As most of us have witnessed over the last decade, many oyster reefs have been affected by increased salinities in bays due to the extended drought of the prior 7 – 10 years. With this years lowered salinity return, oyster populations and reefs should fairly quickly recolonize restoration reef areas.
Over the last several years I’ve heard many hypothesis from anglers as to why the oyster reefs are gone. Many believed they were targets of over-harvest by the oyster fleet, and some believed it was errant shrimp trawlers that turned the reefs to appears almost like coarse sand. While those activities will harm a reef, the truth is that the higher salinity of the drought stricken bays allowed one of the oyster’s predators to enter bays in numbers sufficient to totally obliterate the reefs. The ‘Oyster Drill’ secrets sulfuric acid to create a hole in the shell of an oyster and feed on the protein contained inside. Once the oyster is dead, it’s shell will continue to degrade into small fragments.
If what was formerly a reef does not contain sufficient substrate size of either reclaimed oyster shells, or something hard like rock or metal to hold the new oyster larva or ‘spat’ then that reef may never be re-colonized and may never return to a quality fishing location. That reef would be classified as dead and no longer a good waypoint. However, some of the dead reefs were only partially degraded and will return with this years low salinities.
Photo Courtesy of http://www.nrcs.usda.gov/