“But when we have that opportunity to observe a sudden absence of a particular organism, and see what the impacts of that are, we have a lot more understanding. The following story is an excerpt from Heart of the Coast: Biodiversity and Resilience on the Pacific Edge by Tyee Bridge — a new, beautifully photographed introduction to B.C. Image courtesy Grant Callegari/Hakai Institute. Observing sea otters and kelp beds on Amchitka — both onshore and during scuba dives — led Estes to question the links between them. Perhaps the biggest challenge is that the waters of the Central Coast are rarely still. Killer whales have started eating them. But when there are not enough predators like sea otters to feed on sea urchins, the urchins graze over and effectively wipe out kelp forests. Estes had seen what is now known as an urchin barren, the result of a trophic cascade. “Planet Earth,” says marine ecologist Jenn Burt, “is actually Planet Ocean.”. Enter your e-mail address above. Teams of scuba divers go underwater to survey the plants and animals of the kelp forest. Flashcards. Fish thrive in kelp forests, as do mussel beds, for example. Sea otters have not always been a rare sight. Researchers have long known about the intricate relationship between sea otters, kelp forests and sea urchins. “Bob listened to my account of what I had seen while diving," Estes recalled in his 2016 memoir Serendipity, "and what I thought it might mean and then abruptly suggested a simple but radically different change in perspective. However, these smaller urchins are a favourite food of sunflower stars. Some of the abiotic â ¦ Sea urchins exploded in number after their predator, the Aleutian sea otter, became functionally extinct in the 1990's. But, according to ocean mammal researcher Ed Bowlby, Washington’s otters aren’t out of the woods yet. Salomon notes that although many ecologists had suspected that sunflower stars played a role in the resilience of kelp forests, that role had not yet been measured or acknowledged. He’s curator of mammals and birds at the Seattle Aquarium. “Sunflower stars mop up the little sea urchins,” says Anne Salomon. The publication, as well as. The Atomic Energy Commission had sponsored his research there ahead of a contentious nuclear test on the island. At 2012 prices (US$47 per ton of C), this stored C would be valued at US$205 million–$408 million on the European Carbon Exchange. The other possibility is that sloughed-off pieces of kelp may sink to the deep ocean where the trapped carbon can be stored for longer periods of time. Her mentors and colleagues include renowned coastal ecology experts Jane Watson and Anne Salomon. You feel like you’re on another planet, in a zero-gravity environment with all this life that you don’t normally get to see.”. This was my 'aha moment,' a profound realization that would set a path for the remainder of my life.". They live along 100 miles of the Washington coast. Weekly updates to help you use Science News for Students in the learning environment. One square inch of it contains 1 million hairs—10 times as many hairs as on your entire head. magazine, are published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education. The divers count every organism in an area or fly over the bottom on an underwater scooter, recording the plants and animals with a video camera. “Sea star wasting disease came and did the experiment for us, and research on the Central Coast with Jenn Burt provided evidence of the important role that sunflower stars have,” says Salomon. Also known as seaweed, there are red, green and brown varieties of marine algae, among others. Researchers found that when sea otters arrive in an area from which they have been absent, they begin snacking on urchins. They provide nourishment to the grazing herbivores that feed on them, such as sea urchins and abalone. The research will shape a new plan to help otter populations thrive. He found that about 350 kilometres to the west of Amchitka, off a remote island called Shemya. Beneath the kelp live algae, the shrubs of the underwater forest. An otter is “no more than a mouthful” for a killer whale, Bowlby says. Post was not sent - check your e-mail addresses! Unfortunately, their teddy-bear qualities were nearly their downfall. Kelp is a giant, yellow-brown, rubbery seaweed stretching from the sea floor to the surface. Just as terrestrial forests support a vast range of life, the stipes and fronds of a kelp forest benefit everything from sea anemones to rockfish to whales. To understand the relationship between the two, Estes needed to find an area that was devoid of otters and see what the kelp forests looked like. 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. He and other scientists are working to find out what new threats otters face and why Washington’s otters have done better than others. Using a dataset collected over four years, Burt and her colleagues learned that sea otters are not the only predators that have a significant effect on urchins, and thus not the only creature that can help ensure the health and abundance of kelp forests: the less cute but nonetheless impressive sunflower star also plays a major role. Fortunately, sea otters have an appetite for urchins. Many people are trying to figure out why. Are you ready? For 150 years, sea otters were hunted so heavily for their fur that, by 1910, they had disappeared from the waters off Washington and Oregon. The crucial connection, he discovered, was sea urchins. A lot of sea otter research focuses on kelp. But a new twist on this relationship, usually understood as a three-way interaction between urchins, kelp and sea otters, has recently come out of the work done on the Central Coast by Jenn Burt and her Hakai Institute colleagues. Because sea otters live very close to land, any pollution running off to the ocean will definitely affect them. The waters around the Hakai Institute on Calvert Island are at the leading edge of this expansion, and like the Aleutian Islands, are well suited to this sort of study. They can be as small as a human blood cell or reach lengths of over 45 metres. California otters seem to be getting sick more often than they used to. Otter researchers such as Casson know better. Beginning in 2013, Burt and her colleagues studied rocky reef areas around Calvert Island on the Central Coast of B.C., initially trying to better understand the effect that sea otters were having on undersea ecological communities. But hungry killer whales aren’t finding enough of their preferred prey: seals and sea lions. These pollutants … “They’re the teddy bears of the ocean,” says C.J. Kelp plants also shelter fish, sea urchins, and other creatures. Now, descendants of those otters number more than 600. The sea water used was kept at 21°C, 7.86 pH, and 33‰. The need to stick with your “dive buddy” and communicate with hand signals or by scrawling on a slate can slow things down, as can murky water. This sequesters carbon for a time, but as pieces of kelp wash ashore and decompose, the carbon is released back into the atmosphere. Consequently, the sea otters die from hypothermia. As keystone species, sea otters balance the ecosystems in which they live. That gave the team some hunches about what they wanted to look at more closely in the data. Algae species that had been missing make an appearance, along with fish that like to hide out in the canopy. Sea urchins are related to starfish and look like small, purple hedgehogs. He would go on to realize that sea otters are a keystone predator that increases the abundance of a diverse array of sea life. Rather than using roots — as seagrasses do, which unlike algae are true plants — they cling to the rocky seafloor using growths called holdfasts. It’s ironic that the undersea world is so alien to most of us, since it makes up over 70 per cent of the globe. Enduring the challenges of underwater experimentation and monitoring, however, can lead to groundbreaking insights. The researchers have to implant the devices under the otters’ skin because the clever animals always figure out how to remove radio collars and anklets. Walk along a wild, rocky stretch of the Washington State coast and you might catch a glimpse of a furry creature bobbing on its back in the waves. Founded in 2003, Science News for Students is a free, award-winning online publication dedicated to providing age-appropriate science news to learners, parents and educators. Sea otters are known as a keystone species, filling such an important niche in ocean communities that without them, entire ecosystems can collapse. Casson. In Alaska, the rapid loss of sea otters turns out to have a shocking cause. Crude oil normally penetrates the fur of the otter destroying the air layer that is trapped next to its skin. As he tells in Serendipity, what he saw when he put on his scuba gear and entered the waters off Shemya shocked him: "When I looked down at the seafloor, I was stunned by the vast numbers of urchins and the absence of kelp… Every place I looked was the same—large and abundant sea urchins over a seafloor of crustose coralline algae with little or no kelp… In the absence of sea otter predation, sea urchins had increased in size and number, and the larger and more abundant urchins had eaten the kelp. These small urchins also readily devour kelp, and if their numbers swell, they begin to thin out kelp forests. Gina_McCarthy1 TEACHER. The kelp ecosystem in these places is either nonexistent or weak. With no predators around, sea urchin populations can multiply, forming herds that sweep across the ocean floor devouring entire stands of kelp. The otter is much smaller than the sea lions and seals, so the killer whales must eat more to get the same nourishment. There’s still plenty of work to do if you’re interested in helping to save sea otters. Wherever sea otters have disappeared, kelp forests have suffered. Sea otters do an excellent job of eating large sea urchins over eight centimetres in diameter, but they tend to leave behind smaller urchins. Sea urchins are related to starfish and look like small, purple hedgehogs. Kelp plants act like the tall trees of a forest. Floating on a bed of seaweed or cracking a clam on its chest, a sea otter looks as if it doesn’t have a care in the world. Without its keystone species, an entire ecosystem can fall apart. Kelp plants also shelter fish, sea urchins, and other creatures. Sea otters are referred to as a keystone species, which means that sea otters are vital to the health of an ecosystem. Learn. A sea otter has thick fur to keep it warm in frigid waters. Their primary food sources include shellfish such as sea urchin (their favorite), sea … Deprived of their normal food, killer whales turned to the sea otter. All rights reserved. PLAY. But most of all, those rich kelp forests – enriched by sea otter activity – play a key role in maintaining global environmental health. Sea otters, in turn, are equally voracious predators of sea urchins. That’s the bigger narrative around this research that I think is really neat.”. All this eating helps make the sea otter what’s called a keystone predator. Confirming the previously uncertain role of sunflower stars in kelp-bed ecology will help researchers as they monitor the resilience of kelp beds across the North Pacific Rim and manage their recovery. Urchins eat kelp. Secondly, oil spills result in the death of sea otters. By creating nearshore habitats rich in fish and other sea life, kelp beds have been significant assets to human coastal communities for thousands of years. Sea otters are a keystone species, meaning their role in their environment has a greater effect than other species. But most of all, those rich kelp forests – enriched by sea otter activity – play a key role in maintaining global environmental health. Rough weather on the outer coast can keep research vessels tied up at the dock for days. When boats are able to go out to gather data — in Burt’s case, counting sunflower stars, or performing an undersea experiment to track urchin feeding rates — divers have only 45 to 60 minutes to complete their task before their oxygen runs out. Sorry, your blog cannot share posts by e-mail. Sea otters, the "keystone predator" of Aleutian kelp forests, experienced dramatic population declines in the 1990's. Conservationists in 1969 and 1970 brought 59 otters to Washington from Alaska. Rather than wondering how the kelp forests affected otters… why not explore how the otters affected the kelp forests?”. Burt’s graduate studies undertaken with the Hakai Institute in British Columbia were focused on the ecological and social impacts of sea otter recovery — including the effects that growing sea otter populations have on coastal Indigenous communities. Urchins eat kelp, and sea otters eat sea urchins. Southern sea otters live in giant kelp forests along the California coast. Juvenile salmon, herring and rockfish all use kelp beds for habitat, as do crabs, sea stars, abalone and other snails. When SSWD struck the region during the winter of 2015, it suddenly brought a new dimension to the research: a rare opportunity to also look at how predatory sea stars influence coastal rocky reef ecosystems. “It really is like that Joni Mitchell line, ‘You don’t know what you’ve got till it’s gone,’” says Burt. The basking animal is likely to be a sea otter. In places where sea otters have disappeared, sea urchins will eat the kelp forest until it’s gone. Burt’s original focus was to track ecological communities before, during and after the arrival of sea otters, which — because of their post-fur trade population recovery — are still recolonizing reef habitats across the North Pacific Rim. Unlike whales and sea lions, sea otters have no layer of blubber to keep themselves warm. Sea otters are a keystone species, meaning their role in their environment has a greater effect than other species. In general, there are two possibilities. And other groups of sea otters in California and Alaska have taken a turn for the worse. In the wake of a devastating disease outbreak that ravaged starfish populations from Alaska to Mexico, researchers like Jenn Burt are just starting to understand the role that sunflower stars play in helping kelp beds to thrive. Kelp plants also shelter fish, sea urchins, and other creatures. There are areas with and without sea otters where researchers can compare the differences in kelp abundance, urchin populations and other aspects of undersea habitat. Kelp forests are influenced by a huge range of physical and biological factors. Estes and his colleagues estimate that a single killer whale will have to eat 1,825 otters a year to get … In turn, these grazers provide food for predators, such as sea otters and certain species of sea stars like the sunflower star. The publication, as well as Science News magazine, are published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education. Burt and her colleagues also carry a panoply of marine science tools: a foldable, two-dimensional box for sampling called a quadrat; sealable bags for collecting everything from kelp to invertebrates; a writing slate with data sheets, pencil and built-in ruler; and meter tapes for measuring survey areas, known as transects. Despite the Cold War considerations that placed him there, his research ended up transforming our modern understanding of coastal ecology. the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water, and other necessities available in the environment. “This is the important element of surprise in science,” says Burt. Bowlby also tracks individual otters by following beeps sent out by radio transmitters. In the waters around Calvert Island, where surface temperatures dip as low as 8 C, subaquatic researchers need an airtight dry suit along with their usual scuba gear. In coastal areas where sea otters regularly consume sea urchins, kelp forests have a greater chance to take hold and endure, and act as an undersea forest habitat for other marine animals. Learn about the connections among sea otters, sea urchins, kelp forests, and climate change. “There are so many interactions in the ocean that we don’t totally understand and probably never will, because we can’t systematically remove and then replace all the animals in the ocean,” says Burt. Thanks to Estes, and the work of subsequent researchers like David Duggins and Jane Watson, the beneficial effects of sea otters in propagating kelp habitats have been well established among ecologists, and increasingly well known to the general public. Without the sea otters, in fact, the kelp ecosystem would struggle, probabaly even die. Sea urchins hide from otters in rock crevices. The sea otter (Enhydra lutris) is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean.Adult sea otters typically weigh between 14 and 45 kg (31 and 99 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals.Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in … Part of a recovering North Pacific population and expanding across the Central Coast over the past three decades, sea otters are a keystone species that indirectly influence the abundance of kelp forest habitat. Write. Bowlby works for the National Oceanic and Atmospheric Administration. Kelp forests in turn provide critical habitat and nutrients to a wide variety of creatures, from the very small to the very large. For Hakai Institute scientists, undersea surveys bring other challenges. On the Central Coast reefs she studied, Burt links the loss of sunflower stars to a startling 300 per cent spike in the population of small and medium-size urchins, and to a resulting 30 per cent decline in kelp density. How Does Climate Change Change Affect Sea Otters ... Sea otters have a noticeably solid influence on the wealth of kelp through the impact they have on sea urchins, said James A. Estes, a professor of ecology and evolutionary biology at the University of California, Santa Cruz who was a co-author on Schmitz 's 2014 review and on the original sea otter study. They’ve made a comeback in Washington with help from scientists and conservationists. Friendly sea otters were easy for fur traders to hunt. Pollution has also become a huge part of the reason sea otters are endangered. Test. 10. A sea otter eats 25 percent of its body weight every day. 1719 N Street, N.W., Washington, D.C. 20036, A new chameleon species may be the world’s tiniest reptile, Giant worms may have hidden beneath the ancient seafloor to ambush prey, A robot made with a Venus flytrap can grab fragile objects, Space travel may harm health by damaging cells’ powerhouses, Harsh Ice Age winters may have helped turn wolves into dogs, Exploding neutron star proves to be energy standout of the cosmos. “We just don’t always know what we’re going to find.”. The carbon is initially trapped in a one-off mechanism by the kelp in its tissues. By … Bowlby says, “They eat pretty much anything they can grab onto.”. Their timing was serendipitous. “When you descend below the surface, it’s like going into space. But Estes didn’t understand the real meaning of what he’d seen until a meeting with veteran ecologist Bob Paine. With no predators around, sea urchin populations can multiply, forming herds that sweep across the ocean floor devouring entire stands of kelp and leaving “urchin barrens” in their place. your subscription today. Without sea otters, sea urchins can overpopulate the sea floor and devour the kelp forests that provide cover and food for many other marine animals. This second prospec… Kelp produce their own food through photosynthesis, absorbing sunlight and organic carbon from the environment. Also, too much sediment or other particles floating in the water absorb heat from sunlight. Free educator resources are available for this article. Still others are investigating what to do about killer whales feeding on sea otters in Alaska. © Society for Science & the Public 2000–2021. From the shore, they can also record how many females have babies. After four years of research, Burt and her colleagues came to a groundbreaking new understanding of the relationships between kelp, urchins and sea otters — thanks to unexpected discoveries about a previously overlooked bottom-dwelling predator. What Burt noticed on underwater surveys after the disease event was that there were more small and medium-size urchins everywhere Burt and her colleagues looked. Fortunately, sea otters have an appetite for sea urchins and they help to keep sea urchins in check, allowing the kelp to … Seals are frequent visitors to kelp forests, and grey whales will feed on the crab larvae they find there — as well as use the kelp to hide their calves from killer whales. They are sensitive to temperature, ripped up by storms and affected by currents and waves. Urchin, and climate change brought 59 otters to Washington from Alaska updates to help otter thrive... The connections among sea otters are referred to as a keystone species, meaning their role their... 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