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Raritan Estuary and Long Island Sound
246
Abstracts / Marine Environmental Research 50 (2000) 243±246
adductor muscle, and the kidney/heart, on a mass weight basis. However, the gonad, having a lower lipid content (1.58% wet wt. lipid content), was able to accumulate a dioxin concentration higher than that of other tissues on a lipid basis. This observation suggested that dioxin distribution was not being driven by the lipid content in the gonad but possibly by a binding receptor. In a separate set of studies TCDD exposure resulted in a poor fertilization rate (52.2±99.0% unfertilized eggs). Eggs that were fertilized had 3.2±0.0% survival, and did not develop beyond the zygote stage. In contrast, the control eggs had 80.3% survival to the straight hinge stage. TCDD concentrations in the gonadal tissue from day 28 of the distribution study (9.69 pg+5.28), corresponded with the range of TCDD detected in the gametes on day 28 of the larval study (1.58 pg+0.038). These studies support the hypothesis that dioxin is incorporated into the developing eggs and/or sperm of the Eastern oyster during gametogenesis. PII: S0141-1136(00)00187-2
Pure compound and sediment elutriate embryo larval assay of winter ¯ounder from the Hudson/ Raritan Estuary and Long Island Sound T.A. Young a, A.M. Daly b, K.R. Cooper a,b a
Joint Graduate Program in Toxicology, UMDNJ, Rutgers The State University of New Jersey, Piscataway, NJ 08855, USA b Departments of Biochemistry and Microbiology, Rutgers The State University of New Jersey, Piscataway, NJ 08855, USA
Abstract Winter ¯ounder (Pseudopleuronectes americanus), a demersal egg layer, is at risk from dioxins and metals in the sediments of the Hudson/Raritan Estuary (the Estuary). The eects of tetrachlorodibenzo-p-dioxin (TCDD), mercuric chloride and sediment elutriates on the embryos of winter ¯ounder from four sites in the Estuary, and a reference site: Long Island Sound (LI) were examined. Embryos were exposed from 2 days after fertilization until 2 days post hatch. TCDD absorption by embryos/larvae ranged from 13 to 44%, with an average 23.4%. One experiment, with the LI population showed a LD50 of 1.8 pg/larva (2.6 ng/g) and LD10 of 0.9 pg/larva (1.4 ng/g). Major observed lesions included pericardial edema (PE), and spinal lesions (SL). Background lesion occurrence in controls was 0.31 lesions/ individual, and 0.27 major lesions/individual. NOELs were observed for PE 0.3±0.5 pg/larva, and SL 1.4±9.0 pg/larva. PE and SL are good indicators of low and high dose eects of TCDD in winter ¯ounder, respectively. With mercuric chloride all populations showed 50% mortality at 100 mg/l, and 50% lesions at 25±50 mg/l. Three of seven sediment elutriates collected from the Estuary were acutely toxic. Site-speci®c variability in sediment toxicity and breeding stock sensitivity to known contaminants was observed. Future studies should incorporate metamorphosis from larva to juvenile. (USEPA:CR825437, NIEHS:ES07148). PII: S0141-1136(00)00188-4
Abstracts / Marine Environmental Research 50 (2000) 243±246
adductor muscle, and the kidney/heart, on a mass weight basis. However, the gonad, having a lower lipid content (1.58% wet wt. lipid content), was able to accumulate a dioxin concentration higher than that of other tissues on a lipid basis. This observation suggested that dioxin distribution was not being driven by the lipid content in the gonad but possibly by a binding receptor. In a separate set of studies TCDD exposure resulted in a poor fertilization rate (52.2±99.0% unfertilized eggs). Eggs that were fertilized had 3.2±0.0% survival, and did not develop beyond the zygote stage. In contrast, the control eggs had 80.3% survival to the straight hinge stage. TCDD concentrations in the gonadal tissue from day 28 of the distribution study (9.69 pg+5.28), corresponded with the range of TCDD detected in the gametes on day 28 of the larval study (1.58 pg+0.038). These studies support the hypothesis that dioxin is incorporated into the developing eggs and/or sperm of the Eastern oyster during gametogenesis. PII: S0141-1136(00)00187-2
Pure compound and sediment elutriate embryo larval assay of winter ¯ounder from the Hudson/ Raritan Estuary and Long Island Sound T.A. Young a, A.M. Daly b, K.R. Cooper a,b a
Joint Graduate Program in Toxicology, UMDNJ, Rutgers The State University of New Jersey, Piscataway, NJ 08855, USA b Departments of Biochemistry and Microbiology, Rutgers The State University of New Jersey, Piscataway, NJ 08855, USA
Abstract Winter ¯ounder (Pseudopleuronectes americanus), a demersal egg layer, is at risk from dioxins and metals in the sediments of the Hudson/Raritan Estuary (the Estuary). The eects of tetrachlorodibenzo-p-dioxin (TCDD), mercuric chloride and sediment elutriates on the embryos of winter ¯ounder from four sites in the Estuary, and a reference site: Long Island Sound (LI) were examined. Embryos were exposed from 2 days after fertilization until 2 days post hatch. TCDD absorption by embryos/larvae ranged from 13 to 44%, with an average 23.4%. One experiment, with the LI population showed a LD50 of 1.8 pg/larva (2.6 ng/g) and LD10 of 0.9 pg/larva (1.4 ng/g). Major observed lesions included pericardial edema (PE), and spinal lesions (SL). Background lesion occurrence in controls was 0.31 lesions/ individual, and 0.27 major lesions/individual. NOELs were observed for PE 0.3±0.5 pg/larva, and SL 1.4±9.0 pg/larva. PE and SL are good indicators of low and high dose eects of TCDD in winter ¯ounder, respectively. With mercuric chloride all populations showed 50% mortality at 100 mg/l, and 50% lesions at 25±50 mg/l. Three of seven sediment elutriates collected from the Estuary were acutely toxic. Site-speci®c variability in sediment toxicity and breeding stock sensitivity to known contaminants was observed. Future studies should incorporate metamorphosis from larva to juvenile. (USEPA:CR825437, NIEHS:ES07148). PII: S0141-1136(00)00188-4