Daniel F. Woodward

Effects on Rainbow Trout Fry of a Metals-Contaminated Diet of Benthic Invertebrates from the Clark Fork River, Montana

Abstract The upper Clark Fork River in northwestern Montana has received mining wastes from the Butte and Anaconda areas since 1880. These wastes have contaminated areas of the river bed and floodplain with tailings and heavy metal sludge, resulting in elevated concentration of metals in surface water, sediments, and biota. Rainbow trout Oncorhynchus mykiss were exposed immediately after hatching for 91 d to cadmium, copper, lead, and zinc in water at concentrations simulating those in Clark Fork River. From exogenous feeding (21 d posthatch) through 91 d, fry were also fed benthic invertebrates from the Clark Fork River that contained elevated concentrations of arsenic, cadmium, copper, and lead. Evaluations of different combinations of diet and water exposure indicated diet-borne metals were more important than water-borne metals – at the concentrations we tested – in reducing survival and growth of rainbow trout. Whole-body metal concentrations (μg/g, wet weight) at 91 d in fish fed Clark Fork inverteb...

Relations between Benthic Community Structure and Metals Concentrations in Aquatic Macroinvertebrates: Clark Fork River, Montana

ABSTRACT We sampled macroinvertebrate communities at six sites on the upper Clark Fork River, Montana, to determine relations between macroinvertebrate community structure and metals in invertebrates and the best benthic community metrics to use for ranking sites based on the relative severity of the effects of metals. Concentrations (μg/g) of six metals in invertebrates were determined: Al (range = 591–4193), As (2.7–34.1), Cd (0.13–8.38), Cu (26–1382), Pb (0.54–67.1), and Zn (212–1665). Concentrations of As, Cd, Cu, Pb, and total metals were significantly correlated with at least one benthic metric. Copper (r = 0.88–0.94) and total metals (r = 0.90–0.97) provided the most highly significant correlations. Based on longitudinal site comparisons of metals in invertebrates, benthic community structure, and differences between proportionally scaled ranks, five benthic metrics provided the best indicators of relative impact: taxa richness, Ephemeroptera-Plecoptera-Trichoptera (EPT) richness, chironomid richne...

Accumulation and Sublethal Effects of a Wyoming Crude Oil in Cutthroat Trout

Abstract Cutthroat trout Salmo clarki were exposed for 90 days to four concentrations of a Wyoming crude oil in water, ranging from 100 to 520 μg/liter. Survival was reduced to 52% among fish held in the 520-μg/liter concentration, but was not affected by three lower concentrations. The growth of cutthroat trout in all four concentrations was significantly slower than that of the control fish. Exposure concentrations of 520 and 450 μg/liter induced gill lesions and development of lesions on the retina and lens of the eye of cutthroat trout. Accumulation of total hydrocarbons in fish tissue was directly related to water concentration, except for fish in the 520-μg/liter concentration. Alkylated mono- and dicyclic aromatic hydrocarbons were accumulated most readily and naphthalenes were the dominant aromatic component in oil, water, and fish. Evidence from this research suggests that discharges of 10 mg/liter oil and grease allowed by several western states are too high.

Sensitivity of Endemic Snake River Cutthroat Trout to Acidity and Elevated Aluminum

Abstract Acidic episodes in waters of the western USA, do not last as long and are not as intense as those in the eastern USA, but we found that the native western cutthroat trout Oncorhynchus clarki is sensitive to even brief reductions in pH. In laboratory studies, fish were exposed to acidity (pH 4.5–6.5) alone or in the presence of aluminum during the first 7 d of the freshly fertilized egg, eyed embryo, alevin, or swim-up larva stages of development. Following exposure to acidity and aluminum, eggs and fish were held under control water quality conditions to 40 d posthatch to assess effects of the exposure on subsequent development. Reductions in pH from 6.5 to 6.0 in low-calcium water (1.4 mg/L) did not affect survival, but reduced growth offish in the early life stages. The presence of as little as 50 μg A1/L at low pH further decreased growth and reduced survival. The most sensitive indicators of stress were loss of ions (determined from whole-body sampling) and reduced swimming in alevins, reduct...

Drilling fluids and the arctic tundra of Alaska: Assessing contamination of wetlands habitat and the toxicity to aquatic invertebrates and fish

Drilling for oil on the North Slope of Alaska results in the release of large volumes of used drilling fluids into arctic wetlands. These releases, usually come from regulated discharges or seepage from reserve pits constructed to hold used drilling fluids. A study of five drill sites and their reserve pits showed an increase in common and trace elements and organic hydrocarbons in ponds near-to and distant from reserve pits. Ions elevated in water were Ba, Cl, Cr, K, SO4 and Zn. Concentrations of Cu, Cr, Fe, Pb, and Si in sediments were higher in near and distant ponds than in control ponds. The predominant organics in drill site waters and sediments consisted of aromatic and paraffinic hydrocarbons characteristic of petroleum or a refined product of petroleum. In 96-hr exposures in the field, toxicity toDaphnia Middendorffiana was observed in water from all reserve pits, and from two of five near ponds, but not from distant ponds. In laboratory tests withDaphnia magna, growth and reproduction were reduced in dilutions of 2.5% drilling fluid (2.5 drilling fluid: 97.5 dilution water) from one reserve pit, and 25% drilling fluid from a second. Growth and reproduction were not affected at these dilutions of fluid from the other three reserve pits. Additional regulations—such as an upper limit on aromatic hydrocarbon content and toxicity to sensitive organisms —are needed to improve safety for aquatic organisms in habitats receiving used drilling fluids.

Sensitivity of Greenback Cutthroat Trout to Acidic pH and Elevated Aluminum

Abstract The greenback cutthroat trout Oncorhynchus clarki stomias is a threatened subspecies native to the upper South Platte and Arkansas rivers between Denver and Fort Collins, Colorado, an area also susceptible to acid deposition. In laboratory studies, we exposed this subspecies to nominal pHs of 4.5–6.5 and to nominal aluminum concentrations of 0, 50, 100, and 300 μg/L; the control was pH 6.5 treatment without Al. We used soft water that contained 1.3 mg Ca/L. Exposures of 7 d each were made for four early life stages: fertilized egg, eyed embryo, alevin, and swim-up larva. Effects were measured at the end of exposure and again after a recovery period lasting until 40 d posthatch. The alevin stage was the most sensitive: at pH 5.0 with no Al, survival was reduced by 68% and swimming duration by 76%; at pH 6.0 and 50 μg Al/L, swimming duration was reduced by 62%, but survival was not affected. Reductions in whole-body concentrations of Na, K, and Ca indicated organism stress. Sodium was reduced most—...

Toxicity of five shale oils to fish and aquatic invertebrates.

The chemical composition and toxicity of three shale crude oils (Tosco, Paraho, and Geokinetics), a hydrotreated oil (Paraho HDT), and a refined shale oil (Paraho JP-4) were assessed to determine the potential hazards to native fish species and food chain organisms posed by accidental spills of such materials. Colorado squawfish (Ptychocheilus lucius), fathead minnow (Pimephales promelas), cutthroat trout (Salmo clarki), and colonies of aquatic invertebrates were exposed to the watersoluble fractions of the shale oils for 96 hr to determine concentrations lethal to 50% of the exposed organisms (LC-50). The behavior of surviving fish was also measured to determine the sublethal influences of exposure. The composition of the five water-soluble fractions was similar to that of the crude and refined shale oils from which they were made. Hydrotreated and refined oils contained fewer aromatic compounds than the crude shale oils. The cutthroat trout, a species endemic to oil shale regions, was less tolerant of shale oil exposure than the other species tested; the LC-50 concentrations were 1.8 mg/L Geokinetics, 2.1 mg/L Tosco, and 1.3 mg/L Paraho. Exposure to concentrations of one-half to one-eighth those causing mortality reduced the swimming capacity of squawfish and significantly impaired their ability to capture prey. The number of invertebrate taxa, species, and organisms colonizing plate samplers declined with increasing oil concentration. The generaBaetis andIsoperla were most sensitive to shale oil exposure; significant mortality occurred at the lowest concentration (0.5–0.7 mg/L) tested for each shale oil.

Leaching of retorted oil shale: assessing the toxicity to Colorado squawfish, fathead minnows, and two food-chain organisms

Abstract Development of a large shale-oil industry in Colorado, Utah, and Wyoming would result in disposal of large volumes of retorted shale. Water percolating through these wastes could leach toxicants into surface waters of the upper Colorado River system. Leachate from field lysimeters containing shale that had gone through the Paraho retorting process 6 years before had high concentrations of K, Li, Mg, Mo, Na, SO 4, and NO 3. Total concentrations of organics in leachate were low; nitrogen-containing aromatic hydrocarbons approximated background concentrations. In 96-h exposures, undiluted leachate was not toxic to fathead minnows Pimephales promelas or Colorado squawfish Ptychocheilus lucius, and was only slightly toxic to the mayfly Hexagenia bilineata and to Daphnia magna. In 30-d exposures to different concentrations of the leachate, a concentration of 6:94 (percent leachate:percent dilution water) caused reduced growth of fathead minnows and reduced survival of mayflies. The highest test concent...

Relationships between Boron concentrations and trout in the firehole river, Wyoming: Historical information and preliminary results of a field study

The Firehole River (FHR) in Yellowstone National Park (YNP) is a world-renowned recreational fishery that predominantly includes rainbow trout (RBT,Oncorhynchus mykiss) and brown trout (BNT,Salmo trutta). The trout populations apparently are closed to immigration and have been self-sustaining since 1955. Inputs from hot springs and geysers increase the temperature and mineral content of the water, including elevating the boron (B) concentrations to a maximum of 1 mg B/L. Both RBT and BNT reside in warm-water reaches, except when the water is extremely warm (≥25°C) during midsummer. They spawn in late fall and early winter, with documented spawning of BNT in the cold-water reach upstream from the Upper Geyser Basin and of RBT in the Lower Geyser Basin reach, where water temperatures presumably are the warmest; however, successful recruitment of RBT in waters containing 1 mg B/L has not been demonstrated conclusively. Thus, we began investigating the relationships among temperature, B concentrations, other waterquality parameters, and the distribution and reproduction of trout in the FHR in spring 1997. However, atypical high water flows and concomitant lower than historical temperatures and B concentrations during summer 1997 preclude conclusions about avoidance of high B concentrations.