Pacific Ocean "Blob" Concerns Scientists
By LAINE WELCH
August 31, 2015
“They call it the Blob because of its original circular shape on the sea surface,” explained Dr. Carol Janzen, an oceanographer and Operations Director at the Alaska Ocean Observing System in Anchorage.
Unusually warm temperatures dominate three areas of the North Pacific: the Bering Sea, Gulf of Alaska and an area off Southern California. The darker the red, the further above average the sea surface temperature. NOAA researchers are tracking the temperatures and their implications for marine life.
“Some people call it the ridiculously resilient ridge,” Janzen said, adding that the ridge reduced the intensity of storms reaching landfall, and led to reduced precipitation on the West Coast.
The Blob’s most immediate impact is on the ocean’s circulation, a prime pump for the entire ecosystem. The warmer water forms a dense “oil and vinegar type” layer that reduces the amount of vertical ocean mixing, and prevents nutrient rich, colder water from reaching the surface.
“And it is in this surface layer that phytoplankton grow and they need light and nutrients to do it,” Janzen said. “Since the phytoplankton are a food source near or at the base of the food chain, if you remove or reduce their quantity, or change their composition, it can impact the entire food chain.”
The Blob has changed the composition in the organisms that make up the normal microscopic mix of phytoplankton – something that has raised a red flag for Alaska. Scientists have seen the arrival of an organism that produces a neurotoxin called domoic acid, similar to Paralytic Shellfish Poison.
“It was significant enough in Washington to close some shellfish fisheries,” Janzen said. “In Alaska we haven’t reached that point, although we are seeing higher concentrations of the organism in water samples. It’s being closely monitored.”
The Blob phenomenon is expected to remain glued to the coasts throughout 2015. Due to high public interest the AOOS launched a Blob Tracker on its website.
Beyond the Blob
The AOOS is part of the national Integrated Ocean Observing System, with a mission since 2003 to be “the eye on Alaska’s coasts and oceans.” The System team monitors sea ice concentrations and movements in Alaska, and last week deployed an ecosystem mooring with advanced optical and measurement sensors that will remain in the Chukchi Sea for a full year.
For three years, the AOOS has sponsored an underwater robotic glider that monitors marine mammal soundings from the Bering Sea northward. It also oversees wind and solar powered radar stations that track nearshore surface currents from Point Lay to Barrow.
AOOS also is hosting its second annual Ocean Film Contest. Any short film under 10 minutes that highlights Alaska’s coasts or oceans is welcome. Top prize is $1,0000. Deadline to enter is Sept. 15.
Crabbers who target golden king crab along the Aleutian Islands are setting out pots for science. And despite cutbacks in research funding, the crabbers are expanding ongoing projects on golden stocks, and beginning a new study for red king crab near Adak. How are they doing it at a time of shrinking state and federal dollars?
“Through cooperative partnerships between crab fishermen and state and federal agencies,” said John Hilsinger, Science Advisor for the Aleutian King Crab Research Foundation, a non-profit group started by crab harvesters four years ago.
Golden king crab from the Aleutian Islands has been Alaska’s most stable crab stock for nearly 35 years, with a conservative annual harvest of six million pounds. Only very limited stock surveys have been done, due to the high costs associated with “doing science” at the distant, deep water fishery.
In Alaska, no surveys mean no chance for a fishery to either begin or grow.
Two years ago the fleet partnered with ADF&G crab scientists in a project that showed the golden crab stocks are healthy and growing. The team also devised a method to survey the entire population of the Aleutian Islands stocks, a habitat spanning over 800 miles. That ambitious project got underway with the August 1 start of the fishery.
“The crabbers divided up designated survey areas, and are volunteering their vessels, time and resources,” Hilsinger said. “By using the crab fleet to collect the data during their fishery, we can survey new and larger areas than ever before.”
In September, the Foundation is partnering with ADF&G and the Adak Community Development Corporation to begin a “recon” project for red king crab near Adak, an area that has not been surveyed since 2002. The hope is to eventually have a small boat crab fishery in the remote region.
Alaska’s total salmon catch has surged to 245 million fish, pushed by record breaking pink salmon catches at Prince William Sound. The pink catch there already has topped 96 million, blowing past the previous record of 93 million fish taken in 2003.
As Alaska’s salmon season winds down, many of the boats begin fishing for other things, from sea cukes to Bering Sea crab.
“More and more you get salmon fishermen who also do dive fisheries or shrimp or other things in the fall. Fishermen have diversified and they fish a portfolio of different fisheries,” said Bill Donaldson, a fishery manager at Alaska Dept. of Fish and Game in Sitka.
Many of the bigger boats that tender salmon during the summer are prepping now for the Bering Sea crab fisheries that open in mid-October. Roughly 75 percent of Alaska’s 6,500 or so fishing vessels are under 50 feet in length, and most are already planning their final lineups for the year.
Southeast Alaska is especially busy in the fall with fishermen getting another shot at Dungeness crab, plus dive fisheries for sea cucumbers, urchins and giant geoduck clams starting in October. The Panhandle’s big spot prawn fishery also kicks off, and hundreds of trollers will be back out on the water for the start of the winter king salmon fishery.
Pollock fishing reopened in waters off of Kodiak this week and boats of all gears and sizes will be targeting codfish in the Gulf starting September 1.
Halibut and sablefish seasons are underway until mid-November for 1,000 or more longliners. Fishing for an assortment of flounders, perch, mackerel, rockfish and countless others also will continue across Alaska all during the fall.
Laine Welch ©2015
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