Article

Movement Patterns of Large Brown Trout in the Mainstream Au Sable River, Michigan

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Abstract

We used radiotelemetry to monitor spring and summer movements of 11 brown trout Salmo trutta (442–584 mm) for up to 904 d in a Michigan stream. Individual brown trout used a few specific locations near cover (referred to as home sites) as resting locations during the day, moved across various distances at night, and generally returned to the same home site the next morning. Home sites were predominantly artificial cover (88%) rather than natural sites, as natural cover was very limited in the study area. Some fish used multiple home sites, and the average separation between multiple home sites for individual fish was over 500 m. Fish tracked for more than 1 year used the same home sites each summer and generally exhibited similar behavior each year. Fish belonged to two general categories of daily movement behavior: mobile or stationary. Mobile fish tended to move frequently and were found within their home sites only 43% of the time at night. Stationary fish did not move far from home sites, even at night. There was a negative correlation between the average gradient and the maximum distance fish moved from their home sites during nocturnal periods. Stationary fish resided in areas of steeper gradient (usually about 0.20%) and moved less often nocturnally than did mobile fish. Three fish were tracked extensively over 36 d to quantify diel activity patterns. The hourly activity of fish increased dramatically at dusk, continued at a lower level overnight, and then increased again at dawn before declining to near zero during the day. This behavior pattern was similar among all individuals tracked and also between the months of June, July, and August for an individual fish. Nocturnal movements involved significantly greater distances than diurnal movements for these fish. The relationship between movement and gradient may indicate energetic tradeoffs between the cost of moving against a current and the energy gained during active foraging. Also, the dominant use of artificial home sites has implications for the value of habitat improvements meant to increase abundance of large brown trout.

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... feeding (Diana et al. 2004). Sutton et al. (2007) found an increase in the number of salmonids within thermal refuge areas throughout the day as river temperatures warmed, particularly when ambient river temperature exceeded 23°C. ...
... The summer activity patterns of lar described as sedentary during the day and actively foraging either locally or over large distances during dusk, dawn and in some cases throughout the night, usually returning to one of several home locations in the morning (Clapp et al. 1990;Diana et al. 2004). ...
... Previous studies have reported that hatchery origin catchable-size brown trout have typically been observed or recaptured close to the location where they were stocked (Cresswell 1981;Clapp et al. 1990;Diana et al. 2004;Popoff and Neumann 2005;Heggenes et al. 2007). For example, most brown trout were recaptured within 4 (1 Connecticut were observed within 500 meters and 930 meters after 2 and 12 weeks, respectively (Popoff and Neumann 2005). ...
... In summer, higher or different activity or movements are reported at night, dusk and dawn in streams (e.g. Jenkins 1969;Kreivi, Muotka, Huusko, Ma¨ki-Petays, Huhta & Meissner 1999;Young 1999;Diana, Hudson & Clark 2004;Ho¨jesjo¨, Ö kland, Sundstro¨m, Pettersson & Johnsson 2007). However, substantial opportunistic variation between individuals and for individuals over time appears common (Bunnell, Isely, Burrell & Van Lear 1998;Giroux, Ovidio, Philippart & Baras 2000;Ovidio et al. 2002). ...
... However, substantial opportunistic variation between individuals and for individuals over time appears common (Bunnell, Isely, Burrell & Van Lear 1998;Giroux, Ovidio, Philippart & Baras 2000;Ovidio et al. 2002). Suggested causal mechanisms are linked to environmental heterogeneity, i.e. not only abiotic factors such as habitat (Young 1994;Ovidio et al. 2002;Diana et al. 2004), and water flow (Bunt, Cooke, Katopodis & McKinley 1999;Brown, Power & Beltaos 2001), light intensity (Clapp et al. 1990;Young 1999;Ho¨jesjo¨et al. 2007), and temperature (Clapp et al. 1990;Young 1999), but also biotic factors (food availability and foraging tactics : Jenkins 1969;Clapp et al. 1990;Kreivi et al. 1999;Young 1999;Giroux et al. 2000;Ovidio et al. 2002;competition: Jenkins 1969;Ho¨jesjo¨et al. 2007;anti-predator behaviour: Young 1999). In winter, studies of trout activity and movement patterns are even less consistent. ...
... Total Channelised Natural studies, indicated that large individual variation in movements is the rule for trout (e.g. Bunnell et al. 1998;Ovidio et al. 2002;Diana et al. 2004), suggesting a potential for local adaptation and variation. Most individuals tend to be stationary most of the time with short movements within the home range, but some individuals undertake sudden longer movements within or between home ranges. ...
Article
Abstract  Radio transmitters were implanted in wild brown trout, Salmo trutta L., in the River Måna at low summer water flows (n = 18), higher flow in summer (n = 20), and variable, peaking flows in autumn (n = 20), and tracked two to four times day and night for 4–5 weeks. Individuals were caught and released in a 4-km uniformly channelised section, and in a 4-km natural diverse river section. Substantial individual variation in home range and total movement (924–85 818 m2 and 295–7014 m) suggested flexibility to adapt to local environmental conditions. Fish were stationary most of the time (median movement 0 m), but some individuals undertook few and apparently sporadic longer movements, sometimes involving shifts in home range. No consistent diurnal pattern in movements was found. Trout in the uniform habitat section appeared to have larger home ranges and moved more than trout in the natural section. Differences were, however, not statistically significant in most comparisons, due to large individual variation. Similarly, larger home ranges and movements between trials related to higher flow were found, but differences were generally not significant. No consistent effects of sudden, extreme peaking flows on area use or movements by the brown trout were observed.
... Understanding the space use of these species in a difficult to sample environment will hinder surveys and the management of these species. This study supports findings of extensive activity patterns of riverine brown Trout (Ovidio et al. 2002;Knouft and Spotila 2002;Diana et al. 2004) and Dace (Clough and Ladle 1997;Clough and Beaumont 1998). We add to the current literature by showing the temporal stability of home range . ...
... In fact, the core home range area for trout was predicted to be approximately one half that of dace, irrespective of individual length. Trout ranges remain relatively stable within a smaller home range, which has also been noted by other authors (Diana et al 2004;Watson et al. 2019). A trend towards a smaller home range was observed from August to November for trout, however, this was not significant. ...
Article
Determining where fish are distributed across days and seasons is valuable for understanding their ecology, evolution and conservation. The results presented here provide insight into the spatial and temporal distribution of brown trout (native salmonid species) and dace (invasive cyprinid species) in an artificially impounded section of lowland river, demonstrating that both species remain relatively local to their release point and do not exhibit wide-ranging movements from late summer into winter. Commonalities in the movement patterns were observed between the species despite their contrasting life histories, but there were also important differences observed both in their home range and activity patterns over the duration of the study. In general dace were much more active than trout. Both trout and dace exhibited clear crepuscular peaks in movement with higher displacement rates being observed during dawn and dusk periods which remained consistent over the duration of the study. Both species exhibited a high residency which may be a direct result of the artificial barrier present, promoting residency. Trout showed a significant increase in displacement rates and a drop in residency in November which may represent putative spawning behaviour. In general home range sizes remained stable over the tracking period for both species. Home range size was affected by fish length for both species, with larger individuals being more localised then smaller individuals. We propose that the diel patterns observed are primarily driven by foraging activity and opportunity which changes with seasonal influences and onset of potential spawning period and/or overwintering behaviour. This study demonstrates how data derived from telemetry studies can reveal movement behaviours of fish species associated with undertaking basic ecological requirements (feeding, shelter etc.) which are regulated by variation in the environment. Understanding the interplay between the environment and an animal’s behaviour is important from a conservation management perspective with increasing environmental pressures and predicted regime changes. From a fishery management viewpoint these data can feed into stock status monitoring in difficult to monitor impounded lowland riverine habitat and also increase our understanding of how potential human induced changes affect fish populations.
... This maximum movement distance should be considered the distance over which a fish is likely to know its habitat well enough to be aware when desirable destinations are available, over the time step. It is an exponential function of fish length (Diana et al. 2004): ...
... It is an exponential function of fish length. Based on literature data (June 1981, Diana et al. 2004), Railsback et al. (2009) estimated a value of 20 for fishMoveDistParamA and of 2 for fishMoveDistParamB for stream-dwelling trout. However, these parameters can be potentially site-specific. ...
... Because mobility and spatial knowledge are assumed to increase rapidly with fish size, we use an exponential function. The parameters fishMoveDistParamA and fishMoveDistParamB are potentially site-specific: fish are likely to explore and be familiar with larger areas in lower-gradient rivers (Diana et al. 2004). ...
... June (1981) observed little movement in newly emerged cutthroat trout <3 cm; dispersal started after they exceeded 3 cm in length. Diana et al. (2004) observed large brown trout that routinely moved between stream locations more than 500 m apart. ...
Article
Full-text available
The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams. © 2015, National Research Council of Canada. All rights reserved.
... Seasonal movements are likely due to spawning migrations and movement between winter and summer habitats. During summer, large brown trout often select the deepest pools with abundant cover, especially overhead cover (Heggenes 1988;Greenberg et al. 2001;Diana et al. 2004). Pool depth and an abundance of complex covers, such as woody debris and undercut banks, are believed to provide more energetically profitable stream positions due to velocity reductions, decrease intraspecific competition through visual isolation, and provide protection from avian and mammalian predators (Bjornn and Reiser 1991;Sundbaum and Näslund 1998;Greenberg et al. 2001). ...
... Pool depth and an abundance of complex covers, such as woody debris and undercut banks, are believed to provide more energetically profitable stream positions due to velocity reductions, decrease intraspecific competition through visual isolation, and provide protection from avian and mammalian predators (Bjornn and Reiser 1991;Sundbaum and Näslund 1998;Greenberg et al. 2001). Although some brown trout exhibit nighttime foraging movements through multiple pools, typically returning to daytime resting locations near cover in their original pool (Clapp et al. 1990; Diana et al. 2004), other brown trout exhibit a complete absence of diel movement during summer (Bunnell et al. 1998). ...
Article
Full-text available
We evaluated summer habitat use of large brown trout Salmo trutta (TL > 380 mm) in pools and stream reaches of southeast Minnesota to test an earlier summer habitat model, to identify other important variables, and to develop a habitat quality classification to guide large trout management. We collected 224 large trout in 126 of 581 pools in 41 stream reaches during 2003 and 2004. The probability (P2) that a large brown trout was present in a pool was positively associated with the pres- ence of water deeper than 90 cm, instream rock, overhead bank cover, and woody de- bris in a logistic regression model. Similarly, large trout abundance in pools was best predicted with a Poisson regression model with four variables (area of water deeper than 60 cm, length of overhead bank cover, pool width, and area of instream rock). Streambank riprap was not significantly associated with either large trout presence or abundance in pools. Large trout abundance in stream reaches increased linearly with mean P2-value, which explained 54% of the variation among study reaches. We cate- gorized habitat quality of stream reaches into four classes based on mean P2-values. In large streams (>0.43 m3/s), with poor to fair habitat quality, habitat management should increase water deeper than 90 cm, instream rock, overhead bank cover, and woody debris. Habitat management for large trout in smaller streams (
... Most of the radio-tagged trout in our study were relatively sedentary, although some were more mobile, traveling up to 41 km during the study. This pattern is consistent with many earlier studies of river resident salmonids (Solomon and Templeton 1976; Diana et al. 2004; Gresswell and Hendricks 2007). We found these two strategies are not fixed for particular members of the populations—that is, previously sedentary fish becoming mobile or previously mobile fish becoming more sedentary (also noted by Harcup et al. 1984). ...
... The movement rates we observed were also similar to the range of movement rates reported for spawning rainbow trout Oncorhynchus mykiss in New Zealand (321–487 m/d; Dedual and Jowett 1999; Venman and Dedual 2005), but lower than that reported for bull trout Salvelinus confluentus (up to 4.4 km/d; Swanberg 1997). The total distances moved by brown trout in our study (up to 41 km) were also within the range reported elsewhere for brown trout (Allen 1951; Clapp et al. 1990; Meyers et al. 1992; Burrell et al. 2000; Knouft and Spotila 2002; Ovidio et al. 2002; Bettinger and Bettoli 2004; Diana et al. 2004; Rustadbakken et al. 2004; Heggenes et al. 2007), although somewhat less than the 76–202 km reported by Young (1994), Wilson and Boubee (1996), and Strickland et al. (1999). Maximum movements are presumably constrained by the size of the catchments studied and the distances among foraging, refuge and spawning habitats. ...
Article
Full-text available
Management of the effects of water quality and flow on fisheries requires an understanding of the factors that control fish movements. We used radiotelemetry to monitor the movements of adult brown trout Salmo trutta in a New Zealand river over 11 months (September 2004 to August 2006) and linked those movements to the changes in flow and water temperature. Individual fish moved up to 41 km during the study. However, most fish moved less than 1 km. All of the trout that showed little movement throughout the summer were living in relatively deep pools that presumably provided cover. The rates of movement declined steadily over the spring–summer period, as flow decreased and water temperature increased. The percentage of fish moving was positively related to the average daily flow during the interval between tracking occasions and negatively related to the average daily water temperature, less than 20% of the tagged fish moving once temperatures were above 19°C. A severe, 50-year flood occurred in March 2005 and was associated with the mortality of 60–70% of the remaining tagged fish, confirming that flood-induced mortality can affect a substantial proportion of an adult brown trout population.
... Because mobility and spatial knowledge are assumed to increase rapidly with fish size, we use an exponential function. The parameters fishMoveDistParamA and fishMoveDistParamB are potentially site-specific: fish are likely to explore and be familiar with larger areas in lower-gradient rivers (Diana et al. 2004). ...
... June (1981) observed little movement in newly emerged cutthroat trout <3 cm; dispersal started after they exceeded 3 cm in length. Diana et al. (2004) observed large brown trout that routinely moved between stream locations more than 500 m apart. ...
Article
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The Forest Service of the U.S. Department of Agriculture is dedicated to the principle of multiple use management of the Nation's forest resources for sustained yields of wood, water, forage, wildlife, and recreation. Through forestry research, cooperation with the States and private forest owners, and management of the National Forests and National Grasslands, it strives—as directed by Congress—to provide increasingly greater service to a growing Nation. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, 1400 Independence Avenue, SW, Washington, DC 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.
... Detailed observations of fish habitat selection and movement in nature also show a great deal of complexity and individual variation (e.g. Armstrong et al. 1997Armstrong et al. , 1999Smithson & Johnston 1999;Diana et al. 2004) that are not readily explained by optimisation models (Thorpe et al. 1998). For example, marked seasonal habitat shifts of fishes during autumn may occur abruptly, without any apparent changes in food availability or habitat quality (Riehle & Griffith 1993;Jakober et al. 1998). ...
... Seasonal migrations and daily home range movements (e.g. Diana et al. 2004) could easily be confused with true emigration movements. Moreover, low recovery of tagged animals that move long distances from sites of tagging can confound interpretation of the effects of emigration on population dynamics and interconnection among populations. ...
Article
Abstract –  The consequences of individual behaviour to dynamics of populations has been a critical question in fish ecology, but linking the two has proven difficult. A modification of Sale's habitat selection model provides a conceptual linkage for relating resource availability and individual habitat selection to exploratory behaviour, emigration and population-level responses. Whole-population experiments with pupfish Cyprinodon macularius that linked all factors along this resource to population continuum lend support to this conceptual model, and illustrate that emigration may be much more common in fish populations than considered in most individual- or population-based models. Accommodating emigration can enhance the ecological appropriateness of behavioural experiments and increase confidence in extrapolation of experimental observations to population-level effects. New experimental designs and advancing technologies offer avenues for assessing population consequences of habitat selection and emigration by individual fish. Emigration often is the key linkage between individual behaviour and population responses, and greater understanding of the underlying factors affecting this often-overlooked demographic parameter could offer new approaches for management and conservation of fishes.
... Additionally, we observed movement patterns that were comparable to other Brown Trout populations within the Black Hills of South Dakota that exhibited small home ranges outside of spawning periods (James et al. 2007;Rehm 2019). While some studies have documented increased movements by resident Brown Trout during nocturnal periods (Clapp et al. 1990;Diana et al. 2004), we only located fish during daylight hours. ...
Article
Full-text available
While long-term impacts to local fish populations in response to habitat work has been researched extensively, impacts to populations during the actual implementation of projects is poorly understood. During this study, fish movement and survival was quantified pre-, during-and post-construction period of an instream habitat manipulation project involving placement of boulders and large-woody debris. Twenty Brown Trout Salmo trutta were implanted with radio transmitters during November of 2015 and located for a period of 13 weeks. Our results indicated that fish moved significantly less post-construction than pre-construction. Additionally, survival was 100% for known-fate fish. This work illustrates that actual installation of instream habitat had little to no impact on the resident fish population. Abstract: *Correspondence to: Davis JL, South
... Stream trout in Michigan are known for migrating on a daily basis while foraging, and on a seasonal basis as they move into spawning, overwintering, or refuge habitats (Clapp et al. 1990;Hayes et al. 1998;Diana et al. 2004). In coastal areas, populations of Brown, Rainbow, and Brook trouts migrate from the ocean to freshwater rivers to spawn. ...
Technical Report
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Management plan for inland trout in Michigan
... Electrofishing, surface observations, and underwater observations have been used in the past to identify habitat use by trout, but each of these approaches has associated shortcomings (see Heggenes 1988). In contrast, radiotelemetry may allow the most precise estimate of a fish's location and is often accomplished without disturbing the fish when researchers are relocating them (e.g., Diana et al. 2004;Zimmer et al. 2010). ...
Article
Full-text available
To determine whether habitat rehabilitation provides functionally similar winter habitat to streams with natural features, we radio‐tagged and tracked 83 large, stream‐resident, Brown Trout Salmo trutta (>330 mm TL) and compared habitat use at pool and microhabitat scales. Brown Trout used pools similarly in streams with and without habitat rehabilitation. In all streams, trout avoided pools lacking depths >60 cm and with <10 m² of cover. Streams with habitat rehabilitation provided similar microhabitat features to natural streams; trout selected sites with depths from 60 to 119 cm near woody debris and with water column velocity <10 cm/s in both. Trout avoided microhabitats with depths <60 cm when the habitats either lacked cover or were under ice shelves or had a water column velocity > 20 cm/s. Brown Trout selected artificially placed overhead bank structures and instream rocks in rehabilitated streams but used these natural features in proportion to their availability in streams without rehabilitation. We conclude that habitat rehabilitation created suitable winter habitat for Brown Trout in upper U.S. Midwestern streams.
... Tagging studies were initiated with wild and hatchery brown trout and brook trout to better understand trout survival and movements, which in turn informed stocking and habitat rehabilitation efforts (Shetter, 1936(Shetter, , 1955. This understanding was later enhanced through radio telemetry studies of brown trout movements in Michigan's Au Sable River (e.g., Clapp et al., 1990;Regal, 1992;DePhilip, 2001;Diana et al., 2004). These studies highlighted the importance of the size of fish, water temperature, season, and availability of food and cover in explaining daily and seasonal use of habitat by brown trout. ...
Chapter
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The history of brown trout Salmo trutta in North America extends back to 1884, when brown trout fry were successfully introduced into a tributary of Michigan's Pere Marquette River. The introduction of brown trout, brook trout Salvelinus fontinalis, and rainbow trout Oncorhynchus mykiss, along with unregulated logging and over-fishing, contributed to the extinction of Arctic grayling, which were the native and primary resident salmonid species in many of Michigan's coldwater streams. Today, stream-resident populations of brown trout and brook trout occur in 31,000 km of 1,500+ Michigan streams. In contrast with trout streams in mountainous areas, Michigan's trout streams are cooled, and their flows stabilized, by large inputs of groundwater associated with deep deposits of coarse-textured glacial drifts. Michigan has a long history of stream trout research. This overview highlights work on topics including hatchery trout stocking and strain evaluations, hooking mortality of trout, predation on trout, effects of sport fishing regulations, population and recruitment dynamics, temperature effects on growth, and factors influencing spatial patterns in trout abundance. Brown trout populations in Michigan are largely self-sustaining, with long-term population dynamics being driven by effects of flow conditions on reproductive success. Abundance, growth, and survival of brown trout in streams are also influenced by factors such as water temperature, nutrient, and instream habitat conditions, as well as intra- and inter-specific trout densities. Larger brown trout in Michigan streams are piscivorous, and often prey on and out-compete stream-resident brook trout. Managing Michigan's trout streams is a daunting task, especially considering that Michigan fisheries biologists are also responsible for 11,000 inland lakes and Michigan's portion (43%) of the Great Lakes. Partnerships are a key to success. Stream trout populations are assessed via surveys at long-term index stations (for trends), randomly selected locations (for a general inventory), and other locations of management interest. Brown trout are managed as recreational fisheries for the public. Minimum size limits, creel limits, fishing and harvest closures, and gear or fishing method restrictions serve as principle tools. Five combinations of these tools (i.e., regulation types) are used to manage stream trout populations. Protection, restoration, and maintenance of stream habitats are critical, given the immense capacity of Michigan streams to support self-sustaining trout populations and provide recreational benefits. These tasks are accomplished through collaboration between Michigan Department of Natural Resources (MDNR), the Michigan Department of Environmental Quality, several federal regulatory agencies, and concerned anglers, citizens, and partners throughout the state. Habitat issues highlighted include riparian habitat changes, chemical discharges, sedimentation, instream woody habitat, dams, fish passage, and water withdrawal. While over 90% of Michigan trout streams support self-sustaining populations, additional trout fishing opportunities are provided by stocking brown trout into waters that provide suitable habitat for year-to-year survival of stocked fish, but provide limited or no natural reproduction of trout. Stocked trout are produced by MDNR Fisheries Division hatcheries that use state-of-the art technology to efficiently produce high-quality, relatively disease-free trout with high genetic integrity. A mean of 729,000 brown trout (typically age-1 fish) have been stocked into Michigan streams annually since 1979.
... However, this may be explained by a difference in size of the experimental fish, as the fish in the current study were of a considerably larger size and thus at different ontogenetic stages. Ontogenetic stage may influence movement pattern, particularly in relation to feeding activity (Diana et al. 2004). Another factor that may explain the different results is that different species were used; in the current study brown trout were used, whereas Atlantic salmon were used in the study by Martin-Smith et al. (2004). ...
... Tagging studies were initiated with wild and hatchery brown trout and brook trout to better understand trout survival and movements, which in turn informed stocking and habitat rehabilitation efforts (Shetter, 1936(Shetter, , 1955. This understanding was later enhanced through radio telemetry studies of brown trout movements in Michigan's Au Sable River (e.g., Clapp et al., 1990;Regal, 1992;DePhilip, 2001;Diana et al., 2004). These studies highlighted the importance of the size of fish, water temperature, season, and availability of food and cover in explaining daily and seasonal use of habitat by brown trout. ...
Conference Paper
Michigan is blessed with an abundance of coldwater streams. In the 1800's, brown trout were introduced into many streams and self-sustaining populations became established and thrived. Today, brown trout populations, as well as native and introduced populations of brook trout, occur throughout much of Michigan are cherished by anglers and citizens alike. The distribution of trout populations throughout Michigan is limited by the availability of groundwater inputs to streams, which in turn, is determined by characteristics of the surface geology of individual watersheds. Despite the extremely stable hydrology of Michigan's rivers, the dynamics of brown trout populations are significantly influenced by flow conditions during critical periods and regionally synchronous. Brown trout sport fisheries are managed through a set angling regulation options, developed with extensive stakeholder input, with each regulation designed to biologically protect the population and provide the desired fishery. Michigan's stream trout populations face numerous potential threats, and research and management efforts have been directed towards those considered most pressing. Specific examples discussed look at impact assessment and management efforts to minimize adverse effects of sedimentation, water withdrawal, and fish passage on stream trout populations in Michigan.
... Nevertheless, hatchery-reared fish displayed a significantly lower night-time activity, while wild fish did not. The more intense nocturnal movement of wild fish may be connected with feeding and predator avoidance (Vanderpham et al., 2012); this difference has been noted for related species, such as for S. trutta (Diana et al., 2004) and Atlantic salmon Salmo salar L. 1758 (Fraser et al., 1993). The night-time activity of wild T. thymallus could also be related to seasonal changes in behaviour; the T. thymallus in this study were observed during the autumn-winter period, which is often reported to be associated with night-time activity in salmonids (Fraser et al., 1993;Valdimarsson & Metcalfe, 1998). ...
Article
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Juvenile wild and hatchery-reared European grayling Thymallus thymallus were tagged with radio-transmitters and tracked in the Blanice River, River Elbe catchment, Czech Republic, to study their behavioural response to stocking and environmental variation. Both wild and hatchery-reared T. thymallus increased their diel movements and home range with increasing light intensity, flow, temperature and turbidity, but the characteristics of their responses differed. Environmental variables influenced the movement of wild T. thymallus up to a specific threshold, whereas no such threshold was observed in hatchery-reared T. thymallus. Hatchery-reared fish displayed greater total migration distance over the study period (total migration) than did wild fish, which was caused mainly by their dispersal in the downstream direction. © 2015 The Fisheries Society of the British Isles.
... Received November 20, 2010;accepted June 9, 2011 fishes in the world and represent one of these species with documented mobile individuals that has further stimulated debate on the importance of fish movement. Brown trout movements can be categorized into at least three distinct temporal scales: (1) diel movements, presumably for feeding (Bunnell et al. 1998;Diana et al. 2004), (2) seasonal movements to complete a portion of the life cycle (e.g., spawning) or avoid seasonally stressful conditions such as winter (Meyers et al. 1992;Burrell et al. 2000;Brown et al. 2001), and (3) movements over an ontogenetic life cycle where juveniles and adults may emigrate to larger downstream rivers as they age (Elliott 1994;Cucherousset et al. 2005). While some streams have a large proportion of mobile individuals (e.g., Cucherousset et al. 2005), others have a much smaller proportion (e.g., Budy et al. 2008). ...
Conference Paper
We estimated how much recruits, survivors, and immigrants contributed to population size in six reaches in southeast Minnesota. Recruitment was determined from population estimates made in September. Survival and emigration were estimated from mark and recapture of individually PIT-tagged brown trout, representing three ontogenetic groups (age 0, age 1 and 2 adults, age 3+ large adults) across reaches and four seasons (see associated Poster). Immigration was calculated as one minus emigration. Recruitment varied among the six reaches and three years of this study (range 0-1,292/km) and was consistently low in all reaches in 2007 due to flooding. Survival and emigration varied by reach or season depending on ontogenetic group (see associated poster). For age 0 trout, immigrants were estimated to contribute 50% or more of age-0 abundance in three of the six study reaches. In the other three reaches, immigrants contributed 0% to 35%. Recruitment (i.e., aging of age 0 trout to age 1) was estimated to contribute more than 50% of age 1 and 2 trout to most reaches, especially in 2006-2007 as a result of a large 2006 year class. Survival was estimated to account for 50% or more of the predicted abundance of age 3+ trout in almost all reaches. Although variable, broad patterns suggest that age-0 populations are dependent on immigration, age 1 and 2 adults on recruitment, and age 3+ trout on survival.
... However, such patterns were not found for this population. Radio-tagged brown trout have been found to move extensively over shorter timescales, such as overnight, before returning to the same pool during the day (Diana et al. 2004). Our study was not designed to assess such intra-season movements and cautions against over-interpreting movement results. ...
Article
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Growth rate variation of three age groups of brown trout, Salmo trutta L. (age‐0, 1 and 2, and 3+), was quantified from recaptured, individually tagged brown trout and related to season, stream reach, relative abundance, initial length and movement to examine factors influencing growth in length in three streams in the Midwestern United States. Total variation in growth was almost five times greater for age‐0 than for age‐3+ trout. Individual trout accounted for about 13% of total variation in age‐0 growth, season about 57%, and trout initial length and relative abundance combined another 2%. The 2006 age‐0 cohort had the fastest growth rates in their second spring and summer (2007) and slowest growth in their first winter (2006–2007). About 53% of total growth variation of age‐1 and age‐2 trout was accounted for by individual trout, season, initial length and stream reach. Predicted growth rates indicated strong effects of season and initial length. A significant interaction between these two factors indicated that, although smaller trout grew faster than larger trout, this length effect was most pronounced in spring and summer. About 35% of total growth variation of age‐3+ trout was accounted for by individual trout and season. Together, season and individual trout characteristics were identified as the most important factors influencing brown trout growth in these streams.
... Our main finding was that fry movement was inversely related to channel complexity. While habitat dependent differences in movement are well documented for juvenile stream-dwelling salmonids (Diana et al., 2004;Harvey et al., 1999;Heggenes et al., 2007;Quinn and Peterson, 1996), nearly all of this past work has focused on the role of physical complexity in relation to rearing or over-winter life stages. The distinguishing feature of our study is the finding that habitat complexity may be important in the ecology of even the youngest life stage of stream-dwelling salmonids. ...
Article
We describe patterns of emergence and downstream movement by recently emerged fry of two non-native salmonids in the Great Lakes region, North America. Our primary objectives were to describe the timing of emergence in relation to spring flooding, and to examine the effects of reach-level complexity of stream habitat on rates of movement. Emergence and movement patterns of coho salmon and brown trout fry were assessed over an eight-week period in two reaches distinguished by differences in channel woody debris. Fry emergence occurred from mid-March to early May, and peaked in early to mid-April. Movement during this period was uncorrelated with upstream densities of resident fry and fish moving downstream did not appear moribund or in poor condition. Nearly twice as many fish moved through the simple reach that lacked woody debris cover even though upstream densities of resident fry were generally greater in the complex reach. The results reported here indicate that peak emergence occurs in close association with the timing of spring floods. Variability in the timing of either emergence or spring floods could have profound effects on the size of coho salmon and brown trout populations within streams of this region. Results from this study further suggest that greater habitat complexity may reduce downstream movements of newly emerged salmonid fry in a natural system.
... If S. trutta populations cannot cope with the new environments fast enough, they can go extinct, and unique genetic variants may be lost (Hansen et al., 2002;Allendorf & Luikart, 2007). To cope with losses of suitable habitat, S. trutta might colonize stream reaches at higher altitudes, depending on their potential to disperse (Diana et al., 2004). Alternatively, it may adapt to the new conditions through physiological and/or life history plasticity. ...
Article
Aim Species inhabiting fresh waters are severely affected by climate change and other anthropogenic stressors. Effective management and conservation plans require advances in the accuracy and reliability of species distribution forecasts. Here, we forecast distribution shifts of S almo trutta based on environmental predictors and examine the effect of using different statistical techniques and varying geographical extents on the performance and extrapolation of the models obtained. Location Watercourses of E bro, E lbe and D anube river basins ( c . 1,041,000 km ² ; Mediterranean and temperate climates, Europe). Methods The occurrence of S . trutta and variables of climate, land cover and stream topography were assigned to stream reaches. Data obtained were used to build correlative species distribution models ( SDM s) and forecasts for future decades (2020s, 2050s and 2080s) under the A1b emissions scenario, using four statistical techniques ( generalised linear models, generalised additive models, random forest, and multivariate adaptive regression ). Results The SDM s showed an excellent performance. Climate was a better predictor than stream topography, while land cover characteristics were not necessary to improve performance. Forecasts predict the distribution of S . trutta to become increasingly restricted over time. The geographical extent of data had a weak impact on model performance and gain/loss values, but better species response curves were generated using data from all three basins collectively. By 2080, 64% of the stream reaches sampled will be unsuitable habitats for S . trutta , with E lbe basin being the most affected, and virtually no new habitats will be gained in any basin. Main conclusions More reliable predictions are obtained when the geographical data used for modelling approximate the environmental range where the species is present. Future research incorporating both correlative and mechanistic approaches may increase robustness and accuracy of predictions.
... It has proven effective for sampling lentic habitats (Dumont and Dennis 1997;Pierce et al. 2001;Schoenebeck et al. 2005) and large rivers (Sanders 1992). Many salmonids seek cover during daylight but are more active at night (Young 1999;Jakober et al. 2000;Diana et al. 2004), which may lead to increased capture efficiency at night, as has been reported for snorkeling (Dumont and Dennis 1997;Thurow et al. 2006). However, this method has never been evaluated in small streams for estimating salmonid abundance. ...
Article
Full-text available
Estimation of stream fish abundance using removal electrofishing is common and allows sampling of fish populations during a single site visit. However, recent evaluations have demonstrated that removal estimators can substantially underestimate fish abundance, raising concerns about using this method. We evaluated removal estimates of trout (family Salmonidae) abundance using night electrofishing in 200–300-m reaches of 8 Rocky Mountain streams and analyzed the data using new methods in Program MARK to account for potential sources of bias. The removal estimates were validated using populations of previously captured and marked resident fish. Overall, removal estimates were accurate estimates of the number of marked fish in study reaches (mean bias, −2.4% [
... However, our results are consistent with other studies that report a strong association of large brown trout in summer with cover in the form of structures (Clapp et al. 1990), pools or undercut banks (Meyers et al. 1992), or deep water (2008) noted that water depth acts as a proxy for space availability for large brown trout and that self-thinning coefficients for such trout declined at sites with the greatest mean water depth. It is common for riverine brown trout to display little daytime movement during the summer (Burrell et al. 2000;Diana et al. 2004). This is consistent with the behavior of brown trout in our study where fish were located almost exclusively in the plunge pool created by the irrigation diversion dam (deep water patch) and rarely moved among habitat patches during the day. ...
Article
Abstract –  We quantified the use of habitat patches by brown trout, Salmo trutta, during summer conditions in a plains stream in the western United States. A Global Positioning System was used to map discrete habitat patches (2–420 m2) consisting of macrophytes, wood accumulation, or deep water. Habitat use by brown trout was monitored by radio telemetry. Brown trout used habitat in a nonrandom manner with 99% of all daytime observations and 91% of all nighttime observations occurring in patches that consisted of combinations of deep water, wood accumulations or macrophytes even though such patches constituted only 9.8% of the available habitat. Brown trout used deep water almost exclusively during the day but broadened their habitat use at night. Most fish stayed within a large plunge pool created by a low-head dam. This pool supplemented the deep-water habitat that was naturally rare in our study area and illustrates how human modifications can sometimes create habitat patches important for stream fishes.
... In a radio-tagging study conducted over 3 months, juvenile Murray cod (likely to be 3-year-old fish) were found to have limited movements with a mean range of 318 ± 345 m and maximum total linear range of 864 m (Jones & Stuart 2007). The observation of larger fish moving greater distances than smaller fish has been demonstrated in a number of studies for other fish species (Auer 1996;Diana et al. 2004) but explanations for this difference have not been explored. ...
Article
Abstract –  This study of Murray cod (Maccullochella peelii peelii) movements in a large lowland river in south-eastern Australia indicated that the species was not sedentary, but undertook complex movements that followed a seasonal pattern. While there were sedentary periods with limited home ranges and high site fidelity, Murray cod also under took larger movements for considerable portions of the year coinciding with its spawning schedule. This generally comprised movements (up to 130 km) from a home location in late winter and early spring to a new upstream position, followed by a rapid downstream migration typically back to the same river reach. Timing of movements was not synchronous amongst individuals and variation in the scale of movements was observed between individuals, fish size, original location and years.
... However, this may be explained by a difference in size of the experimental fish, as the fish in the current study were of a considerably larger size and thus at different ontogenetic stages. Ontogenetic stage may influence movement pattern, particularly in relation to feeding activity (Diana et al. 2004). Another factor that may explain the different results is that different species were used; in the current study brown trout were used, whereas Atlantic salmon were used in the study by Martin-Smith et al. (2004). ...
Article
Rapid growth is often associated with several fitness-related benefits. However, in most organisms growth rates are rarely maximized, suggesting that trade-offs limit the benefits of rapid growth. To enable sustained high growth, behavioural modifications incurring costs may be required, and these may be responsible for evolution of sub-maximal growth rates. In a field experiment it was tested whether rapid growth in brown trout is achieved by increasing potentially costly movement activity. Causal relations were obtained by manipulating the growth rate using bovine growth hormone (GH) implants and monitoring movement activity of stream-dwelling brown trout for two months using radiotelemetry. GH-treated trout grew significantly faster than sham-treated trout both in terms of body mass and length. The GH-treated trout also had a significantly larger absolute movement during the experiment, moving about 68% more than the sham-treated trout. There were no GH effects on diel movement or home range between the two treatments. Plasma GH levels were lower in the GH-treated fish, indicating negative feedback inhibition of native GH secretion, and that the bovine GH implant was still functioning at the end of the study. This is the first study to show increased movement activity in GH-enhanced fish in the wild. Because increased movement is expected to lead to increased metabolic costs, the higher movement activity in the GH-treated trout was likely associated with increased foraging activity. The results demonstrate that increased movement activity is associated with rapid growth in brown trout. Such movement activity may be unfavourable under certain ecological conditions or life stages (i.e. high risk of predation or low resource levels), and may thus represent one component of the cost limiting evolution of maximum growth rates.
... Water temperature is a key driving variable governing the overall biological structure of riverine ecosystems (Bartholow et al., 1993;Wehrly et al., 2003). In particular, fish ecology and community dynamics are strongly tied to water thermal conditions (Diana et al., 2004;Horne et al., 2004;McRae & Diana, 2005;Meeuwig et al., 2005;Wehrly et al., 2006;Diana & Smith, 2008). In salmonids, for instance, life history staging is often triggered by changes in water temperature (Mullan et al., 1992;Newcomb & Coon, 1997;McCullough, 1999;McCullough et al., 2001), and due to their relatively narrow temperature tolerance, species distribution is extremely sensitive to the changes in water temperature (Jager et al., 1997;McCullough et al., 2001;Steen et al., 2010) Since temperature is such a crucial factor in shaping ecology of a riverine system, it is important to understand how climate-induced change may alter the natural spatial and temporal thermal regimes of aquatic ecosystems. ...
Article
As stream water temperature helps shape the biology of riverine ecosystems, it is important to understand how varied human activities alter the natural spatial and temporal thermal regimes. To predict the effects of human-induced thermal changes on fish communities, a modeling approach is required. However, the current models are either too simplistic to capture the dynamic of the system, or too complex to practically apply in a large-scale setting. The goals of my dissertation were to develop a spatially explicit and easy to parameterize heat balance model integrated with a pre-existing multi-modeling system, and to apply it in several different river management contexts. I first describe a newly designed Reduced Parameter Stream Temperature Model. I then use my model to explore the effects of anthropogenic stressors on the distribution and dynamics of thermal habitat conditions for fishes. I included simulation studies of water withdrawal, dam removal, and climate change, and examined the potential shifts in thermal habitat and provided predictions of the timing shifts in the early life history staging of Great Lakes anadromous fishes in the Muskegon River Watershed. In a water withdrawal simulation my model predicted that thermal impacts varied with the patterns of local groundwater flux, surface water to groundwater mixing ratios, and distances of pumping activities to the river. The dam removal simulation predicted that summer stream temperature would be effectively lowered without the dams. This could cause a 8~10 day delay in the timing of spawning, and a 7~15 day delay in fry emergence for steelhead, walleye, and chinook. Removal of the dams could also bring more usable habitat upstream for all the three fish species. In a climate change simulation I found that monthly water temperature could increase 2 to 4.5oC, with the greatest changes occurred in spring. These changes could cause spawning and fry emergence to shift about 3 weeks earlier for steelhead and walleye. Meanwhile, warming climate could cause the early spawning cohort of chinook to delay about 2 weeks, and the late spawning about one month. However, global warming could induce a one month earlier fry emergence for chinook.
Chapter
Fish movements have been extensively studied and variously described for many years and several conceptual frameworks have since been proposed to help organize and understand these movements. Frameworks include ecological scale, the restricted movement paradigm, partial migration, dynamic landscape model, and riverscape approach. We blended reviews of selected frameworks and past studies in the Driftless Area of the upper Midwestern United States to advance an understanding of stream-resident salmonid movements. Past studies examined feeding and exploratory, seasonal migration and dispersal movements using underwater videography, radiotelemetry, capture–recapture method, and genetics method at various spatiotemporal and ontogenetic scales. Movements were complex and changed over the course of ontogeny. Most movement was at the youngest ages and smallest sizes and again at very large sizes as a result of exploratory behavior and feeding movements to seek better physical habitat conditions (e.g., deeper pool habitat) or to avoid competitive or predatory interactions with other salmonids. In between, adult-sized salmonids were mostly sedentary as suggested by the restricted movement paradigm. Restricted movement was likely due to ideal environmental conditions provided by a combination of groundwater-fed springs supporting good baseflow and cold temperatures, productive streams with abundant invertebrate prey, and diverse physical habitat conditions in a small spatial area. Thus, there was little evidence of seasonal migration to fulfill seasonal resource needs as predicted by the dynamic landscape model. Rather, a more general riverscape model best describes the partial migration of Driftless Area salmonid populations. In this model, stream reaches provide adequate seasonal habitat facilitating mostly sedentary adults, but with some inter-reach dispersal at juvenile ages and at the largest adult sizes.
Thesis
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Density-dependent growth is often observed in stream-dwelling Brown Trout Salmo trutta populations. In Spearfish Creek, South Dakota, biomass of adult Brown Trout (>200 mm) is about three times greater than that reported for similar Black Hills streams while mean length of adult fish is about 30% less. Here, we evaluate large-scale density reduction as a management tool for improving growth rate of stream-dwelling Brown Trout. We compared age-specific growth of wild Brown Trout in stream sections receiving 50% reductions in fish abundance. We also assessed the effect of fish density manipulation on Brown Trout movement patterns and home range size. We compared gross movement, net movement and home range size of Brown Trout between stream sections with targeted fish removals to sections with natural fish densities. Annual growth in length and weight of older Brown Trout (> age 2) generally increased following fish removals; we observed significantly greater growth for age 3 and 4 fish (162 to 258 %, g/y) in stream sections receiving density reductions. Bioenergetics modeling revealed that total, annual consumption by smaller Brown Trout (ages 1 and 2) was dominated by aquatic invertebrates (91 %) with terrestrial invertebrates comprising only (9%). In contrast, larger Brown Trout (ages 3-6) consumed more terrestrial prey (35%) in order to meet annual energy requirements. In most cases, consumption of aquatic invertebrates by large Brown Trout was insufficient to meet annual maintenance requirements. As a result, we postulate that growth rate of larger fish is more responsive to density reduction, owing to constrains imposed by availability of aquatic invertebrates. Additionally, we found no evidence that movement patterns or home range size of stream-dwelling Brown Trout differed between sections with natural densities and those where fish density was reduced. There was no relationship between fish density and fish movement parameters or home range size. Brown Trout in Spearfish Creek exhibited limited movement and home range sizes following reductions in fish density. Brown Trout tracked during fall-winter months were observed exhibiting larger gross movement and home range size presumably related to fall spawning activities, although net movement was similar to spring/summer periods – indicating strong site fidelity. A small proportion of radio-tagged (6%) trout exhibited extended movements (> 0.6 km), typical of straying behavior in salmonids. Many factors have been shown to effect variability of movement of stream-dwelling Brown Trout, however, it does not appear that density or large-scale density reduction is among them. Improved growth rate and reductions in intraspecific competition during our study (~1 year) coupled with negligible immigration from natural high-density sections are promising for large-scale density reductions as a management technique to improve the growth of stream-dwelling Brown Trout.
Article
Over recent years, there has been increasing challenge to the accepted wisdom that the environmental impacts of river engineering can be adequately mitigated through the installation of infrastructure, such as fish passes. This has led to a debate on the value of fish passage with some arguing that increased research and development will advance solutions for a variety of structures that are suitable for multiple species and transferable to different regions. Others suggest that policies and management strategies should reflect the realization that current mitigation technology frequently fails and can itself have negative impacts. Meta-analyses of the results of studies on fish passage effectiveness have led to the challenge of conventional views by highlighting lower than expected efficiencies, wide variation between and within fish pass designs, and bias towards consideration of a limited number of commercially important species mainly from northern temperate regions. Results of meta-analyses can also be controversial, and difficulties can arise when nuances associated with individual studies are lost and when metrics used are not standardized. Intrinsic variation in fish passage efficiency between and within species due to differences in patterns of movement and motivation may not be considered, and in many situations, current metrics are not appropriate. Quantification of variation in trends in fish passage efficiency over time and with spatial scale is lacking and should be the focus of future reviews. It is time to accept that fish passage does not provide a universally effective mitigation solution, particularly when designs and strategies are transferred to other regions and species for which they were not originally designed. Admitting to cases of failure is an essential first step to advancing water resources planning and regulation based on well-informed decision-making processes. Copyright
Article
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We assessed recruitment, survival, emigration, and immigration of brown trout Salmo trutta in six interconnected stream reaches to quantitatively estimate how much immigrants contributed to population size in reaches in southeastern Minnesota. We also examined the influence of reach and season on estimates of survival and emigration via mark and recapture of individual trout representing three groups (age-0 juveniles, age-1 and age-2 adults, and age-3+ large adults). Immigration was calculated as 1 minus emigration. Recruitment varied among the six reaches and 3 years of this study (range, 0–1,292 fish/km). Survival of the age-0 group and that comprising ages 1 and 2 varied by season but not reach. Survival was highest in winter for both groups but lowest in spring for age-0 trout and in fall for age-1 and age -2 trout. Emigration varied by season for age-0 trout but by reach for trout of ages 1 and 2. For age-3+ trout, survival and emigration only varied by reach. Survival was highest and emigration was lowest in reaches with the most cover, including deep pools. From these demographic characteristics we estimated the proportions of the population that consisted of brown trout that had survived within a reach, recruited into it, or immigrated into it from some other reach. Immigration was predicted to contribute the most for the youngest age-group (35% or more of the predicted abundance of age-0 trout in most reaches) and is probably important for genetic purposes or to bolster population units in adjacent reaches. Our results for adult brown trout suggest that within-reach recruitment and survival contribute a larger proportion of trout to population units in many reaches than do immigrants. This confirms the appropriateness of current management approaches and suggests that maintenance of the exceptional recreational brown trout fishery in southeastern Minnesota is at least solidly dependent on factors promoting recruitment and survival within most managed stream reaches.Received November 20, 2010; accepted June 9, 2011
Thesis
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The declining condition of river systems associated with rapid development of human societies has lead to substantial reductions in the distributions and populations of many freshwater fish. One consequence of the general decline in river condition has been the loss of in-stream Structural Woody Habitat (SWH). Structural woody habitat is now widely recognised as an important component of stream ecosystems, particularly as fish habitat. As a result, there has been an increase in the number of rehabilitation programs that introduce SWH into rivers globally, and in Australia. However, most rehabilitation works remain unmonitored or inadequately monitored and hence their effectiveness remains largely untested and/or poorly recorded. This thesis assesses fish responses to the introduction of SWH in two coastal rivers of New South Wales, Australia. It is focused on evaluation of the key aspects of experimental design that need to be taken into consideration when planning a monitoring program. The results of this study contribute to a growing literature on the monitoring of fish responses to rehabilitation works using introduced SWH. In 2000 a reach scale experiment was undertaken in the Williams River, NSW, with the introduction of SWH to a test reach compared with a geomorphologically similar control reach. Changes in fish species richness, abundance and assemblage structure were quantified over a period of five years after treatment using a Before-After-Control-Impact-Paired (BACIP) design and analysis. The initial increase in fish species richness observed in the two years following SWH introduction (reported in a previous assessment) appeared to have been sustained three years on (i.e. five years after SWH introduction). This outcome suggests that the increased habitat diversity in the test reach following SWH introduction was sufficient to elicit a detectable and sustained response by fishes over the study period of five years. However, the increased fish abundance noted two years after SWH introduction into the test reach appears to have dissipated over the following three years. Analysis of abundance, excluding a small highly abundant species, Retropinna semoni (Australian smelt), suggested that the initial increase in the test reach was due solely to this species. The most plausible explanation for the decrease in fish abundance after the first two years of the experiment was the decrease in available SWH over the study period due to burial by substrate mobilized during high flow events. The Williams River study is irepresentative of the few rehabilitation projects that attempt to monitor fish responses to SWH introduction and, as such, provided the opportunity to examine inadequacies in experimental design and data analysis. Specifically, the Williams River experimental design suffered from: unbalanced sampling effort between the test and control reaches, irregular sampling, a lack of spatial and temporal replication, and potential spatial autocorrelation. The early success reported for the reach scale experimental introduction of SWH in the Williams River motivated the scaling up of rehabilitation works into a larger river, the Hunter River. Aspects of the Hunter River study that improved upon the Williams River study were: increased replication of treatments and controls that were similar at the start of the experiment, increased temporal replication, balanced sampling effort across all sites, systematic temporal sampling, and an effort to measure the potential for spatial autocorrelation. Fish population responses at the meso-habitat scale (i.e. in riffles and pools) were tested using a Multiple-Before-After-Control-Impact (MBACI) experimental and analytical design. The introduction of SWH into riffles and pools in the Hunter River did not elicit a strong response from fish populations at the meso-habitat scale. In the riffle experiment, the introduction of SWH (deflector jams) appeared to create areas of slack water habitat which were utilised by one native fish species (R. semoni) and one exotic species (Gambusia holbrooki - mosquito fish). No increase in fish species richness or abundance following SWH introduction in treatment pools was detected by the MBACI analysis. The most likely explanation for the lack of response to SWH in Hunter River pools is that the volume of wood introduced was very low (approximately 90% less) relative to natural wood levels in this and other Australian rivers, and therefore insufficient to elicit a measurable response from the fish assemblage at the pool scale. Quantification of the availability of particular habitat types (e.g. banks, etc, etc) within the Hunter River pools suggested that pre-existing in-stream habitat may have been a limiting factor for fish and that the contemporary riparian and in-stream conditions were likely to have facilitated the invasion and subsequent successful establishment of exotic fish species, particularly Cyprinus carpio (common carp) and Gambusia holbrooki. The results from examination of habitat associations and preferences imparted a strong biological rationale for the introduction of SWH to enhance overall habitat availability. While there was no increase in fish species richness or abundance at the pool scale, differences were found between the levels of complexity of SWH within pools. Temporal patterns of change in fish species richness and abundance associated with the introduced SWH in pools suggested that fish were quick to colonise the introduced SWH. However, it was not until several months after SWH introduction that fish species richness and abundance on introduced SWH increased above the levels recorded in pre-existing habitat, and the new woody habitat appeared to become saturated. The provision of increased structural complexity within the introduced SWH, induced by the placement of additional logs within the pool jams provided habitat of higher quality for three of the four most abundant native fish species (Anguilla reinhardtii – long-finned eel, Gobiomorphus coxii - Cox’s gudgeon and Macquaria novemculeata - Australian bass) than the simple SWH placed in the Hunter River pools. The concern that the introduction of SWH would also provide habitat for the two abundant exotic species (C. carpio and G. holbrooki) appears to be unfounded for the Hunter River pools. While C. carpio utilized the introduced SWH, a stronger association was observed with the pre-existing habitat (e.g. bank and mid-channel areas). Gambusia holbrooki displayed a total avoidance of the introduced SWH in the Hunter River pools, being associated mostly with bank habitat. In contrast, the strong association observed for all abundant native species with the introduced SWH in pools suggests that the pool jams provided a habitat type of high quality compensating for the absence of suitable natural habitat structure that appeared to be limiting for native fishes in the study reach. The results of a mark-recapture study demonstrated a strong affinity of native Mugil cephalus (sea mullet) for introduced SWH. Evidence gathered from the mark-recapture study highlights the important contribution that behavioural studies can have in assessing rehabilitation success. Introduced SWH may not suit all species in a river system and this must be acknowledged at the outset when setting ecological goals. This study has identified some of the Australian native fish species that are likely to respond well in future SWH restoration projects, specifically G. coxii, M. novemculeata and M. cephalus. This thesis highlights the need for assessment of a wider range of fish responses to SWH such as how the addition of SWH might affect recruitment and long-term population viability in the river system, not just the treated reach. Such an analysis should be informed at the outset by knowledge of the life history strategies and movement behaviour/migration of fish species and how species possessing a range of traits might be expected to respond to introduced SWH at various spatial scale.
Article
We evaluated the movement of adult brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss in relation to a catch-and-release area in the White River downstream from Beaver Dam, Arkansas. Nine fish of each species were implanted with radio transmitters and monitored from July 1996 to July 1997. The 1.5-km river length of a catch-and-release area (closed to angler harvest) was greater than the total linear range of 72% of the trout (13 of 18 fish), but it did not include two brown trout spawning riffles, suggesting that it effectively protects resident fish within the catch-and-release area except during spawning. The total detected linear range of movement varied from 172 to 3,559 m for brown trout and from 205 to 3,023 m for rainbow trout. The movements of both species appeared to be generally similar to that in unregulated river systems. The annual apparent survival of both trout species was less than 0.40, and exploitation was 44%. Management to protect fish on spawning riffles may be considered if management for wild brown trout becomes a priority. Received August 31, 2010; accepted January 20, 2011
Article
Zimmer M, Schreer JF, Power M. Seasonal movement patterns of Credit River brown trout (Salmo trutta). Ecology of Freshwater Fish 2010: 19: 290–299. © 2010 John Wiley & Sons A/S Abstract – Movement habits in riverine populations of brown trout vary among watersheds. Thus it is important to identify factors influencing differences in individual behaviour so as to improve the information resource base available for the design of river-specific management strategies. Such information is particularly needed in the rapidly urbanising watersheds of eastern North America where relatively little is known about anthropogenic influences on brown trout populations. In this study, we examined the influence of water temperature on brown trout behaviour in the Credit River in south-central Ontario, Canada with respect to seasonal movement patterns. Observed patterns of movement were also correlated with variations in river discharge and habitat quality. Forty-three radio-tagged, adult brown trout were tracked in a confined 39.8 km portion of the Credit River from 15 May 2002 to 28 July 2003. Fish were captured in three sections of the river that differed in distance downstream and habitat quality. Fish size had little impact on movement patterns. However, there was considerable variation in seasonal movement with upstream movements to summer positions, maintenance of summer positions, downstream and often extensive movements in fall. Also observed was maintenance of winter positions and repeated upstream movements in late spring-early summer to previously used summer positions. The elaborate movement behaviour in the Credit River population was attributed to seasonal changes in thermal habitat quality. Fish tagged in less suitable thermal habitats moved significantly more than fish from more suitable thermal habitats.
Article
Introduced brook trout ( Salvelinus fontinalis ) are implicated as a primary factor leading to the decline in distribution and abundance of native cutthroat trout ( Oncorhynchus clarkii ). However, not all introductions are successful, suggesting local conditions influence the success of invasions. Therefore, I sought to determine the multi-scale factor(s) that influence brook trouts’ invasion success of native Bonneville cutthroat trout ( Oncorhynchus clarkii utah ) habitats in Mill Creek, Utah. I conducted patch occupancy surveys to determine watershed-scale brook trout and cutthroat trout distribution. I also determined the relative abundance of brook trout and cutthroat trout at the reach-scale by conducting three-pass depletion electrofishing surveys at ten index sites throughout the drainage. Upon completion of those surveys, I collected key watershed and reach-scale biotic and abiotic data twice during base-flow conditions. In addition, to determine watershed-scale population connectivity and the potential for upstream invasion by brook trout, I assessed fish movement using two-way weir traps. At the watershed-scale, stream slope appeared to limit brook trout invasion into some portions of the drainage. Intermittent stream-flows and extreme levels of stream slope (> 10%) appeared to limit cutthroat trout distribution. At the reach-scale, regression analyses indicated aquatic invertebrate abundance and low winter water temperatures may have influenced the abundance of brook trout, but my models explained little variation in cutthroat trout abundance overall. I observed high rates (74%) of site fidelity amongst brook trout, and mobile brook trout moved short distances (range=62-589 meters) overall. Cutthroat trout also exhibited high site fidelity (92%), but their movement was more variable, as few individuals moved long distances (up to 12.15 km). These findings will help prioritize cutthroat trout management actions in this watershed, and will be useful in determining why brook trout are successful invaders in some systems, yet remain in low and patchy abundance in others.
Article
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Freshwater mussels (Family: Unionidae) are the most imperiled faunal group in North America, yet little is known about factors that influence their distribution in rivers and lakes - especially over large geographic areas. They have a unique life cycle that includes an obligate parasite stage on fish. Throughout their life spans, long range or upstream transport is principally accomplished during the parasitic stage. This brief parasitic phase has lasting effects on adult mussel ecology - particularly in influencing their distribution. The movement of host fish occurs on large scales (e.g., >100m) and both their distribution and abundance likely contribute to the spatial patterns of mussel communities. I estimated the home ranges of host fish to determine the potential movement of larval freshwater mussels and used empirical data to predict the potential ecological consequences of host fish and freshwater mussel spatial relations in the Upper Mississippi River (UMR). Also, the degree of connectivity provided by fish hosts among mussel sites was quantified and I determined if connectivity is correlated to mussel bed condition in the UMR. I show that ecosystem size and shape influence home ranges of fish and home range is not based solely on body size-home range relationships (i.e., allometry). I show that the spatial distribution of mussels and their host fish are highly clustered, suggesting that ecological processes may be occurring on a landscape scale and should be considered into the management plans for these imperiled species. Also, high mussel species richness correlates with high host fish species richness and that most mussel communities in the UMR are located within the estimated home ranges of their host fish. Host fish were directly connected to mussel communities given that the distribution of home ranges of host fish consistently overlapped with the distribution of mussel communities. Mussel community condition was highly correlated with functional connectivity provided by host fish among mussel communities in the UMR. This presents a spatially realistic look at the potential of long range transport that host fish provide mussels. Typescript (photocopy) Thesis (Ph.D.)--Iowa State University, 2006. Includes bibliography.
Article
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Radio telemetry was used to evaluate the seasonal movement, activity level, and home range size of adult brown trout Salmo trutta in the Chattooga River watershed, one of the southernmost coldwater stream systems in the United States. In all, 27 adult brown trout (262–452 mm total length) were successfully monitored from 16 November 1995 to 15 December 1996. During the day, adult brown trout were consistently found in small, well-established home ranges of less than 270 m in stream length. However, 8 of a possible 18 study fish made spawning migrations during a 2-week period in November 1996. The daytime locations of individual fish were restricted to a single pool or riffle−pool combination, and fish were routinely found in the same location over multiple sampling periods. Maximum upstream movement during spawning was 7.65 km, indicating that brown trout in the Chattooga River have the ability to move long distances. Spawning brown trout returned to their prespawning locations within a few days after spawning. Brown trout maintained larger home ranges in winter than in other seasons. When spawning-related movement was deleted from the analysis, brown trout moved more on a weekly basis in fall than in summer. Brown trout were more active in fall and winter than in spring and summer. Apart from spawning migrations, displacement from established home ranges was not observed for any fish in the study. Although summer water temperatures reached and exceeded reported upper thermal-preference levels, brown trout did not move to thermal refuge areas in nearby tributaries during the stressful summer periods.
Article
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Radio telemetry was used to monitor the diel movement of 22 brown trout Salmo trutta (268–446 mm in total length, TL) in the Chattooga River watershed. Forty-seven diel tracks, locating individuals once per hour for 24 consecutive hours, were collected for four consecutive seasons. High variability in movement both within and among individual brown trout resulted in similar seasonal means in total distance moved, diel range, and displacement. The majority of fish moved a total distance of less than 80 m within a diel range of less than 80 m and had a displacement of less than 10 m. Brown trout were more likely to occur in pool habitat independent of season or period of the day. Hourly movement patterns differed among seasons. During the winter and fall, trout moved only around sunrise; during the spring, they moved around sunrise, sunset, and intermittently throughout the night. Large brown trout (>375 mm, TL) were found to move greater total distances and establish wider diel ranges than small brown trout. Overall, most brown trout exhibited restricted diel movement within a single riffle–pool or run–pool sequence.
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We developed and tested a combined foraging and bioenergetics model for predicting growth over the lifetime of drift-feeding brown trout. The foraging component estimates gross energy intake within a fish- and prey size-dependent semicircular foraging area that is perpendicular to the flow, with options for fish feeding across velocity differentials. The bioenergetics component predicts how energy is allocated to growth, reproduction, foraging costs, and basal metabolism. The model can reveal the degree to which growth is limited by the density and size structure of invertebrate drift within the physiological constraints set by water temperature. We tested the model by predicting growth based on water temperature and on drift density and size structure data from postemergence to age 12, and we compared the predictions with observed size at age as determined from otoliths and scales for a New Zealand river brown trout population. The model produced realistically shaped growth curves in relation to the observed data, accurately predicting mean size at age over the lifetime of the trout, assuming 24-h maximum rations and including diurnal drift-foraging costs (predicted versus observed weight r = 0.94; length r = 0.97). The model predicted that, within a given water-temperature regime, growth is limited primarily by reproduction costs but also by increasing foraging costs as trout grow (a phenomenon that is associated with the increasing foraging time that is required in order to feed to satiation on small invertebrate drift prey). Invertebrate drift size structure significantly influenced predicted growth, especially maximum size, through its effect on foraging time. The model has potential in terms of the exploration of growth-limiting factors and has associated use as an environmental-impact tool and as an aid for hypothesis generation in studies of salmonid growth processes.
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We simulated metabolic power consumed by Fraser River sockeye salmon (Oncorhynchus nerka) during upriver migration based on direct measures of activity from physiological field telemetry. The most accurate prediction of energy expenditure was obtained by expressing activity as a fine time scale (5 s) stochastic process. By imposing a daily time step, predictions of energy use were considerably lower than observed energy use, suggesting that the practice of modeling field energetics at a daily time scale, particularly for relatively active fish, may render dubious results. Daily mean power consumption through the Fraser River Canyon by the average migrant was about 20 W, about fourfold higher than for less constricted reaches. Power consumption predicted at fine time scales ranged from
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Little is known about behavior patterns and habitat use of large (400+ mm total length) brown trout Salmo trutta. We used radio telemetry to monitor the movements of eight large (437–635 mm), free-ranging brown trout for up to 346 d. Total range of movement upstream and downstream varied from 370 m to 33,420 m. At some time during the year, six of the fish moved out of an area protected with no-kill fishing regulations, even though none of them were tagged and released closer than 2 km from its boundaries. However, four of five fish tracked during the height of the fishing season spent 87% of their time in the protected area. The fish appeared to have separate winter and summer ranges. Five of six fish tracked during autumn–winter moved upstream about 10 km to slower, deeper parts of the river between August and November, and remained there at least through the following April. The part of the river used as autumn–winter range was considered only marginal habitat for brown trout during summer due to warm water temperatures. Individuals used as many as four specific home sites within their spring–summer range; average separation between home sites was 386 m. The fish typically rotated among sites, spending 2–3 d at one site before moving, usually at night, to another section of river. Activity was divided into two categories: active displacement – long-range travel from one part of the range to another; and foraging – short-range movements that might occur when searching for food. Active displacement appeared to be correlated with stream discharge, Fish displaced themselves an average of 239 m between telemetry observations in spring–summer and 3,103 m in autumn–winter; only 11% of this variation was attributable to variations in the length of time between telemetry observations in spring–summer and autumn–winter. Daily foraging activity varied by month and appeared to be related to light level, food availability, and water temperature, In spring–summer, fish typically moved to midstream to forage at night, then returned to cover at specific home sites during the day. The sites they selected in daytime were characterized by deep (>30 cm), slow (< 10 cm/s) water with heavy log cover and silt substrate.
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We examined the importance of zonation and species additions in explaining longitudinal changes in the fish assemblage of a Rocky Mountain stream that descends onto the Great Plains of Wyoming. Community changes along an elevational gradient from 2,234 to 1,230 m above mean sea level reflected a combination of zonation and downstream addition of species. Zonation was evident on a broad spatial scale as a result of stream temperatures. A coldwater trout (Salmonidae) assemblage dominated headwater reaches but was replaced by a warmwater minnow–sucker (Cyprinidae–Catostomidae) assemblage below 2,000 m. Within the warmwater zone, fish community change was due mainly to the addition of new species downstream. Headwater sites were dominated by members of the insectivore feeding guild, and other trophic guilds were added downstream. The major gradient of habitat change downstream consisted of a decrease in pool habitat and increases in stream width, depth, current velocity, turbidity, and proportion of the channel consisting of run habitat. Minor gradients of habitat change involved streambank condition and substrate particle size. Contrary to streams in forested regions, habitat diversity did not increase downstream, suggesting that increased living space and moderating environmental conditions contributed to the downstream increase in species richness. Local habitat modification due to cattle grazing or alterations in streamflow caused minor changes in fish assemblages but did not disrupt the dominant longitudinal patterns. Broad-scale zonation based on temperature regime and additive patterns within zones should typify other streams originating in montane regions
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Nine brown trout (27.9–42.8 cm FL, 234–995 g) from the Aisne stream (Belgian Ardenne) were tagged with surgically implanted radio transmitters, and their activity patterns were studied at 10-min intervals during twenty-six 24-h cycles from October 1995 to May 1997. The duration and intensity of activity were mainly proportional to water temperature and day length but some differences appeared between individuals. The daily home range in summer was also 3.2 times longer than in winter, and was exploited 2.5 times more intensively. At all seasons, trout were most active at dusk, and seasonal variations in diel patterns consisted mainly in a progressive shift from more crepuscular activity in autumn and winter to more homogenous and intensive activity during spring and summer, but still with a predominance of activity at dusk. This relative consistency of activity rhythm throughout the year was interpreted within the context of foraging risk and efficiency, in view of the scarcity of predators in the Aisne stream, and of drifting macroinvertebrates being consistently more abundant at dusk at all times of the year. However, activity patterns varied substantially between individuals living in different microhabitats, including when fish were investigated on the same day. This suggests that activity patterns are also subordinated to local factors such as habitat structure or abundance of drifting prey.
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Desert lizards are typically either widely foraging or sit-and-wait predators, and these foraging modes are correlated with major differences in ecology. Foraging mode is related to the type of prey eaten by lizards. Widely foraging lizards in the Kalahari desert, the Western Australian desert, and the North American desert generally eat more prey that are sedentary, unpredictably distributed, and clumped (e.g., termites) or that are large and inaccessible (inactive scorpions) than do sit-and-wait lizards. In contrast, sit-and-wait lizards eat more prey that are active. Foraging mode also appears to influence the types of predators that in turn eat the lizards. For example, a sit-and-wait snake eats predominately widely foraging lizards. Crossovers in foraging mode thus exist between trophic levels. Widely foraging lizards may also encounter predators more frequently, as suggested by analyses of relative tail lengths; but tail break frequencies are ambiguous. Daily maintenance energetic expenditures of widely foraging lizards appear to be about 1.3-1.5 times greater than those of sit-and-wait lizards in the same habitats, but gross food gains are about 1.3-2.1 times greater. Widely foraging species also have lower relative clutch volumes, apparently in response to enhanced risks of predation. Foraging mode within one species varies with changes in food availability. Physiology, morphology, and risk of predation might generally restrict the flexibility of foraging mode. Because foraging mode constrains numerous important aspects of ecology, any general model of foraging velocity must be complex.
Article
We developed and tested a combined foraging and bioenergetics model for predicting growth over the lifetime of drift-feeding brown trout. The foraging component estimates gross energy intake within a fish- and prey size-dependent semicircular foraging area that is perpendicular to the flow, with options for fish feeding across velocity differentials. The bioenergetics component predicts how energy is allocated to growth, reproduction, foraging costs, and basal metabolism. The model can reveal the degree to which growth is limited by the density and size structure of invertebrate drift within the physiological constraints set by water temperature. We tested the model by predicting growth based on water temperature and on drift density and size structure data from postemergence to age 12, and we compared the predictions with observed size at age as determined from otoliths and scales for a New Zealand river brown trout population. The model produced realistically shaped growth curves in relation to the observed data, accurately predicting mean size at age over the lifetime of the trout, assuming 24-h maximum rations and including diurnal drift-foraging costs (predicted versus observed weight r ² = 0.94; length r ² = 0.97). The model predicted that, within a given water-temperature regime, growth is limited primarily by reproduction costs but also by increasing foraging costs as trout grow (a phenomenon that is associated with the increasing foraging time that is required in order to feed to satiation on small invertebrate drift prey). Invertebrate drift size structure significantly influenced predicted growth, especially maximum size, through its effect on foraging time. The model has potential in terms of the exploration of growth-limiting factors and has associated use as an environmental-impact tool and as an aid for hypothesis generation in studies of salmonid growth processes.
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Electronic serial mode of access: World Wide Web via the Michigan DNR, Institute for Fisheries Research site.
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The bluegill sunfish, Lepomis macrochirus, is known to select prey on the basis of size. We present evidence that this size selection is related to the optimal allocation of time spent searching for, and handling prey. A model relating search and handling time to energy return is constructed to determine the optimal breadth of diet. Prey are permitted to differ in size and relative abundance. All elements of the model are estimated from experiments with the bluegill feeding on populations constructed from size classes of Daphnia magna. Relative visibility of the different prey sizes markedly affects relative encounter rates or @'effective@' proportions. Effective proportions are determined empirically from feeding experiments and theoretically from reaction distance in order to correct for this bias. Search time is then manipulated by varying absolute abundance of prey. At low absolute abundance, prey of different size are eaten as encountered. As prey abundance is increased, size classes are dropped sequentially from the diet in accordance with the theory. Search and handling times are estimated from these experiments and quantitative comparisons with the model indicate these changes in diet maximize return with respect to time spent foraging.
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A total of 31 Colorado squawfish, Ptychocheilus lucius, were collected from the Green River in 1980 and the Green, White and Yampa rivers in 1981. The fish were surgically implanted with radiotransmitter modules and their movement monitored for up to five months each year. Two movement patterns were linked to fish maturity: mature fish were highly mobile; immature fish were sedentary. A spawning migration of up to 205 km one-way was documented in 1981. Fish migrated upstream and downstream to reach a common spawning ground in the lower Yampa River canyon. Diel studies indicated no diel rhythm in movement existed until after spawning, when the fish were more active from 0800-1200 h. Colorado squawfish were monitored primarily in shoreline habitat over sand substrates. There were significant differences recorded for water depths and velocities selected by Colorado squawfish between the Green, White and Yampa rivers, but no difference occurred between 1980 and 1981 values recorded in the Green River.
Article
This paper analyzes the foraging behaviors of a community of insectivorous birds breeding in a high-altitude willow floodplain. The eight species belong to two guilds. Active searchers are represented by the gleaning guild (warblers): Wilsonia pusilla, dendroica petechia, and Geothlypis trichas; passive searchers are represented by the fly-catching guild (flycatchers): Empidonax oberholseri, Empidonax tralli, Empidonax difficilis, Contopus sordidulus, and Nuttallornis borealis. The paper focuses on the following general questions: (1) What are the different components, and their correlations, of foraging behavior in the eight species? (2) What are the overall adaptive syndromes associated with predatory tactics of active and passive searchers? (3) Are the predictions of several models of optimal foraging supported by the results of the present study? Adaptive syndromes (coordinated sets of characteristics, including the specific manner of resource utilization, and an array of other, related adaptations) are described for each species. Warblers forage primarily by gleaning, concentrating on stationary prey. Their velocity (average number of perches per minute) is @>10.0, their search intensity (perches visited prior to an attack) is @>5.0, and their foraging intensity (number of attacks per minute) is >1.7. They have an attack radius (mean distance from perch to prey) of <0.6m. Members of the gleaning guild may thus be characterized as active searchers (they look for prey difficult to find) but passive pursuers (they attack prey easy to catch). In addition, gleaners exhibit a narrow range of preferences in habitat structure. Flycatchers forage primarily by hovering or sallying, concentrating on prey available via aerial attack. They have both a velocity and search intensity of <4.0, and a foraging intensity of <1.8. They have attack radii ranging from 1 m to >7.5 m. Members of the fly-catching guild may thus be characterized as passive searchers (they look for prey easy to find) but active pursuers (they attack prey difficult to capture). Flycatchers show a broad range of preferences in habitat structure. For all species considered together there is an inverse correlation between body size and velocity, and a positive correlation between body size and attack radius. Three core adaptations identify the adaptive syndromes of actively and passively searching predators. Active searchers have high velocities, high search intensities, and a foraging repertoire associated with passive prey. Passive searchers have low velocities, low search intensities, and a foraging repertoire associated with active prey. Additional characteristics also differentiate the two adaptive syndromes. Search/pursuit ratios critical to numerous optimal foraging models are impossible to measure reliably in the field; thus the concept of active and passive searchers is proposed as a meaningful and readily quantifiable substitute. The data presented here exhibit poor fit with the predictions of several selected models. Predictions concerning differences in diet specialization, the extent of territorial and foraging overlap, and the prevalence of sexual dimorphism are not confirmed. In general, predictions concerning morphological size gradients are upheld; those concerning habitat specialization are confirmed if habitat is measured in structural terms, but are not supported when measured by vegetation type.
Article
Competition between brook trout (Salvelinus fontinalis) and brown trout (Salmo truttta) was studied by measuring characteristics of daytime positions held by brook trout before and after removal of the brown trout from 1800 m of a stream. We used four criteria as indices of position quality: "water velocity difference" (the difference between velocity at the focal point and in the fastest current within 60 cm of the fish), water depth, distance to stream bed, and lighting. After brown trout removal, brook trout larger than 15 cm chose resting positions with more favorable water velocity characteristics and more often in shade. The position shift was greatest for the largest brook trout, those of 20–30 cm. Feeding positions of brook trout changed little upon brown trout removal according to our criteria. The shift in resting positions of brook trout after release from competition with brown trout indicates that brown trout excluded brook trout from preferred resting positions, a critical and scarce resource. The combined effects of such interspecific competition, differential susceptibility to angling, differential response to environmental factors, and predation of brown trout on juvenile brook trout may account for declines of brook trout populations while brown trout populations expand in many streams of the northeastern United States where the two species are sympatric.Key words: brook trout, brown trout, competition, ecological release, microhabitat use, resting positions, feeding positions, stream, Michigan
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Aravaipa Creek in Graham and Pinal counties, Arizona, is a now-isolated, spring-fed tributary of the San Pedro River. This stream acts as a refugium for 7 of the 12 known native fish species of the San Pedro drainage (Gila robusta, Rhinichthys osculus, Agosia chrysogaster, Tiaroga cobitis, Meda fulgida, Catostomus insignis, and Pantosteus clarki). Only two introduced fishes are present (Ictalurus melas and Lepomis cyanellus), and these are restricted to a pond lateral to the creek.
Article
A total of 68 species has been recorded in the main channel of Thompson Creek, Louisiana. Pronounced replacements and/or additions of species and concurrent shifts in relative abundance of shared species were found between the baselevel Mississippi River floodplain, the permanently flowing upland section, and the intermittent headwaters. This gradient was quantified by similarity indices. Another prominent trend was the downstream increase in number of species.
Article
The number of lizard species in the flatland desert habitat is correlated with several different structural attributes of the vegetation. It is shown that both the horizontal and vertical components of spatial heterogeneity are correlated with the number of lizard species. The habits of the twelve component species are considered briefly as they relate to the partitioning of the biotope space. Three species are food specialists, eight display various substrate specificities, and only one species appears to be truly "convex." Two tests of the present interpretation of these results are proposed, and some speculations concerning Australian flatland desert lizards are made.
Article
Wild brown trout Salmo trutta in a fertile, high-conductivity stream in central Pennsylvania were observed from camouflaged towers for three consecutive years in order to quantify the diurnal feeding and social behavior of undisturbed adults. The foraging behavior observed was characterized in general as one of net energy maximization effectuated principally by cost minimization. Individuals ranging in age from young of the year to 8 years spent 86% of foraging time in a sit-and-wait search state, used discrete, energy-saving foraging sites year after year, and fed mainly off drift, taking less than 15% of their food items directly off the bottom. Feeding rates decreased with age, were highest in spring and fall, and showed little effect of time of day except for short peaks at dusk in May and June. The home range of most individuals was established in the first or second year of life and changed little thereafter. The mean size of the home range of individuals was 15.6 m and decreased slightly during the first 4 years of growth. No individual had exclusive use of any home range and no clearly defined territory could be described for any fish. Rather, the social structure evidenced is best described as a cost-minimizing, size-dependent, linear dominance hierarchy of individuals having overlapping home ranges. There was no apparent correlation between dominance and site selection with respect to distance to cover or feeding rate. Use of overhead cover ranged from 17% or less of daylight hours for wild brown trout of age-group 2 to no more than 43% for age-group 5. Length was asymptotic at 40 cm. A rectangular hyperbola described well the overall growth curve of fish in this population, half of the asymptotic length being attained at the age of 23 months. Hatchery brown trout, introduced for experimental purposes, fed less, moved more, and used cost-minimizing features of the substrate less than wild trout. It is postulated that high energy cost is a major cause of mortality among hatchery-reared brown trout stocked in streams, that at high population densities foraging sites are limiting factors, and that growth rate of drift-feeding salmonids is density-independent.Received January 10, 1983 Accepted November 6, 1983
Article
Experiments were conducted to identify stimuli to which stream-dwelling brown trout responded in selecting concealment or “cover.” The trout were 25-30 cm in total length. In each experiment, a group of five trout had choice of two types of cover in a channel 27 m long and 3.4 m wide with water 20-30 cm deep, flowing 22-37 cm/s. The fish preferred overhead cover 10 cm rather than 15 or 20 cm above streambed (P < 0.001), as well as cover with tactual features (P < 0.03). There was no apprent increased response to overhead cover that offered added visual reference features or lateral concealment.
Article
Animals usually encapsulate artificial implants placed in the abdominal cavity, but some fish species are unique in exhibiting transintestinal expulsion of the implant. Gross and histological examination were used to study the mechanisms of expulsion of artificial implants from channel catfish Ictalurus punctatus. Silicone-rubber- or paraffin-coated polystyrene transmitter capsules (0.5% or 2.0% of the fish's body weight) were surgically implanted into the peritoneal cavity of 74 adult channel catfish. Within 23 d, 39 transmitters had been expelled: 14 through the intestine, 24 through the incision, and one through a lesion in the ventral body wall. Two fish died, but 33 fish retained transmitters for the duration of the experiments (14–23 d); at necropsy, four transmitters were free in the abdominal cavity, 11 had limited fibrous proliferation, 14 were fully encapsulated by fibrous connective tissue, and four were partly or fully in the intestinal lumen. A fibrous connective tissue capsule was present in all but three fish that expelled their transmitters. Contraction of myofibroblasts, a prominent cell type in the fibrous capsule tissue, provided the force for expulsion. Expulsion occurred through the incision only when the transmitter was encapsulated over the incision. Anal exits occurred when the transmitter was encapsulated on the intestine and focal inflammation weakened the intestinal tissue layers and allowed the transmitter to pass into the intestine. Tissue reactions and number of incision exits were significantly greater with transmitters 2.0% of body weight than with transmitters 0.5% of body weight. Incision exits were more frequent in gravid females than in males or spent females. The kind of transmitter coating had no significant effect on expulsion.
Article
–Seasonal movements and winter habitat use are not well described for large stream-dwelling brown trout Salmo trutta. Movements and stream reach use by adult brown trout were documented in the Beaver Creek system from April 1988 through March 1990. Radio transmitters were implanted in 22 brown trout (total lengths, 13.9–22.7 in) that were tracked up to 165 d (mean, 90 d). Long-range (4.5–12.5-mi) movements occurred in spring and fall. Brown trout were relatively sedentary at other times, spending the summer in Beaver Creek's lower North Branch, a second-order stream, and the winter in the Peshtigo River, a fourth-order warmwater stream to which Beaver Creek drains. Portions of a system that do not hold brown trout in the summer may be important winter areas. The results verify the importance of barrier-free streams and suggest the importance of a drainage system approach to brown trout management.
Article
SYNOPSIS. Studies on the relation of temperature to tolerance, preference, metabolic rate, performance, circulation, and growth of sockeye salmon all point to a physiological optimum in the region of 15°C. Natural occurrence is limited in time and space at temperatures above 18°C despite being able to tolerate 24°C. Forms of physiological inadequacy can be demonstrated which account for such restrictions in distribution. Predictive power for locating and accounting for concentrations of young fish in thermally stratified lakes appeared to provide "proof" for the controlling influence of the physiological optimum temperature. Early literature on the ecology of sockeye supported this view. Recent studies using midwater trawls and sonar detection reveal a diurnal behavior pattern which points to a more subtle interaction of biotic andabiotic factors governing vertical distribution in which the controlling force appears to be bioenergetic efficiency. It is concluded that a mechanism of behavioral thermoregulation has evolved which favorably balances daily metabolic expenditures in order to conserve energy when food is limited.
Article
The patterns of foraging movements of the teiid species Cnemidophorus tigris (western whiptail) and four iguanid species, Gambelia wislizeni (leopard lizard), Uta stansburiana (side-blotched lizard), Phrynosoma platyrhinos (desert horned lizard), and Callisaurus draconoides (zebra-tailed lizard), were investigated between 1978 and 1981. Rates and frequencies of movement while foraging, based on more than 44 000 minutes of observation of over 500 different lizards, were analysed with respect to temporal variation on yearly, seasonal and daily time scales and compared to expectations froma dichotomous view of foraging modes. The notion of polarized foragiing tactics among lizards was partially supported. Among the iguanid species, only Gambelia exhibited rates of foraging movements that were not always significantly less than those of the active forager, Cnemidophorus. Nevertheless, the analyses also revealed temporal variation in the search tactics of iguanid species. Gambelia exhibited a seasonal decline in foraging movements during three out of four years. Phrynosoma, Callisaurus and Uta all exhibited seasonal declines in their foraging movements in some years, but not in others. The foraging movements of all iguanid species increased during the early-season of 1978, corresponding to a marked increase in late winter/early spring rainfall that year. Uta showed diurnal shifts in foraging movements during most years. Such diurnal variation was also apparent in Callisaurus in some years. Despite consistent differences between Cnemidophorus and most iguanid species, the presence of temporal variability in foraging movements of iguanid lizards indicates a capacity for shifts in tactics in these species. Thus, this variability more realistically reflects a continuum of foraging tactics than it does dichotomous strategies.
Article
This report deals with the migration of wild brook trout and brown trout, over 7 inches long, in Hunt Creek and the upper Au Sable River system. Between 1934 and 1967 we jaw-tagged 3,320 brook trout and 5,615 brown trout; anglers recaptured and reported 346 of the brook trout and 480 brown trout.Brook trout were recaptured close to where they had been tagged and released--88% within 1 mile, the remainder within 11 miles.Migration of brown trout (in the Au Sable system) was more variable. Seven- to 13-inch brown trout remained (56–85%) within 1 mile of tagging sites. Many browns over 13 inches in the North and South Branches Au Sable migrated several miles (some up to 10 to 40 miles), but in the Main Au Sable 90% of the big browns were less than 1 mile from tagging site.Spring-tagged trout produced twice as many returns as did fall-tagged fish. Brook trout recoveries were 97% within the first year after tagging; 67% of the browns came within the first year; the other 33%, in 2 to 5 years.
Article
Fish, like other living systems, must conform to the laws of thermodynamics. Fish gain matter and energy in food, and they lose absorbed matter and energy as a result of catabolism—which provides energy for maintenance and activity—and the elaboration of reproductive products. Physiological energetics, or animal bioenergetics, concerns the rates of energy expenditure, the losses and gains, and the efficiencies of energy transformation, as functional relations of the whole organism. The majority of such presentations commence with an energy-flow diagram indicating the main steps that the energy of food intake follows through the organism, and the paths of energy distribution. Each of these steps with their appropriate values is subject to quantitative change, depending on many biotic and abiotic factors. With the thought that the basis of these energy exchanges needs to be elaborated first, it was deemed more fitting to conclude with a quantitatively expressed flow diagram. An understanding of the physical, chemical, and biological basis on which the energetics is built, and the equivalents employed, constitutes the opening section of this chapter. Some necessary distinctions between mammalian and nonmammalian systems are made. An adequately nutritious diet is assumed; the basic source of fuel for the fire of life is solely derived from the food.
Article
Diurnal periodicity in the drift of invertebrate was observed in Temple Fork (of the Logan River), a small Utah mountain stream in the summer of 1966. The larvae of a caddisfly, Oligophlebodes sigma Milne (Trichoptera: Limnephilidae) exhibited a marked day—active drift periodicity, a type rarely reported. Drift rates as high as 400 g (160,000 individuals) per 24 hr for the entire stream (discharge about 0.34 m ³ /sec) were recorded, with only 4% occurring during the night. Inflections in drift rate were not related to times of sunset or sunrise, as is the case with night—active species. Rather, a close positive correlation with water temperatures, normally higher during the daytime, was apparent. Such correlation suggests that, whereas light intensity is the phase—setting mechanism for night—active drift periodicities, in the present case of a day—active pattern, the phase—setting mechanism was water temperature.
Article
The response of the brown trout to a single, short (c. 1 min) incidence of handling stress was monitored for a period of 1 month post-stress. Significant changes were found in feeding behaviour, in the levels of plasma cortisol, glucose and lactate, in the concentration of circulating lymphocytes and in the degree of epidermal mucification. No changes were detected in the growth rate and coefficient of condition, in the levels of plasma thyroxine, in the concentrations of circulating erythrocytes, neutrophils and thrombocytes or in the thickness of the epidermis. The time-course for recovery of each parameter was examined and from this it was concluded that a minimum of 2 weeks was required for complete recovery and a return to normality.
Article
For the first time, workers in the U.K. with a Home Office licence may surgically implant transmitters into wild fish in order to track them. A laboratory study was designed to investigate the effects of intraperitoneally implanted transmitters on rainbow trout. No significant difference in mortality or growth occurred between control, sham-implanted and implanted groups of fish over a 7-month period. Transmitters became encapsulated by connective tissue, the composition of which is described. Three fish expelled transmitters via the body wall without subsequent mortality or morbidity. Histological evidence suggests pressure necrosis of the body wall adjacent to the tag to be the mechanism of expulsion. With good surgical procedure, intraperitoneal implantation appears to provide a suitable technique for attaching transmitters to fish, and may be preferable to existing methods for many fish.
Article
The annual and diurnal activity cycle for four naturally feeding brown trout separately confined in netting cages on the bed of Windermere is described. All the fish showed a similar annual cycle of maximum activity during May and June, one fish showing a second activity peak during the autumn. The fish also showed a similar diurnal activity rhythm of low activity during the night and increased activity during the day with a pronounced increase at dawn. The possible influence of light and temperature on the fishes activity is briefly discussed.
Article
Twenty-seven fish species were collected from Conowingo Creek at eleven stations during the summer, 1970. Species most abundant wereRhinichthys atratulus, Notropis cornutus, Exoglossum maxillingua, Semotilus atromaculatus andCatostomus commersoni. A Spearman’s rank correlation coefficient matrix was calculated for biological and physical parameters. Distribution of fishes appeared related to width and depth of the stream, but was most influenced by gradient.
Article
As part of a study to quantify use of space and time by wild brown trout (Salmo trutta L.), we tested 12 trout (in four groups of three; four separate experiments lasting 8 days each; 96 total fish-days of data) in an electronic shuttlebox (ichthyotron) under natural winter temperature and photoperiod conditions, to determine their diel patterns of locomotor activity. Activity was quantified as the number of photocell-monitored light-beam interruptions per hour as fish passed between chambers of the shuttlebox. Data from all four experiments, pooled and expressed as hourly percentages of 24-hour diel activity, yielded a bimodal (crepuscular) pattern, with a major peak at dawn and a lesser one around dusk. The fish were not fed during the experiments, so feeding schedules had no effect on these results. Another experiment with a single fish yielded results similar to the three-fish groups. Other experiments failed to demonstrate a free-running circadian rhythm in this species under constant darkness (DD), and this, along with an apparent lack of anticipation of light change in the activity pattern, suggests that the diel activity pattern observed in this species is exogenously controlled by either absolute light intensity or changing light intensity, or both. Field studies are underway to determine whether diel activity patterns of wild brown trout are the same under natural conditions.
Article
Master of Science Natural Resources and Environment University of Michigan, School of Natural Resources and Environment http://deepblue.lib.umich.edu/bitstream/2027.42/40229/1/aag2862.1988.001.pdf
Article
Master of Science Natural Resources and Environment University of Michigan, School of Natural Resources and Environment http://deepblue.lib.umich.edu/bitstream/2027.42/40208/1/aag2862.1845.001.pdf
A growth model for drift-feeding salmonids: a selective pressure for migration
  • R A Bachman
Bachman, R. A. 1982. A growth model for drift-feeding salmonids: a selective pressure for migration. Pages 128-135 in E. L. Brannon and I. O. Salo, editors. Proceedings of the salmon and trout migratory behavior symposium. University of Washington Press, Seattle.
A method of measuring microhabitat components for lotic fishes and its application with regard to brown trout
  • T Gosse
  • W Helm
Gosse, T., and W. Helm. 1982. A method of measuring microhabitat components for lotic fishes and its application with regard to brown trout. Pages 138-149 in N. Armantrout, editor. Proceedings of symposium on acquisition and utilization of aquatic habitat inventory information. American Fisheries Society, Western Division, Special Publication, Portland, Oregon.
Use of artificial instream trout shelters by trout in the
  • J A Nuhfer
Nuhfer, J. A. 1979. Use of artificial instream trout shelters by trout in the Au Sable River, Michigan. Master's thesis. Michigan State University, East Lansing.
Final report, Flaming Gorge tailwater fisheries investigations: trout growth, harvest, survival, and microhabitat selection in the Green River
  • J E Johnson
  • R P Kramer
  • E Larson
  • B L Bonebrake
Johnson, J. E., R. P. Kramer, E. Larson, and B. L. Bonebrake. 1987. Final report, Flaming Gorge tailwater fisheries investigations: trout growth, harvest, survival, and microhabitat selection in the Green River, Utah, 1978–82. Utah Department of Natural Resources, Publication 87–13, Salt Lake City.
Au Sable River watershed project biological report Michigan Department of Natural Resources
  • B F Coopes
Coopes, B. F. 1974. Au Sable River watershed project biological report (1971–1973). Michigan Department of Natural Resources, Fisheries Management Report 7, Lansing.
Hydrology and recreation in the coldwater rivers of Michigan's southern peninsula
  • G E Hendrickson
  • C J Doonan
Hendrickson, G. E., and C. J. Doonan. 1972. Hydrology and recreation in the coldwater rivers of Michigan's southern peninsula. U.S. Geological Survey, Water Information Series Report 3, Lansing, Michigan.
Physiological energetics. Pages 279-352 in
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