Red Tide Algea seen on the Indian Ocean on Clarence Drive. A red tide is a type of harmful algal bloom. that grows out of control producing toxic or harmful effects on people, fish, shellfish, marine mammals and birds.
San Diego, California – After months of unprecedented impact on marine life, experts are now indicating that the worst of the severe algae bloom affecting Southern California waters appears to be subsiding. The Marine Mammal Care Center (MMCC) in San Pedro recently reported a significant decrease in new patients exhibiting symptoms of domoic acid (DA) toxicosis over the past week, with no traces of the causative Pseudo-nitzschia algae detected in Southern California waters as of last Friday.
The recent outbreak, fueled by the neurotoxin domoic acid produced by Pseudo-nitzschia algae, has sickened and killed numerous marine animals, including birds, sea lions, and dolphins, for several months. The influx of afflicted creatures overwhelmed veterinary facilities and care centers along the Southern California coast. Many of these animals, however, received critical treatment and were able to recover from the potentially fatal toxin. The MMCC characterized this event as the “longest, most toxic, and deadliest bloom” on record, acknowledging the vital community support that enabled the rescue of hundreds of marine mammals.
Despite the current signs of improvement, the MMCC is proactively preparing for future challenges by expanding its facilities and increasing patient capacity. The frequency and intensity of such events are escalating, with marine biologists noting an alarming trend of increased occurrences year after year. The warming and acidifying oceans, a consequence of climate change and increased carbon dioxide absorption, create ideal conditions for the proliferation of various algae, including toxin-producing species like Pseudo-nitzschia.
The domoic acid-producing algae emerged earlier this year than previous outbreaks and demonstrated particular severity between Los Angeles and Santa Barbara counties. Wind-driven upwelling, a natural process that brings nutrient-rich deep ocean water to the surface, fuels California’s thriving marine ecosystem but can also contribute to the rapid growth of these harmful algae and the toxins they produce. The current outbreak has disproportionately affected dolphins, with over 100 individuals impacted, a significantly higher number than in previous domoic acid events at this point in the year. Scientists theorize that upwelling may have concentrated the algae in deeper offshore waters, where dolphins are more prevalent.
A notable pulse of upwelling in mid-February is believed to have contributed to the bloom, with marine life first showing signs of distress around February 20 near Malibu. This timeline marks an earlier onset compared to most previous blooms. Researchers are also investigating a potential link between runoff from recent wildfires in Los Angeles and the elevated nutrients offshore that could have further exacerbated the bloom. Scientists aboard the NOAA research ship Reuben Lasker collected samples during the fires to ascertain the potential impact of fire runoff and debris on ocean waters and marine life. In anticipation of recurring events, the MMCC is actively fundraising to bolster its preparedness efforts.
