Algal Blooms: A new summer hazard?

Over the last few summers, you may have seen an increase in “Harmful Algae Bloom” warnings pop-up around your favorite bodies of water, sometimes resulting in a complete shutdown of recreational activity. These blooms are caused by the rapid and excessive growth and accumulation of algae, or phytoplankton in bodies of water. Phytoplankton are not necessarily bad–in fact, they form the base of the marine food–but the blooms that we see occurring lately are generally harmful, and occasionally toxic. These blooms are due to eutrophication, meaning that they are caused by excess nutrients (for example, fertilizer from farms and yards) released into the water.

A main harm of algal blooms is the cutoff of the oxygen supply to the water by blocking the exchange, reducing oxygen in the water for the marine life that needs it. This is only worsened when the algae, particularly blue-green algae, dies. These can become toxic depending upon the chemicals they release when dying, and cause the water and marine life to become harmed, toxic, and/or unsafe to consume. While this occurs naturally, when a major bloom occurs, the level of toxins becomes highly concentrated, preventing normal tidal flow or water currents to dilute and disperse the chemicals.

Long Island has a large problem of nitrogen pollution into the water system, which only adds to the risk of creating a toxic bloom, as blue-green algae feeds off nitrogen.  There have already been reportings of this specific algae in the following waterbodies: Forge Pond; Peconic Lake; Old Town Pond; Spring Lake; Setauket Mill Pond; Wainscott Pond; Georgica Pond; Mill Pond; Maratooka Pond; Agawam Lake.

Another type of bloom, brown algae, has also been popping up throughout the island. Though is not hazardous to human health, it is a major aesthetic turnoff for the region,and it negatively affects local economies by deterring tourists, in addition to killing off shellfish and small marine life. Reports issued to date state that shellfish harvested off Long Island are closely monitored and deemed safe to eat.

In Long Island alone, there have been six different types of Harmful Algae Blooms documented with multiple occurrences throughout the region; brown tide, red tide, rust tide, dinophysis, cyanobacteria, and pfiesteria. Algal blooms aren’t just a problem in Long Island, they also affect Lake Erie, for example.

New York’s algal blooms thus far have not been nearly as bad as the current blooms occurring in Florida, where those that depend on the water have been forced to leave and interrupt their lives due to a noxious smell and the inability to use the resource they depend upon most. This outbreak is in part due to aging infrastructure that is unable to capture all pollutants, providing a feast for the algae in residential inlets. Ocean acidification has also been shown in lab studies to increase the likelihood of toxic algal blooms. These blooms are but another reason to reduce nitrogen pollution and nutrient runoff, repair infrastructure, and prevent further damage done through ocean acidification and nitrogen pollution.