Southern California a good spot for sharks but Northern California is not
Great white sharks are arriving in the waters near Southern California. They spent the winter farther south, near Baja California. Baja California is in Mexico. It is below the U.S. state of California.
Usually, sharks swim south toward Mexico for the winter. The waters there are warmer. Last year was different, though. The sharks stayed in California longer. Then, they came back earlier than usual in the spring.
The sharks are back early again this year. Scientists are not totally sure why.
"We just don’t know what’s going on this year,” Lowe said.
A Serious Shark Bite
Leanne Ericson lives in Vista, California. She is 35 years old. Recently, she was swimming near San Onofre State Beach in San Diego. She was bitten by a shark. She was seriously injured.
Chris Lowe runs a center to study sharks at California State University in Long Beach. It is called the Shark Lab. He said the shark that attacked Ericson was probably not an adult. The young shark probably attacked her by mistake. Young great white sharks mostly eat fish and rays. Rays are flat, bony sea creatures.
Shark attacks are very rare. Young sharks can mistake swimmers for food. In most cases a swimmer or surfer has gone far out in the water. Sharks hardly ever come near a crowded beach.
“It’s not something that happens every day,” Lowe said.
Great Whites Like Warm Water
Adult great white sharks eat sea lions. They eat other sea animals, too. The sharks are normally near the coast of Southern California between May and October. The rest of the year, the water is too cold for them.
Last year, warm waters stayed because of an El Niño. Normally, in the winter there are strong winds across the Pacific Ocean. This stirs up cold water from deep in the ocean. It rises to the top. Sharks do not like cold water. They swim to warmer waters until the summer.
During El Niño, the usual winds slow down. They might stop completely. The cold water does not rise. As a result, the ocean is warmer.
That is why the sharks stayed in California longer last year. But this year is not an El Niño year. The water is not unusually warm. Still, some younger sharks are getting to California earlier.
Leopard Sharks Poisoned By Chemical Waste
That is not the only shark mystery this year. Something unusual has been happening in Northern California, too. Many leopard sharks have died near San Francisco. Leopard sharks are thin and have spotted markings.
Sea life experts are concerned.
Some scientists think they know why the sea animals are dying. For years there was garbage and chemical waste jammed in nearby storm drains and waterways. There were heavy storms this winter. The trash and chemicals finally washed into the sea. The chemicals in the water poisoned the sharks.