Death and Suffering on Padre Island
Its difficult to describe the scene of a massive fish kill. At first it is a terrible assault on the eyes, mile upon mile of intertidal beach plastered with dead fish, the surf rolling new bodies ashore every minute for days. At the same time you start hacking like a smoker because the same miasma killing the fish irritates your lungs, makes your eyes water and anchors a low grade headache. Finally it assaults your nose as the smell of dead fish permeates every space and clings to everything, even following you home, stuck to the wheels and undercarriage of your truck.
This carnage visited Padre and Mustang Islands this week as a second red tide in three years blanketed an area the size of the Atlantic coastline of New Jersey. For days the beach was plastered with the dead bodies of everything from tarpon to mullet. In the first day, larger fish dominated the kill, on the second sardine-size fish succumbed, on the third day the sea, spent of fish, calmed and a blazing sun baked everything.
These fish died because an algae known as Karenia brevis bloomed in these warm Gulf waters leaving a toxin that paralyses the central nervous system of fish and they can’t breath. The harmful algal bloom, more commonly known as “red tide”, is composed of a single cell, plant-like organism that spread into dense patches covering hundreds of near-shore beaches. It can persist for weeks. Living on up-welled nutrients and warm waters and then dying, the bloom releases toxins that paralyses fish and becomes an aerosol that affects people. On our fourth day of work on Padre and Mustang Islands we were still trying to clear the persistent lump in our throats while fending off nausea from the ever-growing stink.
David Newstead, a biologist with the Coastal Bays and Esturary Program centered in Corpus Christi, an intrepid team composed of the many lovers of birds in the area and I, braved this toxic place because we wanted to find out what it was doing to the shorebirds of Padre Island. We started our red knot project three years ago, only trying to understand the status of the small population of knots that we once thought flew through Padre Island on their way to more southerly wintering areas. After recovering five red knots last year that we outfitted with geolocators, we know the birds don’t fly farther south, they stay in Texas but move in the winter to the more remote Laguna Madre, only a few miles from the Gulf Coast beach. Unknowingly, our study has brought some focus on the effect of red tide on shorebirds.
The birds suffered much. Over a few days the population of knots fell from about 150 to only a few lost souls wandering alone along the shoreline half heartedly pecking at small bits washing about in the surf. We caught a few birds and found some in perilous condition, weights as low at 84 grams. The fat free weight of a knot is 125 to 135 grams. Worse, we found stricken knots on the beach unable to move and barely alive. We took them to the Animal Rehab Keep , a rehab facility run by Tony Amos and supported by the University of Texas and by donations. Three birds will probably make it, one died in our truck before we could get him help.
Why does this happen? The science is surprisingly uncertain. Red tides occur naturally all over the world, and there is a long historical record of their occurrence along Gulf shores. Many scientists believe the severity and frequency is influenced by nutrient loading from agricultural runoff and treated sewage effluent. Others see it as another consequence of global warming interacting with other factors.
On Padre Island it doesn’t matter. In my 30 years as a wildlife biologist, I have never seen such devastation, death beyond imagination with no solution in sight.