleurogrammus monopterygius), and various species of seabirds during the period of the recent otter population decline. A new study shows how the high metabolism of adult and baby sea otters begins at the cellular level. These lightning talk events are widely accessible to all with an internet connection. For example, Vicknair and Estes (2012) found that sea otters . Scientists still need to understand the reasons behind the otters disappearances, but Rasher Is hopeful. Rudolf created four habitats with pond water at present-day temperatures and four with heated pond water. Being a small-bodied marine mammal in cold waters presents a real thermal challenge, says Traver Wright, a comparative physiologist at Texas A&M University in College Station. Significant changes in greenling diet occurred between the mid-1980s and the 2000 although the reasons for these changes were difficult to assess because of strong island-specific effects. The captured prey is eaten at sea while the otter swims on its back. With one of their main natural predators absent for so long, abalone could be found exposed on rocks instead of hidden in crevices, sometimes piled several animals deep. Apart from any fair dealing for the purpose of private study or research, no During the event, we received 395 chat messages in the YouTube live chat and had 364 concurrent viewers at the peak. Many of the participants equated the term climate change negatively (i.e. Discover world-changing science. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483). eCollection 2019 Mar. The final registration number was 1,005 people. eCollection 2018 Sep. Wilson TL, Schmidt JH, Mangipane BA, Kolstrom R, Bartz KK. In 2020, the Seattle Aquarium transitioned its Lightning Talk event to a virtual format. Bald Eagles depend on nearshore marine communities for most of their prey in this ecosystem, so we predicted that the recent decline in otter populations would have an indirect negative effect on diets and demography of Bald Eagles. The Lightning Talks: Sea Otters event occurred on Earth Day, 4/22/2021 from 6-7pm PT on YouTube Live. During the event, we received 395 chat messages in the YouTube live chat and had 364 concurrent viewers at the peak. Conrad PA, Miller MA, Kreuder C, James ER, Mazet J, Dabritz H, Jessup DA, Gulland F, Grigg ME. With more hairs per square inch than those of any other mammal, the thick, lush furs fetched enormous sums. Large species within carnivora are large carnivores. After the event, there were >1,000 views of the YouTube video within 12 hours. Get weekly and/or daily updates delivered to your inbox. Credit: Nick Higgins. This same drift kelp feeds the abalone. The main objectives of this project were to: In 2020, the Seattle Aquarium transitioned its Lightning Talk event to a virtual format. Ecol Evol. 2018). Would you like email updates of new search results? But owners were still stressed and lonely. The caloric value of sea otters compares with a range of 0.78 to 3.55 kcal gm -1 of wet weight for fish and other marine mammals that make up the killer whale diet. In a 2018 study he considered how interactions among pond predators (dragonfly larvae) and their herbivorous prey (the tadpoles of gray tree frogs and green frogs) changed amid rising temperatures. These lightning talk events are widely accessible to all with an internet connection. Although abalone are a favorite prey item, they make up only a small proportion of the diet of the sea otter population overall, the remainder consisting of several dozen species of marine invertebrates, including many kinds of crabs, clams, sea urchins, mussels, chitons, octopuses, sea stars, and marine worms. Evidence of this coevolution may be seen in the bodies of animals, like abalone, today. Other mammals including extremely small mice with high metabolisms can also generate heat this way. He raised some tadpoles separated by species, some with mixed species, and others with mixed species and the dragonfly larvae. That means it's pulling carbon from the atmosphere faster than a slower growing plant (though kelp is technically an alga). In temperate rocky reef ecosystems, sea otters (Enhydra lutris) trigger a cascade of direct and indirect effects driving transitions between kelp-depleted and kelp-dominated states. A lock () or https:// means youve safely connected to the .gov website. The 1969 blowout of Union Oil's Platform A off the coast of Santa Barbara sparked the modern environmental movement, leading to the passage of several crucial pieces of federal legislation, including the Marine Mammal Protection Act of 1972 (MMPA) and the Endangered Species Act of 1973 (ESA). Knowledge awaits. Disclaimer. PMC These data allow us to evaluate trade-offs elicited by sea otter recovery and devise management plans for temperate reef systems that incorporate realistic timelines for changes to kelp forest communities. 4. This story was produced with additional reporting by Katarina Zimmer. New methods of reintroduction using juvenile sea otters who stranded as pups and were raised by surrogate sea otter mothers also show great promise. We quantified the indirect effects of sea otter recovery on copper rockfish (Sebastes caurinus) and kelp greenling (Hexagrammos decagrammos) along a gradient in sea otter occupation time on the central coast of British Columbia. googletag.cmd.push(function() { googletag.display('div-gpt-ad-1449240174198-2'); }); A new study by two UC Santa Cruz researchers suggest that a thriving sea otter population that keeps sea urchins in check will in turn allow kelp forests to prosper. Their massive appetites can diminish fishing opportunities for commercial operations and subsistence-based Indigenous communities. Ecosystem Effects of Sea Otters . "A kelp frond that drifts to the seafloor and decomposes, that carbon might be trapped in the sediments for millennia, even millions of years," says Pearson. They note that markets have been established in Europe and the United States to trade carbon credits and thus inject an economic incentive into either reducing CO2 output or increasing CO2 sequestration. When kelp dies, it tends to stay buoyant until those little floats break down. The Seattle Aquarium lightning talks are recorded and available to watch for free on YouTube. When sea otters are absent, urchins decimate kelp, resulting in low net primary productivity. Its headline proclaimed, The extinct sea otter swims back to life.. Tour routes of great scenic drives on National Wildlife Refuges. They are a keystone species, which means they have a big impact on keeping their ecosystem balanced. Another challenge faced by sea otters is the need to obtain enough calories to fuel their extremely high metabolic rates, which requires that sea otters consume the equivalent of 20-25% of their . Several otters are available for an experiment. part may be reproduced without the written permission. But since the return of the otters, the eelgrass has expanded by more than sixfold. The far-sightedness of the MMPA is only beginning to be realized.