What are Phytoplankton?
Phytoplankton are microscopic marine algae that make up the bottom layer of the oceanic food web. They are located in the upper portion of the water column, which is known as the photic zone. Here they can absorb sunlight and inorganic nutrients to undergo photosynthesis and derive energy. As the basis of marine life, their health is essential to the well-being of all other marine species.
While their presence is vital, high concentrations of phytoplankton occurring from a bloom may pose a risk. Harmful algae blooms (HABs) are a result of high density phytoplankton clusters that threaten environmental and public health. These algal blooms may be problematic simply as a result of the increased plant biomass produced, or further due to the potential toxicity of the phytoplankton species. Some species have the ability to produce toxins at various stages of development and when environmental factors are conducive. When toxins are produced, they may be processed and stored by various filter feeders, such as shellfish. These toxins can bioaccumulate in the animal and become a public health risk to anything that consumes them.
The Monitoring Program
There are three major potentially toxic species of phytoplankton in the Gulf of Maine: Alexandrium spp., Pseudo-nitzschia spp., and Dinophysis spp. These species have the ability to produce biotoxins that are known to cause paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), and diarrheic shellfish poisoning (DSP) respectively.
To maintain public health, CEHL is working with the Maine Department of Marine Resources Public Health Division to support the Community Phytoplankton Monitoring Program. Volunteers assess phytoplankton health at three different locations on Mount Desert Island by collecting water samples and other environmental variables on site, and conducting target cell counts back in the lab. View the full operating procedure for volunteer phytoplankton monitors.