Words from the Water: Harmful Algal Blooms

Algae are simple plants that can range from microscopic, single-celled organisms to large seaweeds. Harmful algal blooms, or HABs, are becoming more widespread and more frequent in recent years all over the world. Although harmful algae species are a normal part of the ecology of a water body, changes in things such as nutrient inputs and weather can trigger the blooms. Toxic byproducts from some of these algae occasionally reach high enough levels as to pose risks to recreational water use, drinking water and human health – often resulting in serious economic consequences to coastal communities.In mid July, NY Sea Grant organized two conferences in Buffalo and Auburn on Harmful Algal Blooms in the Lower Great Lakes. Topics included the history of HABs, how they form, HAB toxins, how to detect or predict HABs in our waters, how to manage and monitor them and why they are increasing. These workshops were funded by a grant from the Research Foundation of SUNY.Two representatives from the Wayne County SWCD attended the conference in Auburn. There was a great deal of information presented at the conference and a few of the highlights are listed below:· Total phosphorus loading to Lake Ontario was at an all-time high by the mid 1900’s, which caused an increase in the occurrence of HABs. By the 1970s, through environmental policies, regulation, and control, total phosphorus loading started to drastically decrease, as did the occurrence of HABs.· In the 1980s, with the introduction of invasive mussels in Lake Ontario, there was a slight increase in total phosphorus concentrations and also the occurrence of HABs. This is mostly due to the fact that invasive mussels have a tendency to filter out green algaes rather than blue-green algaes. · Blue-green algae, also known as cyanobacteria, have a gliding motility and can control their buoyancy which allows them to move throughout the water column. This allows them to move to a certain depth in search of optimal light intensity, available nutrients, and to avoid predators. At night, they are unable to control their buoyancy without light. They float to the surface and form a scum that will remain until wind and wave action dissipate them.· Eating fish from waters affected by blue-green algae blooms is an unknown health risk. Though definitive research is limited, there have been no reports of people becoming sick from eating fish caught during a bloom. Algae toxins have been found to accumulate in the internal organs (liver and kidneys), but studies suggest that the muscle tissue is less affected.

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