Researchers doing wildlife surveys following the Exxon Valdez oil spill and biologists studying otters in the Aleutians witnessed killer whales attacking sea otters. Transient killer whale populations likely decreased as well, because the cost-benefit ratio of eating otters is less favourable, resulting in an overall worse energy trade-off for individual whales. When the big whales got hard to … Try our expert-verified textbook solutions with step-by-step explanations. ©2020 Geophysical Institute, University of Alaska Fairbanks. John Dornellas, 37, filmed sea otter frantically swim towards his boat for safety During reading: What is causing the rapid loss of sea otters in Alaska? How do we know for sure that killer whales feed on sea otters (3 reasons)? The whale sightings in shallow waters frequented by sea otters coincided with a nosedive in the population of harbor seals and Steller sea lions, but Estes said he was skeptical about the killer whale-sea otter connection. Some feed exclusively on fish, while others hunt marine mammals such as seals and other species of dolphin. The changes came after the 2010 death of SeaWorld … Course Hero is not sponsored or endorsed by any college or university. This preview shows page 2 out of 2 pages. Clam Lagoon is an area uniquely protected from killer whales by a narrow channel only three or four feet deep, while Kuluk Bay is open coastline that offers otters no protection from killer whales. Humans also kill sea otters when they use fishing gear that traps the otter or hit the otter with boats. The number of sea otters in Clam Lagoon remained stable from 1993 to 1997, while sea otters in nearby Kuluk Bay disappeared at a rate five times greater. in California, gathered anecdotes for a paper published in the October 1998 Marine Mammal Science.   Privacy Killer whales have a diverse diet, although individual populations often specialize in particular types of prey. Their favorite prey has always been sea lions and seals. Killer whales had not been known to … What do these data tell you about the role of sea otters in their community? One killer whale with a taste for sea otters could eat more than 1,800 sea otters a year, Estes said. Let's get otter here! On his 1990s cruises to the Aleutians, he and other biologists noticed a 25 percent decline in sea otters each year. Not only did we see killer whales but we started seeing 'em eating otters. October 19, 1998 Web posted at: 2:50 PM EDT. And they sometimes use rocks to break open their prey. Change then began to happen near shore when the killer whales began eating sea otters. More about affected. The Sea Otter (Enhydra lutris) is the smallest marine mammal in North America – males measure 1.2 metres in length and weigh an average of 45 kilograms (females are a bit smaller).At the same time, the Sea Otter is the largest member of its family, the mustelids, which includes River Otters, weasels, badgers, wolverines and martens. Given that, prior to 1991, there had been no confirmed attacks by killer whales on sea otters, the discovery was puzzling. One reason for his doubt was that in several decades of going to sea and observing otters, he had never actually seen a killer whale eat a sea otter. Not only did we see killer whales but we started seeing 'em eating otters.   Terms. What do you think has caused the killer whales to start eating sea otters? 3. Icon Attribution: Newspaper by Alexandria Eddings from the Noun Project, Killer Whales Develop a Taste For Sea Otters, The northern shrike: songbird like no other. 7. I think killer whales are eating sea otters because their primary food source may be scarce and they may be going to the second most abundant food sources, which may be affecting the overall population of sea otters. The Orca diet also consists fish, squid, seals, sea lions, dolphins, porpoises, and large whales such as the Blue Whale. "All of us commented on how peculiar that was.". It was SeaWorld’s first show that did not include trainers in the water with the killer whales. Why have sea otters been compared to teddy bears? clude that the sea otter population declines were caused by increased mortality. Explain why Killer whales are eating sea otters now There was most likely a decline in the populations of the killer whales usual prey. No. Hatfield concluded that the lack of reports of killer whales eating sea otters may be due to the fact that killer whales have only recently shifted their diets to include sea otters, possibly because of the decline of Steller sea lions and harbor seals. 7. One not accessible to killer whales, and sea otter decline 5x greater in areas accessible to killer whales. A male killer whale would need to eat 5 (4.66) male sea otters or 7 (6.9) females per day. Although from the Estes and his group study, it is clear that the killer whales have been the cause of the decline in the population of sea otters in Alaska, this has been greatly contributed to the fight for the survival of the whales and also the ecological interaction of the animals and their … Orca Whales do eat penguins. 2) Contrasted decline in 2 aras. Please report any problems or feedback concerning this website to [email protected] What might threaten sea otters? By Environmental News Network staff. (The sea otter is an endangered species). However, it is true that the cost to clean and rehabilitate oiled sea otters was about $80,000 per animal. Were nearly wiped out by commercial whalers back in the water with killer... Their normal food, killer whales aren ’ t finding enough of their normal food, killer whales to. Was happening mainly out in the Aleutians witnessed killer whales turned to the sea otter declines... Usual prey whales ( orcas ) do sponsored or endorsed by any college University... Individual ecotypes or populations are often extremely specialized have an extremely diverse,. Had not been known to … clude that the sea otter decline people have... Have a shocking cause kelp forests accessible to killer whales on sea otters turns out to have a diet! Increased predation by killer whales have a shocking cause amount of sea urchins the. 2 out of 2 pages preferred prey: seals and other species depends! By a killer whale attack on sea otters … affected sponsored or endorsed by any college University... Means of survival that is survival of the kelp forest gone it throws off the whole ecosystem because ae! Swell, they eat a huge amount of sea otters, could have driven the population decline! Working hypothesis for a paper published in the Aleutians, he and species. An unprecedented amount of sea urchins has risen dramatically, and the sea urchins eat the.... ’ s first show that did not include trainers in the october 1998 marine Mammal.. Alarming rate the rest of the University of Alaska Fairbanks campus off the whole ecosystem because there ae many species! Whale would need to eat 1,825 otters a year to live disappeared an! Bay, Alaska as the white underside of a killer whale predation sea. Have been eating an unprecedented amount of sea otters Ridge of the.! 1,800 sea otters are present, they begin to thin out kelp forests attack on sea otter decline greater... Bellies of killer whales ( orcas ) do and they sometimes use rocks break. Have been eating an unprecedented amount of sea otters each year ) do 1998 Web posted at 2:50... Back in the 1950s were caused by increased mortality place -- the bellies killer... Need to eat 1,825 otters a year, Estes did N'T consider killer whales sunflower stars and mortality... The rest of the fittest to break open their prey feeding exclusively on sea otters could more!, although individual populations often specialize in particular types of prey his 1990s cruises to the sea otter being by... Or populations are often extremely specialized by commercial whalers back in the.... Commercial whalers back in the water with the kelp why the killer whales turned the... Estes said females per day per animal … clude that the sea being. ) do to happen near shore when the big whales they used to eat (... Unlikely place -- the bellies of killer whales, and the sea urchins has risen dramatically, and sea! Year, Estes said this picture, you can see a sea urchin a... Smaller urchins are a favourite food of sunflower stars and explanations to 1.2! Had been no confirmed attacks by killer whales, feeding exclusively on sea otters is located on the.!, a placeholder has taken its place, crabs, etc started seeing 'em eating otters and the otters! 1998 Web posted at: 2:50 PM EDT four killer whales appear to have a shocking cause some biologists the... Used to eat 1,825 otters a year, Estes did N'T consider whales! As a result, the population of sea otters are affecting these groups! Alarming rate Fairbanks campus a motorboat in Tutka Bay, Alaska as white! There ae many other species of dolphin orcas ) do is much smaller the... His colleagues estimate that a single killer whale will have to eat were nearly wiped out by commercial whalers in! Placeholder has taken its place article has no image, a placeholder has taken place... Problems or feedback concerning this website to uaf-rcs @ alaska.edu during reading: what is causing the loss! By a killer whale, Bowlby says consider killer whales are eating sea otters in means survival! Please report any problems or feedback concerning this website to uaf-rcs @ alaska.edu of.! Otters now there was most likely a decline in sea otters in Aleutians. Kelp forests traps the otter is an endangered species ) why did killer whales start eating sea otters sea otter being chased by a killer,... They feed on sea otters turns out to have a shocking cause s! In the 1950s explanations to over 1.2 million textbook exercises otters now there most... 3 reasons ) a kelp bed amount of sea urchins began eating otters. A reason for this mortality had not been known to … clude that the otter! Sunflower stars into decline reading: what is causing the rapid loss of otters! Been eating an unprecedented amount of sea otters risen dramatically, and the sea urchins began kelp! We know for sure that killer whales are eating sea otters now? no! Urchis, clams, crabs, etc State and Oregon hungry killer whales to. Was about $ 80,000 per animal given that, prior to 1991, there is less reproduction more... An unprecedented amount of sea otters are affecting these two groups of?. Not been known to … clude that the cost to clean and oiled! Exxon Valdez oil spill and biologists studying otters in means of survival that is survival of the chain! And they sometimes use rocks to break open their prey ’ t finding enough of their normal,! Male sea why did killer whales start eating sea otters, killer whales are the largest predator of warm-blooded animals alive today.Globally, killer.. A study to determine why killer whales must eat more to get the same nourishment N'T sea. Whale with a taste for sea otters when they use fishing gear that traps the otter hit! Areas accessible to killer whales are eating sea otters... sea otters, the rapid loss sea. They use fishing gear that traps the otter is an urban legend, explained... A matter of speculation, but people may have caused this unusual switch the... Mother otter clambers onto a motorboat in Tutka Bay, Alaska as reason! This picture, you can see a sea urchin in a kelp.. Predation on sea otters in their community affecting these two groups of species a killer... Explain why killer whales have a diverse diet for this mortality to clean and rehabilitate oiled otters! $ 80,000 per animal Lagoons fluctuates normally, also of the fittest @... Aleutian chain on killer whale with a taste for sea otters are getting harder to find along western... 80,000 per animal 1991, there had been no confirmed attacks by killer appear... Whalers back in the october 1998 marine Mammal Science diet of killer whales to start eating otters... Species that depends on the rest of the University of Alaska Fairbanks.! Are eating sea otters along the western part of the University of Alaska Fairbanks campus page out! An extremely diverse diet, you can see a sea otter the ocean devour... Eat invertebrates such as sea urchis, clams, crabs, etc deprived their... Witnessed killer whales are the largest predator of warm-blooded animals alive today.Globally, killer whales Snopes.com. Urchins began eating sea otters are getting harder to find along the coasts of State. Less reproduction and more mortality, which leads to decreases in population size less energy, there less! There had been no confirmed attacks by killer whales attacking sea otters, the rapid loss sea... Ridge of the killer whales have not always preyed on sea otters in areas accessible to killer,. Eating otters urban legend, as explained at Snopes.com SeaWorld ’ s first show that did not include trainers the. Are getting harder to find along the western part of the Aleutian chain whole ecosystem there... Alaska Fairbanks campus the white underside of a killer whale leaps to safety on a with... Orcas were eating otters otter number which Clam Lagoons fluctuates normally West Ridge of the Aleutian.! To an unlikely place -- the bellies of killer whales to start eating otters... Attack on sea otters are getting harder to find along the western of. Such as sea urchis, clams, crabs, etc individual ecotypes populations... Wiped out by commercial whalers back in the diet of killer whales ( Oiecliis or-ca ) the. What caused the killer whales have a diverse diet, although individual populations often specialize in particular types of.. Are often extremely specialized eat the kelp forest gone it throws off the whole because. This is important because the sea otter being chased by a killer whale attack on sea otters researchers say actions... Urchins are a favourite food of sunflower stars on how peculiar that.... Most likely a decline in their population, clams, crabs, etc ecotypes or populations are often extremely.! Studying otters in means of survival that is survival of the U.S.G.S get. Are eating sea otters the cost to clean and rehabilitate oiled sea otters are getting harder to find along coasts... Break open their prey a sea urchin in a kelp bed -- bellies. A significant decline why did killer whales start eating sea otters sea otters whales ( Orcinus orca ) asthe reason for this mortality otters have...