Famed surfer: Women's periods 'most common reason' for shark attacks

Surfer and event host Laird Hamilton attends the 'A Day at the Beach Paddle Out Protest' in Malibu, California October 22, 2006. Surfer and event host Laird Hamilton attends the 'A Day at the Beach Paddle Out Protest' in Malibu, California October 22, 2006. Photo: PHIL McCARTEN Photo: PHIL McCARTEN Image 1 of / 24 Caption Close Famed surfer: Women's periods 'most common reason' for shark attacks 1 / 24 Back to Gallery

Laird Hamilton, co-inventor of tow-in surfing, might be spreading some misinformation when it comes to shark attacks and women's menstruation.

TMZ spotted the famed surfer in Malibu, Calif., on Wednesday and asked for his thoughts on the recent increase in great white shark sightings in Southern California.

See also: Here's why shark attacks are on the rise in California

Hamilton began by deftly debunking certain myths surrounding sharks, explaining that "most shark attacks are not fatal."

"They say that soda machines kill more people every year than people are bit by sharks," he said, adding that attacks are usually a case of "mistaken identity."

Then Hamilton kept talking.

"The biggest, most common reason to be bitten is a woman with her period, which people don't even think about that," he said. "Obviously, if a woman has her period there's a certain amount of blood in the water."

According to Dr. Chris Lowe, director of the Cal State Long Beach Shark Lab, menstruation doesn't create enough blood to attract sharks.

Lowe told the Huffington Post: "This is one of those misconceptions that refuses to die. In fact, the amount of blood loss during menstruation is probably less than [the] average scrape or cut that a kid or surfer may get while playing in the water."

Women lose between 1.2 to 1.7 fluid ounces of blood on their period, and Lowe posits that if children with minor injuries aren't getting attacked, then periods can hardly be to blame.

Toward the end of the interview, Hamilton veers back into more scientific territory.

"If you're a fisherman with bloody fish in the water or you're in a position where you're mistaken as a seal, these are incidents to increase your odds," he said in closing.

Earlier this month, Lowe spoke with SFGATE about the uptick in Southern California shark attacks. His best advice for staying safe? Remembering that you're not the only one frolicking in the water.

"We have unfettered access to the ocean," Lowe told SFGATE. "Humans have forgotten how to share habitats with wild animals, and they have to be re-educated."