Contributing Factors in the Depletion of Naiades in Eastern United States

To the European malacologist, the disappearance of an indigenous fauna accompanying what is considered an advancing civilization is perhaps not unusual. Workers on the European continent are also well aware of the damage inflicted upon particular molluscan groups in many areas there. Yet, in view of the limited knowledge of conditions in Europe which most American conchologists have, the writer will hazard the guess that few foreign workers realize what is happening to some of the important regions in the United States. With this situation in mind the following outline is given of conditions observed to influence our North American Naiad fauna within the past ten years. Most of the factors which prove detrimental to the Naiades will naturally be damaging to other groups, but because the writer’s main interest has thus far centered about the Naiad fauna, only that group will be considered here. As is generally known, the eastern half of the United States has the richest recorded fauna of freshwater mussels. For convenience this area may be divided into the following drainage systems: I. Mississippi River II. Tennessee River III. Alabama River system IV. Apalachicola drainage V. South Atlantic Coastal drainages VI. Rivers of the Great Lakes drainage in Michigan