Natural Resource Damage Assessment and Restoration Program
M/T Athos I Crude Oil Spill
United States of America
Habitat Creation; Habitat Enhancement; Population Support
Affected DOI Resources:
To compensate for the injuries to natural resources in the Delaware Estuary as a result of the M/T Athos I oil spill, funding was provided to restore oyster beds in Delaware Bay. Oyster reefs provide many ecological benefits in coastal bays and estuaries. Numerous species of fish and crabs take up residence in the cavities and crevices, and sessile organisms including barnacles and mussels settle on the hard substrates. Schools of forage fish congregate around the reefs, and larger predatory species such as striped bass, summer flounder, black drum, and bluefish utilize these habitats as feeding grounds. Oyster reefs help protect shorelines and aquatic vegetation from erosion by buffering them from wave action. Oysters are also effective filter feeders, removing algae, suspended sediments and excess nutrients from the water. Oyster populations have experienced a sharp decline since the early 1900s due to unsustainable harvesting, and diseases caused by protozoan parasites such as Dermo and MSX.
Eastern oysters begin their lives as free-swimming larvae. When they find a hard substrate such as shells or rocks, they attach themselves to the surface where they will live for the rest of their lives. Once settled, the small oysters are known as spat. They typically grow around one inch per year, and become juveniles at one year of age, and adults by their third year. For this restoration project, the New Jersey Division of Fish and Wildlife's Bureau of Shellfisheries followed a two-step process to enhance the "Middle Seed" oyster beds on the New Jersey side of the bay. In June and July 2011, more than 26,000 bushels of crushed clamshells were placed into mesh shell bags and placed on a sandbar near Reeds Beach in the lower reaches of Delaware Bay. This was a historic oyster bed area with higher salinity and high spat settlement rates. After allowing spat to settle for three to six months, the spatted shells were harvested and transported up-bay to the Middle Seed beds near the mouth of the Delaware River. These oyster beds were impacted by the Athos spill in 2004 but have significantly lower natural mortality rates because the protozoans that cause Dermo and MSX prefer areas with higher salinity. The process was repeated in 2012 and 2013, and a monitoring program was initiated to evaluate growth and survival for five years. This built on a successful pilot project that was conducted in 2003 that enhanced a nearby oyster bed by planting over 30 million oysters.
New Jersey Department of Environmental Protection
Fish and Wildlife Service
Oyster larvae are free-swimming until they encounter a hard substrate such as a shell or rock. Once they permanently attach, they are known as spat., Credit: Steve Luell
After the spat settle on the shells, the cultch was transported up-bay and deposited onto the oyster reef., Credit: NJDEP
New Jersey Ecological Services Field Office
4 East Jimmie Leeds Road, Suite 4, Galloway, NJ 08205 | (609) 383-3938 | http://www.fws.gov/northeast/njfieldoffice/