Golden Algae Bloom Update


On Saturday, November 4, the Lago Santa Margarita Lake began to experience a golden algae bloom otherwise referred to as a “fish kill.” You may have noticed a rather strong odor and unpleasant sight. Historically, the Lago Santa Margarita experienced its first ever golden algae bloom in October 2014, and again in October/November 2015, which resulted in a similar ecology incident.

For incidents such as these, the timeline can vary from a couple days to a week or potentially longer. Factors as to why this incident occurred can only be theorized by fluctuations in the weather, water runoff from rain or other natural occurrences. As soon as SAMLARC staff noticed that the fish were perishing due to the algae bloom, staff immediately started to remove the expired fish from the Lake to dispose of them properly and continue to do so multiple times per day.

Many factors come into account when managing a Lake affected by golden algae. The water cannot be completed eradicated of the algae as reintroduction of the algae is inevitable. Golden algae (Prymnesium parvum) is a single-celled organism that occurs worldwide, primarily in coastal waters, but it is also found in rivers and lakes. The presence of golden algae doesn't always cause problems, but when it "blooms," (enters a phase of rapid growth and reproduction) the algae can produce toxins that cause a “fish kill.” The toxins affect organisms that have gills including; all types of fish, freshwater mussels and clams, and the gill-breathing juvenile stage of frogs and other amphibians. The turtles, birds and crayfish should not be affected by golden algae.

Unfortunately, once a bloom is underway there is no proven method of stopping the bloom. Per SAMLARC consulted aquatic life experts, the only viable option is to let nature take its course. SAMLARC staff will continue to work with the Lake management vendor to monitor the Lake both by boat and on shore with extra ongoing daily clean-up of the Lake for the duration of the golden algae bloom.

While Golden algae runs its course, L