ysboston@cs.utexas.edu (Yee-Sing Tsai) (08/08/89)
Chemicals endanger rare Big Bend falcons [Austin-American Statesman, August 1989] BIG BEND NATIONAL PARK (AP) -- The rare peregrine falcon could be further endangered by traces of DDT and dozens of other toxic chemicals that have been found in the park's river and wildlife, according to a report. A study performed in March by the U.S. Fish and Wildlife Department found 67 chemical contaminants in 53 samples of fish, birds, turtles, insects, and Rio Grande sediment, said Tom Alex, resource management specialist with Big Bend National Park. In addition to finding DDT and poisonous byproducts the insecticide produces when it breaks down in nature, scientists found relatively low levels of hydrocarbons, cancer-causing PCBs and heavy metals such as mercury. Wildlife specialists are most concerned about the DDT. Fish and Wildlife spokesman Tom Smylie said there was enough DDT in the falcons' blood to make their eggshells perilously thin and prone to break before the chicks are ready to hatch. The Fish and Wildlife Department commissioned the study after Big Bend officials noticed a leveling of the park's peregrine population, Smylie said. Alex said it is unknown whether any eggs in the park have broken prematurely because of DDT, but added that eggshells are thinner than they should be. Six pairs of peregrine falcons set up aeries, or rocky nests, on cliffs in Big Bend and adjacent land in Mexico last spring, Alex said. Five chicks survived long enough to leave the aeries, he said. It is unknown exactly how many chicks hatched. DDT is illegal to use in the United States, but its use is legal in Mexico. It is still made in the United States for export, Smylie said. The Fish and Wildlife report says most of the DDT found in the park appears to come from the fruit- and vegetable-growing area of Mexico that drains into the Rio Conchos. That river empties into the Rio Grande above Presidio, 50 miles up stream from the park. The report says some of the DDT apparently drains into the Rio Grande from the U.S. side of the river, an indication that DDT remains in the environment for longer than was previously believed, Smylie said. -- Mother cooked a big breakfast. When she cleared off the table, she found a quarter and a dime and three pennies by Father's coffee cup. He'd tipped her. ------------------------------------------------------------------------------ Ghostie * Austin,TX * (512) 471-1082 * ystsai@grumpy.cc.utexas.edu