Sub-lethal Effects of 2,4-D Exposure on Golf Course Amphibians

Amphibians are among the most common vertebrates inhabiting golf courses. They are frequent inhabitants of golf course wetlands, where they are likely to be episodically exposed to small quantities of herbicides in proper golf course maintenance. The goal of this study was to investigate whether amphibian larvae subjected to sublethal concentrations of a common herbicide used in golf course maintenance would likely result in significant life history, locomotor, or behavioral effects (e.g., changes in growth, swimming speed, or feeding ability). For these experiments we selected as models tadpoles of the southern leopard frog (Rana sphenocephala) and the herbicide 2,4- dichlorophenoxyacetic acid (2,4-D). The study’s findings include: Some life history traits (e.g., survival to metamorphosis) may be affected by chronic exposure at high doses, but other traits (e.g., growth, timing of metamorphosis, and size at metamorphosis) are not affected. Acute exposure is unlikely to have significant impact on life history traits. Acute exposure does not alter locomotor ability. Acute exposure to 2,4-D reduces the activity of tadpoles, and it also reduces feeding activity when predators are present. We conclude that 2,4-D does not represent a particularly strong threat to amphibian larvae inhabiting golf course where the herbicide is applied responsibly