Seabird die-off in Vancouver – 07/16/2005

  • October 30, 2013 at 2:06 am #844

    Didn’t a similar event happen recently in the UK?
    this looks to be a huge story, tho i haven’t seen
    anything reported on the regular news….

    VANCOUVER — As he scrambled over the rocky outcrops of remote
    Triangle Island this spring, seabird population biologist Mark
    Hipfner knew immediately something had gone wrong.

    Tens of thousands of nests that should have been brimming with eggs
    were empty. And in the weeks that followed, as hundreds of thousands
    of seabirds flocked to the windswept islet, 45 kilometres north of
    Vancouver Island, the problem only got worse.

    Data are still being collected, but with the nesting season almost
    over, Mr. Hipfner says, it is now clear that Triangle Island’s
    internationally significant seabird population is experiencing the
    worst breeding year on record.

    “We are seeing a very severe nesting failure — the worst ever,” said
    Mr. Hipfner, who works for the Canadian Wildlife Service. According
    to Mr. Hipfner, the Cassin’s auklet population of 500,000 pairs is
    unlikely to produce even one chick that survives.

    Several other bird species, all hampered by a lack of food, are also
    struggling to reproduce, although they are not as hard hit as
    Cassin’s auklets.

    “Most Cassin’s auklets did not lay eggs. The birds that laid eggs
    failed to hatch them and those that did hatch, have failed to raise
    the chicks,” said Mr. Hipfner, who ties the problem to a coast-wide
    collapse of oceanic plankton.

    The plankton blooms, which are caused by upwelling of cold ocean
    currents, didn’t occur this year for reasons that aren’t clear, but
    which may be linked to global warming. Without the plankton, the
    small fish species that support the seabirds have died off, creating
    a scenario where the adult birds lack the energy to produce eggs and
    the chicks that do hatch soon starve to death.

    The nesting failure could be an early warning sign of problems facing
    other species — from sockeye salmon to baleen whales — that depend
    on zooplankton such as krill, a tiny shrimp-like crustacean that has
    vanished along much of the West Coast.

    “If you’ve got a failure at the base, it cascades throughout the food
    web,” Mr. Hipfner said. “It’s a single big system that’s all
    interconnected. . . . Without plankton, essentially the whole system
    comes to a standstill.”

    He said oceanic plankton has disappeared along the full length of the
    California Current, which circulates on the West Coast of North
    America from California to British Columbia’s mid coast.

    Triangle Island, which supports one of the most significant seabird
    nesting colonies in North America, marks the northern edge of the
    California Current.

    Mr. Hipfner said seabird populations farther north, on the Queen
    Charlotte Islands, are in a different ocean regime and this year are
    enjoying a highly successful breeding season.

    But the failure at Triangle Island is of international significance.
    The rocky outcrop, so blasted by winds that trees don’t grow on it,
    has an estimated population of one million Cassin’s auklets — half
    the world’s supply — 60,000 tufted puffins, 80,000 rhinoceros
    auklets and 8,000 common murres.

    “It’s a remarkable place,” Mr. Hipfner said. “Personally, it is very
    difficult to be in a colony where you know there is such a
    significant nesting failure. But as a scientist, you know the birds
    are making the right choice. The key for the species is to survive to
    breed a number of times, so the loss of one season is not that

    Mr. Hipfner said there have been poor breeding seasons in past years
    and the colony should bounce back if conditions are good next year.

    “The concern is that these [oceanic] events could become more
    frequent because of global warming. That is the real worry.”

    Not only are the birds having difficulty reproducing, but many adults
    are also growing weak, and it is expected the number that survive to
    breed again will decline sharply. In a typical year, 85 per cent of
    the adults survive. This year the survival rate is expected to drop
    to 60 per cent.

    Seabird biologists from B.C. to California are noting breeding
    problems this year.

    Bill Sydeman, director of marine ecology at the Point Reyes Bird
    Observatory in California, has said the Farallon Islands, off San
    Francisco, are experiencing the worst breeding season ever recorded.

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