Papers by Joseph Rasmussen
The role of the zebra mussel ( Dreissena polymorpha) in structuring macroinvertebrate communities... more The role of the zebra mussel ( Dreissena polymorpha) in structuring macroinvertebrate communities on hard substrata
Freshwater Biology, 2017
Many freshwater systems receive substantial inputs of terrestrial organic matter. Terrestrially d... more Many freshwater systems receive substantial inputs of terrestrial organic matter. Terrestrially derived dissolved organic carbon (t‐DOC) inputs can modify light availability, the spatial distribution of primary production, heat, and oxygen in aquatic systems, as well as inorganic nutrient bioavailability. It is also well‐established that some terrestrial inputs (such as invertebrates and fruits) provide high‐quality food resources for consumers in some systems. In small to moderate‐sized streams, leaf litter inputs average approximately three times greater than the autochthonous production. Conversely, in oligo/mesotrophic lakes algal production is typically five times greater than the available flux of allochthonous basal resources. Terrestrial particulate organic carbon (t‐POC) inputs to lakes and rivers are comprised of 80%–90% biochemically recalcitrant lignocellulose, which is highly resistant to enzymatic breakdown by animal consumers. Further, t‐POC and heterotrophic bacteria...
Brook trout as a percentage of the trout population over the last four decades in streams stocked... more Brook trout as a percentage of the trout population over the last four decades in streams stocked with brook trout in the late 1 940s compared to unstocked streams 15 vm
Journal of Animal Ecology, 2006
1. Migratory and resident forms of salmonids coexist in many river systems. Although such coexist... more 1. Migratory and resident forms of salmonids coexist in many river systems. Although such coexistence is widespread, little is known about its ecological basis and no studies have compared the habitat use of premigratory juveniles and residents. 2. We employed a comparative approach to explore the differential habitat use of juvenile anadromous and resident brook trout. This required the investigation of habitat use in streams closed to anadromy, containing only resident brook trout Salvelinus fontinalis ('resident-only' streams) and streams open to anadromy, containing coexisting Atlantic salmon Salmo salar and anadromous and resident brook trout ('migrant-resident' streams). 3. We demonstrate that fast habitats (riffles) are occupied more frequently in streams with migratory brook trout relative to riffle habitats of streams with only resident brook trout. In contrast, occupation of slow current velocities (pools) was observed in both migrant-resident and resident-only streams as both stream types contain resident brook trout. The net effect is a wider distribution of occupied habitats (pool and riffles) in migrant-resident streams relative to resident-only streams, resulting in few, if any, unused habitats. 4. These results are consistent with previously reported bioenergetic, morphological and stable isotope differences observed between anadromous and resident brook trout. 5. Our findings suggest that a link exists between juvenile habitat use, metabolic costs and life-history strategies.
Ecological Applications, 2001
Mass balance models have frequently been used with laboratory-derived bioenergetic models to exam... more Mass balance models have frequently been used with laboratory-derived bioenergetic models to examine the accumulation of mercury (Hg) in fish. The accumulation of Hg in fish has usually been successfully described by these models. However, this has generally been achieved by adjusting the parameters of these models until there was a close fit between observed and predicted values. In this study, we present a simple Hg mass balance model (MMBM) to predict Hg concentration in fish. This MMBM was applied with three methods of estimating food consumption rates to predict Hg concentration in three freshwater fish species. The MMBM accurately predicted the accumulation of Hg in the three fish species examined in this study when it was combined with food consumption rates that were determined with a radioisotopic method. The MMBM tended to underestimate Hg concentration in fish when it was combined with food consumption rates determined using laboratory-derived bioenergetic models, possibly because activity costs derived under laboratory conditions do not adequately represent activity costs of fish in the field. When feeding rates were estimated with a bioenergetic model implemented with site-specific estimates of activity costs, the MMBM accurately predicted the concentration of Hg in fish. Therefore, until activity costs can be accurately estimated in situ, predictions obtained with the MMBM implemented with a laboratory-derived bioenergetic model should be interpreted cautiously.
Conservation Biology, 1999
Since 1900, 123 freshwater animal species have been recorded as extinct in North America. Hundred... more Since 1900, 123 freshwater animal species have been recorded as extinct in North America. Hundreds of additional species of fishes, mollusks, crayfishes, and amphibians are considered imperiled. Using an exponential decay model, we derived recent and future extinction rates for North American freshwater fauna that are five times higher than those for terrestrial fauna. Assuming that imperiled freshwater species will not survive throughout the next century, our model projects a future extinction rate of 4% per decade, which suggests that North America's temperate freshwater ecosystems are being depleted of species as rapidly as tropical forests.
Ecotoxicology, 1997
The effects of bleached kraft mill effluent (BKME) on blood cortisol levels and the morphology of... more The effects of bleached kraft mill effluent (BKME) on blood cortisol levels and the morphology of the pituitary-interrenal axis were investigated in two species of teleost fish, the northern pike, Esox lucius, and the yellow perch, Perca flavescens, sampled upstream and downstream from a pulp and paper mill on the St Maurice River, Québec. Fish were acutely stressed by a standardized capture and sampling protocol at both sites, and their ability to elevate blood cortisol levels in response to the capture stress was compared. Blood cortisol levels in fish from the upstream site (.100 ng/ml plasma) were higher than the levels in fish from the BKME site, and the pituitary corticotropes and the interrenal steroidogenic cells of the upstream fish were larger and had larger nuclei compared with cells from the downstream fish. The low blood cortisol levels in fish exposed to BKME were correlated to cellular atrophy within the hypothalamo-pituitary-interrenal (HPI) axis. The reduced ability to elevate blood cortisol in response to an acute stress may be an endocrine dysfunction occuring in fish chronically exposed to chemical stressors in their environment.
Freshwater Biology, 2005
1. Benthic invertebrate community composition and yellow perch (Perca flavescens) diet, growth an... more 1. Benthic invertebrate community composition and yellow perch (Perca flavescens) diet, growth and activity levels from lakes along a metal-contamination gradient were used to assess the importance of a naturally diverse prey base for maintaining energy transfer to growing fish, and how this transfer is disrupted by metal contamination. 2. Zoobenthic communities had lower diversity in metal-contaminated lakes, with a notable absence of large bodied invertebrate taxa. 3. The average mass of non-zooplankton prey items was significantly greater for 2+ and 3+ perch from the reference lake, and increased significantly with age in all except the most contaminated lakes where prey choice was limited. 4. Benthivorous perch from all contaminated lakes exhibited slowed growth. Perch from one of the contaminated lakes exhibited faster growth during piscivory, indicating slowed growth only while benthivorous. 5. Estimates of fish activity, using the activity of the glycolytic enzyme Lactate dehydrogenase in perch white muscle tissue as a proxy, suggested that shifts in diet to larger prey (in reference and intermediately contaminated lakes) lowered activity costs, which may explain how diet shifts maintain growth efficiency as perch grow larger.
Fisheries, 2011
The red drum on the cover photo for the October issue of Fisheries was my largest of the trip at ... more The red drum on the cover photo for the October issue of Fisheries was my largest of the trip at 32 pounds (as well as my largest red drum ever). I considered having it mounted but upon reflection following the photo session released it unharmed back into the Gulf of Mexico. Doing so warmed my heart (the rest of me was already drenched in sweat)." Don Jackson, AFS Past President.
Journal of Animal Ecology, 2009
Freshwater and Estuarine Radioecology, Proceedings of an International Seminar
Nature
12. Wasserman, E., Stixrude, L. & Cohen, RE Thermal properties of iron at high pr... more 12. Wasserman, E., Stixrude, L. & Cohen, RE Thermal properties of iron at high pressures and temperatures. Phys. Rev. B 53, 8296±8309 (1996). 13. Stixrude, L., Wasserman, E. & Cohen, RE Composition and temperature of the Earth's inner core. J. Geophys. Res. 102, ...
Journal of hazardous materials, Jan 5, 2018
Bioaccumulation of pharmaceuticals in aquatic organisms is increasingly reported in the peer-revi... more Bioaccumulation of pharmaceuticals in aquatic organisms is increasingly reported in the peer-reviewed literature. However, seasonal instream dynamics including occurrence and bioaccumulation across trophic positions are rarely studied, particularly in semiarid streams with flows influenced by seasonal snowmelt and municipal effluent discharges. Thus, we selected East Canyon Creek in Park City, Utah, USA to examine spatio-temporal bioaccumulation of select ionizable pharmaceuticals across trophic positions using trophic magnification factors calculated at incremental distances (0.15, 1.4, 13 miles) downstream from a municipal effluent discharge during spring (May), Summer (August), and fall (October). Nine target analytes were detected in all species during all sampling events. Trophic dilution was consistently observed for amitriptyline, caffeine, diphenhydramine, diltiazem, fluoxetine, and sertraline, regardless of seasonal instream flows or distance from effluent discharge. Calcul...
Chemosphere
Growth in extraction of bitumen from oil sands has raised concerns about influences of this indus... more Growth in extraction of bitumen from oil sands has raised concerns about influences of this industry on surrounding environments. Water clearance rate (a surrogate of feeding rate by Daphnia magna) in water containing D. magna exposed to oil sands process-affected water (OSPW) and its principal components, dissolved component (DC) and suspended particulate matter (SPM), was reduced to 72, 29, and 59% of controls, respectively. This study also examined several possible mechanisms for the observed changes algal cell density (i.e., feeding rate). There was no change in the digestive enzymes trypsin or amylase when D. magna were exposed to DC or SPM; however, exposure to total OSPW reduced trypsin activity. Mandible rolling or post-abdominal rejections, which are indicators of feeding and palatability of food, were not affected by any exposures to OSPW. Beating of thoracic limbs, which provides water flow toward the feeding groove, was reduced by exposure to SPM or total OSPW. Peristaltic activity was reduced by exposure to DC, which then might result in reduced digestion time in D. magna exposed to DC, SPM or whole OSPW. All treatments caused an increase in numbers of intact algae cells in the hindgut and excreted material. These results suggest that both DC and SPM affect feeding of D. magna by impairing actions of the digestive system, but most probably not by reducing rates of ingestion.
Environmental Management
Aquatic invertebrates form the base of the consumer food web in lakes. In coal-mining end-pit lak... more Aquatic invertebrates form the base of the consumer food web in lakes. In coal-mining end-pit lakes, invertebrates are exposed to an environment with potentially challenging physical and chemical features. We hypothesized that the physical and chemical features of end-pit lakes reduce critical littoral habitat and thus reduce invertebrate diversity, thereby limiting the potential for these lakes to be naturalized. We used a multivariate approach using principle component analysis and redundancy analysis to study relationships between invertebrate community structure, habitat features, and water quality in five end-pit lakes and five natural lakes in the Rocky Mountain foothills of west-central Alberta, Canada. Results show a significantly different invertebrate community structure was present in end-pit lakes as compared with reference lakes in the same region, which could be accounted for by water hardness, conductivity, slope of the littoral zone, and phosphorus concentrations. Habitat diversity in end-pit lakes was also limited, cover provided by macrophytes was scarce, and basin slopes were significantly steeper in pit lakes. Although water chemistry is currently the strongest influencing factor on the invertebrate community, physical challenges of habitat homogeneity and steep slopes in the littoral zones were identified as major drivers of invertebrate community structure. The addition of floating wetlands to the littoral zone of existing pit lakes can add habitat complexity without the need for large-scale alterations to basing morphology, while impermeable capping of waste-rock and the inclusion of littoral habitat in the planning process of new pit lakes can improve the success of integrating new pit lakes into the landscape.
Scientific Reports
Selenium (Se), an essential micro nutrient, is toxic to aquatic life at slightly higher water con... more Selenium (Se), an essential micro nutrient, is toxic to aquatic life at slightly higher water concentrations. Watersheds receiving leachate from selenium rich sources require large-scale, long-term treatment to mitigate Se toxicity. We applied the principles of anaerobic bacterial bioreactors, previously successful in small scale Se mitigation, to a whole end-pit lake ecosystem. Fertilization of the lake with N and P increased primary production, creating a meromictic, anoxic layer, and enhanced the habitat for locally present, anaerobic, Se and sulfur reducing bacteria. Within two years, Se concentrations were reduced tenfold , reaching water-quality guideline values. The successful experiment demonstrated a novel treatment of large volumes of Se-contaminated water, and introduced an inexpensive method to mitigate a persistent aquatic pollutant of global concern.
Environmental Toxicology and Chemistry, Aug 1, 2001
We have developed a method to concentrate aqueous samples for toxicity testing. This method relie... more We have developed a method to concentrate aqueous samples for toxicity testing. This method relies on the phenomenon of freezing exclusion, whereby solutes are rejected from the interstices of a growing ice crystal. Tenfold freeze concentration gave excellent recoveries of inorganic and organic analytes, phenol and ZnSO 4 toxicity from spiked natural waters, and toxicity of both pre-and postdischarge municipal wastewater. Simultaneous 10-fold concentration of strong mineral or humic ambient matrices did not substantially modify the expressed toxicity of phenol or ZnSO 4 , and it did not seem to generate spurious toxicity to the marine bioassay organism used (Vibrio fischeri). Hundredfold freeze concentration permitted the quantification of low levels of ambient toxicity in a wide variety of natural waters using a rapid, inexpensive microbioassay. Precipitation of matrix elements may limit the degree of concentration that can be achieved with highly mineralized or strongly humic waters. This approach is well suited to ambient toxicity testing, because it is nonspecific and has low potential for solvent contamination. Furthermore, the low temperatures involved minimize volatilization and degradation of organic contaminants.
Can J Fisheries Aquat Sci, 1997
Stable nitrogen isotope ratios (δ 15 N) are commonly used to represent the trophic structure of a... more Stable nitrogen isotope ratios (δ 15 N) are commonly used to represent the trophic structure of aquatic systems, yet the ability of δ 15 N to indicate the trophic position of aquatic consumers remains untested using traditional dietary methods. Interpreting the δ 15 N of aquatic consumers relative to large, long-lived primary consumers such as unionid mussels provides a continuous measure of an organism's trophic position that adjusts for among-system variation in baseline δ 15 N. We used this method to estimate the trophic position of eight littoral fish species from 36 lakes in Ontario and Quebec. We validated these δ 15 N measures of trophic position by compiling literature dietary data from 342 populations of these same fish species and calculated a continuous measure of trophic position for each population. Mean dietary trophic position estimates corresponded closely to 15 N estimates, with mean trophic position ranging from 3.3 for pumpkinseed (Lepomis gobbosus) to 4.4 for walleye (Stizostedion vitreum). Both methods indicated approximately one trophic level of variation among populations of a species. This study confirms the ability of baseline-adjusted δ 15 N to represent the trophic position of aquatic consumers. Résumé : Les rapports d'un isotope stable de l'azote (δ 15 N) sont couramment utilisés pour représenter la structure trophique des systèmes aquatiques; pourtant, la capacité du δ 15 N d'indiquer la position trophique des consommateurs aquatiques n'a pas encore été testée employant des méthodes alimentaires traditionnels. L'interprétation de δ 15 N des consommateurs aquatiques par rapport aux consommateurs primaires de grande taille et de longue durée de vie comme les moules de la famille des unionidés fournit une mesure continue de la position trophique d'un organisme qui s'ajuste pour tenir compte de la variation intersystèmes de δ 15 N de base. Nous avons utilisé cette méthode pour estimer la position trophique de huit espèces de poissons littoraux dans 36 lacs du Québec et de l'Ontario. Nous avons validé ces mesures de position trophique par δ 15 N en rassemblant, dans la documentation scientifique, les données sur le régime alimentaire de 342 populations de ces mêmes espèces de poisson et avons calculé une mesure continue de la position trophique de chacune de ces populations. La valeurs estimées de la position trophique alimentaire moyenne correspondaient étroitement aux valeurs estimées de 15 N, la position trophique moyenne variant de 3,3 pour le crapet-soleil (Lepomis gobbosus) à 4,4 pour le doré jaune (Stizostedion vitreum). Les deux méthodes ont indiqué une variation d'environ un niveau trophique entre les populations d'une même espèce. Cette étude confirme la capacité du δ 15 N ajusté en fonction de la ligne de base de représenter la position trophique des consommateurs aquatiques. [Traduit par la Rédaction]
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Papers by Joseph Rasmussen