Port Royal Sound's fishery
Fishing in the waters of the Port Royal Sound system is truly great – we have healthy stocks of redfish, cobia, tarpon, sharks, and other fun-to-catch game species. But why is that the case?
This blog is a guest post by my wife, Kristen, an environmental educator for the LowCountry Institute.
The Port Royal Sound watershed is unique from other watersheds on the east coast. We have very high tides – at 8.5 ft. on average they are the highest on the east coast outside of New England. This phenomenon relates to the shape of the coastline. Port Royal Sound is located at the apex of the curve called the South Atlantic Bight. Tidal waters are funneled into a smaller and smaller area, making the amplitude very large. Since there are no major freshwater rivers flowing into the watershed, this also means that salinities are very high and there is little sediment being brought into the system so channels and creeks remain deep.
The high tidal amplitude and lack of sediment and freshwater input to the system create an area dominated by huge expanses of salt marsh. Salt marsh is a highly productive ecosystem. As the marsh grass, Spartina alterniflora, breaks down, it is fed on by microscopic organisms in the water. This is the beginning of the marine food web. Filter feeders such as oysters and menhaden then filter these food particles out of the water and are in turn fed on by larger game fish, crabs, dolphins, sharks, and ospreys among others. The salt marsh serves as a nursery for many of our fish species, with nearly 70% of commercially important marine species spending at least part of their lifecycle in the salt marsh.
In addition to the high diversity associated with large expanses of salt marsh, we have clean waters with low pollution. The Port Royal Sound watershed is geologically isolated from larger, surrounding watersheds so water quality is very much a product of local conditions (which also means that protection of these waters must take place on a local level to ensure their continued health).
All of this makes for a healthy fishery where there are many species to catch and an abundance of them. Port Royal Sound has an amazing assortment of shark species – blacktips, lemons, tigers, and hammerheads are caught in inshore waters! This sounds scary but in fact indicates that our fishery is healthy, with plenty of baitfish to sustain these apex predators that enter our water to drop their pups during the summer months. Many of these shark species provide great sport fishing opportunities including blazing runs and spectacular jumps. Cobia and bull reds are other great examples of fish species which enter Port Royal Sound waters to reproduce. We have ideal conditions for breeding for these fish and studies have shown that unique sub-populations return from the ocean year after year to these same waters to reproduce.
There are many ways you can help maintain our lowcountry fishery – follow size and catch limits so that we don’t overfish our marine resources, practice catch and release, and use best practices to maintain lawns and gardens to minimize any pollution that could enter the salt marsh to keep our water clean. Want to learn more about the Port Royal Sound system? Click the image below to watch an episode of Coastal Kingdom all about the Port Royal Sound which features Capt. Chris catching cobia with Tony Mills.