By David L. Brown
“Red Tide.” It may sound like the title for the latest Tom Clancy novel, but it’s a very real phenomenon. I observed its effects today on the Texas Gulf Coast as evidenced by tens of thousands of dead fish littering the beaches of Padre Island.
So-called red tides are caused by blooms of algae that deplete oxygen and in some cases yield toxins that are fatal to fish, birds and other animals living in or near the water. According to locals, the present outbreak began about a month ago and is the first to strike the region in about four years. Red tides develop quickly and dissipate as the algae uses up existing nutrients and oxygen and proceeds to die off. Little is understood about the causes of the blooms, which are named for the discoloration in the water that sometimes takes place, often reddish but sometimes green or brown. Warnings had been posted against consuming oysters and other mollusks that could be contaminated with toxins produced by the algae.
Padre Island is a long barrier island extending along the Texas coast from Corpus Christi south to near the Mexican border. It is a favorite recreational area, and yet when I visited the Padre Island National Seashore headquarters today there were few tourists and a hostess told me it was as quiet as she had ever seen it.
I strolled along the beach observing tiny crabs scuttling for shelter as I approached and seabirds clustering at the water’s edge in search of their lunch. Arrayed in a band near what must have been the previous high water mark were thousands of dead fish of all sizes, from minnows to fairly large mullet. Here is a photo showing some of the dead fish I observed.
Although algae blooms sometimes result from runoff of agricultural fertilizer, this is by no means the only cause. The phenomenon has been observed for thousands of years and appears in many parts of the world.