No abstract

In March 1984, the U.S. Environmental Protection Agency (EPA) issued a significant change in procedures regulating toxic materials in effluents through the National Pollutant Discharge Elimination System (NPDES). Concurrent with this toxicity‐based effluent control policy, the EPA established the marine/estuarine component of the Complex Effluent Toxicity Testing Program (CETTP). The CETTP was established to provide reliable, sensitive and environmentally meaningful test protocols that could be used to detect toxic industrial and municipal effluents within the NPDES. Five toxicity test methods have been developed and validated for the program since 1984 using a marine plant (Champia parvula), two invertebrate species (Arbacia punctulata and Mysidopsis bahia) and two fish species (Cyprinodon variegatus and Menidia beryllina). The laboratory precision test results for the methods were acceptable; coefficients of variation for all methods were less than 54%, averaging 34%. Numerous field tests were conducted using these methods and the results indicate that tests on receiving waters (in which effluent concentrations could be estimated through controlled dye studies) accurately reflect the toxicity of the effluents measured directly. Receiving water impacts, when observed, were generally near‐field in nature. The test methods developed are sensitive, efficient, reliable and environmentally relevant measures of effluent toxicity and offer promise for reducing adverse impacts from point‐source discharges in near‐coastal waters.

Eggs of the sheepshead minnow (Cyprinodon variegatus) were artificially fertilized and maintained at temperatures from 15 to 35 C and in salinities from 0 to 35%o to determine efficient culture conditions. Fertilization was not affected by temperature or salinity ranges chosen, but hatching success was greatest (x2; a • 0.01) at a temperature range of 24 to 35 C and a salinity range of 15 to 30%•.Artificially fertilized sheepshead minnow eggs were exposed to logarithmic concentrations of Aroclor 1254 (10.0 to 0.1 •zg/liter) in seawater averaging 30 C and 24%• in a flow-through bioassay. Fertilization was not affected but significantly fewer embryos developed in the 10.0 gg/liter concentration, and fewer fry survived in concentrations greater than 0.1 gg/liter. Fry were more susceptible to Aroclor 1254 than were embryos, juveniles, or adults. Polychlorinated biphenyls (PCB's) occur in estuaries in many states(Butler 1973), and the occurrence of one, Aroclor 1254, in nearby Escambia Bay, Florida and its acute toxicity to estuarine animals has been documented (Duke, Lowe and Wilson 1970). Hansen, Parrish and Lowe (1971) found 5 gg/liter of Aroclor 1254 toxic to the juvenile estuarine fishes, pinfish (Lagodon rhomboides) and spot (Leistomus xanthurus), in 14-to 45day bioassays. Because Escambia Bay is a nursery ground for many marine species of fish, it is important to determine the effect of Aroclor 1254 on the early life stages of these fish.

No abstract