In one-day, sea otters can eat 25%-30% of their body weight to support their high metabolism. What’s for Dinner – A sea otter’s favorite food is sea urchin, the horribly spiny little echinoderm (which ironically enough means “spiny skin”). For a time, otters were not around to eat urchins. An army of these urchins, when no starfish or sea otters are there to stop them, can easily turn a kelp forest into an urchin barren. They keep the population of certain benthic (sea floor) herbivores, particularly sea urchins, in check. Sea urchins eat kelp and when killed drop their shells (can be placed as an entity on the ground) and sea urchin meat. Fortunately, sea otters feed on sea urchins resulting in the preservation of the kelp forests. In fact, they are now recognised as being a … Sea urchins are one of the favourite foods of many lobsters, crabs, triggerfish, California sheephead, sea otter and wolf eels (which specialise in sea urchins). That’s a good thing for some kelp beds. When the sea otter population dwindled, sea urchin numbers grew. They are often seen above water chatting and playing, and sharing food. Sea otters eat sea urchins, helping to keep their numbers down so ocean plants can thrive. Sea otters were nearly hunted to extinction during the fur trade in the 18th and 19th centuries. Without the urchins’ natural predator to keep them in check, urchins have transformed the seascape – first by mowing down the dense kelp forests, and now by turning their attention to the coralline algae that form the reef. Sea Otters vs Climate Change provides a model for investigating the interdependence that characterizes ecosystems and the larger concept of system thinking. A keystone species dramatically affects the structure and complexity of their environment. The meat is used to breed the otters. Other urchins are more like farmers. Urchins use their long and sharp spines as a defense shield against their most common predators: lobsters, triggerfish, crabs, California sheep head, wolf eels, and sea otters. GASP!! Sea otters are voracious predators of large invertebrates such as urchins, crabs, and clams. Strengths. With few otters, the urchin population is out of control in the Aleutian Islands, starting west of Samalga Pass and the Islands of Four Mountains. More kelp forests result in fewer urchin barrens, as well as an increase in the absorption of carbon dioxide from the atmosphere through photosynthesis and release oxygen back into the air. But through conservation efforts, sea otters have been restored to much of their historic range in North America. Sea otters are a classic example of a keystone species; their presence affects the ecosystem more profoundly than their size and numbers would suggest. Without otters to control urchin numbers, the spiky shellfish can devour the beds, leaving barren seascapes behind. The otter, named Katmai, was filmed going to town on the urchin and stuffing her face at Vancouver Aquarium on Saturday, 26th September. She takes in a big gulp of fresh air – she’d been holding her breath underwater for four minutes!! As it grows thick, they eat it away. Unlike other marine mammals, sea otters lack an insulating layer of blubber and rely on their fur and high metabolism to keep warm instead. 1991) and shoreline ohg surveys (ADEC 1989, ADNR 1991). Sea otters have adapted to the coast of many colder regions. According to the Seattle Aquarium, sea otters … Sea otters are a keystone species in nearshore marine environments. Tomoleoni stresses that urchins have always been a major prey item for sea otters in California, and in fact, recent observations show more urchins … Sea otters eat sea urchins in abundance where they both occur but also prey on crabs and other crustaceans and mollusks. The trajectory of oil from the Exxon Valdez oil spill is given by the hatched area in (A). This, in turn, provides shelter for sea otter pups and a variety of other marine life, including fish. Fortunately, sea otters have an appetite for sea urchins and they help to keep sea urchins in check, allowing the kelp to flourish and capture CO 2. When otters are present, urchins hide in crevices and snack on kelp scraps. Without sea otters around, local sea urchin populations have exploded. When feeding on sea urchins, an otter balances a rock on his stomach as a “plate,” and use another rock to smash the urchin open and eat the meat inside. These favorites are in turn passed on to their young. Sea otters are such voracious eaters, West Coast crab and sea urchin fishermen have gone on record with concerns and cautions. Sea Otters vs. Urchins in Canada’s Kelp Forests “When you see a sea otter, they’re usually either eating or digesting,” often munching on urchins, says ecologist Anne Salomon, a Pew marine fellow. Sea otters use rocks to crack open the spiny shells of sea urchins. Sea otters are the only otters to give birth in the water. Recent Posts. All these animals carry particular adaptations (teeth, pincers, claws) and a strength that allow them to overcome the excellent protective features of sea urchins. Survey areas for sea otters are indicated by hatching in (B). They hunt another new mob: the sea urchin. They are not at the top of the food web, however, and are eaten by orcas, great white sharks and other large predators. Sea otters are known to eat 33 different types of prey – but each otter has its favorite 2 or 3, and usually sticks to these preferences its entire life. In this manner, sea otters are keystone predators in the kelp forests where they live. FOOD!! Sea otters are such voracious eaters, West Coast crab and sea urchin fishermen have gone on record with concerns and cautions. According to the Seattle Aquarium, sea otters consume around 25 percent of their body weight in food every day to stay warm and survive in the cold Pacific Ocean. Sea otters, sea urchins, and kelp are connected. They pick a rocky outcrop to stash away in. What do Sea Otters Eat? Lower urchin density reduces grazing pressure on kelps, resulting in a more diverse nearshore ecosystem. But if sea otters are abundant, they eat sea urchins and keep the urchin population in check, which allows kelp to flourish. They often occur between living things in an environment. Kelp is particularly efficient at sequestering CO2 from the atmosphere through photosynthesis. Credit Courtesy of J. Tomoleoni / U.S. Geological Survey. Sea otters such as this one are the primary natural predators of sea urchins. So when otters keep the population of urchins down, kelp forests expand. Sea otters were hunted to near-extinction for their fur in the 1700s and 1800s. California sheephead and spiny lobsters may be helping to control sea urchin populations in Southern California kelp forests, where sea otters — a top urchin predator — have long been missing, according to a new study published in the journal Ecology. Sea urchins graze on the lower stems of kelp, causing the kelp to drift away and die. These kinds of connections are called food chains. The urchins devoured entire kelp forests until they were essentially gone. Having thinned the region's once-dense kelp forests, these voracious herbivores have begun gnawing their way … At night they hold hands and sleep while floating on the ocean. Sea urchins exploded in number after their predator, the Aleutian sea otter, became functionally extinct in the 1990s. Eagles may also grab young otters if given the opportunity. This allows other marine, and even terrestrial animals, to have abundant amounts of prey. Sea otters eat things besides sea urchins. Sea otters aren’t just cute – these marine mammals play a vital role protecting the kelp forests which maintain our climate and prevent storm damage. Without otters to keep them in check, urchins and their compatriots grew in size and abundance. The research provides new insight into the complex predator-prey relationships in kelp forests that can be seen in the absence of sea otters. The connection is through food. 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