Laboratory testing and field trials have established that TBT is toxic to nontarget aquatic organisms at low environmental concentrations. This toxicant is slow-acting and can adversely affect aquatic organism development from fertilized egg through various early life stages, as well as, reproductive functions in mature individuals. Sensitivity to TBT varies among aquatic species with gastropods and bivalves being the most susceptible (0.02-0.14 ppb), followed by crustaceans (0.09-0.14 ppb), algae (0.1-0.35 ppb), and fish (

ppb).