LA mystery as millions of fish float belly up in harbour

StephenW

http://www.smh.com.au/environment/animals/la-mystery-as-millions-of-fish-float-belly-up-in-harbour-20110309-1bn8m.html

Some speculated about the apocalypse but fishermen and harbour chiefs are puzzled after millions of dead sardines were found floating in a marina just south of Los Angeles on Tuesday.
            Experts said the fish, found at a harbour in Redondo Beach, may have died from lack of oxygen due to algae, while locals wondered if high winds overnight might have had something to do with it.
            "It looks like what happens to goldfish when you don't change the water in the tank, mouth open and belly up," local official Bill Workman said, cited by the Los Angeles Times newspaper.
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                                                                        Millions of dead sardines float in a marina in Redondo Beach. Photo: AFP
        
            "There are no visible signs of any toxins that might have caused [the deaths] and our early assessment is that this was oxygen depletion," he said, adding: "There are no oil slicks or leaking of substances into the water."
            Locals at Redondo Beach, where the stench from the dead fish hung over King Harbour, suggested that high winds could have driven the fish into the harbour, where their sheer numbers would have reduced the oxygen available.
            Experts were cautious.
                                                                        Millions of sardines  lie dead in the harbour area of Redondo Beach, south of Los Angeles. Photo: Reuters
        
            "What we're trying to tease apart is whether it's a consequence of algal build-up, a fish build-up or something toxic in the water," David Caron of the University of Southern California said.
            California Department of Fish and Game spokesman  Andrew Hughan told Reuters: "Essentially Basin 1 of Redondo Beach Harbour is full of dead sardines  floating on the water, probably 5 per cent of the total basin harbour is filled  with sardines that are dead."
            Mr Hughan said biologists had tentatively concluded that the massive group of  fish, known as a "bait ball" and initially identified by police as anchovies,  died from oxygen deprivation after being driven into a closed-off pier area by  rough seas and heavy winds.
                                                                        Millions of sardines  lie dead in the harbour area of Redondo Beach, south of Los Angeles. Photo: AP
        
            "It looks like they just swam in the wrong direction and ended up in a corner  of the pier that doesn't have any free-flowing oxygen in it," Mr Hughan  said.
            "There's nothing that appears to be out of sorts, no oil sheen no chemicals,  no sign of any kind of illegal activity," he said. "As one fisherman just told  me, this is natural selection."
            Mr Hughan said such incidents were rare but not unheard of.
            While biologists concluded their investigation, the dead fish drew curious  onlookers, some who took pictures of the floating clusters of silver fish  covering the surface of the water.
            "The issue now is clean-up because we have tonnes and tonnes of dead fish rotting  and putrefying, which obviously creates hazardous material," Redondo Beach  Police Sergeant Phil Keenan said.
            Authorities who initially said they would consider dumping the dead fish  several kilometres out to sea later decided to truck them instead to organic waste  recycling centers, where they could be turned into fertiliser.
            Trudy Padilla, the marina's tenant services co-ordinator, said the dead fish  suddenly began showing up overnight, and that one end of the marina had been  blocked off as clean-up operations got organised.
            King Harbour Marina provides 850 boat slips to private vessels.
            Meanwhile readers of the Los Angeles Times website were offering their suggestions.
            One said: "Instead of hauling the dead anchovies to the dump the city should make some money by selling them to bait shops - like the saying, 'When life gives you lemons, make lemonade.'"
            Another, Captain Willy Hampton, said: "This happens on the east coast every year when the blue fish chase the bait fish into a closed area and the massive number of bait fish simply deplete the oxygen in the water. Don't waste your $ on figuring it out. Use the dead fish for fertalizer. This is something that just happens."
            AFP, Reuters, smh.com.au