NIELSEN: DeMaster is director of the federal government's Alaska Fisheries Science Center. They are easy to identify because of their distinctive white and black colouring. Ms. TERRY WILLIAMS (University of California at Santa Cruz): It's a bizarre way of hunting, where these killer whales have learned to swim upside down, below a sea otter that's resting on the water's surface. They are found in all the world's oceans, from the cold of the Arctic to the tropical seas. Marine scientists suggest the Southern Resident orcas face problems centered on their diet. Copyright © 2005 NPR. For the moment this debate is largely academic; nobody is seriously talking about killing orcas to protect otters, seals and sea lions. Orcas were eating otters because the really big whales they used to eat were nearly wiped out by commercial whalers back in the 1950s. " he says. But not everyone is buying the theory. An analysis of the DNA will determine if this is actually a completely new species or just an unusual subtype. Killer whales, just like their dolphin cousins, communicate through underwater sounds with one another. NIELSEN: Environmental groups say the orca paper does a disservice to the cause of conservation by diverting attention from what they say is the real problem in the Bering Sea: overfishing. 1 Global PCB concentrations in killer whales. Last year, he assembled a team to go to Cape Horn, in Chile, to look for what's now technically called the "type D" killer whale. It lives in parts of the ocean near Antarctica — and it could be the largest animal to have remained unidentified by biologists. In recent decades, several populations of killer whales have declined and some have become endangered. "We left that night," Ballance recalls, and "pounded into the seas so that we could get to our spot at first light the next morning. If there were more fish, they say, marine mammals and orcas would have plenty to eat. Pitman says it must have looked like a fishing line with fish on it — it looked like breakfast. Ms. WILLIAMS: And you end up with a whopping 300,000 sea otters in a single year potentially eaten by these animals. The team had lowered an underwater microphone over the side on a long cable, with cameras attached. The killer whale, also known as an orca (Orcinus orca), is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. There are fewer fish available for them to eat, more noise in the water affecting their ability to find the fish, and more pollution in the water that impacts their health when they are not well fed. (A) Conceptual model of PCB bioaccumulation and magnification, leading to elevated PCB concentrations in killer whale populations. K Pod K pod is the smallest of the three pods in the Southern Resident killer whale community with only 17 members. Since 1990, otter populations off the Aleutian islands have plummeted by as much as 80 percent. 2). ", "There they were," Ballance recalls, for a moment at a loss for words. ", Pitman picks up the story: "The sun came up in the morning at 5:50. When the big whales got hard to find, Williams says, the orcas switched to big, stellar sea lions and then to medium-sized seals. And baby makes 75: newborn orca boosts endangered whale population. They are the largest dolphins. For Pitman, the hunt was on. Then she multiplies that number by 365 days. Accuracy and availability may vary. Mr. DeMASTER: The people who really know killer whales, who spend their lives following them around and studying them--they just don't find any evidence that large whales are an important part of their diet. NPR’s John Nielsen reported that this caused up to an 80% decline in the otter population. . Ms. WILLIAMS: Followed lastly by sea otters, which, you know, still give you calories, but it's going to take you a bit to fill up on them. "And you can imagine them thinking, 'Hey, where's our fish?' ", There was no mistaking its peculiar look, says Ballance. Second, we evaluated the impact of killer whales on sea otter populations at Adak Island by contrasting otter population trends and sur- vival rates between Clam Lagoon, an area uniquely inaccessible to killer whales, and ad- jacent Kuluk Bay, an open coastal environment (Fig. "And I looked down, and there they were, the New Zealand killer whales," he recalls. "Visibly," she says, "this form is the most unusual and distinct form of killer whale on the planet.". It's gone. Ecologists say killer whales are eating the otters. Although the population size and status of killer whales in the Aleutian Islands are unknown, these animals are commonly seen. ", It was a slow start. Lifestyle. Different populations of killer whales make different vocalizations, and different pods within these populations may even have their own dialect. They can tell, even in the darkest parts of the sea, where items are by how quickly their noises bounce back. Since 1990, otter populations off the Aleutian Islands have fallen by as much as 80 percent. Other researchers are studying why California’s sea otters seem to have become more vulnerable to disease and parasites. (B) Global overview of PCB concentrations in killer whale blubber (ppm, parts per million).Light and dark green circles represent males and females, respectively. I'm Michele Norris. This text may not be in its final form and may be updated or revised in the future. (The sea otter is an endangered species). "The idea is that, if we can figure that out, we might be able to find some ways that we can further help recover the endangered population, like Southern residents." Populations of otters along the Alaskan and Canadian coast, which had recovered to a few hundred thousand, were driven back down to just a few thousand. This is ALL THINGS CONSIDERED from NPR News. A new theory suggests a massive decline in seals, sea lions and sea otters in the North Pacific may have been triggered by over-fishing of great whales. It is estimated that there are around 50,000 killer whales globally. These patches were unusually small, in some cases almost nonexistent. Mr. DOUG DeMASTER (Director, Alaska Fisheries Science Center): This hypothesis is too simplistic, and it's not ready for the textbooks yet. Some feed exclusively on fish, while others hunt marine mammals such as seals and other species of dolphin. Second, we evaluated the impact of killer whales on sea otter populations at Adak Island by contrasting otter population trends and sur-vival rates between Clam Lagoon, an area uniquely inaccessible to killer whales, and ad-jacent Kuluk Bay, an open coastal environment (Fig. People raised on movies like "Free Willy" tend to think of killer whales as well-meaning, fence-jumping giants who want nothing more than to live in perfect harmony with all the other creatures in the ocean. SCIENCE. The primary focus of CWR research is the Southern Resident population of killer whales (orcas). Scientists recently found that as many as half of the world’s killer whale populations may not survive the next 100 years because of PCB pollution. And I said, 'That's it! As they documented more attacks, they began wondering why a 10-ton orca would waste its energy on a 65-pound sea otter. NIELSEN: But it's not just whale-huggers who hate the orca hypothesis. hide caption. It's one of those moments that biologists live for. One killer whale would need to eat 1,825 otters a year to live. Their ship at Cape Horn was trapped at anchor for eight days by howling weather. "And most importantly," Pitman adds, "they had a little tiny eye patch," a white spot under each eye characteristic of killer whales. Since 1990, otter populations off the Aleutian Islands have fallen by as much as 80 percent. "From the beginning, I had referred to it as the needle in the haystack," she says. Killer whales, or Orcas (Orcinus orca) are toothed whales in the oceanic dolphin family. Some researchers can distinguish individual pods, and even matrilines (the line of relationship that can be traced from one mother to her offspring), just by their calls. Each pod has distinctive noises, so whales in one pod can sense if another whale is part of its group. Danita Delimont/Getty Images Reproduction and Offspring . But Jim Hasties, a federal biologist and a major proponent of the orca theory, says there is one solution that almost everyone can agree on: continuing efforts to rebuild the region's stocks of great whales. Ms. WILLIAMS: We all want to think they're smiling at us and happy and they'll eat a few dead fish, and we're out there saying, `Well, gosh, no. December 9, 2011 at 4:12 pm . They use these sounds to help travel underwater. Scientists say they've found a mysterious type of killer whale that they've been searching for for years. Populations of mammal-eating transient orcas, gray whales and humpback whales are increasing. Either way, the mystery killer whales of the Southern Ocean have been found. Sea otter numbers were stable from 1993 through 1997 in Clam Lagoon, whereas in Kuluk Bay they declined by 76%. A group of ecologists says it has solved the mystery of Alaska's missing sea otters. And by the late 1990's, I'd see 'em three or four times a day. NPR's Allison Aubrey reports on a new development among sea otter populations off the coast of Alaska. A rare photo of "type D" killer whales off South Georgia island, located between South America and Antarctica, shows the whales' blunt heads and tiny white eye patches. I can't even ... it was thrilling for all of us." You know, they're killing cute, little, fuzzy sea otters.' PCBs first came under scrutiny in the 1970s, when birds, seals, and otter populations began rapidly decreasing. The domino effect reaches even farther. They live in pods. A rare photo of "type D" killer whales off South Georgia island, located between South America and Antarctica, shows the whales' blunt heads and tiny white eye patches. Serious scientists, like Doug DeMaster, don't think much of it either. He also says the original idea that these orcas once ate the great whales can't be proven. Washington’s sea otter population isn’t growing as fast as it once was. Many people are trying to figure out why. (killer whales spouting water) I would see a killer whale on average of probably once every three or four years in the '70s and '80s. New Type Of Killer Whale Found Swimming In Southern Ocean The notion that there might be some new kind of killer whale emerged in 1955, when photos from New Zealand showed a … First, Williams determines that the average orca needs to eat the equivalent of five to seven sea otters a day just to get by. NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. Orcas Gobbling Alaskan Otters / Change in Killer whale diet puts ecosystem on edge of ruin Carl T. Hall, Chronicle Science Writer Oct. 16, 1998 Updated: Feb. 3, 2012 4:14 a.m. Killer whales have a diverse diet, although individual populations often specialize in particular types of prey. Increased killer whale predation is the likely cause of these declines. Courtesy of J.P. Sylvestre All rights reserved. Scientists are finding the same trend around the world. NOAA biologist Lisa Ballance, who's married to Pitman, was part of the team. NIELSEN: In the current issue of the journal Ecology, Williams and her colleagues show just how big the killer-whale bite out of the otter population is. Whale researchers spotted a baby orca swimming energetically with its mother west of San Juan Island on Friday. Where do sea otters live? The whales were smaller than other killer whales, and they had rounded heads and pointier fins. Then she multiplies five to seven by 170, which is the estimated number of mammal-eating orcas living near the Aleutians. Killer Whale Predation on Sea Otters Linking Oceanic and Nearshore Ecosystems J. Killer whale, (Orcinus orca), also called orca, largest member of the dolphin family (Delphinidae). 2). The photograph above was taken on July 7, 2010. affected. These giant pectoral fins come up on either side of the sea otter. A. Estes,* M. T. Tinker, T. M. Williams, D. F. Doak After nearly a century of recovery from overhunting, sea otter populations are in abrupt decline over large areas of western Alaska. Terry Williams, a marine biologist at the University of California at Santa Cruz, says that's because the killer whales eat them. Later, they realized why the whales swam up to them. I should point out that killer whales around the world are doing fine, but this population is listed as endangered on both sides of the border of the U.S. and Canada. The killer whale is easy to identify by its size and its striking coloration: jet black on top and pure white below with a white patch behind each eye, another extending up each flank, and a variable “saddle patch” just behind the dorsal fin. What kinds of other animals share the sea otters’ habitat? We had type D killer whales swimming around our boat. This suggests that four killer whales, feeding exclusively on sea otters, could have driven the population into decline. The chemicals were affecting their ability to reproduce. "It's a big ocean, and it's a rough ocean. The mouth comes up, takes the sea otter, grabs it and gulps it down. That's the New Zealand killer whale!' A group of ecologists says it solved the mystery of Alaska's missing sea otters. The authoritative record of NPR’s programming is the audio record. Visit our website terms of use and permissions pages at www.npr.org for further information. Lull for killer whales. "But that was definitely the way to bring them to the boat.". Orcas have mostly black skin with white patches. Fig. Approximately 2,500 killer whales live in the eastern North Pacific Ocean—home to the most well-studied killer whale populations. Killer whales in the north Pacific switched to eating Harbor seals, Northern fur seals, Steller sea lions, and finally Sea otters, thinning each species’ populations out one-by-one. The team was able to snip off small tissue samples from the whales by firing a harmless dart, attached to a line, into their skin. Pitman adds: "It's like seeing a dinosaur or something. When the sea lion population crashed, they started fishing sea otters. He says the authors of the orca paper greatly overestimate the number of sea otters being eaten by the killer whales, partly because he's sure these killer whales are also eating lots of other things, like fish. Then in 2005, Pitman met a French biologist at a science conference who showed him a photo of an odd-looking killer whale swimming in the southern Indian Ocean. Then, when seals became rare, the killer whales turned to sea lions. John Nielsen, NPR News, Washington. Ecologists say killer whales are eating the otters, but as NPR's John Nielsen reports, not everyone buys that theory. Williams says the answer turned out to be a simple one. All three pods uniting is referred to as a s uper pod. This is due to the fact that killer whales are used to eating animals two to five times the size of otters, so they need to eat two to five times as many otters as seals or sea lions. Share this: Facebook; Twitter; Reddit; Google Classroom; Email; Print; By Science News for Students. As a result, populations of sea otters in the Aleutian Islands have declined from an estimated 60,000 animals in the mid-1980s to under 10,000 by 2000. "This was a very different-looking group of killer whales," says Robert Pitman, a marine ecologist with the National Oceanic and Atmospheric Administration. Before reading: Describe a sea otter. It's still waiting to be tested. Scientists found extremely high PCB levels in the animals’ bodies. But sea otters living in the Bering Sea off Alaska probably think differently. The killer whale (also known as the orca) generally did not consume sea otters in the past, but now consumes thousands of otters. NIELSEN: Williams says it's hard to overstate how much these findings upset people who all but worship killer whales. And a lot of people don't like hearing that. Local fishers had been complaining that some kind of whale was stripping fish off their lines. The Navy estimates the southern population of killer whales in the Puget Sound region could be subject to the non-lethal take two to 51 times a year during the seven years of Navy activity. But then they got a 12-hour quiet spell. Photos from New Zealand showed a bunch of whales stranded on a beach. Sea otters are still classified as endangered. "This study was really a decade-long look at what do killer whales die from, from California to Alaska all the way out to Hawaii," he sasy. NIELSEN: Williams is part of a team that first observed these sneak attacks seven years ago when they were studying the otter die-off along the Aleutian Islands. Question Sheet: Sea Otters, Kelp, and Killer Whales. 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