One of hundreds of dead tuna crabs that have washed ashore on Fiesta Island, California, in 2015, part of the collapse of the Pacific forage fish populations. Photo: San Diego Reader

By Sheila Pell
11 July 2015

(San Diego Reader) – A ban on U.S. Pacific sardine fishing that took effect July 1 will mean more food for starving sea lions, pelicans, and other creatures. But there’s no shutting down the other forces rattling the food chain.

Weird weather conditions are being linked to mass casualties and the stranding of sea creatures up and down the coast.

A giant plume of warm water known as “the blob” lurks about 1000 miles off the coast and is creeping up on California, pushing sea temperatures two to six degrees above average.

Then there’s the warming caused by El Niño, which has been gaining strength since March and may help the drought next winter, but it’s hardly helping sea life. Along with fueling new diseases and altering habitat, the warmer conditions weave a tangled food web.

“Warming, such as has occurred with the blob in the past 1-2 years, stratifies the water column,” says Dave Checkley of Scripps Institute of Oceanography. That reduces the availability of nutrients.

Left high and dry in May was the Velella velella, crepe-paper-thin cousins of jellyfish equipped with sails that washed up by the millions on county beaches, pushed and pulled by wind and currents. They made a rare appearance last summer, too, and a gusty winter El Niño was also predicted — but fizzled out.

In June, beaches were red with piles of crimson tuna crabs drawn up from Baja to become fish food and selfie-fodder.

Hot pink slugs called “nudibranchs” have been migrating from the south coast to populate the tide pools of Central and Northern California. Sea stars are still struggling with a wasting disease, which now seems to also be melting the spines off their prey; the urchins that have come out of hiding as sea stars disappear.

Among the worst off is the sea lion. In Southern California, the “unusual mortality event” of 2013 is no longer unusual. Now it’s called the 2013-2015 Sea Lion Unusual Mortality Event. According to NOAA, last year’s sea-lion crash was likely due to food scarcity, “especially sardines.” And this year is worse. [more]

That rattling sound is the food chain

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