With a new theory surfacing that toxic algae rather than asteroids killed
the dinosaurs, scientists are still trying to unravel the mystery of what
caused a massive algae bloom off the north west coast [of the UNited
States] that left thousands of seabirds dead and may have sickened some
surfers and kayakers. The bloom, which stretches roughly 300 miles [480 km]
from Newport, Oregon, north to the Canadian border, still persists, though
it's a shadow of its September and October [2009] peak.
Whipped by waves and storms, the microscopic phytoplankton, which had
turned the ocean a rust color, broke apart, releasing toxins and creating a
meringue-like foam that coated the feathers of birds like spilled oil. Up
to 10 000 birds died of hypothermia in September, and researchers are still
trying to come up with a count for October.
Researchers are also checking reports that surfers and kayakers who came in
contact with the foam may have suffered cold-like signs, including
temporary loss of smell and taste. The toxins also may have become
aerosolized and affected beachcombers. In another strange twist,
pathologists performing necropsies found that some of the birds lacked
normal bacteria in their stomachs and other internal organs.
Blooms of the single-cell, saltwater algae species known as _Akashiwo
sanguinea_ have been found in Puget Sound, the Chesapeake Bay, and
elsewhere around the world. The bloom off the north west coast, however, is
huge compared with others. At its height, there were 1.5 million algae
cells per quart of water. The bloom was up to 65 feet [20 m] deep and miles
wide. In only one other instance -- a smaller bloom in 2007 in California's
Monterey Bay -- have the cells broken apart to create a toxic froth. And
this particular specie of algae usually likes warmer water than that found
off the north west coast.
No one is sure what ignited the bloom. Some scientists think it could be
caused by climate change, which has raised ocean temperatures and made the
water more acidic -- both conditions could favor this algae species. Others
say it could be the result of such weather conditions as El Nino or the
Pacific decadal oscillation, a long-lived El Nino-like pattern of Pacific
climate variability. The bloom could have been fed by nutrients washed down
the Columbia River from farms in eastern Washington and Oregon, or from an
ocean condition known as upwelling, where cold water rich with nutrients is
pushed toward the surface by the wind.
Or, it could just be the rhythms of the ocean, which scientists are just
starting to understand. "The ocean does have a natural pulse," said Vera
Trainer, a Seattle-based research oceanographer for the National Oceanic
and Atmospheric Administration. "Is this part of the pulse or is this
something different? We want to find out. But some of this is very unusual.
We are looking at this very intensely."
One of the scientists who developed the theory linking toxic algae to mass
extinctions said it fit in with the research he and his partner were
working on. "That's exactly what we are talking about," said John Rodgers,
an ecotoxicologist at Clemson University in South Carolina, who along with
James Castle, a geologist at Clemson, developed the killer algae theory.
Rodgers was on the road last week in the [American] Midwest, collecting
samples of algae to analyze back in his lab. He said he and Castle have
found ancient deposits of blue-green algae that produce toxins and deplete
oxygen that coincide with 5 mass extinctions millions of years ago. Though
he said algae may not have been the only cause for the extinctions, he said
it was a major factor.
The blue-green algae were freshwater algae in ponds, lakes, and rivers that
could have been ingested by prehistoric animals. The toxins also may have
been absorbed by plants that were later eaten by animals or become airborne
and breathed in by animals. "They certainly didn't die on the same day or
week," Rodgers said. "This happened over hundreds of years." Even though
there are thousands of species of algae, only several hundred produce
toxins, he said.
Though the bloom off the north west coast is in salt water rather than
fresh water, Rodgers said such blooms were well worth keeping an eye on.
"They are changing, expanding their ranges into places never seen before
and in densities never seen before," Rodgers said. "It's hard to ignore,
and as the data grows, we are becoming more and more convinced." Rodgers
said his theory has been peer reviewed and is gaining acceptance among
scientists. Current climate conditions are becoming strikingly similar to
those that existed during the time of the mass extinctions, he said.
In a paper published in March [2009] in the journal Environment
Geosciences, Rodgers and Castle wrote that their finding "gives us cause
for concern and underscores the importance of careful and strategic
monitoring as we move into an era of global climate change." Scientists
studying the bloom off the north west are wary when asked about Rodgers'
and Castle's theory. "I would be cautious about it," Trainer said. Raphael
Kudela, a toxic algae expert and ocean sciences professor at the University
of California at Santa Cruz, thinks algae blooms such as those off the
north west coast are becoming more frequent. "It is consistent with climate
change," Kudela said, adding that a bloom like this in the chilly waters of
the north west was "very unusual."
As for the killer algae theory, Kudela said, "People who study harmful
algae don't dismiss it. But it can't be proved."
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