On May 13th, the first annual State of our Coast Conference was hosted in Biloxi, Ms. by the Mississippi Department of Marine Resources. Speakers included Jamie Miller, the MDMR Director, Secretary of State, Delbert Hosemann, and State Tourism Director, Malcolm White. While the morning sessions focused on economics and tourism, the afternoon sessions branched out into coastal processes: land loss, marsh creation and the ongoing restoration of the state’s oyster growing areas to support the seafood industry. Marine Resources Department staff geologist, George Ramseur, explained that Mississippi coastal waters don’t have enough sediment to build marshes naturally. He showed a time series of photos of Hancock County marsh shorelines near the mouth of the Pearl River. Marsh shorelines have receded northward hundreds of feet in recent decades, eroded by waves, storms and rising sea level.
George described marsh creation projects using dredge spoil moved by barge to restoration sites so land can be created by pumping a sediment slurry into shallow areas. Spoil from channel dredging in Mississippi is now being shared with Louisiana to build up areas of the Biloxi Marshes of St. Bernard Parish. These marshes are situated south of Hancock County, Mississippi and were damaged most recently by Hurricane Katrina and the BP oil spill. One result of the marsh destruction is higher salinities. Western Mississippi Sound salinities have been increasing as Mississippi’s barrier islands have eroded and as Louisiana’s Biloxi Marshes have broken up due to storms and sea level rise. Brackish marshes and oysters don’t do well in high salinity seawater, so restoration of barrier islands with sand placement, and marsh creation projects using dredge spoil are defensive tools to reduce salinities in these coastal waters.
Allan Sudduth of Chevron in Pascagoula chairs the Oysters in the Environment Committee for the Governor’s Oyster Council. He gave a preview of the Council’s report to Governor Bryant, expected in June. Oyster harvests have declined rapidly in recent years, dropping from some 500,000 sacks around 2009 to 26,000 sacks this year. The productivity of oyster beds in the Mississippi Sound and nearby marshes in Louisiana and Mississippi depends on the health and restoration of the marshes and barrier islands so salinities don’t continue increasing, but they also depend on coastal rivers continuing to deliver adequate fresh water to the Sound. Mr. Sudduth specifically mentioned that the report to the Governor will discuss “inland projects that cause fresh water depletion”. I asked him if he meant dams by this statement and he replied “yes.”
The afternoon’s update on marshes, sediment and oysters supported the idea that Mississippi doesn’t need projects on coastal rivers that reduce fresh water discharge or change the timing or seasonality of river flows. It is no surprise that the western Mississippi Sound’s waters are sediment-poor. The Pearl River has a large 50 year-old dam on it, and dams are sediment traps. This fact, in combination with sea level rise and storm damage is bad news for brackish marshes and oysters. More dams cannot improve the situation at the coast. Oysters need moderate salinities, and salinities are rising in the Sound. Restoration of barrier islands and marshes by sand and spoil placement projects can help hold back higher-salinity sea water, but Mississippi must also protect the fresh water flows that enter the Sound from its coastal rivers. Protecting the Pearl River is an obvious necessity when restoration projects are happening near its mouth in the western Mississippi Sound, Hancock County and St. Bernard Parish. We need to hold back the salt water if possible, but let’s also keep the fresh water coming.