SAN DIEGO — It’s that time of year when onlookers gather at San Diego County beaches just after sunset in hopes of catching a glimpse of the “red tide” otherwise known as harmful algal bloom. 

Santos Peña has lived in San Diego since 2004. Seeing the spectacular bioluminescent display along the beaches of La Jolla has become a family tradition. “We’ve seen it in the past during the pandemic up at Windansea, so we saw it there with our kids and it was just pretty amazing,” Peña tells FOX 5. 

While the stunning neon display draws attention both near and far, geologist Patrick Abbott warns it could bring increased bacteria along the coast. “A lot of the seafood, the seashells and all, become polluted because of that high load of microorganisms decaying. Another common source of pollutants is the phytoplankton blooms,” Abbott explained.  

San Diego County currently has 10 advisories, one warning and one closure currently in effect due to bacterial concerns. Most have been issued Monday and Tuesday, notifying people that ocean water samples in Coronado, La Jolla, Oceanside, Mission Bay, Pacific Beach and Imperial Beach exceed state health standards due to high levels of bacteria. 

Pathogens that may be found in swimming water contaminated by sewage or urban runoff could lead to certain illnesses and symptoms like stomach cramps, fever and diarrhea.What we’ll do is we’ll tend to go a little bit more north to the beaches where it will be safe to swim,” said Peña. 

The ocean shoreline from the south end of Seacoast Drive in Imperial Beach to Carnation Avenue was issued a warning Monday. Bacteria levels there also exceed health standards and the county is urging residents and tourists to avoid water contact in the warning areas.

Dr. Abbott confirms bacterial warnings and advisories in the Imperial Beach area are more common than most due to bacterial pollution traveling north from the Tijuana River. 

The recent hurricane season is another factor that could be bringing pollution along the coast, like San Diego recently experienced with the remnants of Kay. “A lot of those storms that come up from the south change the surface ocean circulation, so in other words, the waters are blown more from the south towards the north, which just does not happen in the winter or the rest of the year,” explained Dr. Abbott.