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Marine researchers attempt to breed endangered abalone


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Posted by JefF Shaw on July 13, 2011 at 16:54:05:

Marine researchers attempt to breed endangered abalone

By Sandy Mazza Staff Writer

Cabrillo Marine Aquarium researchers gathered around four buckets in the aquatic nursery Tuesday afternoon, waiting patiently for the endangered white abalone inside to get in the mood.

White abalone are believed to be nearly extinct, and the San Pedro aquarium partnered with the Aquarium of the Pacific in Long Beach this week to try to beef up the research population.

There are at least eight species of abalone living in waters off the California coast. They are all in decline because of decades of fishing and withering syndrome, a disease that causes their feet to atrophy and makes them vulnerable to predators and starvation.

"White abalone is probably the most imperiled" of all the abalone species, the
aquarium's research curator Kiersten Darrow said. "We've thinned out the population so much, we've definitely overfished them. The wild population is pretty much done for. Researchers (in California) are the only ones breeding this species."

Cabrillo Marine Aquarium has nine fist-size white abalone that have lived there for eight years. They are sisters and brothers born in a marine laboratory at the University of California, Davis.

On Tuesday, Darrow and several staff members chose the healthiest two males and two females to participate in a scientifically proven process to trigger a chemical reaction in the gastropods, causing them to spawn.

The sea snails were dehydrated and rehydrated to mimic tidal waters, and then soaked in a light hydrogen peroxide solution. Then they were washed in fresh water - the final step in a process meant to trigger their reproductive hormones.

It wasn't long before one female began shooting out greenish-yellow plumes of eggs. One female abalone can produce millions of eggs at a time. The researchers buzzed about excitedly, collecting the best of them.

"It really is neat to see how the chain reaction occurs with the hydrogen peroxide," said laboratory assistant Andres Carrillo. "Every animal's physiology is different."

Jim Ellingson of Torrance brought his grandson, Austin, to see the abalone spawning.

"A million eggs, how about that!" Ellingson said as he stared at the yellowish cloud in the water around the ovulating female abalone. "That's very fascinating. I used to catch abalone and eat them when I was a kid."

Abalone are considered "broadcast spawners" because the males and females each shoot clouds of eggs and sperm into the ocean and hope that the two meet. Abalone must be near each other and spawning at the same time for the process to work.

In this case, only one female was enticed to release eggs. Without sperm from the males, the researchers were not able to fertilize any of the eggs. Still, Darrow froze many of them for future genetic testing or possible cloning.
They counted 720,000 viable eggs from the female abalone, Darrow said. None of the white abalone at the Aquarium of the Pacific spawned on Tuesday, she said.

"We were all feeling very optimistic just because our animals looked so healthy," Darrow said. "To get one out of four animals spawning was outstanding. We might give our animals a break and try it again in the fall."

sandy.mazza@dailybreeze.com



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