How Lowcountry oysters came to call our waterways home

The oyster is a valuable, small sea animal in the food pyramid providing rich nutrients for consumption. Out of 500 million eggs produced by an average size oyster along the Eastern Seaboard, one scientist concluded that only one out of 1,145,000 will reach adult size, which takes 3 to 4 years. Left undisturbed, oysters can live 20 years. A majority of the original mass of eggs are eaten by other fish during the two-week period they spend in the larva stage. At this stage, the oyster tests different spots to fasten itself to, and, when one is found, it will spend its entire life there.

Oysters spawn in summer when water temperatures are at their warmest, making them thin and milky because of the converted glycogen into sperm and eggs. Warmer water temperatures also result in higher concentrations of a large algae growth, thus creating a higher level of “red tide” that can be full of toxins.

With oysters feeding off of what is filtered through its mouth, a person consuming a lot of oysters containing those toxins could risk paralytic shellfish poisoning. That bacteria is naturally more prevalent in warmer waters than the cooler waters occurring in the fall and winter months.

A Jan. 11 article in The Island Packet — “Oysters year-round: Good news for shellfish lovers” — states that the S.C. Department of Health and Environmental Control has approved the summer harvest of mariculture oysters. A bill under consideration by state lawmakers is expected to be presented to the General Assembly so South Carolina oyster lovers can enjoy shucking and slurping fresh shellfish year-round.

So what happened to change the long-standing rules of “legally gathering” oysters during the Sept. 16 through May 15 season for health purposes?

I’m just old-school enough to play it safe and stick to the standard rules already stipulated by SCDNR; I wait until the water temperature averages in the 50-degree range to gather oysters. When water reaches the stage it’s warm enough to swim in, you can bet bacteria likes it, too.

In our neck of the woods, a lot of rivers and inlets where a multitude of oyster beds are found also have numerous homes that have septic tanks. In low-lying areas during a heavy rain season, excess water can cause septic overflow that ends up in our creeks, and the state has sometimes closed down shell-fishing for health reasons.

Barnacles, like oysters, are salt-water shellfish that fasten themselves in the same fashion to objects under water, therefore landing on and covering oyster shells with their shells. They, like oysters, after attaching themselves to an object with its hard lime-like box forming around it, will live their entire life in that original spot, creating their own squatter’s rights.

This story was originally published February 13, 2017 at 6:35 AM with the headline "How Lowcountry oysters came to call our waterways home."