A well-known rule States: mussels only in months, ate, the Name of a "r" contains, i.e. from September to April. This practice might be ancient: scientists report that people held in regard to the oysters well-known thousands of years ago to the R-rule.
US scientists have discarded oyster shells on the island of St. Catherines, off the coast of Georgia analysed and it was found that the inhabitants harvested already oysters, 4,000 years ago, mainly in the late autumn, Winter and spring. May the residents have used in the summer, then other food, wanted to avoid inedible oysters, the risk of pathogens or decrease the stock spare, so that a sustainable harvest is guaranteed. "The understanding of how people are dealt with in the past, with their environment, and these have influenced our present-day efforts to protect the environment unterstützen" Nicole Cannarozzi from the natural history Museum in Florida, commented on the new discovery.
But how do the researchers know have collected the oysters, when the inhabitants of the island? Have you found out by investigating the level of development of parasitic snails that live on the shells of the oysters, this drilling and a trunk from the Inside of the shell to feed. The snails have a life cycle of twelve months, by the estimate made when the oysters &ndash died; for the researchers a tiny times of the year-at.
The reason for the well-known R-rule is the following by the way: mussels feed on, among other things, of algae, which, however, leave small amounts of poison in the mussel meat. In the summer, this amount can reach a considerably high concentration so that the consumption of such shellfish can be extremely harmful to health.