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This page tracked the 2005 New England red tide bloom and is no longer being updated. For information about the current New England red tide bloom, visit the Center for Sponsored Coastal Ocean Research Alexandrium Red Tide in New England Web site.



The Issue

Many algal species form blooms commonly referred to as "red tides," each with distinct impacts. The New England Harmful Algal Bloom event is caused by the toxic alga Alexandrium fundyense. Blooms of this microscopic alga occur periodically in the Gulf of Maine, but rarely at the density and geographic extent being witnessed since May, 2005. 

Red tide blooms, also known as harmful algal blooms or HABs, can produce potent neurotoxins that accumulate in filter-feeding shellfish and other parts of the marine food web. Shellfish contaminated with the toxin from Alexandrium, if eaten in large enough quantity, can cause illness or death from paralytic shellfish poisoning or PSP.

This year's Alexandrium bloom, the largest recorded in New England waters since 1972, began in the Gulf of Maine in early May. The bloom spread into Massachusetts Bay forcing the closure of shellfish beds as far south as Buzzards Bay, Nantucket Island and Martha's Vineyard. It also spread offshore, resulting in a temporary closure in federal waters.

Cell counts indicate that the bloom has mostly dissipated. On September 9, NOAA Fisheries Service re-opened federal waters that had been closed as a result of the bloom to the harvest of most bivalve mollusks. States have reopened many areas to shellfish harvesting, but some areas remain closed. It is important to check state Web sites for the latest information on shellfish closures.


The NOAA Response

NOAA Science Services Supporting New England HAB Response 

NOAA is mandated by the Harmful Algal Bloom and Hypoxia Amendments Act of 2004 - Public Law 108-456 - to assist in responding to HAB events.

NOAA has responded to the New England event with:

NOAA provided critical analytical laboratory services and delivered short-term emergency funding to engage a key, NOAA regional partner, the Woods Hole Oceanographic Institution (WHOI), in the response effort. NOAA emergency funding enabled WHOI's HAB experts to design and operate a sampling program to answer key short-term response questions such as:

  • Where is the bloom located and in which direction is it headed?
  • Are cell and toxin concentrations increasing or decreasing?
  • When will the bloom and related shellfish closures end?
  • Is the bloom expanding?
  • Is there an increased likelihood for future blooms?

Engaging WHOI scientists in this response has the added benefit of advancing the NOAA goal for a New England regional HAB prediction capability that will mitigate future bloom impacts. This effort is being coordinated throughout NOAA and with other partners to ensure that agency mandates safeguard sustainable fisheries, protect public health, and protect endangered species.

To learn more about New England HAB research and response efforts visit:

NOAA's Center for Sponsored Coastal Ocean Research

Woods Hole Oceanographic Institution's Northeast PSP Web page



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General Information

NOAA News Releases

Partner News Releases

Reporting Incidents

Seafood Safety

More about Red Tides and Harmful Algal Blooms

Fishery Assistance Information

NOAA Fisheries Service, Magnuson-Stevens Act 312(a) Information

NOAA Responds to New England Red Tide – A Questions & Answer Resource (pdf, 44kb)

Small Business Administration Red Tide Assistance Information

Regional Information, Including Maps

NOAA Fisheries Regional "Hot News" Red Tide Web Site

Woods Hole Oceanographic Institution's Red Tide in New England: Update on the Spring 2005 Outbreak

State Closure Information

Revised June 19, 2009 | Questions, Comments? Contact Us | Report Error | Disclaimer | About the Site | User Survey
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