December 1, 2013 at 7:48 pm #1580MikeKeymaster
Grey Whales Showing Malnutrition
Note: There are other factors besides warming seawater, affecting the lives of living beings in our oceans. The full assault of geo-engineering and weather modification practices should be kept in mind…. (Mike C)
Gray whales showing signs of malnutrition
SCIENTISTS: WARMER SEAWATER MAY BE TO BLAME
By Kenneth R. Weiss
Los Angeles Times
Article Launched: 07/07/2007 01:33:09 AM PDT
SAN SIMEON – Scientists from Mexico to the Pacific Northwest are reporting an unusually high number of scrawny gray whales this year for the first time since malnourishment and disease claimed one-third of the population in 1999 and 2000.
So far this year, scientists haven’t seen a decline in numbers, and they are not sure what’s causing the whales to be so thin.
They suspect the cause might be the same thing that triggered the die-off eight years ago: rapid warming of Arctic waters where the whales feed. Whales depend on cocktail-shrimp-size crustaceans to bulk up for their long southerly migration. As Arctic ice recedes, fat-rich crustaceans that flourished on the Bering Sea floor are becoming scarce.
Skinny whales were first spotted this year in the protected waters of San Ignacio Lagoon in Baja California, where gray whales spend the winter breeding and nursing their calves before returning every summer to the Arctic.
That’s where a team led by Steven Swartz of the National Marine Fisheries Service in Silver Spring, Md., and Jorge Urban of the Autonomous University of Baja California Sur noticed that about 10 percent looked more bony than blubbery, a telltale sign of malnutrition.
Instead of making steady progress during their long migrations, the whales have been stopping often to eat along the way.
They have been seen straining mysid shrimp from kelp beds off California and British Columbia, sucking up mouthfuls of sand in Santa Barbara Harbor and skimming surface waters for krill-like crustaceans all along the West Coast.
Such opportunistic feeding has its risks. Switching to new food can expose the whales to harmful parasites as well as other hazards. There have been at least two fatal accidents in the spring near San Francisco’s Golden Gate Bridge. Gray whales, surfacing to breathe after dining on sea-floor snacks, have been ripped apart by propellers on cargo vessels.
It used to be a rare occurrence to see gray whales off Barrow, Alaska, said Craig George, a North Slope Borough wildlife biologist since the 1970s. In recent years, they have become summertime regulars, churning up mud plumes along the shoreline in search of food.
Historically, the eastern Pacific gray whales congregated every summer in the shallows of the Chirikov Basin, a place in the north Bering Sea known for its vast sea-floor carpets of crustaceans called amphipods. The whales sucked in great mouthfuls, straining out the sand and mud, packing on the pounds in the few months before their long annual journey to Baja and back.
Now the carpets of crustaceans are frayed – and, in some places, gone.
Scientists first thought that the gray whale population, which had been hunted nearly to extinction in the 1930s, had simply grown too large for its primary food source and eaten more than nature could provide. Such overgrazing was thought to have been responsible for the mass die-off in 1999 and 2000 that saw the population drop from 26,600 to about 17,400.
Now scientists suspect the climatic changes in the Bering Sea played a role in the population plunge by reducing the whale’s primary food: amphipods that appear to be affected by warming temperatures and vanishing sea ice.
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