Jordan Stuart Rosenfeld

• Province of British Columbia

Regulatory ratchets arise when governance appears to be effective, but actually masks a steady loss of natural capital. This occurs when biases in environmental impact assessment (EIA) systematically underestimate the true impact of large developments, generated by statistical convention fixing α at 0.05 (Type 1 error or false positive rate; i.e.,...

Riverine fishes face many challenges including habitat degradation and climate change, which alter the productivity of the riverscapes in which fish live, reproduce, and feed. Understanding the watershed portfolio of foraging and growth opportunities that sustain productive and resilient fish populations is important for prioritizing conservation a...

The Nooksack Dace (Rhinichthys cataractae sp. cataractae) is a federally endangered riffle specialist endemic to the lower Fraser Valley of British Columbia, Canada, with historic population declines associated with riffle loss from stream dredging, channelization, and excessive sediment inputs. To assess the effectiveness of riffle restoration as...

Elucidating the habitat-related processes driving variation in juvenile recruitment and population fluctuation is crucial for the conservation of freshwater fishes, particularly for species at risk, where recruitment variation increases at small population size. We used a combination of instream enclosure experiments and habitat use observations to...

Trout growth and production are controlled by (1) the area and quality of habitat for sequential life history stages, (2) the availability and production of invertebrate prey, and (3) stage-structured population dynamics, in particular, the degree of recruitment limitation associated with serial habitat bottlenecks or stochastic disturbance events...

Trout growth and production are controlled by (1) the area and quality of habitat for sequential life history stages, (2) the availability and production of invertebrate prey, and (3) stage-structured population dynamics, in particular, the degree of recruitment limitation associated with serial habitat bottlenecks or stochastic disturbance events...

Stressor-response (SR) functions quantify ecological responses to natural environmental variation or anthropogenic stressors. They are also core drivers of cumulative effects (CE) models, which are increasingly recognized as essential management tools to grapple with the diffuse footprint of human impacts. Here, we provide a process framework for t...

Habitat loss is a primary threat to seahorses, pipefishes, and their relatives (family Syngnathidae) globally. Conservation intervention is difficult or ineffective when species lack critical habitat information. To better understand the habitat associations of syngnathids we conducted underwater visual surveys of 79 sites in three habitat categori...

To understand the drivers of variation in digestive performance and their effects on growth, we examined relationships among food consumption, digestive metabolism, food processing efficiency, and growth rate in juveniles of fast‐growing piscivore versus slow‐growing insectivore ecotypes of rainbow trout reared at satiation rations on the same diet...

Defining the context dependence of ecological states or processes is a fundamental goal of ecology. Stressor-response functions are the quantitative representation of context dependence, where the context (environmental contingency) is defined by location on the stressor (x) axis, and represents a unifying concept in biological science.

Divergent energy acquisition and processing strategies associated with using different microhabitats may allow phenotypes to specialize and coexist at small spatial scales. To understand how ecological specialization affects differentiation in energy acquisition and processing strategies, we examined relationships among digestive physiology, growth...

Control of hypoxia is a key element of water quality management, and guidelines are usually based on qualitative reviews of hypoxia impacts. In this study we use segmented regression to identify both thresholds for growth reduction and rate of decline of fish growth and food consumption under hypoxia; and then evaluate whether current freshwater gu...

The behavioural and metabolic attributes that favour post‐emergence dispersal by larval fish may differentiate juvenile phenotypes along downstream ecological gradients in riverine systems, but the extent to which fish with contrasting dispersal capacities differ in underlying metabolic, behavioural and life‐history traits remains unclear. In this...

To evaluate the consequences of declining summer discharge for drift abundance and energy flux to drift-feeding fish, we collected monthly drift samples from April to September in three small British Columbia salmonid streams. We complemented this with an analysis of published studies to test for broader-scale effects of summer low flows across mul...

Effective conservation requires that species recovery measures are informed by rigorous scientific research. For imperilled freshwater fishes and mussels in Canada, numerous research gaps exist, in part owing to the need for specialized research methods. The Canadian Freshwater Species at Risk Research Network (SARNET) was formed and identified or...

Conventional hydraulic‐habitat modelling methods are time‐consuming to implement. In response to repeated calls for more efficient and practical approaches, researchers have developed a geomorphic instream‐flow tool (GIFT) that combines a method to simulate reach‐averaged hydraulics at flows less than bankfull and depth and velocity frequency distr...

Salmonids make flexible and adaptive trade-offs between foraging efficiency and predation risk that result in variable patterns of diel activity and habitat use. However, the following remains unclear: (1) how patterns differ among salmonid species; and (2) how this affects the interpretation of habitat suitability models that inform instream flow...

A proactive‐reactive continuum integrating multiple (i.e., 3+) dimensions of animal behaviour has been reported as a major axis of behavioural differentiation, but its stability along a biological hierarchy from individuals to populations remains speculative. Piscivore and insectivore rainbow trout (Oncorhynchus mykiss) represent closely related ec...

Habitat simulation approaches (e.g., PHABSIM) have been used to model instream flows in thousands of streams and rivers and remain the most widely implemented detailed instream flow methodology. However, recent studies suggest that conventional habitat simulation models incorporate assumptions that may systematically underestimate instream flow nee...

Effective management of freshwater fish habitat is essential to supporting healthy aquatic ecosystems and sustainable fisheries. In Canada, recent changes to the Fisheries Act enhanced the protection of fish habitat, but application of those provisions relies on sound scientific evidence. We employed collaborative research prioritization methods to...

The Salish sucker (Catostomus sp. cf. catostomus) is a federally Threatened species in Canada, inhabiting small lowland streams along with juvenile coho salmon (Oncorhynchus kisutch) in southwestern British Columbia and adjacent Washington State. Experiments were conducted in two ponds to determine the effects of reduced flow on dissolved oxygen, g...

To understand the effects of widespread urbanization and agricultural impacts on recovery of Salish sucker (Catostomus sp. cf. catostomus), a federally threatened catostomid endemic to the lower Fraser Valley of British Columbia, we assessed (i) the current extent and effects of hypoxia on the distribution of Salish sucker and juvenile salmonids, (...

Adaptive trade‐offs are fundamental mechanisms underlying phenotypic diversity, but the presence of generalizable patterns in multivariate adaptation and their mapping onto environmental gradients remain unclear. To understand how life history affects multivariate trait associations, we examined relationships among growth, metabolism, anatomy and b...

User manual for the BioenergeticHSC software program. Includes conceptual background, details on the various sub-models, instructions for how to use the program, and some guidance on how to interpret model output. This will be updated as new features are added to the software.

Habitat Suitability Curves (HSCs) are the biological component of habitat simulation tools used to evaluate instream flow management trade‐offs (e.g., the Physical Habitat Simulation Model). However, traditional HSCs based on empirical observations of habitat use relative to availability have been criticized for generating biased estimates of flow...

Juveniles of different salmonid species often co-exist along environmental gradients, making them a useful model for identifying dominant trade-off axes and their stability within a biological hierarchy (e.g., from individuals to populations to species). In this perspective, we use multivariate trade-offs among juvenile coho salmon (Oncorhynchus ki...

Hydraulic heterogeneity can strongly influence habitat selection by stream fishes. Velocity gradients created by channel roughness and flow obstructions may be particularly important for species that feed on drifting invertebrates, where maintaining focal points in low velocity microhabitats adjacent to faster water allows fish to scan a larger wat...

Periods of summertime low flows are often critical for fish. This study quantified the impacts of forest clearcutting on summertime low flows and fish habitat and how they evolved through time in two snowmelt‐dominant headwater catchments in the southern interior of British Columbia, Canada. A paired‐catchment analysis was applied to July‐September...

Quantitative habitat suitability models (HSMs) are frequently used to inform the conservation and management of lotic organisms, often in the context of instream flow management. Correlative statistical models relating hydraulic variables to habitat preferences (habitat suitability curves based on use:availability ratios) are the most common form o...

Sampling invertebrate drift in high‐gradient boulder‐bed channels or large turbulent rivers is challenging, because the traditional approach of driving stakes into the stream bed to secure drift nets may not work. We describe a simple method using a split wading rod to collect drift samples from the wadeable river margin or bank as an alternative m...

Increasing habitat availability (i.e. habitat suitable for occupancy) is often assumed to elevate the abundance or production of mobile consumers; however, this relationship is often nonlinear (threshold or unimodal). Identifying the mechanisms underlying these nonlinearities is essential for predicting the ecological impacts of habitat change, yet...

To identify the mechanisms whereby substrate embeddedness and water velocity influence Nooksack dace (Rhinichthys cataractae subsp. cataractae) prey capture efficiency, we stocked dace in foraging arenas with varying substrate types over a range of velocities (0, 25, 35 cm s⁻¹) and measured their efficiency of prey capture. We stocked a known numbe...

• Empirical relationships between stream flow and ecological responses (flow–ecology relationships) are essential for establishing environmental flows and evaluating tradeoffs between instream values and out‐of‐stream uses. Establishing the shape of flow–ecology relationships (i.e. slope, linearity versus nonlinearity) is particularly important to...

The influence of stream channel structure on the production of prey for drift-feeding fish is not well understood. We quantified drift production, the entry rate per streambed area, and drift flux, the total export rate per channel unit, in three second-order, forested streams in southwest British Columbia, Canada. We tested whether (1) drift produ...

Pulsed flow disturbances strongly influence invertebrate drift in lotic ecosystems. However, drift‐flow relationships are often context dependent and non‐intuitive, suggesting that local abiotic and biotic conditions mediate the impacts of flow on the physical and behavioural drivers of drift entry. Two factors may be particularly important: physic...

Biogeoscience is a rapidly growing interdisciplinary field that aims to bring together biological and geophysical processes. This book builds an enhanced understanding of ecosystems by focusing on the integrative connections between ecological processes and the geosphere, hydrosphere and atmosphere. Each chapter provides studies by researchers who...

Instream flow models link a physical habitat model that predicts flow-related changes in hydraulics to a biological model that predicts the response of fish to altered velocity and depth. Habitat suitability curves (HSCs) based on frequency of habitat use (fish occurrence relative to available habitat) remain the most widely used biological models...

Hatfield and Paul (2015) note the potential for hidden value trade-offs in desktop models used for establishing environmental flows, which highlights the need to separate the contributions of science vs. values when developing flow regulations. This is best achieved with regulatory frameworks that clarify underlying values and objectives, identify...

Adaptive trade-offs define the trait combinations that differentiate taxa and allow coexistence along environmental gradients. To understand the physiological trade-offs associated with growth, we examined relationships among metabolic rate, digestive capacity, tissue energy content, and growth in juveniles of three strains of rainbow trout (Oncorh...

Invertebrate drift, the downstream transport of aquatic invertebrates, is a fundamental ecological process in streams with important management implications for drift-feeding fishes. Despite long-standing interest, many aspects of drift remain poorly understood mechanistically, thereby limiting broader food web applications (e.g., bioenergetics-bas...

The positive effects of biodiversity on the functioning of ecosystems are well demonstrated in laboratory microcosms but the precise mechanisms underlying higher ecosystem process rates in natural assemblages are less well understood. We investigated, under semi-natural conditions (field enclosures), the potentially interactive effects of species i...

Although billions of dollars have been spent restoring degraded watersheds worldwide, watershed-scale studies evaluating their effectiveness are rare. To mitigate damage from past logging activities, the floodplain of the upper Chilliwack River watershed (∼600 km²) was extensively restored from 1996 to 2000 through off-channel habitat restoration....

Presented in this paper is a hydraulic model that combines a rational regime theory with an at-a-station hydraulic geometry simulator (ASHGS) to predict reach-averaged hydraulic conditions for flows up to but not exceeding the bankfull stage. The hydraulic conditions determined by ASHGS can be paired with an empirical joint frequency distribution e...

Predictions of optimal flows using PHABSIM are extremely sensitive to the shape of velocity and depth habitat suitability curves (HSCs). HSCs therefore need to accurately reflect the fitness (or population level) consequences of habitat use for model predictions to be meaningful. Frequency-based habitat suitability curves are based on the observed...

Understanding the impacts of hydrological drought, and the role that refugia play in mitigating these impacts, is crucial to the conservation of freshwater fishes. This is especially true for species adapted to riffles, which are typically the first habitats to dewater at low discharge. We examined the relationship among decreasing stream discharge...

Mass‐specific standard metabolic rate ( SMR , or maintenance metabolism) varies greatly among individuals. Metabolism is particularly sensitive to variation in food consumption and growth creating the potential for significant bias in measured SMR for animals that are growing (e.g. juveniles) or of uncertain nutritional status. Consequently, interp...

We developed predictions of habitat quantity and quality for three life stages of rainbow trout, Oncorhynchus mykiss, across a range of stream sizes characterized by mean annual discharge of 1 to 50 m3 s−1. The physical habitat template was created by nesting a reach-scale two-dimensional hydrodynamic model (River2D) within a downstream hydraulic g...

Self-thinning theory predicts that decline in density with increasing individual mass should match the exponent of the metabolism–body mass relationship (∼0.9 in salmonids). However, self-thinning assumes energy equivalence (constant energy available to a cohort as it ages), which may be unrealistic for mobile taxa. I evaluate this assumption using...

Accurately measuring productive capacity in streams is challenging, and field methods have generally focused on the limiting role of physical habitat attributes (e.g. channel gradient, depth, velocity, substrate). Because drift-foraging models uniquely integrate the effects of both physical habitat (velocity and depth) and prey abundance (invertebr...

Common applications of models to predict the response of fish habitat to altered stream flow (such as the Physical Habitat Simulation Model; PHABSIM) assume that fish abundance is directly related to the area of suitable habitat for limiting life stages and usually ignore flow effects on prey abundance. However, if prey availability is flow sensiti...

Environmental change, including that caused directly or indirectly by invasive species, presents a major threat to the persistence of native freshwater biodiversity. The invasive American signal crayfish (Pacifastacus leniusculus (Dana, 1852)) has recently been implicated in the collapse of a pair of threespine stickleback (Gasterosteus aculeatus L...

1. Consistency of differences in standard metabolic rate (SMR) between individual juvenile salmonids and the apparently limited ability of individuals to regulate their SMR has led many researchers to conclude that differences in individual SMR are fixed (i.e. genetic). 2. To test for the effects of food ration on individual performance and metabol...

Threespine stickleback (Gasterosteus aculeatus) species pairs are found in four watersheds in southwestern British Columbia, Canada, and are listed as Endangered under the federal Species at Risk Act. Their origin is thought to be through a double-invasion process followed by character displacement; however, this hypothesis does not consider whethe...

Territoriality is one of the best examples of interference competition and generally results in larger, dominant individuals gaining preferential access to food. However, the expectation of higher growth of dominant individuals among juvenile salmonids has received only mixed support. We used outdoor semi-natural stream channels stocked with varyin...

Describing the velocity and depth attributes of stream channels is a basic goal of theoretical and applied hydrology and is also essential for modeling biological processes in streams. We applied frequency distributions (gamma probability functions fit to point velocity and depth data) to evaluate their ability to describe variation in hydraulic co...

1. Adaptive trade-offs are fundamental to the evolution of diversity and the coexistence of similar taxa and occur when complimentary combinations of traits maximize efficiency of resource exploitation or survival at different points on environmental gradients. 2. Standard metabolic rate (SMR) is a key physiological trait that reflects adaptations...

Sediment size and supply exert a dominant control on channel structure. We review the role of sediment supply in channel structure, and how regional differences in sediment supply and land use affect stream restoration priorities. We show how stream restoration goals are best understood within a common fluvial geomorphology framework defined by sed...

Even at sublethal concentrations, various anthropogenic pollutants may disrupt the transfer of chemosensory information, often inducing maladaptive behavioral responses. Recent studies of freshwater prey fishes have shown impaired abilities to respond to damage-released chemical alarm cues from conspecifics under weakly acidic conditions (pH ; 6.0)...

Abstract –  To evaluate the effects of habitat, foraging strategy (drift vs. limnetic feeding) and internal prey subsidies (downstream transport of invertebrate drift between habitats) on fish production, we measured the growth of juvenile coho salmon confined to enclosures in flowing (pond inlets and outlets) or standing water (centre of pond) hab...

Abstract The application of a drift-foraging bioenergetic model to evaluate the relative influence of prey abundance (invertebrate drift) and habitat (e.g. pool frequency) on habitat quality for young-of-the-year (YOY) and yearling juvenile cutthroat trout, Oncorhynchus clarki (Richardson) is described. Experiments and modelling indicated simultane...

Abstract  Electric fishing depletion systematically underestimates fish abundance in streams. Electric fishing mark-recapture estimates are unbiased, but only when performed over several days to allow marked fish to recover from electric fishing. A mark-recapture procedure that can be performed in 1 day and produces unbiased population estimates is...

Population viability analysis (PVA) is an effective framework for modeling species- and habitat-recovery efforts, but uncertainty in parameter estimates and model structure can lead to unreliable predictions. Integrating complex and often uncertain information into spatial PVA models requires that comprehensive sensitivity analyses be applied to ex...

Numerous artificial side channels have been constructed in British Columbia and the Pacific Northwest to compensate for habitat loss from floodplain development. We reviewed data from published studies on natural and restored side channel habitats to determine how design features influence productive capacity for juvenile coho salmon Oncorhynchus k...

In this study, we focused on the drivers of micro- and mesohabitat variation of drift in a small trout stream with the goal of understanding the factors that influence the abundance of prey for drift-feeding fish. We hypothesized that there would be a positive relationship between velocity and drift abundance (biomass concentration, mg/m3) across m...

The River Continuum Concept lacks a quantitative physical model to represent downstream trends in habitat. We evaluate whether hydraulic geometry relationships can be used as a physical template to predict longitudinal trends in habitat availability and optimal flows for different life-history stages of rainbow trout (Oncorhynchus mykiss). Optimal...

The core assumptions of critical habitat designation are a positive relationship between habitat and population size and that a minimum habitat area is required to meet a recovery target. Effects of habitat on population limitation scale from (i) effects on performance of individuals (growth, survival, fecundity) within a life history stage, to (ii...

To understand how fish density and food availability affect habitat selection and growth of juvenile coho salmon (Oncorhynchus kisutch), we manipulated fish density (2-12 fish·m-2) and natural invertebrate drift (0.047- 0.99 mg·m-3) in 12 experimental stream channels constructed in a side-channel of Chapman Creek, British Columbia. Increased food r...

1. Enclosures were installed in a fishless stream and divided transversely into upstream and downstream sections. Downstream sections were further divided longitudinally, and one of the downstream sections in each enclosure was stocked with juvenile coho salmon (Oncorhynchus kisutch), and the other side was left as a fishless control. Densities of...

With the widespread decline and endangerment of freshwater fishes, there is a need to clearly define habitat requirements for effective species management and habitat restoration. Fish biologists often infer habitat requirements on the basis of correlative habitat associations in the wild. This generates descriptive models that predict species pres...

The characteristics and function of large woody debris (LWD) were measured in 41 small (1.2-11.2-m bank-full channel width), fish-bearing streams in coastal British Columbia to determine how total LWD abundance and the features of individual LWD pieces (diameter, length, orientation, and presence of a rootwad) influenced the effectiveness of pool f...

Multiple studies have shown that biodiversity loss can impair ecosystem processes, providing a sound basis for the general application of a precautionary approach to managing biodiversity. However, mechanistic details of species loss effects and the generality of impacts across ecosystem types are poorly understood. The functional niche is a useful...

Although it is broadly recognized that extinction has negative effects on biodiversity values (e.g., Ghilarov 2000), there has been considerable recent debate over the effect of species loss on ecosystem function (e.g., Hector et al. 1999; Huston et al. 2000). A series of exper-iments has been carried out with artificial plant assem-blages in an at...

Previous research indicates that the abundance of small coastal streams is often underestimated on topographic maps, and their relative contribution to total salmonid habitat within coastal drainages is unknown. To document the extent and distribution of streams in different channel-width classes and to estimate the proportion missing on topographi...

Multiple studies have shown that biodiversity loss can impair ecosystem processes, providing a sound basis for the general application of a precautionary approach to managing biodiversity. However, mechanistic details of species loss effects and the generality of impacts across ecosystem types are poorly understood. The functional niche is a useful...

We intensively sampled fish in rivers and streams within a single major drainage basin (the Blackwater River) and across major drainages in British Columbia to assess the factors influencing distribution of chiselmouth, Acrocheilus alutaceus, and to develop models for predicting chislemouth presence. Chiselmouth were typically absent from sites wit...

To assess freshwater habitat requirements of juvenile anadromous cutthroat trout, Oncorhynchus clarki, we measured habitat preference and growth rates of young-of-the-year (YOY) and 1- to 2-year-old fish confined to either pools or riffles in Husdon Creek, British Columbia, during 1999. YOY preferred pools to riffles in habitat-preference experimen...

Combined effects of predation by benthic and drift-foraging fish (prickly sculpin ( Cottus asper) and coho salmon (Onchorhynchus kisutch) parr) on benthic invertebrate community and trophic structure were evaluated in May- fly Creek, a previously fishless stream in the Coast Range Mountains of British Columbia. The role of microhabitat (substrate)...

Management of fish biodiversity and individual fish species requires the ability to understand and predict expected species distributions. Models predicting species distributions can provide insight into habitat requirements, help identify unique outlier populations, and determine potential biodiversity hotspots. Our goal was to determine whether r...

The distribution, abundance, and habitat associations of juvenile anadromous coastal cutthroat trout (Oncorhynchus clarki) and coho salmon (Oncorhynchus kisutch) were evaluated using survey data from 119 sites in coastal British Columbia. Both cutthroat and coho occurred at their highest densities in very small streams (< 5 m channel width), and ba...

The effects of fish predation on invertebrate community structure and algal biomass were contrasted in a fish-bearing and previously fishless stream in the coast mountains of British Columbia. Predator impact was assessed by stocking coho salmon (Onchorhynchus kisutch) juveniles and prickly sculpin (Cottus asper) in replicate enclosures. Abundance...

Thesis (Ph. D.)--University of British Columbia, 1998. Includes bibliographical references.

Algal production, bacterial production, and invertebrate biomass were measured in pool and riffle habitats in six southern Ontario streams. Rock substrata in riffles were found to be areas of higher primary production and low to moderate bacterial production, while fine sediment in pools were areas of lower primary production and high bacterial pro...

Studies of benthic invertebrates in lakes and streams suggest thatlarge-bodied herbivores are more efficient grazers than smallerones. In order to assess the effect of larger herbivores on smallergrazing invertebrates, the presence of dominant grazer taxa wasmanipulated in streamside troughs in a first order temperaterainforest stream in British Co...

We used artificial stream channels to conduct feeding trials with wild rainbow trout Oncorhynchus mykiss at three levels of suspended sediment. To examine the effects of turbidity on reactive distance and pursuit speed, we fed rainbow trout (87–185 mm standard length) pieces of mealworms Tenebrio sp. as test prey. A video camera system was used to...

Dependence of the invertebrate and fish community on terrestrial versus aquatic carbon sources in southern Ontario streams was studied using stable carbon isotope analysis. Algal carbon was significantly more 13C depleted (-35.5‰) than terrestrial carbon (-27‰), but high variability in algal δ 13C precluded use of a quantitative mixing model. δ 13C...

Primary production was measured in forested and open streams in southern Ontario to identify the main factors influencing algal growth, and to test the assumption that autochthonous inputs are negligible in forested headwater streams. In low order streams in southern Ontario, primary production is related primarily to light, temperature, and substr...

We review the factors that govern the temperature of groundwater and the influence of groundwater on salmonine ecology in an attempt to show the role groundwater will play in the impact of climate warming on stream salmonines. The mechanisms of energy transfer from the atmosphere through groundwater to stream water are complex. Groundwater temperat...

The ratio of gross photosynthesis to total ecosystem respiration (P/R) indicates whether a stream ecosystem is a net producer or consumer of organic matter, but does not show the extent to which stream consumers are supported by autochthonous or allochthonous matter. The transition between autotrophy and heterotrophy in streams is not properly expr...