The Indians of the South-East of North America for thousands of years was collected virgin oysters without harming the local ecosystem. To such conclusion researchers have come, having analysed almost forty thousand shells from fifteen archaeological sites. For almost the entire pre-Columbian era, their average size increased, indicating a healthy population. In our days the number of virgin oysters undermined by the commercial fishery at the turn of XIX-XX centuries and the authors hope that the experience of Indians will help to restore it. The results of the study were published in the journal Science Advances.
Large bivalves have long served as humanity a valuable source of protein. For example, the North American Indians for thousands of years, collecting of virgin oysters (Crassostrea virginica) on the Atlantic coast. Thus, when in the XIX century the commercial exploitation of oyster reefs began Americans of European descent, the population of mollusks rapidly declined. By the beginning of XX century large-scale fishing of oysters in this area became impossible.
A team of researchers led by Victor Thompson (Victor D. Thompson) from the University of Georgia decided to find out how many years of gathering the Indians influenced the population of oysters. To do this, they measured 37805 empty shells from fifteen archological excavations on the coast of Georgia and South Carolina. Finds dated back to two historical periods — the late archaic (4500-3500 years ago) and Mississippi (1000-500 years ago). In addition, the analysis added data on the distribution and the number of virgin oysters in the late nineteenth century and 1970.
In pre-Columbian era, the number of Indians living on the Atlantic coast in South-Eastern United States, and grew, and their communities became more complex. Based on these data, the authors expect to see a gradual decrease in the size of oysters to be evidence of excessive collection. However, the real picture was more complicated.
In some areas, the size of the oysters really decreased in the period of late archaic times, which probably indicates intensive harvesting. Overall, however, the size of the clams has grown for several millennia, reaching its maximum in the period before commercial operation. This not only demonstrates that oysters were able to grow to large sizes, but also indicates the stability of their habitat: as shown by the analysis of the maps of the nineteenth century, the value of oysters correlates with the area of oyster reefs.
Thus, native Americans for a long time collecting oysters without harming their population. How exactly they did it is unclear. The authors of the study suggest that in the hierarchical society of the Indians of the Mississippi period there was a system of private property rights to land, where he made the collection of shellfish. In addition, decisions to open or close certain reefs to fishing could be made at a higher level.
After the arrival of Europeans, the number of the Indian population of the South-East of North America fell sharply. The size of the oysters and the productivity of oyster reefs as a result has increased, but not for long: the commercial harvest of millions of tons of shellfish in the late nineteenth century caused serious damage on the population, which is still being felt. According to some estimates, the result of fishery total area of oyster reefs on the coast of South Carolina and Georgia decreased by 86 percent.
According to the authors of the study, the study of the Indian experience could be the basis for new approaches to resource management, which would make the extraction of virgin oysters are environmentally sustainable. In our days, when these mussels are faced not only with the consequences of overfishing, but also climate change, it is especially important.
The culture of many native American peoples has been lost or changed dramatically after contact with Europeans. To find out what it was originally, sometimes it is necessary to apply sophisticated technologies. For example, through experimentation and chemical analysis, scientists have establishedthat the indigenous inhabitants of the North-Western States of the United States smoked sumac and local type of tobacco.