The slgae in South Texas, scientists have proved through DNA testing, belongs to an altogether new class, Pelageophycae. These microscopic organizsms almost always are present in coast bays, but concentrations normally are so low as not to be noticeable. They are legitimate links in the estuarine food chain and have several natural predators which, in turn, nourish larger species. These sudden and unexpected proliferations have occurred as far north as New England. Until now, though, until the Laguna Madre, brown tides have been temporary.
Scientists still are uncertain what triggers abnormal blooms.
It is that close scrutiny beforehand on which they base hypotheses as to the origin of this phenomenon. The Laguna Madre is a vast, shallow bay system in which there is relatively little exchange from either fresh water inflow or tidal movement. Upon reconstruction of the Kennedy Causeway at Corpus Christi in 1961, circulation throughout the area came to a halt. The nearest significant tidal exchange point now is more than 100 miles to the south. In the winter of 1989, all of Texas was gripped by a severe freeze.