A shortage of dissolved oxygen, likely caused by a rapid overnight algae bloom and low wind and tide conditions, is being blamed for last week’s fish kill reported in the Mississippi Sound near Pass Christian.

Mississippi Department of Marine Resources spokesperson Melissa Scallan confirmed the fish kill happened overnight on Tuesday, June 23, and had started to subside by early Wednesday afternoon. Scallan said most of the fish were cleaned up from the beaches and the Sound by the weekend.

Scallan also said that though water tests showed dissolved oxygen levels too low to support most aquatic life, it was not a water quality issue and no beaches or waters were closed.

While MDMR did not issue a media release, it did investigate after the public reported seeing fish and shrimp breaching the water near shore between Long Beach and Pass Christian.

Two bits of good news about the kill: No evidence of a red tide was found and it was a short-lived event.

Fish kills are not rare in the Sound in the summer months, particularly when there’s a combination of low wind and low tide added to warm water temperatures.

Chemical spill drill underway

In other news from the MDMR, officials are asking the boating public to avoid the area around the Bangs Lake area of the Grand Bay National Estuarine Research Reserve where a simulated industrial spill is held this week.

The exercise will help scientists study the effect of a chemical spill in the NERR. The NOAA Disaster Response Center and its Aircraft Systems Program office will assist NERR scientists. Others participating in the exercise include the Northern Gulf Institute, University of Southern Mississippi, Dauphin Island Sea Lab, Mississippi State University and the University of West Florida.

For two to three days, participants will study the movement of a dye plume that will simulate a large-scale release of phosphate from a nearby industrial facility. During this time, the NERR staff asks local anglers and boaters to avoid the area and Marine Patrol officers with the Mississippi Department of Marine Resources will be at the entrance to the lake to answer questions about access.