After weeks of contaminating local waters, a naturally occurring red tide, which some say can cause health problems in ocean swimmers, appears to be drifting out to sea.
By Mollie Vandor/Special to The Malibu Times
A red tide invaded Malibu this summer, and it’s not always pretty-or healthy.
While many experts assert that red tide, which is caused by naturally occurring algal blooms, is not inherently harmful to beach-goers, “some believe that swimming, boating, or breathing sea spray that is affected with
red tide organisms can cause
eye irritations, skin discomfort, and sore throats,” said Vicki Wawerchak, education manager at the Santa Monica Pier Aquarium. “So be careful out there.”
Shellie Luce, staff scientist for the ocean-monitoring organization, Heal the Bay, elaborated on
the dangers of red tide. “Some dinoflagellates produce a toxin that is poisonous to animals,” she said. “However, it takes quite a lot of it. It could harm humans if people ate shellfish, for example, from the Santa Monica Bay, because shellfish filter so much water that they concentrate toxins, and if a person ate it they would get a high dose of toxins and feel sick. That’s why it’s illegal to harvest shellfish from
the Bay.
“Red tide is a bloom of phytoplankton called dinoflagellates,” Luce continued, “which are single-celled organisms that are red in color. When there is enough of them they tint the water red or brown.” She also said red tide is a natural phenomenon that “happens periodically
and may be related to water temperature or to currents and upwellings that bring high nutrient water close to shore.”
Many agree the brownish tinge is also unsightly. Beach-goers from Topanga to County Line have compared the oceanic discoloration to everything from blood to sewage.
“It’s definitely gross,” Malibuite Jaclyn Newman said.
Avid beach-goer Morgan Roberts complained that “the water stinks and it makes you sick.”
The unique thing about this year’s red tide is its duration. Roberts said that in all of his years in Malibu, “I never saw a red tide last such a long time.”
Newman added, “When I went away to school about a month ago, the red tide was kind of bad. But now it’s disgusting. When I came home to Malibu recently I was shocked because not only was it still here, but it actually looked worse than I’ve ever seen it before.”
Despite similar reactions from many local residents, County Lifeguard Capt. Nick Steers said the phenomenon has not significantly affected beach attendance. Steers said that in terms of tourism, “We haven’t had any change; the normal crowd patterns have been consistent throughout the summer. People do ask us about the red tide just because they don’t know what it is, but we tell them that the Health Department checks the water on a daily basis and as long as they don’t give us any warnings, there’s no reason for concern.”
As of this week, the phenomenon appears to be leveling off. “One-quarter-, one-half-mile offshore there are still red tides, but the inside has cleared up nicely,” Steers said.
The unusual characteristics of this year’s red tide have many scientists blaming people, not plankton. “It could be that people have contributed nutrients to the water through run-off and through treated sewage discharges,” Luce said. “It is a natural phenomenon, but we may be increasing its frequency.”
Wawerchak agreed that humans have affected the frequency of red tides. “Transport in ballast water of ships and pollution, sewage, and fertilizer found in urban runoff” are probable human causes for the increase, she said, adding that the experts lately have been “bombarded with questions regarding the polluted waters.”
Red tide is not all bad, though. As Roberts pointed out, colorful tides can sometimes be fun, because “at least it glows at night.”
Wawerchak agreed. “If you have the chance to visit the ocean at night, check out the bioluminescence that occurs in the waves. These dinoflagellates can take energy from a chemical reaction and convert it to light energy so that they produce an awesome blue-green light that looks like a fireworks show in the water.”