Richard A. Frank

Fathead minnow (Pimephales promelas) reproduction is impaired in aged oil sands process-affected waters.

Large volumes of fluid tailings are generated during the extraction of bitumen from oil sands. As part of their reclamation plan, oil sands operators in Alberta propose to transfer these fluid tailings to end pit lakes and, over time, these are expected to develop lake habitats with productive capabilities comparable to natural lakes in the region. This study evaluates the potential impact of various oil sands process-affected waters (OSPW) on the reproduction of adult fathead minnow (Pimephales promelas) under laboratory conditions. Two separate assays with aged OPSW (>15 years) from the experimental ponds at Syncrude Canada Ltd. showed that water containing high concentrations of naphthenic acids (NAs; >25 mg/l) and elevated conductivity (>2000 μS/cm) completely inhibited spawning of fathead minnows and reduced male secondary sexual characteristics. Measurement of plasma sex steroid levels showed that male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone whereas females had lower concentrations of 17β-estradiol. In a third assay, fathead minnows were first acclimated to the higher salinity conditions typical of OSPW for several weeks and then exposed to aged OSPW from Suncor Energy Inc. (NAs ∼40 mg/l and conductivity ∼2000 μS/cm). Spawning was significantly reduced in fathead minnows held in this effluent and male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone. Collectively, these studies demonstrate that aged OSPW has the potential to negatively affect the reproductive physiology of fathead minnows and suggest that aquatic habitats with high NAs concentrations (>25 mg/l) and conductivities (>2000 μS/cm) would not be conducive for successful fish reproduction.

Fathead minnow (Pimephales promelas) reproduction is impaired when exposed to a naphthenic acid extract

Previous studies have demonstrated that oil sands process-affected water (OSPW) impairs the reproduction of fish and that naphthenic acids (NAs), a natural constituent of oil sands, are suspected of being responsible. This study evaluates the potential impact of NAs on the reproduction of adult fathead minnows (Pimephales promelas) under laboratory conditions. Fathead minnows exposed to a 10 mg/l naphthenic acid extract (NAE) for 21 days spawned fewer eggs and males had reduced expression of secondary sexual characteristics. Male fathead minnows exposed to a 5 mg/l NAE had lower plasma levels of 11-ketotestosterone whereas those exposed to a 10 mg/l NAE had lower concentrations of both testosterone and 11-ketotestosterone. Since OSPW also contains high concentrations of salts, this study also investigated whether they modify the toxicity of NAEs. Spawning was significantly reduced in fathead minnows exposed to a 10 mg/l NAE alone and in combination with NaHCO₃ (700 mg/l), typical of concentrations in OSPW(.) Interestingly, the addition of NaHCO₃ reduced the inhibitory effects of the NAE on the numbers of reproductive tubercles and plasma testosterone levels. Further studies showed that NaHCO₃ acted by reducing the uptake of the NAE to the fish. NaHCO₃ but not NaCl or Na₂SO₄ reduced the acute toxic effects of the NAE on fathead minnow embryo and larvae mortality. Collectively, these studies show that the NAs in OSPW have the potential to negatively affect reproduction in fathead minnows and that HCO₃⁻ reduces the acute and chronic toxicity of NAs.

Organochlorine Residues, Mercury, Copper and Cadmium in Yellow Perch, White Bass and Smallmouth Bass, Long Point Bay, Lake Erie

Abstract Three collections of yellow perch, white bass and smallmouth bass were made in May, July and late October for analyses of DDT, PCB, mercury, copper and cadmium. Fat content varied seasonally among collections, lowest in spring and highest in fall. Total DDT residues were low for all species. Means ranged from 0.09 to 0.27 μg/g and exhibited no seasonal changes. No difference among species existed for DDT in spite of differing fat content, but concentrations within a species increased with increasing fat and subsequently age. PCBs were up to 6.5 times greater than DDT levels. PCB residues, lowest in yellow perch and highest in white bass, did not vary with season but increased with increasing fat. Dieldrin was low and no trends relating to season or fat were apparent. Only two specimens contained mercury residues above 0.5 μg/g. Mercury was apparently related to size and subsequently age. Copper was slightly higher in yellow perch, means ranged from 1.29 to 1.56 μg/g, but copper and cadmium were ...

Reproductive and health assessment of fathead minnows (Pimephales promelas) inhabiting a pond containing oil sands process-affected water.

Previous laboratory based studies have shown that oil sands process-affected waters (OSPWs) containing high concentrations of naphthenic acids (>25 mg/l) have adverse effects on the reproductive physiology of fish. The purpose of this study was to assess the reproductive development and health of a wild population of fathead minnows (Pimephales promelas) inhabiting an OSPW pond that has moderate concentrations of naphthenic acids (~10 mg/l). Fathead minnows were collected at various times during the period of 2006 through 2008 from Demonstration Pond (OSPW) located at Syncrude Canada Ltd., and two reference sites, Beaver Creek reservoir and Poplar Creek reservoir, which are all north of Fort McMurray, AB, Canada. Condition factor, gill histopathology, gonadosomatic indices, liver somatic indices, male secondary sexual characteristics, and plasma sex steroids were examined. Depending on the time of year that fathead minnows were collected, there were differences in the condition factor, gonadosomatic indices, liver somatic indices, and secondary sexual characteristics of fathead minnows (in males) from Demonstration Pond when compared to the fathead minnows from the reference sites. In comparison to reference fish, lower concentrations of 11-ketotestosterone were measured in the plasma of male fathead minnows collected from Demonstration Pond in June 2006 and July 2007. Black spot disease and Ligula intestinalis were prevalent in fathead minnows from the reference sites but were not observed in fathead minnows from Demonstration Pond. The opercula of fathead minnows from Demonstration Pond also differed from those of reference fish. An examination of the gills of fathead minnows from Demonstration Pond revealed that were a number of proliferative and degenerative alterations relative to reference fish. Even though the fathead minnow population has been maintained in this OSPW pond since 1993, the results of this study demonstrate that the OSPW continues to affect the reproductive development and health of the fathead minnows compared to fish collected at reference sites.

Monitoring wood shaving litter and animal products for polychlorophenols residues, Ontario, Canada, 1978–1986

Timber is extensively treated with the wood preservative pesticides collectively called the polychlorophenols (PxCP) which include tri-(T3CP), tetra-(T4CP), and pentachlorophenol (P5CP). These treatments are intended to protect lumber against the attacks of wood eating or boring insects and the wood decaying and staining fungi. Wood shavings are a by-product of the lumber industry that have been utilized widely in agriculture for many years as a major bedding litter for poultry, swine, and cattle and a minor litter for other domestic animals. Complaints were lodged within the Province of Ontario of off-flavors in locally produced poultry meat. Many local poultry producers reported having difficulties with (1) the fertility of their breeding flocks and (2) the ineffectiveness of vaccines among poultry raised on wood shavings but which disappeared when raised on cereal straw. An Ontario Ministry of Agriculture and Food service was offered whereby producers could have their wood shavings analyzed and receive guidance on the advisability of use. This paper reports on this service started in 1978 for wood shavings, and on a follow-up monitoring program to determine residues of PxCP in domestic animal products.

Molecular responses of Walleye (Sander vitreus) embryos to naphthenic acid fraction components extracted from fresh oil sands process-affected water

Naphthenic acid fraction components (NAFCs) are constituents of oil sands process-affected water (OSPW), which is generated as a result of unconventional oil production via surface mining in the Athabasca oil sands region. NAFCs are often considered to be major drivers of OSPW toxicity to various taxa, including fishes. However, the molecular targets of these complex mixtures are not fully elucidated. Here we examined the effects in walleye (Sander vitreus) embryos after exposure to NAFCs extracted from fresh OSPW. Eleutheroembryos (exposed to 0, 4.2 or 8.3mg/L NAFCs from 1day post-fertilization to hatch) were subsampled, measured for growth and deformities, and molecular responses were assessed via real-time polymerase chain reaction (PCR). Fourteen genes were evaluated, with a focus on the aryl-hydrocarbon receptor (AhR) - cytochrome P450 pathway (arnt, cyp1a1), the oxidative stress axis (cat, gst, sod, gpx1b), apoptosis (e.g. casp3, bax and p53), growth factor signaling (e.g. insulin-like growth factors igf1, igf1b, and igf1bp), and tissue differentiation (vim). NAFC exposure was associated with an increase in the expression of cyp1a1, and a decrease in gpx1b and ribosomal protein rps40. These results indicate that NAFC effects on walleye early-life stages may be mediated through oxidative stress via pathways that include AhR.

Organochlorine residues in bird species collected dead in Ontario 1972-1988

Organochlorine residues have been reported in many species of birds found dead or shot around the Great Lakes Basin. Raptors and fish-eating birds have had very high residues in the past while terrestrial seed- and insect-eaters have had relatively low residues. Most of the organochlorine insecticides like DDT, aldrin, dieldrin, chlordane, endrin and heptachlor have been removed from field use, and controls have been placed on the dispersal of organochlorine industrial chemicals like mirex and PCB. These substances are very persistent. The major sources of contamination now are environmental residues picked up by birds in their normal feeding. These compounds bioaccumulate in bird species, and the highest residues accumulate at the top of the food chain. This paper is a compilation of data obtained from dead birds collected in the Great Lakes Basin over the last 16 years and analyzed for organochlorine contaminants.