(NaturalNews) Various types of marine life are vanishing off the West Coast, some of them in droves, including marine birds, sea lions, forage fish and sea stars. The National Oceanic and Atmospheric Administration (NOAA) has been accused of failing to recognize a sharp decline in the number of forage fish, such as Pacific sardines, due to overfishing.
While the cause of the massive die-off of sea stars is still widely unknown, researchers theorize that a pathogen may be responsible, but for the marine birds and sea lions that are perishing, a depleted forage fish population may be to blame.
White-winged scoters, surf scoters, long-tailed ducks, murres, loons and some seagulls are experiencing dramatic population decreases according to Washington Fish and Wildlife workers.
Several species of marine birds have declined over the last few decades. Scoter populations are down 75 percentsince the 1970s, with murres and western grebes bordering extinction, according to The Seattle Times.
Last year, EcoWatch reported that more than 1,600 sea lions washed up either dead or close to it along the shores of Southern Calif. An unprecedented number of sea lion pups washed ashore emaciated, dehydrated and severely underweight. Many of the pups were discovered near Santa Barbara, San Diego and Orange, Calif., a region also experiencing massive sea star die-offs.
This year, NOAA has reported even more stranded pups in central, southern and northern Calif., and opposed to last year, the agency has admitted that the cause is mostly likely due to an unavailable food source. Sea lion pups and nursing mothers depend on a nutrient-rich diet acquired through fatty forage fish like sardines.
The same may be true for marine birds. New studies indicate a decline in marine birds could be related to a lack in forage fish including herring, anchovies, sand lance and surf smelt. Due to diverse migratory patterns, the relationship between marine birds and the food they eat is rather complex.
Exhaustive analysis of bird diets and population trends, as reported by The Seattle Times, found that the birds which dive for forage fish like herring were 16 times more likely to be affected by dwindling populations than birds that eat surface-dwelling fish.
"The result was remarkably strong," said study author Ignacio Vilchis, formerly with the SeaDoc Society at the University of California, Davis. "It showed that it's the diving birds that go after forage fish which are much more likely to have a declining trend."
Forage fish, particularly herring, are the cornerstone of the ocean's inhabitants, providing food to a variety of species including whales, dolphins, birds, sea lions and other fish.
"They are the central node of the marine ecosystem," said Iain McKechnie, a coastal archaeologist with the University of British Columbia. "They aren't the base, they aren't the top, but they are the thing through which everything else flows."
Centuries ago, Native Americans living along the Northwestern coast also relied heavily upon herring, a crucial food source for the indigenous people. Back then, herring populations were far more stable than they are today.
McKechnie recently found that herring used to live eight to 10 years but now survive for only three or four years, inhibiting their ability to replenish their populations.
While marine birds have declined in the past in similar regions, researchers ponder whether or not they'll make a comeback this time. "If that part of the food web is in decline, there may be a food problem for some birds," Mckechnie said.
In March of this year, the NOAA reported the sardine population to have declined by 74 percent since 2007, with no sign of recovery, but the agency has done nothing to encourage stricter fishing regulations.