Acute toxicity of tributyltin to selected Chesapeake Bay fish and invertebrates

Acute tributyltin (TBT) toxicity experiments were conducted on selected Chesapeake Bay biota. Four invertebrate and five fish species were evaluated. Tests were conducted using continuous-flow conditions and TBT concentrations were measured every 24 h in test containers. Test solutions were generally within 10–15% of the predicted concentrations. Estuarine copepods were very sensitive to TBT. A 72-h LC 50 of 0.6 μg 1 −1 TBT was reported for Eurytemora affinis; Acartia tonsa had a 48-h LC 50 of 1.1 μg 1 −1 TBT. The most resistant invertebrate tested was the grass shrimp, Palaemonetes sp. (96-h LC 50 > 31 μg 1 −1 TBT). The most sensitive fish species tested were larval inland silversides ( Menidia beryllina), (96-h LC 50 = 3.0 μg 1 −1 TBT) and juvenile Atlantic menhaden ( Brevoortia tyrannus), (96-h LC 50 = 4.5 μg 1 −1 TBT). Mummichogs ( Fundulus heteroclitus) and sheepshead minnow ( Cyprinodon variegatus), (96-h LC 50 = 23.8 and 25.9 μg 1 −1 TBT, respectively) were the most resistant fish species tested. Concentrations of TBT exceeding the LC 50 values reported for both copepod species have been found in the water column from marinas in northern Chesapeake Bay. Acute TBT toxicity data and its application to environmental concentrations in Chesapeake Bay are discussed.