Where have all the seabirds gone? A tufted puffin on Prince William Sound, Alaska. At left, a pair of murrs sit on the cliff on St. Paul Island, Alaska (AP photos)
Where have all the seabirds gone?
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The number of seabirds, including gulls, puffins and auklets, has dropped significantly in the Gulf of Alaska and northeast Bering Sea. It is a possible consequence of warmer waters. That is according to a preliminary federal analysis of nearly 40 years of surveys.

U.S. Geological Survey experts found the seabird population density declined 2 percent annually from 1975 to 2012. This occurred in the northeast North Pacific. That's according to John Piatt, research wildlife biologist at the USGS Alaska Science Center.

"Biologically speaking, that's a pretty major change," he said.

Piatt and researcher Gary Drew suspect the decline may be tied to less food availability. It's a consequence of warmer ocean temperatures. They occur in cycles over decades.

Seabird populations could bounce back as water cools, Piatt said. But 10-year cycles could ultimately be superseded by global warming.

"That's what a lot of people are concerned about," he said. "We don't know. We're just learning about the Pacific Decadal Oscillations and that they're important."

The analysis of seabird surveys began in earnest in 1989.

"We started pulling together some of these data bases after the Exxon Valdez oil spill. It was clear we needed to get a better handle on densities of birds at sea to assess damages," Piatt said.

The result was the creation of the North Pacific Pelagic Seabird Database. It includes bird counts from 350,000 ship transects. Those are the plotted paths to systematically make measurements.

To make sense of the numbers, researchers looked for blocks of water where at least 10 surveys had been conducted in a given year in all four decades.

"We pulled out places where there was repetition. It gave us 72 blocks of water for which we had data spanning 40 years," Piatt said.

Exxon Valdez oil killed a lot of birds, Piatt said. But seabird numbers also declined outside the spill area.

"It was much bigger than the oil spill," Piatt said.

Starting in the late 1970s, atmospheric circulation changed. Water temperatures that had been colder than average for a decade shifted to several degrees warmer than average for more than 30 years.

The changes were tied to effects from Pacific Decadal Oscillations. The term describing climate variability was coined by fisheries scientist Steven Hare. He researched connections between Alaska salmon production cycles and Pacific climate. NASA describes the oscillations as long-term ocean fluctuations that wax and wane every 20 to 30 years.

With warmer water, phytoplankton bloomed earlier. Zooplankton fed on phytoplankton and developed earlier, providing abundant food for early spawning fish such as halibut, pollock and cod. That left less food for late spawners such as capelin, a type of smelt consumed by seabirds.

"This was a magnitude-9 earthquake in the ecosystem," Piatt said. "Everything changed afterward, including marine birds."

Counts at bird colonies were not part of the USGS review. U.S. Fish and Wildlife Service seabird researcher David Irons said trends at colonies are generally in sync with the at-sea data. Seabird numbers fell at some colonies in the mid-1980s and afterward. But they eventually leveled off or increased.

"Basically the decline leveled off around 2000," Irons said.

The USGS review goes through 2012. As water temperatures have cooled in recent years, some bird numbers have ticked up, Piatt said. The historical record indicates wildlife such as salmon has booms and busts in population. They correspond to natural cycles in the environment.

"The animals are responsive to changes in the environment," he said.

The more worrisome issue is global warming that could supersede decadal, or 10-year, pulses.

"The background increase in global temperature is a happening fact," he said. "It's not hypothetical."

Critical thinking challenge: How did warmer water lead to fewer birds?

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COMMENTS (47)
  • Eric0221-YYCA
    4/03/2015 - 03:51 p.m.

    I think that this is bad for birds that only live in coastal areas, but their are now fewer coastal birds right now because the birds that I just saw everyday there are only few of them in Los Angeles but they aren't safe from extinction, this may cause by the BP oil spill in the Bering sea that is in Alaska, which made gulls or other kind of coastal birds really cold that they're freezing in the oily water until they died. If the gulls or other birds are now moving to different places that is slightly cold but mostly warm, I think that the birds are moving to someplace that is a bit cold but a lot warmer than the other place that they just went to.
    Critical thinking challenge: How did warmer water lead to fewer birds?
    Answer: Warmer water had lead to fewer birds because fish lives in cold water not warm water, so if the birds live somewhere that the water is warm, the fish would move to colder water that will let the birds to starve.

  • ksadat-5
    4/03/2015 - 03:54 p.m.

    The number of seabirds in the Gulf of Alaska has dropped tremendously. Sources say that the sudden drop of population may be because of the warmer weather. Gary Drew, a researcher, believes that the decrease in Seabird population may be because of the lack of resourses and food. The North Pacific Pelagic Seabird Database keeps track of bird populations in over three hundred thousand areas.

    This is very interesting article. The amount of seabirds in the Gulf of Alaska has dropped significantly. Many people say that Global Warming does not exist, but this is an actual fact that it does. Both theories about why the population decreased are because of the heat.

  • MiloW-4
    4/03/2015 - 05:17 p.m.

    The populations of seabirds has dropped recently according to recent studies and observations. The cause is not one hundred percent known. One reason is the temperature of the waters rising. Another reason is that enough food is available. This is interesting because it tells how animal populations can change a lot.

  • allies-4
    4/03/2015 - 06:56 p.m.

    Seabirds are fleeing the North because of the temperature rise. The population has declined to about 2000, birds have a natural response to the environment changing and have flocked to new places. The bigger issue for the world is that global warming could supercede in 10 years.

  • SebastianH-1
    4/03/2015 - 07:27 p.m.

    In the last few decades, the seabird population around the Arctic ocean has been declining. There are many possible causes, but global warming is the most effective. It messes up the ecosystem, providing the birds with less food. This article was a good size and had good information, but could use a bit more organization.

  • Tiffany0307-yyca
    4/03/2015 - 07:30 p.m.

    I kind of feel bad for the birds because they have to survive through hard times which is going to make them die. I just want to get rid of the oil and all the pollution and global warming, although I can not do that. The world would be better without toxic and polluting things. I think that those birds are really poor. I wish somebody found a way to save them and then they could live and still survive. I just want to protect all the animals.

  • annabel1226-yyca
    4/03/2015 - 08:55 p.m.

    I think L.A is kind of weird because in L.A they have a lot of birds ( which I don't like about them ) but in Gulf of Alaska and northeast Bering Sea it says that there are less birds. So if we want to keep more birds saved we should keep our environment clean, don't trash oil or waste in the ocean, and give foods to them but not human food because they might die because our food is poison to them. So my point is never trash food, plastic, or other things that could harm the birds or other animals. The good thing is to me is it is not my fault ( some of it ) because sometimes the water is kind of warm so the fish kind of got spoiled and the birds eats it and it died.

    Critical thinking challenge: How did warmer water lead to fewer birds?

    Answer: Water lead to fewer birds because sometimes the fish could get spoiled and then the birds eats it and then it didn't survived.

  • KellerB-2
    4/03/2015 - 09:42 p.m.

    This article is about birds disappearing. These birds such as puffins, goals and auklets could be disappearing because of climate changes caused by humans. I think that these birds need to be safes or one day they could disappear for good.

  • Mixicofre
    4/04/2015 - 06:27 p.m.

    the reason that the seabirds decrease is probably due to the lead in the sea modify their habitat , and this product should migrate to another place

  • MaraCceres
    4/05/2015 - 12:10 a.m.

    The article is about how the global warming has caused seabirds has had to migrate to other places, the reason is for the gradual increase in the temperature, this problem makes those birds can't find their food and many die.

    Answering to the question: The birds cant find food in abundance,so this is why they should migrate to other places for living.
    The plankton, their food, is being consumed by fishes that live there.

    I think it is very important to change the minds of people, so there can be an improvement in their behavior about the problem, and be able to pause in the global warming consequences. Also, I think that companies should work consciously to stop throwing contaminants that may be harmful to the flora and fauna of the world. In addiction, I believe the governments should supervise to the companies and individuals, so they can be able to stop environmental pollution.

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