Green/red tides

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Green/red tides

Human Health Risk

Ecological Risk

Socioeconomic Risk

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Green and red tides are caused by excessive growth, or “blooms” of specific classes of single-celled plants in coastal waters. Blooms occur naturally under low flow conditions, and cause a red or green discoloration of the water. Blooms may result in fish and shellfish mortality, beach and shellfish bed closures, and mild to severe illness in humans. These can range from minor skin irritation associated with swimming in affected waters to serious illness associated with shellfish consumption.

What’s at risk?

There have been chronic red tide blooms of various species in the Hudson-Raritan Estuary and New Jersey coastal waters for over three decades. Green tide has appeared as a greenish discoloration of the near shore coastal waters from Ocean City to Atlantic City during the summers of 1984-85. Algal blooms contribute to ecological problems in New Jersey, but there are few cases on record of human toxicity from algae in New Jersey waters, with the exception of moderate discomfort or illness reported from specific blooms.

What are the ecological impacts in New

Jersey?

New Jersey has experienced chronic red tide blooms over many years, with green tide organisms appearing less frequently. Blooms are associated with reduced oxygen levels in the water, shellfish mortality, and fish kills.

What are the socioeconomic impacts in

New Jersey?

The occasional appearance of discolored water may be considered a moderate aesthetic impact, but red and green tides have little impact on employment or property values, nor do the blooms impose any economic costs of significance.

What’s being done?

The New Jersey DEP Bureau of Marine Water

Monitoring monitors algae blooms throughout the summer. State and county officials have the authority to close beaches deemed unsafe because of algae. Harmful algal blooms are the subject of a national task force formed under the Harmful Algal Bloom and Hypoxia Research and Control Act of 1998.

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Final Report of the New Jersey State Comparative Risk Project

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