Establishment of freshwater biota in an inland stream following reduction of salt input.

Abstract

Replacement of halophilic organisms by freshwater ones in and near an inland stream is reported, apparently for the first time. Wolf Creek has received salt waste from a processing plant for almost 100 yr. By 1926 the salinity ranged from marine to brackish. Enteromorpha intestinalis and Ruppia maritima grew abundantly. On a flat near the salt works were Salicornia europea, Spartina patens and Juncus gerardii. Insects in the stream were limited to Ephydra subopaca, Culicoides varipennis and 2 other species. The submered plants have now been replaced by freshwater algae and species of Potamogeton, with freshwater emergents now also present. On the flat only J. gerardii remains of the halophyte species. In the spring of 1979, with the stream generally in the freshwater range of salinity, 17 families, including 21 identifiable genera, of aquatic insects were found.-from Authors