Recognizing toxic species in aquatic habitats: a potential concern in lake management

Recognizing Toxic Species in Aquatic Habitats: A Potential Concern in Lake Management

The importance of distinguishing toxic and non-toxic algal species is becoming a more common problem for management decisions associated with various freshwater and estuarine habitats. An example is given where two dinoflagellates, originally unidentified as closely resembling the toxin producing Pfiesteria spp., have been compared to these species. In order to clarify any relationship to Pfies...

Risk Assessment and Toxic Effects of Metal Pollution in Two Cultured and Wild Fish Species from Highly Degraded Aquatic Habitats

Lake Qaroun is an inland lake at the lowest part of El-Fayoum depression, Egypt. It receives agricultural and domestic non-treated drainage waters, which are also used for aquaculture in Qaroun area. The results of the present study aimed to provide comparable data between wild (collected from Lake Qaroun) and cultured (collected from Qaroun fish farms and the reference site) Nile tilapia Oreoc...

Transfer of Non-indigenous Aquatic Species: a Growing Concern to Aquatic Resource Users

Toxic sulphide can accumulate in aquatic environments

when organic material is decomposed under oxygen-limiting conditions (Nedwell, 1982). (The term sulphide is intended to include undissociated H2S, the bisulphide anion HS− and the sulphide anion S2−.) In marine sediments, sulphide production is enhanced by bacterial sulphate reduction (Jorgensen and Fenchel, 1974; Nedwell, 1982). Species inhabiting intertidal flats or salt marshes are, therefor...

Invasive Species in Agriculture: a Rising Concern

Invasive species are not new phenomena in U.S. agriculture, as illustrated by these 1920s lyrics from the Boll Weevil folksong. The boll weevil entered the United States via Mexico in the 1890s, and by the 1920s, this pest had spread to all cotton producing states, wiping out tens of thousands of acres of cotton, costing billions of dollars, and literally driving thousands of farmers off the la...