The theory is outlined in a paper released online today (September 7, 2012) in Frontiers in Ecology and the Environment by lead authors UC Santa Cruz professors Chris Wilmers and James Estes. They enter a dormant state, biding their time under new kelp sprouts, and then revving back into action to eat the young seaweed. 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. The large hind feet are broad and flipperlike. Researchers have also uncovered other surprising indirect effects, such as sea otters' beneficial effects on seagrass abundance and even its genetic diversity. We dont know if this is inherent, Wright says, or if this is something that quickly comes on after birth as a means of generating heat on demand.. But researchers didnt understand the cellular origins of that revved-up metabolism for heat generation, Wright says. . See how sea otters maintain the balance of kelp-forest ecosystems by consuming sea urchins, Wild Words from the Animal Kingdom Vocabulary Quiz, This article was most recently revised and updated by, Abundant Animals: The Most Numerous Organisms in the World, Falling Stars: 10 of the Most Famous Endangered Species, https://www.britannica.com/animal/sea-otter, International Union for Conservation of Nature and Natural Resources. Ecosystem Effects of Sea Otters . They will remain accessible to anyone who wants to watch them in the future. Effects of predator depletion or recovery are frequently accompanied by time lags, which are often context-dependent. 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Although the International Union for Conservation of Nature and Natural Resources listed the sea otter as a species of least concern in 1996, population declines since the 1980s due to the effects of pollution from oil spills, conflicts with fisheries, predation by sharks and killer whales, and disease prompted the organization to reclassify the sea otter as an endangered species in 2000. Please select the most appropriate category to facilitate processing of your request. Your feedback is important to us. The idea of restoring predators to blunt the impacts of warming has been simmering in ecology for decades. www.esajournals.org/doi/abs/10.1890/110176, Journal information: However, in the 1700s and 1800s, fur traders hunted their population down to about 2,000 animals. Disclaimer. The sea otters keystone role in nearshore marine ecosystems was first recognized in 1974, initiating an extensive body of work on sea otters indirect effects, including increases in the abundance of kelp-associated finfish. Please refer to the appropriate style manual or other sources if you have any questions. doi: 10.1126/sciadv.aav1139. Crabs eat animals that clean the estuary's sea grass of algae, which is caused by farm pollution. Reisewitz, J. MA-043219 to R. Davis). An official website of the United States government. amount of work on sea otter-sea urchin-macroalgal relationships, our study focuses on the indirect effects of this trophic cascade on kelp forest fishes. of carbon sequestration through their positive indirect effect on kelp ( Wilmers et al., 2012 ). The survey itself showed that people learned something new that they had not known before. Increases in kelp and seagrass due to sea otters can translate into increased carbon sequestration. Corrections? CO2 concentration in the atmosphere has increased 40 percent since the beginning of the industrial revolution, causing global temperatures to rise, the authors write. And in both these ecosystems, otters might have the added benefit of storing carbon. To fuel this metabolism, sea otters need to consume about a quarter of their body weight in prey each day. In 1911, most Californians werent thinking about sea otters. From the moment Berings men returned home to Russia with sea otter pelts, the species was in mortal danger. The final registration number was 1,005 people. That perspective is echoed in a soon to be published paper by University of Colorado Boulder ecologist Laura Dee, who points to the many indirect effects warmer temperatures can have on a species. I believe the speakers did an amazing job at articulating climate change through an animal lens, and they highlighted multiple ways that climate change will impact the marine environment and how sea otters can help mitigate those changes. Subscribers, enter your e-mail address for full access to the Science News archives and digital editions. The sea otter is the largest otter, reaching 100-160 cm (40 . The biologist collects the following data: Dive temp. Read the assessment here. Rising ocean temperatures and acidification are compounding the damage. eCollection 2018 Aug. 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. In fact, every species that feeds on these relatively chemically undefended macroalgae of the North Pacific may owe a debt to sea otters. To dwell in cold oceans, mammals must have developed ways to regulate their body temperature amid the chill. Sea otters were transferred from state management to federal management, and in 1977 the U.S. Quantifying the effect of otters might help ease some of the impacts to fisheries. To me, this is probably one of the clearest pieces of evidence saying, Heres how they did it, Williams says. Sea otters can greatly affect the environment they live in. Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. 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. During the event, we received 395 chat messages in the YouTube live chat and had 364 concurrent viewers at the peak. Fish and Wildlife Service. But these perpetually hungry mammals don't only protect kelp ecosystems. But a few biologists working for the California Department of Fish and Game had a secret: There was a tiny, precarious population that had survived near Bixby Cove, off Californias central coast. The actions of the wind, differences in temperature within the ocean and differences in density and salt concentration all act together to produce the great ocean currents that flow around the world. After wolves were reintroduced in 1995, though, they became the main cause of elk mortality and created a steadier carrion supply that helped sustain other animals throughout the cold months. Every print subscription comes with full digital access. Predatory fish invasion induces within and across ecosystem effects in Yellowstone National Park. The voracious echinoderms not only mowed down the kelp but are also tearing apart and devouring the massive, slow-forming limestone reefs on which this seaweed grows, Rasher and his colleagues recently reported in Science. 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. Simenstad. Explore our digital archive back to 1845, including articles by more than 150 Nobel Prize winners. Over an ecosystem area of approximately 5.1 10 10 m 2, the effect of sea otter predation on living kelp biomass alone represents a 4.4-to 8.7-teragram increase in C storage. The Service aims to be inclusive, thoughtful, and scientifically rigorous as we consider actions to support sea otter recovery and ecosystem restoration now and in the future. During the event, we received 395 chat messages in the YouTube live chat and had 364 concurrent viewers at the peak. "Just in my own soul, it was an important thing," he says of his early observations of that stark difference. On June 20, 1938, Life magazine published a photo of what it called one of the rarest sights on eartha large raft of sea otters near Bixby Bridge, south of Monterey. Sea otters are lean and compact, the smallest mammals in the ocean, bobbing like furry barrels on waves. The herbivorous urchins then basically clear cut the kelp, chewing through the holdfasts at their base and sending the rest of the giant algae to wash away. Before Fish and Wildlife Service listed the southern sea otter as threatened. Apart from any fair dealing for the purpose of private study or research, no PMC However, copper rockfish fishable biomass was negatively correlated with canopy kelp stipe density, likely due to the successional transition as sea otters return to an area from the disturbance-tolerant annual kelp Nereocystis to the perennial kelp Macrocystis. Our study highlights the power of trophic cascades in nature and the potential for large predators to ameliorate some of the effects of climate change in the near term, Rasher and his co-authors wrote. They will remain accessible to anyone who wants to watch them in the future. sea otter, (Enhydra lutris), also called great sea otter, completely marine otter species of the northern Pacific, usually found in kelp beds. Epub 2019 Dec 19. 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. Large areas that had been alive for centuries or millennia were crumbling and bleached, indicating urchins had recently killed them. Aboard the ship Svyatoy Petr (Saint Peter), Vitus Berings second Kamchatka expedition foundered in storms and wrecked near an uninhabited island, later named after Bering himself, who was buried there. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form. Conrad PA, Miller MA, Kreuder C, James ER, Mazet J, Dabritz H, Jessup DA, Gulland F, Grigg ME. If you liked this story,sign up for the weeklybbc.comfeatures newsletter, called "The Essential List". Scientists dont yet know how otters cells turn this process on and off. This can be done in a creative and captivating way, leaving audiences with one or two main take away points. The thick lustrous coat is reddish to dark brown. Sea otters are also the smallest marine mammal in the northern hemisphere. If sea otters return, however, their feasting can put the herbivores in check and allow the kelp to flourish once again. The Lightning Talks: Sea Otters event occurred on Earth Day, 4/22/2021 from 6-7pm PT on YouTube Live. This could be a game changer in terms of how we think about the evolution of all marine mammals, not just sea otters, says Terrie Williams, an ecophysiologist at the University of California, Santa Cruz, who was not involved in the study. The key to that difference has to do with sea otters' voracious appetites. It could be that warmer conditions slow the larvaes metabolism, prompting the predators to eat less, Rudolf says. T. Wright et al. For general feedback, use the public comments section below (please adhere to guidelines). In the absence of sea otters, these areas would have an NPP of 25-70 g C m 2 yr 1 and biomass density of 8-14 g C m 2. At the beginning and end of the event, I conducted a survey using PollEverywhere to learn more about the audience and to gauge the effectiveness of our climate communication. The Seattle Aquarium lightning talks are recorded and available to watch for free on YouTube. This document is subject to copyright. Continue reading with a Scientific American subscription. I believe my capstone project was successful in accomplishing all of the learning objectives. I think were all coming to realize that theres going to be a lot of synergies between species loss and climate change, says Hillary Young, an ecologist at the University of California, Santa Barbara, who was not involved in the new study. Get weekly and/or daily updates delivered to your inbox. Randall Davis (Image obtained under USFWS Marine MammalPermitNo. Int J Parasitol. sharing sensitive information, make sure youre on a federal And a 2020 study found that the monetary benefit of sea otters due their restoration of kelp habitat and associated increase in fish stocks, carbon sequestration, and ecotourism value outweighs the losses to shellfish fisheries. . They are primarily found in kelp forests, which are underwater forest-like systems, home to many species. Click here to sign in with That's more carbon than that emitted from a million passenger cars for a year. 2018 Jun 27;8(15):7346-7354. doi: 10.1002/ece3.4259. At locations where sea otters were present and sea urchins rare, the lower limits of giant kelp forests extended 3.7 times deeper than they did at locations without sea otters. Sea otters began slowly and methodically to expand their range to the north and south of Bixby Cove. The main objectives of this project were to: In 2020, the Seattle Aquarium transitioned its Lightning Talk event to a virtual format. While some Native peoples within the sea otters range had traditionally conducted local hunting of sea otters, the scale of slaughter in the maritime fur trade was unprecedented, nearly eliminating sea otters from their global range. Indirect food web interactions: sea otters and kelp forest fishes in the Aleutian archipelago. To communicate the science behind these concepts to a wide and diverse audience, I hosted a virtual Lightning Talk event with my employer, the Seattle Aquarium. devouring the massive, slow-forming limestone reefs, warmer winters in Yellowstone National Park, Social Capital in Black Communities Is Often Overlooked, How Starting Brush Fires Could Save Africa's Disappearing Lions, Do Animals Really Anticipate Earthquakes? Tour routes of great scenic drives on National Wildlife Refuges. Because of the high rate of uptake of atmospheric CO2, it has been hypothesized that sea otters might increase the rate Sea otters help ecosystems capture carbon from the atmosphere and store it as biomass and deep-sea detritus, preventing it from being converted back to carbon dioxide and contributing to climate change. Like kelp, seagrass absorbs carbon as it grows, and stores much of that carbon in its roots. In 2012, a team of ecologists including Estes published a study on the potential for sea otter carbon sequestration in the North Pacific between the Aleutian archipelago and Vancouver Island. If urchin populations grow unchecked, they can graze down a kelp forest very quickly, called a trophic cascade. 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 those kelps get dislodged they can travel and circulate on the surface for a 1,000km [620 miles]," says Hughes. Springer-Verlag 2005. But if those protons leak back over the membrane before being used for work, that energy is lost as heat. Restoring otter populations could rein in the urchins and help protect the larger ecosystem, and ecologists are increasingly interested in applying this idea more broadly. The video link was shared 53 times. 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. Indirect food web interactions: sea otters and kelp forest fishes in the Aleutian archipelago. This site uses cookies to assist with navigation, analyse your use of our services, collect data for ads personalisation and provide content from third parties. What participants took away was the deep connection between kelp forest ecosystems, urchins and sea otters as a keystone species. Sea otters (Enhydra lutris) are a small mammal in the weasel family. In 2020, the Seattle Aquarium transitioned its Lightning Talk event to a virtual format. The final registration number was 1,005 people. Their dense coat is one of two primary adaptations to maintain internal body temperature. Floating on its back, it opens mollusks by smashing them on a stone balanced on its chest. However, sea otters could still be indirectly affected via impacts to their prey. Because sea otters (Enhydra lutris) exert a wide array of direct and indirect effects on coastal marine ecosystems throughout their geographic range, we investigated the potential influence of sea otters on the ecology of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Islands, Alaska, USA. It inhabits coastal waters from the Kuril Islands to the Aleutian Islands southward to the coast of California. Although the indirect effects of sea otters are widely known, this example is unique because the food-web pathway transcended five species and several trophic levels in linking one apex predator to another. 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. and transmitted securely. Today, there are about 3,000 southern sea otters, and although their condition has improved since the time of ESA listing, they remain far from the MMPA goal of restored ecological relevance. Wolf C, Betts MG, Levi T, Newsome TM, Ripple WJ. 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 . part may be reproduced without the written permission. The appetite of the sea otter is a threat to individual abalone who have not hidden themselves in deep rocky crevices, but where sufficient crevice habitat is available, this same appetite brings benefits to abalone populations. All rights reserved. Not only can a wider audience be reached, but speakers from throughout the world can participate. These slugs and snails often don't eat the seagrass; instead they scrape away the algae that grows on the grass, which allows the seagrass to absorb more sunlight and grow more efficiently. Epub 2005 Sep 27. Thanks for reading Scientific American. Thanks for reading Scientific American. Because sea otters (Enhydra lutris) exert a wide array of direct and indirect effects on coastal marine ecosystems throughout their geographic range, we investigated the potential influence of sea otters on the ecology of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Islands, Alaska, USA. As sea otters declined (for reasons scientists are still trying to understand), their favorite preysea urchinsexploded in number. But owners were still stressed and lonely. Kelp forests have been found to sequester, or hold onto, carbon in the marine environment. And similar situations likely hold true for other ecosystems across the globe. that the number of potential indirect interactions is vastly greater than the number of potential direct interactions in all but the simplest interaction webs (Estes et al. Sea otters eat sea urchins (Strongylocentrotus spp), which are voracious invertebrate herbivores that graze on kelp. Rudolf created four habitats with pond water at present-day temperatures and four with heated pond water. Its headline proclaimed, The extinct sea otter swims back to life.. The spreading kelp can absorb as much as 12 times the amount of CO2 from the atmosphere than if it were subject to ravenous sea urchins, the study finds. The spreading kelp can. While diving in Alaska's Aleutian Islands in the 1970s, James Estes, a marine ecologist with the University of California, Santa Cruz, documented that kelp forests without sea otters essentially become underwater deserts. The talks are catered to a wide range of ages and no science background is required. Then, using a device called a respirometer, researchers measured otter muscle cells respiratory capacity in different states of oxygen flow compared with other animals including humans, Iditarod sled dogs and elephant seals. or, by Guy Lasnier, University of California - Santa Cruz. Find out more about how we calculated this figure here. 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. The top-down effects of sea otters on coastal ecosystems result mostly from the direct limiting influences of sea otters on their macroinvertebrate prey and through the indirect knock-on effects on other species and ecological processes. Contrary to our hypothesis, we found no appreciable enrichment of the 13C signature across the gradient of sea otter occupation time associated with an increase in the amount of kelp-derived carbon within fish. The loss or recovery of apex predators can have profound positive or negative ecological and socio-economic impacts. One of the easiest ways that anyone can support bird habitat conservation is by buying duck stamps. While much focus has been placed on the effects of heat stress on scleractinian corals-including bleaching, mortality, and loss of reef structural complexity-and many studies have documented changes to reef fish communities arising indirectly from shifts in benthic composition, the direct impacts . With more hairs per square inch than those of any other mammal, the thick, lush furs fetched enormous sums. Share sensitive information only on official, secure websites. Questions or comments on this article? Breeding success and productivity of Bald Eagles also increased during this time period, which may be due to the higher nutritional quality of avian prey consumed in later years. The emissions from travel it took to report this story were 0kg CO2. 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. Sea otters secret to staying warm isnt in thick stores of blubber. Heres how, A sapphire Schrdingers cat shows that quantum effects can scale up, how otters meet the challenge of staying warm at sea, Other marine mammals have high metabolisms to cope with cold water, eating 25 percent of their body mass in food every day. But when dead kelp sinks to the sea floor, it might not surface (and therefore decompose and produce carbon dioxide) for thousands of years. Sea otters high leak capacity is not necessarily what theyre running all the time, Wright says, but probably can be activated when otters need to generate more warmth. In the mid-1980s, the two islands with high-density otter populations supported dense kelp forests, relatively few urchins, and abundant rock greenling whereas the opposite pattern (abundant urchins, sparse kelp forests, and relatively few rock greenling) occurred at islands where otters were rare. In determining these effects, it's important to recognize that sea otters alter ecosystems via both direct and indirect pathways. Epub 2014 Nov 22. Scientists still need to understand the reasons behind the otters disappearances, but Rasher Is hopeful. The story was also updated July 23, 2021, to correct the description of otters' proton leaks. Join one million Future fans by liking us onFacebook, or follow us onTwitterorInstagram. Scientists already knew sea otters rely on an extreme metabolism to maintain, on average, a 37 Celsius body temperature, eating 25 percent of their body mass in food every day (SN: 6/13/14). Far below their vantage point at the edge of the rugged Big Sur cliffs, tossed on rough waters, was a cluster of buoyant, dark forms. MeSH The eeriness did not end there: during a boat ride, one of Rashers colleagues pointed to a cove where he had seen hundreds of sea otters splashing in the frigid water in the 1970s. Her thesis focused on the impacts of a marine heatwave on coral reef fish communities on the Big Island of Hawaii. Everything we know about ecology is that as things get more complex, they change, Rudolf says. The .gov means its official. eCollection 2018 Sep. Wilson TL, Schmidt JH, Mangipane BA, Kolstrom R, Bartz KK. Sea otters eat sea urchins, resulting in large healthy kelp forests and high pet primary productivity. This loss of otters demonstrated their indispensable role in kelp forests. 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. https://www.youtube.com/watch?v=gZmiqJ12Mms, Autumn 2021 Current Climate Change Research Seminar: IPCC AR6 WG1 Chapter Summaries, Winter 2021 Current Climate Change Research Seminar: A PCC/CHanGE Partnership, Spring 2022 Current Climate Change Research Seminar: IPCC AR6 WG2, Cooperative Institute for Climate, Ocean, & Ecosystem Studies.