Page 28 - aruba-today-20190406

A28 SCIENCE
Saturday 6 april 2019
Biologists: Killing hungry sea lions saving imperiled fish

By GILLIAN FLACCUS the vulnerable steelhead
PORTLAND, Ore. (AP) — A and salmon as the fish
plan to kill California sea li- power their way upriver
ons to save an endangered to the streams where they
run of fish on a river that hatched.
cuts through Portland, Or- Steelhead start life as fresh-
egon, appears to be work- water trout and then travel
ing just months after wildlife to sea from inland rivers,
officials began euthanizing grow to adulthood as steel-
the giant marine mammals, head in the Pacific Ocean
biologists said Thursday. and then return to their na-
The Oregon Department tal river to spawn. They can
of Fish and Wildlife began grow to 55 pounds (25 ki-
killing the sea lions in Janu- lograms) and live up to 11
ary after getting permission years.
from federal authorities The sea lions breed each
late last year. They have summer off Southern Cali-
killed 16 so far, including fornia and northern Mexi-
three on Wednesday, said co, then the males cruise
department spokeswoman up the Pacific Coast to for-
Michelle Dennehy. age. Hunted for their thick
In the same period, 2,400 fur, the mammals’ num-
steelhead fish have bers dropped dramatically
reached the upper Willa- but have rebounded from
mette River and its tributar- In this March 14, 2018 file photo, a California sea lion designated #U253 heads towards the Pacific 30,000 in the late 1960s to
ies to spawn this spring — Ocean after being released in Newport, Ore. about 300,000 today be-
the most in three years and Associated Press cause of the 1972 Marine
double last year’s tally, the River south of Portland, said steelhead making it over the returning adults each Mammal Protection Act.
agency said. Shaun Clements, ODFW’s the falls this year. spring, Clements said. Up to With their numbers grow-
Less than 30 years ago, senior policy analyst. After a weeklong lull, state 40 sea lions are preying on ing, the dog-faced sea li-
the number of steelhead “We’ve definitely been biologists are now killing a the chinook, he said, while ons are venturing ever far-
making that journey was able to reduce predation second wave of sea lions only 12 were going after ther inland up the Colum-
at least 15,000 a year but this year and provide some that have traveled to the the steelhead. bia River and its tributaries
pollution and the construc- relief to the fish,” he said. base of the falls to munch The adult male sea lions, in Oregon and Washington.
tion of dams on key rivers “We’re saving consider- on another salmonid spe- which weigh nearly 1,000 The two states have had a
reduced that number dra- able numbers of them.” cies, the spring chinook. pounds (454 kilograms) similar program in place for
matically. Clements added that oth- The spring chinook run is each, have learned that years to kill California sea
Sea lions have been eat- er factors, such as better also listed under the En- they can loiter under Wil- lions that eat threatened
ing an additional 25% of conditions in the Pacific dangered Species Act and lamette Falls, a horseshoe- and endangered salmon
all returning steelhead at Ocean, are also contrib- biologists estimate sea li- shaped waterfall south of at the Bonneville Dam on
that spot in the Willamette uting to larger numbers of ons are eating up to 9% of Portland, and snack on the Columbia River.q

Explorer to trace flow of plastics

down 10 rivers into seas

By COLLEEN BARRY final stop will be the Great ocean plastic was made
Associated Press Pacific Ocean garbage clear with the death last
MILAN (AP) — Italian ex- patch. month of a whale that
plorer Alex Bellini plans to Bellini, who has rowed beached on the northern
travel down the world’s solo across two oceans for coast of Sardinia in Italy with
10 most polluted rivers on more than 35,000 kilome- 22 kilograms (48.5 pounds)
makeshift rafts, tracing the ters (nearly 22,000 miles), of plastic in its belly.
routes of plastics that pol- said he became aware of “The ocean is a no-man’s
lute the world’s oceans. pollution in the ocean while land, meaning what is
In this Sunday, Dec. 14, 2008 file photo, Italian solo rower Alex Bellini said Thursday that rowing from Peru to Austra- found in the ocean be-
Bellini arrives at the Opera House in Sydney, Australia. he was inspired by a 2018 lia in 2008. But he said he longs to no one, therefore
Associated Press study by a German scientist was surprised to learn that it is no one’s responsibility
that found 80% of plastic in most plastics in the seas ar- to go take away that stuff,”
the world’s oceans arrives rive by rivers and not from Bellini said. “But research
from just 10 rivers. coastal areas. brings the problem closer
He began with a voyage His new journeys are aimed to us, in the rivers. So every-
down the Ganges River in at raising awareness about one needs to take his own
India on a raft built from the source of ocean plas- responsibility.”
garbage last month and tic, which according to the Bellini is supported by the
intends to complete jour- U.N. environment assembly One Ocean Foundation,
neys on all 10 on similarly is accumulating in oceans founded by the Yacht Club
constructed rafts by 2021, at a rate of 8 million tons a Costa Smeralda in Sardinia,
including the Yangtze, the year. with a mission to safeguard
Niger and the Mekong. His The damage to wildlife of the seas. q