Algae Blooms and Pfiesteria

Algae can be found in waters around the world from the Gulf of Mexico to Antarctica and even in your fish tank. Algae can be as large as the kelp forests off California or so small that they can’t be seen by the naked eye. Algae are a vital part of the food chain, serving as a primary food source for many types of fish. Most algae are harmless in small quantities, but large quantities of algae can deplete oxygen levels threatening other marine organisms. Some algae can even be toxic to both marine life and humans. When these toxic algae multiply rapidly in an area it is often referred to as a Harmful Algal Bloom, or Red or Brown tide.

Why Should I Care?

Harmful Algal Blooms, while rare, can negatively impact water quality and human health. As someone who enjoys being out on the water it is important to know if there is a Harmful Algal Bloom in your area. Your state’s Department of Natural Resources monitors local water conditions and will provide information on Algal blooms in your area. It is important not to swim or fish in waters where there is a Harmful Algal Bloom. The toxins in the algae can accumulate in fish tissue and harm humans.

It is difficult to prevent Harmful Algal Blooms as their causes are still somewhat unknown. It is best to stay informed about your local water quality conditions when fishing and swimming. If you are on the water and notice unusual conditions such as reddish colored water or large numbers of sick or dead fish contact your state’s Natural Resource agency.

What is Pfiesteria?

Pfiesteria piscicida is a microorganism that belongs to a group of algae known as "dinoflagellates". It occurs naturally in waterways along the East Coast (has for thousands of years) in at least 24 known life stages. All but four stages are harmless. Under certain conditions, populations may suddenly increase (bloom) and change into one of the four toxic life stages. The Pfiesteria cells then emit toxins that stun fish and dissolve their scales and skin, enabling them to feed on the fish and cause deep ulcers (lesions). Pfiesteria has been linked to fish lesions and fish kills in coastal waters from Maryland to North Carolina.

What should I do if I see a fish kill or large numbers of fish with lesions?

• Avoid contact with the water.
• Use caution when handling fish with lesions. Wear gloves or release fish without touching by using a dehooking tool.
• Leave area immediately.
• Contact the appropriate state agency to report your observations.