Red Tide Bloom Closes Maine Waters to Shellfishing

Maine officials have closed some parts of the coast, banning shellfishing as a "mild red tide bloom" continues to contaminate shellfish with a harmful neurotoxin.

Red tide blooms, often referred to by officials as harmful algae blooms (HABs), are most commonly characterized by a rusty red color of the blooming phytoplankton dinoflagellate Alexandrium - a type of single celled green algae - but are not always red in color.

Like in many other shallow-water regions along the East Coast, Alexandrium is a common sight in Maine. However, it is not generally so concentrated to pose a threat to both shellfish and humans alike, according to the state's Department of Marine Resources (DMR).

What makes HAB's harmful is that they release saxitoxin - a neurotoxin that builds in "blooming" Alexandrium cells that are then consumed by shellfish, causing paralytic shellfish poisoning (PSP).

This toxin can harm humans who consume affected shellfish, causing muscular incoordination, muscle paralysis, and respiratory failure in worst case scenarios.

HABs arealso infamous for ruining once thriving shellfishing industries, such as the industry once based in New York's Long Island waters.

This is why the DMR keep a vigilant watch of Maine waters during HAB season - between April and October. As of May 14, the DMR has issued four closures of connected waters, banning the fishing of six species of shellfish; with the most recent closure of Permaquid Point to Stockton Springs, Deer Isles, and Stonington being enacted on Wednesday.

Maine has also become the first state on the East Coast to enact laws to fight ocean acidification, a factor that some ecologists suggest is contributing to HAB prevalence and the vulnerability of shellfish species to PSP.