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.
That s because in most instances, they materialize without warning in systems that otherwise appear healthy and well balanced. Normally, it isn t until the brown tide is in an advanced stage that study begins. If local biologists hold any advantage over the Laguna Madre s brown tide, though, it is that they were in the midst of a comprehensive research project when the first indications of a bloom arose. 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.