GULF OF MEXICO — The Mississippi Department of Environmental Quality (MDEQ), in coordination with the Unified Incident Command in Mobile, Ala., is launching an initiative this week to systematically sample for submersed oil in the Mississippi Sound.
This intensive effort will extend from Mobile Bay to the Louisiana state line, and the initial phase is expected to be completed in approximately fourteen days with weather permitting.
“Fish, shrimp and crabs in Mississippi waters are safe to eat based on the extensive water and seafood sampling conducted by multiple federal and state agencies. We are implementing this monitoring effort to provide a more complete picture of whether any oil remains in our waters and to address the questions we all have about potential underwater oil. A three-pronged sampling effort should provide a good picture of what is or is not in the Mississippi Sound. If there is oil in water column, we want to know about it and deal with it. If it is not, then we want to put an end to the underwater oil assertions which is only damaging the marketability of our seafood, ” said Trudy Fisher, MDEQ executive director.
This plan, employing Vessels of Opportunity and six of the state-owned skimmers, includes three separate and unique tactics to investigate the existence of submerged oil in the Mississippi Sound:
• Sorbent Probes Deployment and Water Sampling — The first method uses about 30 private vessels from the Vessels of Opportunity Program using sorbent probes and depth finders to find and delineate areas of suspected oil below the water’s surface. The Mississippi Sound will be divided into a grid, made up of areas that are approximately two miles on each side, an area of approximately four square miles. This grid formation will create approximately 180 distinct areas of approximately equal size that will be thoroughly surveyed for the presence of submerged oil.
The six sampling boats, staffed by MDEQ, will collect samples from any areas of suspected oil identified by the surveying vessels. The surveying vessel will deploy sorbent probes at regular intervals along the survey route, and also when depth finder readings indicate something suspicious below the surface. If the probe indicates that potential submerged oil is present, the survey team will contact the MDEQ sampling team to initiate sample collection activities. Samples will be analyzed for petroleum compounds, dispersants, and phytoplankton or algae.
• Fluorometer Readings and Water Sampling — The second sampling technique will involve the continuous measurement of oil in the water column as a vessel will tow a submersible fluorometer along a specified course from Mobile Bay to the mouth of the Pearl River on the western side of Hancock County. This instrument will continuously monitor for oil plumes, and this real-time data will be coupled with GPS locational data and other routine water quality data including oxygen, temperature and salinity. Sampling technicians aboard the vessel will collect additional samples when the flourometer detects the presence of oil in the water column. This technique has been used successfully in deepwater studies aboard oceanographic research vessels, but this will be the first time this has been used in Mississippi Sound.
• Sediment Grabs — The third part of this sampling effort will focus on oil in or on the bottom sediments of the sound. A separate vessel and crew will be dedicated to this task. The crew will collect sediment samples along a specified course throughout the Sound. The samples will be inspected visually and by smell for the presence of oil, and if oil material is suspected, samples will be collected for further analysis.