Alfred J. Wilson

Toxicity and distribution of Aroclor® 1254 in the pink shrimp Penaeus duorarum

The polychlorinated biphenyl Aroclor® 1254 was released in an accidental leakage of heat-exchange fluid from an industrial plant, into the Escambia River, near Pensacola, Florida, USA. This material was carried downstream, and is now found in the fauna of Escambia Bay and its contiguous waters, prime nursery areas for fishes and invertebrates such as penaeid shrimp. The significance of pollution by this chemical was assessed by establishing toxicity levels, determining routes of entry, and investigating its movement and distribution in various tissues of shrimp under controlled conditions in the laboratory. Aroclor 1254 added to the water was toxic to the juvenile pink shrimp Penaeus duorarum at a concentration of 1.0 part per billion within 15 days, but was less

Kepone® bioconcentration, accumulation, loss, and transfer through estuarine food chains

Accumulation, transfer, and loss of Kepone in estuarine organisms were studied in laboratory bioassays. Kepone was bioconcentrated by oysters (Crassostrea virginica), mysids (Mysidopsis bahia), grass shrimp (Palaemonetes pugio), sheepshead minnows (Cyprinodon variegatus), and spot (Leiostomus xanthurus), from concentrations as low as 0.023 μg/l seawater. Bioconcentration factors ranged from 10 to 340 in static exposures and 900 to 13,500 in flow-through bioassays, and were dependent on species and exposure duration.

Mysidopsis bahia : An Estuarine Species Suitable for Life-Cycle Toxicity Tests to Determine the Effects of a Pollutant

This study documents the successful use of a mysid, Mysidopsis bahia, for life-cycle toxicity tests. These tests were conducted to determine acute and chronic toxicities of metal (cadmium) and pesticide (Kepone). Delay inthe formation of mysid brood pouches and release of young were noted in low concentrations ≤6.4 μg cadmium/litre. Fewer young produced per female and decreased growth were other indicators of effects of Kepone.

Acute toxicity of Kepone® to four estuarine animals

Recent contamination of the James River estuary, Virginia, with Kepone prompted acute flow-through bioassays to determine the 96-hour toxicity of the insectivide to four estuarine species native to that ecosystem. The species and their 96-hour LC50 values were: grass shrimp (Palaemonetes pugio), 121 μg/liter; blue crab (Callinectes sapidus), >210 μg/liter; sheepshead minnow (Cyprinodon variegatus), 69.5μg/liter; and spot (Leiostomus xanthurus) 6.6μg/liter. Surviving animals were analyzed for Kepone. Average bioconcentration factors (the concentration of Kepone in tissues divided by the concentration of Kepone measured in seawater) were: grass shrimp, 698; blue crab 8.1; sheepshead minnow, 1,548; and spot, 1,221.

Acute Toxicity to and Bioconcentration of Endosulfan by Estuarine Animals

Acute (96-h) flow-through toxicity tests with endosulfan (Thiodan) were conducted with several estuarine animals. The test species and their 96-h lethal concentration for 50 percent of the organisms (LC 5 0 ) values were: pink shrimp (Penaeus duorarum), 0.04 μg/litre; grass shrimp (Palaemonetes pugio), 1.3 μg/litre; pinfish (Lagodon rhomboides), 0.3 μg/litre; spot (Leiostomus xanthurus), 0.09 μg/litre; and striped mullet (Mugil cephalus), 0.38 μg/litre. In a 56-day bioconcentration study (28-day uptake, 28-day depuration), striped mullet were exposed to 0.008 and 0.08 μg endosulfan/litre seawater. The two endosulfan isomers (endosulfan I and II) were rapidly metabolized to endosulfan sulfate; only trace amounts of each isomer were detected in edible tissue or offal of mullet exposed to 0.08 μg/litre (0.035 μg/litre measured) for 28 days. Maximum bioconcentration factors of endosulfan were 2249 in edible tissue and 2755 in whole-body analyses. After 48 h in pesticide-free seawater, endosulfan was not detected in the previously exposed mullet. Our studies suggest that endosulfan in the estuarine environment would be a hazard because of its acute toxicity and bioconcentration potential, but animals surviving exposure and moving to areas free of endosulfan would lose the chemical rapidly.

Kepone®: Chronic effects on embryo, fry, juvenile, and adult sheepshead minnows (Cyprinodon variegatus)

We investigated the toxicity of Kepone to, and uptake by embryo, fry, juvenile, and adult sheepshead minnows (Cyprinodon variegatus) using intermittent-flow toxicity tests. Concentration of Kepone and percentage of adult fish surviving in a 28-day exposure were: Control, 95%; 0.05 μg/liter, 95%; 0.16 μg/liter, 100%; 0.80 μ/liter, 78%; 1.9 μg/liter, 20%; and 7.8 μg/liter and 24 μg/liter, 0%. Concentration factors (concentrations in fish divided by concentrations measured in water) for adult fish averaged 5,200 (range 3,100 to 7,000). Symptoms of poisoning included scoliosis, darkening of the posterior one-third of the body, hemorrhaging near the brain and on the body, edema, fin-rot, uncoordinated swimming, and cessation of feeding. Adults surviving the first exposure were spawned, and the embryonic development, hatching, and survival and growth of fry and juveniles were monitored in a 36-day exposure to Kepone concentrations of 0.08, 0.18, 0.72, 2.0, 6.6, and 33 μg/liter. A significant number of embryos from adult fish exposed to 1.9 μg of Kepone/liter of water developed abnormally and died even when incubated in Kepone-free water. Kepone in water was not as lethal to progeny as to adults: 36-day LC50 for juveniles was 6.7μg/liter; 28-day LC50 for adults, 1.3 μg/liter. However, the average standard length of juvenile fish was significantly reduced by exposure to 0.08 μg of Kepone/liter of water; some fish developed scoliosis. Concentration factors in juvenile sheepshead minnows averaged 7,200 and increased from 3,600 to 20,000 as exposure concentrations decreased.

Kepone®: Toxicity and bioaccumulation in blue crabs

Two long-term studies were conducted to determine toxicity, uptake and depuration of Kepone in blue crabs (Callinectes sapidus). In the first, Kepone was administered to crabs in seawater (0.03 or 0.3 μg Kepone/I) or food (eastern oyster,Crassostrea virginica, containing 0.25 μg/g Kepone). Uptake of Kepone in 28 days was primarily through the contaminated oysters. When these crabs were held in Kepone-free seawater and fed Kepone-free oysters for 28 days, no loss of the insecticide was evident. There were adverse effects on molting and survival in crabs fed oysters that contained 0.25 μg/g Kepone.A second study was conducted to determine: (1) the depuration of Kepone over a 90-day period in blue crabs fed oysters from the James River, Virginia (containing 0.15 μg/g Kepone); and (2) the effects of Kepone on molting and survival of blue crabs fed James River oysters or laboratory-contaminated oysters that contained 0.15 or 1.9 μg/g Kepone. Crabs fed Kepone-contaminated oysters followed by a diet of Kepone-free oysters for 90 days had detectable concentrations of the insecticide in tissues. Also, blue crabs that ate oysters containing Kepone in concentrations similar to those found in oysters from the James River, died or molted less frequently than crabs fed Kepone-free oysters meats.

Toxicity and uptake of Kepone in marine unicellular algae

Four species of marine unicellular algae were exposed to Kepone in laboratory bioassays. EC50 values after seven days’ growth, in mg/liter (ppm), were:Chlorococcum sp., 0.35;Dunaliella tertiolecta, 0.58;Nitzschia sp., 0.60;Thalassiosira pseudonana, 0.60. When exposed to 100 μg/liter (ppb) Kepone for 24 hr, residues associated with the algae, in mg/kg (ppm) wet weight, were:Chlorococcum sp., 80;D. tertiolecta, 23;Nitzschia sp., 41;T. pseudonana, 52.