MDEQ Issues Contact Advisory for Portion of Pearl River Due to Harmful Algal Bloom
September 26, 2025
(JACKSON, MS) – The Mississippi Department of Environmental Quality (MDEQ) is issuing a contact advisory for a section of the Pearl River from the Highway 25 bridge to the Low Head Dam due to the presence of a Harmful Algal Bloom (HAB).
On September 24, 2025, MDEQ received a report of an algal bloom in the Pearl River upstream of the Low Head Dam. MDEQ staff investigated the report and collected samples for analysis. The results confirmed the presence of several species of algae that could be harmful to humans if contact occurs. Because of this, MDEQ advises the public to avoid contact with the affected waters until further notice. Exposure to HABs can pose risks to people and mammals through skin contact, inhalation, or ingestion.
Harmful Algal Blooms develop when nutrients in the water combine with environmental conditions such as slow or stagnant water flow, excessive sunlight, and warm temperatures. At this time, MDEQ is not aware of any unnatural occurrences that may have contributed to this bloom.
MDEQ will continue to monitor the affected area and will revise the advisory as necessary or when conditions improve. See attached fact sheet (also located at www.mdeq.ms.gov) (MDEQ Issues Contact Advisory for Portion of Pearl River Due to Harmful Algal Bloom – MDEQ ) for additional information.
