Jenifer McIntyre - Academia.edu (original) (raw)

Papers by Jenifer McIntyre

Chemosphere, Jan 6, 2015

Green stormwater infrastructure (GSI), or low impact development, encompasses a diverse and expan... more Green stormwater infrastructure (GSI), or low impact development, encompasses a diverse and expanding portfolio of strategies to reduce the impacts of stormwater runoff on natural systems. Benchmarks for GSI success are usually framed in terms of hydrology and water chemistry, with reduced flow and loadings of toxic chemical contaminants as primary metrics. Despite the central goal of protecting aquatic species abundance and diversity, the effectiveness of GSI treatments in maintaining diverse assemblages of sensitive aquatic taxa has not been widely evaluated. In the present study we characterized the baseline toxicity of untreated urban runoff from a highway in Seattle, WA, across six storm events. For all storms, first flush runoff was toxic to the daphniid Ceriodaphnia dubia, causing up to 100% mortality or impairing reproduction among survivors. We then evaluated whether soil media used in bioretention, a conventional GSI method, could reduce or eliminate toxicity to juvenile c...

The Science of the total environment, 2014

Urban stormwater contains a complex mixture of contaminants that can be acutely toxic to aquatic ... more Urban stormwater contains a complex mixture of contaminants that can be acutely toxic to aquatic biota. Green stormwater infrastructure (GSI) is a set of evolving technologies intended to reduce impacts on natural systems by slowing and filtering runoff. The extent to which GSI methods work as intended is usually assessed in terms of water quantity (hydrology) and quality (chemistry). Biological indicators of GSI effectiveness have received less attention, despite an overarching goal of protecting the health of aquatic species. Here we use the zebrafish (Danio rerio) experimental model to evaluate bioinfiltration as a relatively inexpensive technology for treating runoff from an urban highway with dense motor vehicle traffic. Zebrafish embryos exposed to untreated runoff (48-96h; six storm events) displayed an array of developmental abnormalities, including delayed hatching, reduced growth, pericardial edema, microphthalmia (small eyes), and reduced swim bladder inflation. Three of ...

Transactions of the American Fisheries Society, 2009

Lakes Sammamish and Washington are two large, urban lakes in close proximity to Seattle, Washingt... more Lakes Sammamish and Washington are two large, urban lakes in close proximity to Seattle, Washington. The two lakes have similar assemblages of apex predators, but differences in lake size, species richness, and forage fish assemblages contribute to contrasting trophic relationships. We used stable isotope and diet analyses to assess lake-specific differences in the trophic structure of fish and invertebrates from these lakes. Estimates of d 15 N-based trophic elevation revealed that the food web in Lake Sammamish was truncated by approximately one complete trophic level relative to that of Lake Washington. The shorter food chain in Lake Sammamish reflected the absence of longfin smelt Spirinchus thaleichthys and minimal consumption of threespine stickleback Gasterosteus aculeatus, emphasizing the importance of these species as primary forage fishes and trophic links between invertebrates and piscivores in Lake Washington. As two highly 15 N-enriched and 13 C-depleted energy sources, longfin smelt and threespine sticklebacks effectively stretched the isotopic endpoints of the Lake Washington food web by contributing to more pronounced ontogenetic shifts in isotope values for piscivores in Lake Washington than for those in Lake Sammamish.

Transactions of the American Fisheries Society, 2006

Stable isotopes of nitrogen and carbon and stomach content analysis were used to determine the tr... more Stable isotopes of nitrogen and carbon and stomach content analysis were used to determine the trophic position and relative importance of benthic and pelagic pathways for different life stages and species of the major fishes and invertebrate prey in Lake Washington. Significant coupling of the benthic and pelagic pathways was evident in this complex food web across seasons and fish ontogenies. Among apex predators, cutthroat trout Oncorhynchus clarkii and northern pikeminnow Ptychocheilus oregonensis shifted ontogenetically from benthic omnivory to pelagic piscivory, whereas yellow perch Perca flavescens shifted from pelagic zooplanktivory to benthic piscivory. Apex predators continued to rely on benthic prey seasonally, particularly in winter and spring. Benthic pathways were less important to the current diets of apex predators than they were during the recovery from eutrophication in the 1970s. Surprisingly, the d 15 N values for copepods during winter and for zooplanktivorous longfin smelt Spirinchus thaleichthys and threespine sticklebacks Gasterosteus aculeatus were similar to those for top piscivores, whereas the significantly lower values for zooplanktivorous juvenile sockeye salmon O. nerka were more similar to expectations. Nitrogen and carbon isotope ratios of pelagic planktivores and invertebrates also varied seasonally. Mixing model results showed that stable isotopes and stomach contents were comparable for determining ontogenetic trends, but stable isotopes established these trends with many fewer samples and less variability and accurately portrayed ontogenetic trends when few stomach samples were available. However, stomach content analysis was critical in delineating seasonal trends in diets and for identifying specific prey species.

Science of The Total Environment, 2007

Understanding the mechanisms of bioaccumulation in food webs is critical to predicting which food... more Understanding the mechanisms of bioaccumulation in food webs is critical to predicting which food webs are at risk for higher rates of bioaccumulation that endanger the health of upper-trophic predators, including humans. Mercury and organochlorines were measured concurrently with stable isotopes of nitrogen and carbon in key fishes and invertebrates of Lake Washington to explore important pathways of bioaccumulation in this food web. Across the food web, age and trophic position together were highly significant predictors of bioaccumulation. Trophic position was more important than age for predicting accumulation of mercury, ∑DDT, and ∑-chlordane, whereas age was more important than trophic position for predicting ∑PCB. Excluding age from the analysis inflated the apparent importance of trophic position to bioaccumulation for all contaminants. Benthic and pelagic habitats had similar potential to bioaccumulate contaminants, although higher ∑-chlordane concentrations in organisms were weakly associated with more benthic carbon signals. In individual fish species, contaminant concentrations increased with age, size, and trophic position (δ 15 N), whereas relationships with carbon source (δ 13 C) were not consistent. Lipid concentrations were correlated with contaminant concentrations in some but not all fishes, suggesting that lipids were not involved mechanistically in bioaccumulation. Contaminant concentrations in biota did not vary among littoral sites. Collectively, these results suggest that age may be an important determinant of bioaccumulation in many food webs and could help explain a significant amount of the variability in apparent biomagnification rates among food webs. As such, effort should be made when possible to collect information on organism age in addition to stable isotopes when assessing food webs for rates of biomagnification.

Journal of Biomolecular Techniques : JBT, 2014

Normalization of fluorescence-based quantitative real-time PCR (qPCR) data varies across quantita... more Normalization of fluorescence-based quantitative real-time PCR (qPCR) data varies across quantitative gene expression studies, despite its integral role in accurate data quantification and interpretation. Identification of suitable reference genes plays an essential role in accurate qPCR normalization, as it ensures that uncorrected gene expression data reflect normalized data. The reference residual normalization (RRN) method presented here is a modified approach to conventional 2 Ϫ⌬⌬Ct qPCR normalization that increases mathematical transparency and incorporates statistical assessment of reference gene stability. RRN improves mathematical transparency through the use of sample-specific reference residuals (RR i ) that are generated from the mean C t of one or more reference gene(s) that are unaffected by treatment. To determine stability of putative reference genes, RRN uses ANOVA to assess the effect of treatment on expression and subsequent equivalence-threshold testing to establish the minimum permitted resolution.

Environmental Toxicology and Chemistry, 2009

Conventional water chemistry parameters such as hardness, alkalinity, and organic carbon are know... more Conventional water chemistry parameters such as hardness, alkalinity, and organic carbon are known to affect the acutely lethal toxicity of copper to fish and other aquatic organisms. In the present study, we investigate the influence of these water chemistry parameters on short-term (3 h), sublethal (0-40 g/L) copper toxicity to the peripheral mechanosensory system of larval zebrafish (Danio rerio) using an in vivo fluorescent marker of lateral line sensory neuron (hair cell) integrity. We studied the influence of hardness (via CaCl 2 , MgSO 4 , or both at a 2:1 molar ratio), sodium (via NaHCO 3 or NaCl), and organic carbon on copper-induced neurotoxicity to zebrafish lateral line neurons over a range of environmentally relevant water chemistries. For all water parameters but organic carbon, the reductions in copper toxicity, although statistically significant, were small. Increasing organic carbon across a range of environmentally relevant concentrations (0.1-4.3 mg/L) increased the EC50 for copper toxicity (the effective concentration resulting in a 50% loss of hair cells) from approximately 12 g/L to approximately 50 g/L. Finally, we used an ionoregulatory-based biotic ligand model to compare copper toxicity mediated by targets in the fish gill and lateral line. Relative to copper toxicity via the gill, we find that individual water chemistry parameters are less influential in terms of reducing cytotoxic impacts to the mechanosensory system.

Environmental Science & Technology, 2008

Dissolved copper is an important nonpoint source pollutant in aquatic ecosystems worldwide. Coppe... more Dissolved copper is an important nonpoint source pollutant in aquatic ecosystems worldwide. Copper is neurotoxic to fish and is specifically known to interfere with the normal function of the peripheral olfactory nervous system. However,the influence of water chemistry on the bioavailability and toxicity of copper to olfactory sensory neurons is not well understood. Here we used electrophysiological recordings from the olfactory epithelium of juvenile coho salmon (Oncorhynchus kisutch) to investigate the impacts of copper in freshwaters with different chemical properties. In low ionic strength artificial fresh water, a short-term (30 min) exposure to 20 microg/L dissolved copper reduced the olfactory response to a natural odorant (10(-5) M L-serine) by 82%. Increasing water hardness (0.2-1.6 mM Ca) or alkalinity (0.2-3.2 mM HCO3-) only slightly diminished the inhibitory effects of copper. Moreover, the loss of olfactory function was not affected by a change in pH from 8.6 to 7.6. By contrast, olfactory capacity was partially restored by increasing dissolved organic carbon (DOC; 0.1-6.0 mg/L). Given the range of natural water quality conditions in the western United States, water hardness and alkalinity are unlikelyto protect threatened or endangered salmon from the sensory neurotoxicity of copper. However, the olfactory toxicity of copper may be partially reduced in surface waters that have a high DOC content.

Ecological Applications, 2012

Copper contamination in surface waters is common in watersheds with mining activities or agricult... more Copper contamination in surface waters is common in watersheds with mining activities or agricultural, industrial, commercial, and residential human land uses. This widespread pollutant is neurotoxic to the chemosensory systems of fish and other aquatic species. Among Pacific salmonids (Oncorhynchus spp.), copper-induced olfactory impairment has previously been shown to disrupt behaviors reliant on a functioning sense of smell. For juvenile coho salmon (O. kisutch), this includes predator avoidance behaviors triggered by a chemical alarm cue (conspecific skin extract). However, the survival consequences of this sublethal neurobehavioral toxicity have not been explored. In the present study juvenile coho were exposed to low levels of dissolved copper (5-20 lg/L for 3 h) and then presented with cues signaling the proximity of a predator. Unexposed coho showed a sharp reduction in swimming activity in response to both conspecific skin extract and the upstream presence of a cutthroat trout predator (O. clarki clarki ) previously fed juvenile coho. This alarm response was absent in prey fish that were exposed to copper. Moreover, cutthroat trout were more effective predators on copper-exposed coho during predation trials, as measured by attack latency, survival time, and capture success rate. The shift in predator-prey dynamics was similar when predators and prey were co-exposed to copper. Overall, we show that copperexposed coho are unresponsive to their chemosensory environment, unprepared to evade nearby predators, and significantly less likely to survive an attack sequence. Our findings contribute to a growing understanding of how common environmental contaminants alter the chemical ecology of aquatic communities.

Bulletin of Environmental Contamination and Toxicology, 2004

... Temperature С pH Dissolved oxygen (mg/L) Treatment Av Min Max Av Min Max Av Min Max Control R... more ... Temperature С pH Dissolved oxygen (mg/L) Treatment Av Min Max Av Min Max Av Min Max Control R-11 12.77 12.29 11.5 11.4 13.6 13.3 6.6 6.6 6.4 6.5 6.7 6.8 9.20 8.11 7.85 5.95 11.50 9.37 Control LI 700 12.03 12.01 10.3 10.8 13.0 12.9 6.4 6.3 6.2 6.0 6.7 6.5 8.81 8.67 8.00 ...

PLoS ONE, 2011

Several Seattle-area streams in Puget Sound were the focus of habitat restoration projects in the... more Several Seattle-area streams in Puget Sound were the focus of habitat restoration projects in the 1990s. Post-project effectiveness monitoring surveys revealed anomalous behaviors among adult coho salmon returning to spawn in restored reaches. These included erratic surface swimming, gaping, fin splaying, and loss of orientation and equilibrium. Affected fish died within hours, and female carcasses generally showed high rates (.90%) of egg retention. Beginning in the fall of 2002, systematic spawner surveys were conducted to 1) assess the severity of the adult die-offs, 2) compare spawner mortality in urban vs. non-urban streams, and 3) identify water quality and spawner condition factors that might be associated with the recurrent fish kills. The forensic investigation focused on conventional water quality parameters (e.g., dissolved oxygen, temperature, ammonia), fish condition, pathogen exposure and disease status, and exposures to metals, polycyclic aromatic hydrocarbons, and current use pesticides. Daily surveys of a representative urban stream (Longfellow Creek) from 2002-2009 revealed premature spawner mortality rates that ranged from 60-100% of each fall run. The comparable rate in a nonurban stream was ,1% (Fortson Creek, surveyed in 2002). Conventional water quality, pesticide exposure, disease, and spawner condition showed no relationship to the syndrome. Coho salmon did show evidence of exposure to metals and petroleum hydrocarbons, both of which commonly originate from motor vehicles in urban landscapes. The weight of evidence suggests that freshwater-transitional coho are particularly vulnerable to an as-yet unidentified toxic contaminant (or contaminant mixture) in urban runoff. Stormwater may therefore place important constraints on efforts to conserve and recover coho populations in urban and urbanizing watersheds throughout the western United States.