ABSTRACT
The history of the exhaustion of the French oyster banks shows that the territory of a bank is also populated by other organisms. The oyster banks of Schleswig-Holstein and those at the mouth of the English rivers are even richer than any other area at the bottom of the sea. The author lists the many animal and plant organisms that coexist there. On a single oyster, he found up to 221 animals belonging to three different species. Each oyster bank is, then, to a certain extent, a community of living beings. The word “biocönose” is proposed to designate such a community, in which “all the species and individuals, being mutually limited and selected by the average external living conditions, have continued to occupy a given area” by reproducing. In these communities, the modification of one of the factors defining the biocönose also modifies the others. In France, the over-exploitation of the banks thus completely modified the biocönose. This situation has practical consequences: the oysters raised in trenches are smaller than those raised in open sea because they have less food. To compensate for this, they can be spaced out in the farms. The various constraints on productivity indicate that oysters are no different than other farm animals in terms of their nutritional requirements. Moebius believes that it is not practical to fatten the oysters artificially, in particular due to the risk of pollution. He then examines the importance of temperature. Certain equilibrium mechanisms are described, as well as certain population fluctuations. A comparison is made with the fluctuations in population for livestock and America bison on the Great Plains. The modification of a biocönose by over-exploitation of the target population can lead to its extinction or to a disastrous dwindling in numbers, as is the case of the Greenland right whale, Balaena mysticetus L., among others. Cases of territorial expansion are analyzed. A comparison is then made with the productivity on the biocoenotic territory of homo sapiens. There are no exceptions to the biocoenotic principles, and oyster farmers who pretend or hope otherwise or await a miracle will ruin themselves as they ruin the banks.
