Changes in contaminant levels in New Jersey osprey eggs and prey, 1989 to 1998.

Ospreys are good indicators of the health of estuarine areas because they feed almost exclusively on fish with the balance on other aquatic biota. Through the 1980s, ospreys nesting on Delaware Bay in New Jersey had reduced reproductive success relative to those nesting on the Atlantic coast and the Maurice River, a tributary of Delaware Bay. Earlier research suggested that elevated levels of DDT and polychlorinated biphenyl (PCB) contaminants identified in addled osprey eggs contributed to this reduced productivity. We repeated egg and prey sampling initially conducted in 1989 to evaluate the trends of contaminants in the last decade. Most organochlorine contaminants declined in osprey eggs in 1998 relative to 1989. Across three study areas, PCBs decreased from 4.1-7.7 ppm in 1989 to 1.8-3.2 ppm in 1998; DDE decreased from 1.2-3.2 ppm in 1989 to 0.7-1.2 ppm in 1998. Lead in eggs increased from an average of 0.01 to 0.30 ppm wet weight, and mercury averaged 0.12 ppm and increased only in Atlantic coast eggs. Most of these contaminant changes were also found in typical prey fish: PCBs decreased from 0.18-1.2 ppm in 1989 to 0.06-0.43 ppm in 1998; DDE decreased from 0.05-0.69 ppm in 1989 to 0.03-0.13 ppm in 1998. Lead and mercury increased in most fish samples. The improvement in most organochlorine contaminants in osprey eggs and prey reflected improved nest success in the Delaware Bay study area, and the nesting populations in the Atlantic and Maurice River study areas increased approximately 200% since 1989. PCBs and DDE in osprey eggs were below levels considered to be toxic to egg development. This study documents significant improvements in organochlorine contaminants in southern New Jersey ospreys, but justifies continued monitoring of heavy metals, such as lead and mercury, in aquatic ecosystems.

Food chain aspects of chlordane poisoning in birds and bats.

We have observed recurring chlordane poisonings of large numbers of common grackles (Quiscalus quiscula), European starlings (Sturnus vulgaris), and American robins (Turdus migratorius) at suburban roosts in New Jersey during the month of July. This paper describes aspects of the food chain uptake of chlordane that account for the periodicity of these poisonings. Chlordane concentrations ranged from < 0.02 to 20.3 microg/g wet weight in 11 soil samples collected from residential lawns and a golf course near one roost. Of the 10 species of insects and soil invertebrates collected from the area, two scarab beetles, the oriental beetle (Anomala orientalis) and Japanese beetle (Popilla japonica), had the highest concentrations of chlordane-related compounds (15.1 and 5.9 microg/g wet weight, respectively). Concentrations in the other eight species ranged from < 0.04 to 1.3 microg/g. Oriental and Japanese beetles collected from a rural location had concentrations of 0.03 and < 0.02 microg/g, respectively. Emergence of adult beetles peaked in mid- to late July, when bird mortality also peaked. Fecal pellets collected near the roost (n = 24) contained the remains of 1-5 beetles each (mean = 2), and scarab beetles accounted for 40% of the total number of insect parts in the stomach contents of common grackles (n = 8). Unlike soil samples, in which cis- and trans-chlordane predominated, beetles contained large amounts of the more toxic metabolites heptachlor epoxide and oxychlordane. Total chlordane-related compounds ranged from < 0.05 to 18.4 microg/g in Japanese beetles collected from 16 sites in New Jersey and 2 sites in Ohio. The highest concentrations were found in beetles from suburban areas and golf courses. We also analyzed brain tissue from insectivorous bats (15 big brown bats, Eptesicus fuscus, and 5 little brown bats, Myotis lucifugus) that were submitted to the New Jersey Rabies Laboratory in late June/July 1998 and 1999 but found to be rabies-negative. We suggest that high concentrations in three of the bats caused debility or abnormal behavior that may have precipitated submission for rabies testing.

Effects of lead-contaminated surface water from a trap and skeet range on frog hatching and development.

Pickerel frogs (Rana palustris) and bullfrogs (Rana catesbeiana) were exposed from the egg stage to lead-contaminated surface water from a trap and skeet range. Seven experimental treatments were employed: 25, 50, 75 and 100% range water, 100% range water plus a chelating agent (sodium citrate), control water and control water plus chelating agent. Total lead concentrations in 100% range water treatments varied from 840-3150 microg litre(-1), with the filterable form accounting for approximately 4-5% of the total. Hatching was not affected in either species (p > 0.2). There were highly significant differences in mortality among treatments for R. palustris (p = 0.0001), with tadpoles exhibiting 100 and 98% mortality after 10 d of exposure to 100 and 75% range water, respectively. Mortality in the 100% range water + citrate treatment was similar to controls (p > 0.05). There were no significant differences in mortality among treatments for R. catesbeiana after 10 d of exposure (p = 0.7119). Exposure to lead in the range water did not adversely affect the growth of surviving R. palustris or R. catesbeiana tadpoles after 14 weeks and 10 weeks, respectively. In both species, the intestinal mucosa in tadpoles exposed to range water was reduced in thickness. Scanning electron micrographs of R. palustris tadpoles that died in 100% range water revealed stunted tail growth, incurvation of the spine, hydropsy and generally reduced body size.

The uptake and effects of lead in small mammals and frogs at a trap and skeet range.

This study was performed to evaluate the bioavailability and effects of lead in wildlife at a trap and skeet range. The total lead concentration in a composite soil sample (pellets removed) was 75,000 micrograms/g dry weight. Elevated tissue lead concentrations and depressed ALAD activities in small mammals and frogs indicate that some of the lead deposited at the site is bioavailable. Mean tissue lead concentrations (micrograms/g dry wt.) in white-footed mice (Peromyscus leucopus) at the range liver = 4.98, kidney = 34.9, femur = 245) were elevated (P < 0.01) 5- to 64-fold relative to concentrations in mice from a control area. Tissue lead concentrations in the only shorttail shrew (Blarina brevicauda) captured at the range (liver = 34.1, kidney = 1506, femur = 437) were elevated 35- to 1038-fold. Femur lead concentrations in green frogs (Rana clamitans) at the range (1,728 micrograms/g) were elevated nearly 1000-fold, and the lead concentration in a pooled kidney sample (96.2 micrograms/g) was elevated 67-fold. There was significant depression of blood ALAD activity in mice (P = 0.0384) and depression of blood and liver ALAD activity in frogs (P < 0.001). Hematological and histopathological lesions associated with lead toxicosis were observed in some animals. Hemoglobin concentrations were reduced 6.7% in mice (P = 0.0249), but hematocrit was not significantly affected in mice or frogs. Intranuclear inclusions were present in the renal proximal tubular epithelium of two of the mice and the shrew that were captured at the range, and necrosis of the tubular epithelium was also evident in one of the mice. Kidney:body weight ratios were similar in range and control mice. Soil ingestion may be a significant route of lead uptake in small mammals at the range. However, the tendency of lead to concentrate in the bones rather than in more digestible soft tissues may minimize food chain uptake of lead by predators, especially raptors that regurgitate undigestible material.

Cadmium contamination of deer livers in New Jersey; human health risk assessment.

Eighty-six liver samples were collected from hunter-killed deer at various locations in New Jersey and analysed for cadmium. Concentrations ranged from 0.07 to 23.2 micrograms/g dry weight. Three of the highest concentrations were measured in samples collected from an area with known cadmium contamination resulting from past waste disposal practices. Significant differences in liver cadmium concentration were noted among deer from different areas (p less than 0.01) and among different age groups (p less than 0.01). No sex-related differences were observed (p = 0.48). A survey of deer liver consumption was conducted and the data were used in formulating a health advisory. The lack of knowledge about the effects of cadmium on wildlife health is discussed in relation to an expected increase in the land disposal of sewage.