Page 28 - ARUBA TODAY

A28 SCIENCE
Tuesday 19 sepTember 2017

Warm waters off West Coast has lingering effects for salmon

By PHUONG LE mospheric Administration food web isn’t yet clear.
Associated Press fisheries administrators last Fisheries managers are
SEATTLE (AP) — The mass of month that poor ocean also seeing lower runs of
warm water known as “the conditions may mean poor steelhead to the Columbia
blob” that heated up the salmon returns to the Co- River system this year.
North Pacific Ocean has lumbia River system over Joe DuPont, a regional fish-
dissipated, but scientists the next few years. eries manager with Idaho
are still seeing the lingering “There was hardly any Fish and Game, blames
effects of those unusually salmon out there,” Burke poor feeding conditions
warm sea surface temper- said. “Something is eating when juvenile steelhead
atures on Pacific Northwest them and we don’t know went out to the Pacific
salmon and steelhead. what and we don’t know Ocean last year.
Federal research surveys precisely where,” he add- Warm waters brought less
this summer caught among ed. nutrient-rich copepods,
the lowest numbers of ju- Seabirds such as common tiny crustaceans at the
venile coho and Chinook In this photo taken Thursday, Sept. 14, 2017, salmon circle murres could be the cul- base of the food chain.
salmon in 20 years, sug- just below the surface inside a lock where they joined boats prits. Researchers caught Meanwhile, northern co-
gesting that many fish did heading from salt water Shilshole Bay into fresh water Salmon fewer forage fish, such pepods richer in lipids, that
Bay at the Ballard Locks in Seattle.
not survive their first months Associated Press as herring, anchovy and young steelhead eat, were
at sea. are confronting an ocean “That’s going to have a re- smelt. less abundant.
Scientists warn that salmon ecosystem that has been ally big impact on the dy- When forage fish are low, It’s the second year of
fisheries may face hard shaken up in recent years. namics in the ecosystem,” avian predators may be consecutive low steelhead
times in the next few years. “The blob’s fairly well dis- Burke said. forced to eat more juve- runs, said Tucker Jones,
Fisheries managers also sipated and gone. But all “They’re all these new nile salmon. Seabirds near ocean salmon and Colum-
worry about below aver- these indirect effects that players that are normally the mouth of the Columbia bia river program manager
age runs of steelhead re- it facilitated are still there,” not part of the system.” River may have feasted on with the Oregon Depart-
turning to the Columbia Brian Burke, a research Researchers with NOAA more juvenile salmon as ment of Fish and Wildlife.
River now. fisheries biologist with the Fisheries and Oregon State they entered the ocean. “There’s a lot of circum-
Returns of adult steelhead Northwest Fisheries Sci- University Cooperative In- The North Pacific Ocean stantial evidence to point
that went to sea as juve- ence Center. stitute for Marine Resources had been unusually warm to an unhappy river experi-
niles a year ago so far rank Marine creatures found Studies have been survey- since the fall of 2013 with ence and meeting ocean
among the lowest in 50 farther south and in warm- ing off the Pacific North- “the blob,” but sea surface conditions that were far
years. er waters have turned up west for 20 years to study temperatures have recent- from hospitable,” Jones
Scientists believe poor in abundance along the juvenile salmon survival. ly cooled to average or said.
ocean conditions are like- coasts of Washington and In June, they caught re- slightly warmer than aver- “The ‘blob’ especially
ly to blame: Cold-water Oregon, some for the first cord numbers of warm- age conditions. changed the zooplankton
salmon and steelhead time. water fish such as Pacific Changes in the marine food web structure that
pompano and jack mack- ecosystem are likely to be was out there,” he added.
CALL FOR OUR MODEL, GIRL & STRIPPERS erel, a potential salmon seen for a while. Fisheries managers have
predator. But the catch of The research surveys also put some fishing restrictions
juvenile coho and Chinook pulled up weird new crea- in place due to low fore-
salmon during the June tures that had not been cast of steelhead expect-
survey — which has been netted before. ed back this season.
tied to adult returns — was Researchers have caught While the mechanisms for
among the three lowest in tens of thousands of tube- steelhead and salmon
Tour to the Red Light Lipstixaruba@outlook.com 20 years. shaped, jelly-like pyro- may be different, “large
District with a Private Burke and other scientists somes, which are generally scale changes to the
Guide & a FREE bottle warned in a memo to Na- found in tropical waters. ocean are driving all of it,”
of wine... tional Oceanic and At- Their impact on the marine said Burke.q