NEUMAN-LEE, L.A.; JANZEN, F.J.; Iowa State Univ., Ames, IA; Iowa State Univ., Ames, IA: Effects of Atrazine on the Performance, Survival, and Behavior of Embryonic Map Turtles (Graptemys)i>

Atrazine is one of the most widely applied herbicides in the United States. Used as a nonselective pre-emergent chemical for broadleaf control, atrazine can be found in most sources of water, including rain. Since atrazine (a known endocrine disrupting chemical) is applied in the late spring and early summer, its effects on species like turtles that nest seasonally in water-saturated areas (e.g., sandbars) are of special interest. To examine the possible effects of atrazine on embryonic turtles, I obtained 80 eggs from 10 clutches of the false map turtle, Graptemys pseudogeographica. Eggs were randomly separated such that two eggs from each clutch were subjected to four concentrations of atrazine (vehicle, 0.1ug, 10ug, 100ug). The incubation period as well as time to complete emergence after pipping was observed. After hatching, turtles were subjected to performance tests; righting, time to surface of water, and movement through an open area. The hatchlings were also massed and measured (carapace length and width) prior to these tests. Forty turtles were then sacrificed for gonadal sex data. The other 40 turtles were placed in individual containers and monitored over several months to determine long term effects. The full effects of atrazine on the physiology and behavior will be discussed.