What causes an algal bloom?


What causes an algal bloom?

Most of us have heard the word “algae”, but don’t really know where it comes from or how they affect our water bodies. An algal bloom can consist of a broad range of organisms that “bloom” at different concentrations and in various colors, from green to red to brown. Algal blooms fall into two broad categories: freshwater algal bloom or harmful algal bloom.

Freshwater algal blooms form due to excess nutrients, specifically certain phosphates. The algae condense from phosphates that enter the watershed through runoff. Some causes may be from fertilizers used in agriculture and recreation and household cleaning products containing phosphorous. Other causes could be from excess nitrogen and carbon. These algae have short life spans and the matter eventually decays, absorbing much of the available oxygen supply. This deprives plants and animals in the ecosystem of their most valued resource, thereby devastating their population.

Harmful algal blooms occur in the ocean and originate in much the same way as freshwater algae, excess nutrients getting into water bodies. These algae naturally produce toxins that damage many organisms’ faculties, which can include developmental, neurological and reproductive. Not only are the marine animals affected, but humans that consume them are also susceptible to the dangers of these toxins.

Luckily scientists continue to research the best methods to reduce these nutrient concentrations, but it is also our responsibility to prevent them from getting into our waterways in the first place.