For the seventh week straight, hundreds of sharks have been washing up dead on the shores of the San Francsico.
The executive director and founder of the Peglafc Shark Research Foundation, Sean Van Sommeran said that he has been getting calls every day since March of sharks washed up along the waterways of San Mateo County, Alameda and even Lake Merritt.
"We cannot actually keep up with the volume of calls we get on a day-to-day basis," Van Sommeran said.
Van Sommeran has been seeing hundreds of leopard sharks washing up. He estimated the number of dead and dying sharks in the bay could be in the thousands.
"This is just the tip of the iceberg," Van Sommeran told SFGATE. "We're only seeing a fraction of the actual losses."
Years of research have led Sommeran to believe that the explanation for the stranded sharks can be found in Redwood City. "That appears to be the epicenter of all these incidents," he said.
He explained that it all come down to the city, where residents near inland waterways use tide gates, to keep from flooding during the rainy season. The city closes its tide gates during low tide. And when they are heavy rains, the extra precipitation does not combine with high tides to flood homes along with the water.
Sommeran said, the problem is that leopard sharks come into the shallow waterways to mate and pup during the spring and summer, so they often get trapped when tide gates close.
The storm runoff that fills the waterways is not good for sharks' health, but years of drought followed by an extremely rainy season have exacerbated the damage
"During drought, stuff that would usually get washed away congeals and backs up," Van Sommeran explained in an interview. "So with the hard rain there is extra crud going into the watershed."
The stagnant water in these inland waterways quickly goes foul (just like a home aquarium would if not regularly cleaned) and sickens the sharks. "The water becomes toxic and the sharks can't cope with it," Van Sommeran added.
When the tide gates are reopened, the rotting and decaying sharks are washed back into the bay, where Sommeran fears they could be contaminating more animals.
AMandeep
