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Handling effects on dispersal of PIT ‐tagged Flannelmouth Sucker
Abstract
Objective
Handling and tagging migrating fish might alter their behavior, limiting inference from mark–recapture studies. Posthandling flight of tributary spawning Flannelmouth Sucker Catostomus latipinnis was previously identified in Coal Creek in the upper Colorado River basin. Our objective was to determine if similar issues were present at McElmo Creek in the San Juan River basin.
Methods
We compared emigration timing of Flannelmouth Sucker that had been handled and tagged with passive integrated transponder tags during their tributary spawning run to individuals tagged in previous years and detected both entering and exiting the tributary. Linear mixed‐effects models were used to examine intrinsic and extrinsic factors contributing to exit timing.
Result
Sex and tagging year were associated with emigration timing, but handling did not result in posthandling flight from McElmo Creek. Females exited the tributary ~3 days before males, and larger fish emigrated earlier than smaller adults.
Conclusion
Differences in capture technique and timing, available spawning habitat, and fish motivation across river systems may contribute to differences in posthandling emigration of tributary spawning Flannelmouth Sucker.
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Spawning phenology and associated migrations of fishes are often regulated by factors such as temperature and stream discharge, but flow regulation of mainstem rivers coupled with climate change might disrupt these cues and affect fitness. Flannelmouth sucker (Catostomus latipinnis) persisting in heavily modified river networks are known to spawn in tributaries that might provide better spawning habitat than neighboring mainstem rivers subject to habitat degradation (e.g., embedded sediments, altered thermal regimes, and disconnected floodplains). PIT tag data and radio telemetry were used to quantify the timing and duration of flannelmouth sucker tributary spawning migrations in relation to environmental cues in McElmo Creek, a tributary of the San Juan River in the American Southwest. We also tested the extent of the tributary migration and assessed mainstem movements prior to and after tributary migrations. Additionally, multiyear data sets of PIT detections from other tributaries in the Colorado River basin were used to quantify interannual and cross‐site variation in the timing of flannelmouth sucker spawning migrations in relation to environmental cues. The arrival and residence times of fish spawning in McElmo Creek varied among years, with earlier migration and a 3‐week increase in residence time in relatively wet years compared to drier years. Classification tree analysis suggested a combination of discharge‐ and temperature‐determined arrival timing. Of fish PIT tagged in the fall, 56% tagged within 10 km of McElmo Creek spawned in the tributary the following spring, as did 60% of radio‐tagged fish, with a decline in its use corresponding to increased distance of tagging location. A broader analysis of four tributaries in the Colorado River basin, including McElmo Creek, found photoperiod and temperature of tributary and mainstem rivers were the most important variables in determining migration timing, but tributary and mainstem discharge also aided in classification success. The largest tributary, the Little Colorado River, had more residential fish or fish that stayed for longer periods (median = 30 days), whereas McElmo Creek fish stayed an average of just 10 days in 2022. Our results generally suggest that higher discharge, across years or across sites, results in extended use of tributaries by flannelmouth suckers. Conservation actions that limit water extraction and maintain natural flow regimes in tributaries, while maintaining open connection with mainstem rivers, may benefit migratory species, including flannelmouth suckers.
Individual growth can exert strong control on population dynamics but is constrained by resource acquisition rates. Difficulty in accurately quantifying resource availability over large spatial extents and at high temporal frequencies often limits attempts to understand the extent to which resources limit individual growth. Daily estimates of stream metabolism, including gross primary productivity (GPP), are increasingly available but have not, to our knowledge, been linked to fish growth. Here we examine how environmental variables such as GPP, water temperature, turbidity, and high-flow releases from a dam are linked to spatiotemporal variation in the growth of flannelmouth sucker (Catostomus latipinnis) in the Colorado River within the Grand Canyon. We fit state-space growth models to 6 years of mark–recapture data collected in four river reaches spanning 300 river kilometers. Consistent with past research in this system, we find that all four environmental variables influence growth in length of a native primary consumer fish. GPP and temperature have a positive influence on growth, while turbidity and high-flow events have a negative influence. Water temperature is the dominant driver of spatiotemporal variation in growth, while the link between high-frequency GPP and fish growth is relatively novel. Fish growth is likely to be linked to stream metabolism in other systems where overall productivity, not the quality of primary producers, limits the food webs that support fish growth.
The zebrafish (Danio rerio, Hamilton, 1822) is one of the most important fish model species in scientific research, with millions of fish housed in laboratory animal facilities around the world. During husbandry, it is necessary to regularly handle the fish, which could cause short‐ and long‐term stress, possibly affecting both fish welfare and experimental outcomes. In two experiments, the authors studied effects of transferring adult zebrafish, by chasing them with a net and/or exposing them to air (netting) on different endpoints: cortisol levels, reproduction parameters and behavioural parameters. They used realistic chase and air‐exposure times to mimic normal zebrafish husbandry and investigated the potential to habituate to handling stressors. Finally, the potential welfare improvements of a nutritional reward after handling were studied. All types of handling induced a stress response, but the authors did not find a correlation with the intensity of the stressor. Realistic (short) handling routines also caused stress, both after the first time and after regular handling over a long period of time. Cortisol levels peaked after 15 min, were still elevated after 30 min and dropped to resting level after 60 min. This should be taken into account by researchers when carrying out measurements or behavioural trials within an hour after handling. There is a minor potential benefit of nutritional rewards that may contribute to a faster recovery of normal behaviour. They did not find evidence of habituation to chasing and netting stress. Taking the stress response after handling into consideration will improve fish welfare and health and minimise husbandry‐associated sources of variation.
Movement of fishes in the aquatic realm is fundamental to their ecology and survival. Movement can be driven by a variety of biological, physiological and environmental factors occurring across all spatial and temporal scales. The intrinsic capacity of movement to impact fish individually (e.g., foraging) with potential knock‐on effects throughout the ecosystem (e.g., food web dynamics) has garnered considerable interest in the field of movement ecology. The advancement of technology in recent decades, in combination with ever‐growing threats to freshwater and marine systems, has further spurred empirical research and theoretical considerations. Given the rapid expansion within the field of movement ecology and its significant role in informing management and conservation efforts, a contemporary and multidisciplinary review about the various components influencing movement is outstanding. Using an established conceptual framework for movement ecology as a guide (i.e., Nathan et al., 2008: 19052), we synthesized the environmental and individual factors that affect the movement of fishes. Specifically, internal (e.g., energy acquisition, endocrinology, and homeostasis) and external (biotic and abiotic) environmental elements are discussed, as well as the different processes that influence individual‐level (or population) decisions, such as navigation cues, motion capacity, propagation characteristics and group behaviours. In addition to environmental drivers and individual movement factors, we also explored how associated strategies help survival by optimizing physiological and other biological states. Next, we identified how movement ecology is increasingly being incorporated into management and conservation by highlighting the inherent benefits that spatio‐temporal fish behaviour imbues into policy, regulatory, and remediation planning. Finally, we considered the future of movement ecology by evaluating ongoing technological innovations and both the challenges and opportunities that these advancements create for scientists and managers. As aquatic ecosystems continue to face alarming climate (and other human‐driven) issues that impact animal movements, the comprehensive and multidisciplinary assessment of movement ecology will be instrumental in developing plans to guide research and promote sustainability measures for aquatic resources.
High reproductive performance is the key attribute of male fitness, especially due to the high reproductive skew among the males of most animal species. Males of long-lived iteroparous species have opportunities to improve upon their previous reproductive attempts with increasing age. We collected individual-specific reproductive behaviour and age data on a cyprinid fish, the asp (Leuciscus aspius), from 2015 to 2019. We tested whether males changed their performance over time using a unique dataset where individual performance was recorded yearly with passive telemetry. Individual fish behaviour was tracked from one to five reproductive seasons at least a year after the tagging. Fish were scored by measures of quality (first arrival time, number of visits and time spent in the reproductive grounds, and encountered proportion of males to all adult fish). In general, fish improved in the first three metrics with age, suggesting a shift towards behaviours likely to enhance reproductive success as individuals aged. A larger size at tagging was predictive of earlier fish arrival on the spawning ground in subsequent years. Our study therefore demonstrates the importance of age as a factor when considering the potential reproductive success of long-lived fish species. High reproductive performance is the key attribute of male fitness. Males of long-lived species reproducing multiple times in their life have opportunities to improve upon their previous reproductive performance with increasing age. In this 5-year study, we tracked a large cyprinid fish with telemetry systems during their reproduction. We investigated the age-related behavioural changes in males and demonstrated the improvement of male reproductive timing and length of stay with potential repercussions for male’s reproductive output. We emphasize the importance of old and experienced individuals among the fish population, which are often targeted and selectively removed from the human-managed waters.
Numerous laboratory and field studies have found that female Pacific salmon have higher mortality than males during their once-in-a-lifetime upriver spawning migration. However, the proximate cause(s) of this increased mortality are poorly understood. This study exposed sockeye salmon (Oncorhynchus nerka) to a mild capture and tagging stressor and evaluated physiological recovery and movement behaviour at 1 and 4 h postrelease. Female sockeye salmon did not expend more anaerobic energy in response to the stressor but did have higher plasma lactate levels 4 h after the stressor, indicating that females took longer to physiologically recover compared with males. In addition, female salmon had lower plasma glucose but higher plasma cortisol, plasma K⁺, and cardiac lactate levels compared with males. Male and female salmon had markedly different postrelease behaviours within the first hour of release; males were more likely to hold position within the staging area. Two potential mechanisms leading to increased mortality in female salmon were identified in this study: (a) prolonged recovery duration (possibly mediated by elevated plasma cortisol levels) and (b) insufficient oxygen delivery to the heart.
This study used acoustic telemetry and a multistate Cormack–Jolly–Seber model to determine the seasonal movement patterns of blue sucker Cycleptus elongatus from 2015 to 2017. Several hypotheses were ranked using AICc, and it was determined that the movement patterns of blue suckers in a mainstem reach below a hydropower dam (i.e., tailwater) differed from those of blue suckers tagged in the major tributaries (perennial with stream order >3). This study estimated a low probability (≤0.13) blue suckers would leave the tailwater reach at any time during the study. Conversely, blue suckers tagged in the major tributaries had a high probability (≥0.88) of leaving after the spawning season (February–May). Blue suckers tagged in the major tributaries displayed a high probability (0.83) of returning to the tributaries in the spawning season of 2016 when discharges were high. Blue suckers also had a higher probability of fidelity to the tributary where they were tagged (0.65) rather than straying to different tributaries (0.18). The majority of tagged blue suckers that strayed selected the only undammed tributary in the study area. In 2017, spring discharges were low, and the probability of blue suckers returning to any major tributary was low (0.19), with little difference in the probability of displaying site fidelity (0.10) vs. straying (0.09).
Intermittent or ephemeral streams make up a large percentage of all stream habitats and may have significant roles in spawning, foraging, refugia and early life history habitat for many fishes. From 2015 – 2017 we examined use of Cottonwood Creek, an intermittent tributary in the Gunnison River Basin, Colorado, by spawning Flannelmouth Sucker Catostomus latipinnis, Bluehead Sucker C. discobolus and Roundtail Chub Gila robusta. We used combinations of a stream‐spanning picket weir and PIT‐tag antennae near the mouth of the creek to determine fish movement in and out of the stream, which was more effective for suckers than for Roundtail Chub. Large numbers of suckers used the stream each year despite very different flow regimes. The timing of initial fish entry varied by six weeks across three years of study, from March 17 to May 6. Immigration was only loosely and inconsistently correlated to abiotic factors (various stream temperature metrics, and discharge) among years, and was most heavily dependent on the presence of water in the stream sufficient to permit fish passage. Average residency times of suckers ranged from 26 – 37 days depending on year and species, and spawning fish lost 10 – 18% of their body weight depending on species and sex. Both sucker species displayed a high level of annual site fidelity, with 61 – 71% of fish returning the year after being tagged. Larval drift was sporadic with many larvae failing to evacuate the stream before flow ceased each year. While further research is needed to assess the overall recruitment contribution from Cottonwood Creek to the regional population, this study revealed use of an intermittent tributary by thousands of native Colorado River fishes, highlighting the importance of non‐perennial waters for completion of the life‐histories of some large‐river fish species. This article is protected by copyright. All rights reserved.
Hatcheries and stocking programs have become necessary to repatriate or augment populations of imperiled fishes worldwide. Over nearly two decades, millions of endangered juvenile Colorado Pikeminnow Ptychocheilus lucius have been stocked into the San Juan River (CO, NM and UT, USA); however, recruitment of these individuals to adult life stages (age ≥6) remains low. Using a mark‐recapture data set collected from annual river‐wide electrofishing efforts between 2003 and 2016, we investigated apparent survival and capture probabilities of stocked Colorado Pikeminnow to identify age‐specific bottlenecks contributing to this lack of recruitment. With relatively high capture rates, which averaged between 0.34‐0.39 for the first two years following an individual's first encounter, our results indicated survival was consistently less than 0.25 for young age groups (i.e., ages 1‐3) and no appreciable increase in survival occurred until fish had been in the river for at least three years (i.e., age ≥4+). Although age and capture effects were confounded for most age groups, for age 2 fish, capture appeared to reduce apparent survival by approximately 50%. The confounding effects of age, a complete hatchery‐originated population, and extensive environmental alterations to the San Juan River make it difficult to disentangle factors associated with this overall reduced juvenile survival.
This article is protected by copyright. All rights reserved.
Hydropower-related damage to fish remains a great challenge, making objective monitoring of turbine-related fish injury a necessity. The catch of fish at turbine outlets is currently realised by net fishing, but potential catch-related injuries are largely unknown. Catch efficiency and fish-friendliness in relation to fish handling, exposure time, floating debris and fish biomass of four fish recovery installations were assessed using seven species. Highly species-specific lethal and sublethal effects were observed. Exposure time had the strongest effects on catch-related damage, being up to 150-fold increase after 12 hr compared to 1 hr. Up to 84% mortality occurred in the most sensitive species Thymallus thymallus L. Besides exposure time, higher current speed and biomass within the net resulted in greater fish damage. To minimise catch-related effects, keeping emptying periods <1–2 hr and considering the effects of current speed, fish and debris biomass are crucial to increase data comparability among studies.
Autonomous passive integrated transponder (PIT) tag antenna systems continuously detect individually marked organisms at one or more fixed points over long time periods. Estimating abundance using data from autonomous antennas can be challenging because these systems do not detect unmarked individuals. Here we pair PIT antenna data from a tributary with mark–recapture sampling data in a mainstem river to estimate the number of fish moving from the mainstem to the tributary. We then use our model to estimate abundance of non-native rainbow trout (Oncorhynchus mykiss) that move from the Colorado River to the Little Colorado River, the latter of which is important spawning and rearing habitat for federally endangered humpback chub (Gila cypha). We estimate that 226 rainbow trout (95% confidence interval: 127–370) entered the Little Colorado River from October 2013 to April 2014. We discuss the challenges of incorporating detections from autonomous PIT antenna systems into mark–recapture population models, particularly in regards to using information about spatial location to estimate movement and detection probabilities.
Quantifying fish movements in river networks helps identify critical habitat needs and how they change with environmental conditions. Some of the challenges in tracking fish movements can be overcome with the use of passive integrated transponder (PIT) tagging and antennas. We used PIT technology to test predictions of movement behaviour for four fish species at a mainstem–tributary confluence zone in an arid-land river system. Specifically, we focused on the McElmo Creek tributary confluence with the San Juan River in south-western Utah, USA. We quantified variation in species occurrences at this confluence zone from May 2012 to December 2015 relative to temporal and environmental conditions. We considered occurrences among species relative to tagging origins (tributary versus mainstem), season and time of day. Generally, fishes tagged in the focal tributary were more likely to be detected compared to fish tagged in the mainstem river or other tributaries. Additionally, adults were most likely to be detected across multiple years compared to subadults. Based on a Random Forests model, the best performing environmental variables for predicting seasonal detections included mainstem discharge during run-off season (razorback sucker Xyrauchen texanus), tributary discharge during monsoon season (Colorado pikeminnow Ptychocheilus lucius) and mainstem water temperature (flannelmouth sucker Catostomus latipinnis and channel catfish Ictalurus punctatus). The variable responses by endemic and introduced fishes indicate tributary habitats provide several key functions within a fish community including spawning, rearing, foraging and refuge.
Habitat alterations and establishment of nonnative fishes have reduced the distributions of Flannelmouth Sucker Catostomus latipinnis and Bluehead Sucker C. discobolus to less than 50% of their historical ranges in the Colorado River basin. Tributaries are sometimes less altered than main-stem habitat in the basin and may be important to support various life history processes, but their role in the maintenance of Flannelmouth Sucker and Bluehead Sucker populations is poorly understood. Using mark-recapture techniques, we show tributaries are important habitat for native suckers in the upper Colorado River basin and report three main findings. First, both Flannelmouth and Bluehead suckers likely respond to a thermal cue that initiates spawning movement patterns. Suckers moved into Coal Creek from the White River beginning in mid-May of 2012 and 2013 to spawn. The majority of sucker spawning movements occurred when water temperatures inWhite River exceeded 11-14°C and those in Coal Creek were 2.5-4°C warmer, while flows varied between years. Second, based on PIT tag detection arrays, 13-45%of suckers showed spawning site fidelity. Sampling only with fyke nets would have resulted in the conclusion that site fidelity by native suckers was only 1-17%, because nets were less efficient at detecting marked fish. Third, most suckers of both species emigrated from Coal Creek within 48 h after being captured while suckers that were detected only via arrays remained resident for 10-12 d. The posthandling flight response we observed was not anticipated and to our knowledge has not been previously reported for these species.Remote PIT tag antenna arrays allowed for a stronger inference regarding movement and tributary use by these species than what could be achieved using just fyke nets. Tributaries are an important part of Flannelmouth Sucker and Bluehead Sucker life history and thus important to conservation strategies for these species.
Passive integrated transponder (PIT) tags, commonly used to individually identify fish, are assumed to not hinder survival or alter the behavior of the fish and to be retained throughout the duration of the study. While these assumptions have been verified for many species, other species have exhibited poor retention or survival, or altered behavior. In this study, we evaluated short-term PIT tag retention and recapturability of PIT-tagged fish in wild populations of migrating and spawning Bluehead Sucker Catostomus discobolus and Flannelmouth Sucker C. latipinnis. We trapped fish as they entered a spawning tributary of the Gunnison River near Delta, Colorado, USA. We abdominally injected 12.5 × 2.1 mm PIT tags and externally marked 2,645 fish; another 2,660 fish were given an alternative external mark but were not PIT-tagged. When we recaptured fish as they exited the tributary, we found a PIT tag retention rate >99% and recaptured a greater proportion of PIT-tagged fish than of control fish for both species. We did not identify any tag loss in females, suggesting that tags were not expelled with eggs while spawning. Abdominally injected PIT tags are an effective way of marking these species.
Received November 22, 2016; accepted February 26, 2017
Recognizing how stream fish communities—and their habitats—differ across space and time relative to their position in stream networks (i.e., main-stem versus tributary habitats) is increasingly important for the conservation of imperiled native fish communities in altered river networks such as those in the Colorado River basin. We studied the patterns (community composition) and processes (movements) that shape species occurrences and distributions in two tributaries of the San Juan River, Utah and New Mexico, between 2012 and 2014. Our results show that distance from the San Juan River was a strong driver of tributary fish community structure, whether through declines in species richness (Chaco Wash) or species turnover (McElmo Creek), and that these patterns coincided with habitat gradients (i.e., depth, substrate, and width). Occurrences of passive integrated transponder (PIT)–tagged fish at a stationary antenna in McElmo Creek just upstream of its confluence with the San Juan River varied by species but generally were associated with spring spawning migrations (Flannelmouth Sucker Catostomus latipinnis, Razorback Sucker Xyrauchen texanus), exploratory movements (Colorado Pikeminnow Ptychocheilus lucius), and monsoon flooding (Channel Catfish Ictalurus punctatus, Razorback Sucker). Occurrences of PIT-tagged fish in Chaco Wash were dominated by endangered Razorback Suckers and Colorado Pikeminnows, suggesting that this habitat supplies useful habitat, forage, or both. Given the common occurrences of native fishes in these tributaries, incorporating these habitats into basinwide management actions seems necessary to fully understand the spatiotemporal dynamics of native and nonnative fish communities.
Received October 2, 2014; accepted May 20, 2015
Electrofishing injury rates in rainbow trout and juvenile steelhead Oncorhynchus
mykiss and juvenile spring chinook salmon O. tshawytscha were quantified in samples collected
in four tributaries to, and one reach of, the Yakima River, Washington. Estimated electrofishing
injury rates at the reach and stream scales were generated by using sample injury rates, derived
from this study, multiplied by capture probabilities and the fraction of habitat sampled. Sample
injury rates in small O. mykiss and juvenile spring chinook salmon were low. Mean electrofishing
injury rate in O. mykiss samples captured in tributaries was 5.1%. Only 2.0% of the juvenile spring
chinook salmon captured by electrofishing in the Yakima River were injured. Larger O. mykiss
(250 mm FL)
was 2.1%. Stream scale injury rates for all groups examined were below levels that we would
expect to affect our long-term monitoring data. The distribution, conservation status, size structure,
lifespan and annual mortality of the population, the fraction of the habitat sampled, sampling
frequency, and availability, effectiveness, and cost of alternative sampling methods, must all be
balanced against the need for data when establishing research or monitoring efforts that use
electrofishing.
Maximum likelihood or restricted maximum likelihood (REML) estimates of the
parameters in linear mixed-effects models can be determined using the lmer
function in the lme4 package for R. As for most model-fitting functions in R,
the model is described in an lmer call by a formula, in this case including
both fixed- and random-effects terms. The formula and data together determine a
numerical representation of the model from which the profiled deviance or the
profiled REML criterion can be evaluated as a function of some of the model
parameters. The appropriate criterion is optimized, using one of the
constrained optimization functions in R, to provide the parameter estimates. We
describe the structure of the model, the steps in evaluating the profiled
deviance or REML criterion, and the structure of classes or types that
represents such a model. Sufficient detail is included to allow specialization
of these structures by users who wish to write functions to fit specialized
linear mixed models, such as models incorporating pedigrees or smoothing
splines, that are not easily expressible in the formula language used by lmer.
An overview of electronic tags that can be used in fish research is given, including radio and acoustic transmitters, data storage tags (DST, also termed archival tags), pop-up satellite archival tags (PSAT) and passive integrated transponder tags (PIT-tag). Fish telemetry is a term used to describe the application of these methods. Typically, an electronic tag is attached to a free-swimming fish, and information on position, movements and/or measurements of environmental and physiological parameters can be recorded wirelessly by use of a mobile receiver or stationary loggers. For most methods, the fish need not to be recaptured to achieve data. However, DSTs record and store information on environmental and/or physiological parameters in the tag, and therefore need to be retrieved for downloading data. In the case of PSATs, stored data is transferred to satellites when the tag loosens from the fish and pops up to the surface, and in addition, the pop up position is recorded. The developments of telemetry methods have provided opportunities to reveal previously unknown information on fish behavior, habitat use and migrations in fresh water, estuaries, near-coastal areas and oceans, especially since extensive long-term data can be collected repeatedly from individual fish. Detailed information on fish behaviour and migrations is needed to better understand, protect and manage fishes in freshwater and marine systems. The development of successful management measures depends on knowledge of where fish reside and migrate during the day, season and year. There has been a tremendous increase in the use of electronic tagging methods, especially during the last 10-20 years. In addition to descriptive and ecological studies, the methods have been used to assess effects of for instance hydropower production, other river regulations, migration barriers, protected areas, fishing regulations, catch-and-release angling, hatchery-rearing, fish aggregating devices (FADs), water pollution and aquaculture. The main methods for attaching electronic tags to fish are 1) surgical implantation in the body cavity, 2) external attachment, and 3) gastric insertion via the mouth. Potential negative handling effects are inflammations, infections, tag expulsion, altered behavior, decreased swimming performance, reduced feeding, reduced growth and increased mortality. The catch, handling and tagging procedures should have minimal effects on the fish. If not, an anomalous behaviour caused by the tagging may be recorded instead of the natural behaviour, and the study is a failure from a scientific point of view. Furthermore, optimal anaesthetic and tagging methods are required to meet the ethical standards for use of experimental animals, and to ensure fish survival and welfare.
Time-series analysis is used widely in ecology to study complex phenomena and may have considerable potential to clarify relationships of genetic and demographic processes in natural and exploited populations. We explored the utility of this approach to evaluate population responses to management in razorback sucker, a long-lived and fecund, but declining freshwater fish species. A core population in Lake Mohave (Arizona-Nevada, USA) has experienced no natural recruitment for decades and is maintained by harvesting naturally produced larvae from the lake, rearing them in protective custody, and repatriating them at sizes less vulnerable to predation. Analyses of mtDNA and 15 microsatellites characterized for sequential larval cohorts collected over a 15-year time series revealed no changes in geographic structuring but indicated significant increase in mtDNA diversity for the entire population over time. Likewise, ratios of annual effective breeders to annual census size (N b /N a) increased significantly despite sevenfold reduction of N a. These results indicated that conservation actions diminished near-term extinction risk due to genetic factors and should now focus on increasing numbers of fish in Lake Mohave to ameliorate longer-term risks. More generally, time-series analysis permitted robust testing of trends in genetic diversity, despite low precision of some metrics.
Flannelmouth suckers Catostomus latipinnus and bluehead suckers C. discolobus in the Grand Canyon of the Colorado River are among the few native species to persist after river conditions changed with the completion of Glen Canyon Dam in 1963. To evaluate the effectiveness of adaptive management manipulations to the system for recovering native species, it is necessary to estimate basic demographic and population dynamic parameters for the species of interest, such as growth, mortality, and recruitment. With this in mind, we present a two-stage analysis in which we first estimated growth and individual ages using a field-based bioenergetics model and then input the age estimates into age-structured mark–recapture (ASMR) models to estimate mortality and recruitment. The analysis was based on 18,500 flannelmouth suckers and 13,975 bluehead suckers that had been tagged with passive integrated transponder tags in the main-stem Colorado River in Grand Canyon and its tributaries since 1989. The bioenergetics estimates of growth suggest that the growth of flannelmouth suckers is faster and that of bluehead suckers slower than in the tributaries reported in other studies. The results from the bioenergetics model provide necessary parameters for input into future ecosystem models. The ASMR models that include the effects of age-specific gear vulnerability indicate that annual natural mortality rates are about 0.2 for flannelmouth suckers and 0.4 for bluehead suckers, which is in agreement with independent estimates from growth parameters and longevity. The estimates of age-1 sucker recruitment and adult abundance correspond well with independent electrofishing catch rate data. The estimated recruitment and abundance estimates provide insights into the efficacy of adaptive management actions targeted to benefit native fishes over the past two decades.Received March 27, 2011; accepted May 20, 2011
The blue sucker (Cycleptus elongatus) was sampled as individuals arrived, spawned, and departed from a spawning rime in the Grand River of northcentral Missouri, USA. The Grand River basin was not known to support blue sucker reproduction with few individuals ever recorded. The spawning site is unique in character for the lower river. Individuals began arriving in early April when water temperatures reached 10–12 °C. Females with freely-flowing roe were sampled in late April after a large rise in river stage and concurrent lowering of the water temperature 4–5 degrees to 16.5 °C. The spawning aggregation had a mean age of 15 y and ranged from 9 to 22 y based on scales that probably underestimated true ages. Males outnumbered females 5.5:1. Mean length was 659 mm for males and 721 mm for females. Females were longer at age than males and no significant age-length relationship was evident.
The lower perennial corridor of the Little Colorado River in Grand Canyon, Arizona, is numerically dominated by endemic desert fishes and therefore significant for conservation of these species. From 2000 to 2012, the U.S. Fish and Wildlife Service conducted monitoring of native fishes in the Little Colorado River near its confluence with the Colorado River. The primary focus of these efforts was to estimate the spring and fall abundance of native fishes, especially the federally endangered humpback chub Gila cypha. Because humpback chub in Grand Canyon are influenced by operations of Glen Canyon Dam, our efforts provide managers of the Glen Canyon Dam Adaptive Management Program with abundance estimates and trends of humpback chub in the Little Colorado River, the most important tributary in Grand Canyon for spawning and production of this species. From 2001 to 2006, the spring abundance estimates of humpback chub >=150 and >=200 mm remained relatively low (<=3,419 and <=2,002 fish, respectively), thereafter significantly increasing to highs of 8,083 and 6,250, respectively, by spring 2010. Also from 2000 to 2006, the fall abundance estimates of humpback chub were substantially below those abundances estimated
after 2006. In addition, flannelmouth sucker Catostomus latipinnis and bluehead sucker Catostomus discobolus showed post-2006 increases in relative abundance, suggesting a systemwide event occurred that was beneficial to native fishes. Most of the increases of humpback chub occurred during the spring season in the reaches of the Little Colorado River between 5 and 13.57 km upstream from the confluence. Successful production of age 0 year classes of humpback chub may be partially driven by hydrograph dynamics of the Little Colorado River, whereas water temperatures and predation pressures in the mainstem Colorado River likely influence survivorship of native fishes into subadult and adult life stages.
Thesis (M.S.)--University of Wyoming, 2005. Includes bibliographical references (leaves 66-74).
Each year, thousands of fishes are tagged with electronic devices to study their biology and inform fisheries management. Such research assumes that the process of capturing, tagging, and then holding fish to allow them to recover before release (i.e., the “tagging process”) does not alter the physiology, behavior, and survival of these fish. However, the fish can experience physiological challenges during the tagging process that may affect their behavior and survival. We have observed that the rationale used to establish protocols for holding durations and conditions of fish before and following surgery has received little attention. Here, we provide a perspective that: (1) provides an overview of the tagging process and its effects on the physiology, behavior, and survival of fish; (2) highlights the diverse holding conditions and durations used by researchers (that are often inadequately described and seem arbitrary); and (3) identifies key research needs. We conclude that decisions of whether, how, and for how long to hold tagged fish before release depend on diverse circumstances that need to be evaluated by researchers. We recommend that researchers explicitly report the details of how, when, where, and why tagged fish are held to facilitate protocols that benefit fish welfare, science, and management.
Advantages of passive integrated transponder (PIT) tags are their small size, longevity, and low‐cost compared to other tags. PIT tags are often used in fisheries to study movement patterns, survival, or estimate population size. However, PIT tags are limited by their short detection distance. Mobile PIT antennas may increase the utility of PIT tags in fisheries. In this study, we synthesize the current detection‐efficiency literature on mobile PIT antennas, determined physical factors (e.g., tag size, distance from the antenna) that influencing PIT‐tag detection probability by manually testing an antenna, experimentally determined factors that influenced PIT‐tag detection efficiency by determining the proportion of PIT‐tagged suckers (tag size: 4×23 mm) detected by our raft‐mounted mobile antenna, and summarize techniques used to increase observations of PIT‐tagged suckers with raft‐mounted mobile antennas in a wadable stream. Our literature review indicated tag size and orientation were the most important factors affecting detection probabilities. However, our manual testing suggested the detection probability for our antenna was primarily influenced by water depth of the tag and distance from the antenna. Our sucker detection data showed detection efficiency in our stream was most influenced by discharge, turbidity, and sample date. Tracking methods that include targeting key habitats (e.g., rootwads) and using natural features to congregated tagged fishes (e.g., riffles or pinch points) may increase detection efficiency in wadable streams. This is the first formal review of factors affecting mobile PIT antenna detection efficiency. The published literature, combined with our study results, indicate several factors need to be considered prior to mobile PIT antenna tracking.
The goal of this study was to compare the possible locations, timing, and characteristics of potentially spawning shovelnose sturgeon (Scaphirhynchus platorynchus), blue sucker (Cycleptus elongatus), and associated species during the spring of 2007–2015 in the 149-km-long lower Wisconsin River, Wisconsin, USA, a large, shallow, sand-dominated Mississippi River tributary. A 5-km index station of two pairs of rocky shoals surrounded by sandy areas was electrofished for shovelnose sturgeon and blue sucker in a standardized fashion a total of 40 times from late March through mid-June, the presumed spawning period. On one date in 2008 and two dates in 2012, all rocky shoals and adjacent sandy areas in the lowermost 149 km of the river were also elec-trofished for both species. Shovelnose sturgeon and blue sucker appeared to spawn in the limited rocky areas of the river along with at least four other species: mooneye (Hiodon tergisus), quillback (Carpiodes cyprinus), smallmouth buffalo (Ictiobus bubalus), and shorthead redhorse (Moxostoma macrolepidotum), usually at depths of 0.8–2.0 m and surface velocities of 0.4–1.0 m/s. However, apparently spawning shovelnose sturgeon were found only on mid-channel cobble and coarse gravel shoals within a single 7-km segment that included the 5-km index station, whereas apparently spawning blue suckers were encountered on these same shoals but also more widely throughout the river on eroding bluff shorelines of bedrock and boulder and on artificial boulder wing dams and shoreline rip-rap. Both species showed evidence of hom-ing to the same mid-channel shoal complexes across years. Blue sucker tended to concentrate on the shoals earlier in the spring than shovelnose sturgeon, usually from late April through mid-May at water temperatures of 8.0–15.5°C along with quillback and shorthead redhorse. In comparison, shovelnose sturgeon usually concentrated on the shoals from mid-May through early June at 13.5–21.8°C along with mooneye and smallmouth buffalo. Based on recaptures of tagged fish, at least some shovelnose sturgeon and blue sucker returned to the shoals at one-year intervals, although there was evidence that female blue sucker may have been more likely to return at two-year intervals. Most shovelnose sturgeon could not be reliably sexed based on external characteristics. Spawning shovelnose sturgeon ranged from 487 to 788 mm fork length,
Desert fishes are some of the most imperiled vertebrates worldwide due to their low economic worth and because they compete with humans for water. An ecological complex of fishes, 2 suckers (Catostomus latipinnis, Catostomus discobolus) and a chub (Gila robusta) (collectively managed as the so-called three species) are endemic to the U.S. Colorado River Basin, are affected by multiple stressors, and have allegedly declined dramatically. We built a series of occupancy models to determine relationships between trends in occupancy, local extinction, and local colonization rates, identify potential limiting factors, and evaluate the suitability of managing the 3 species collectively. For a historical period (1889-2011), top performing models (AICc) included a positive time trend in local extinction probability and a negative trend in local colonization probability. As flood frequency decreased post-development local extinction probability increased. By the end of the time series, 47% (95% CI 34-61) and 15% (95% CI 6-33) of sites remained occupied by the suckers and the chub, respectively, and models with the 2 species of sucker as one group and the chub as the other performed best. For a contemporary period (2001-2011), top performing (based on AICc ) models included peak annual discharge. As peak discharge increased, local extinction probability decreased and local colonization probability increased. For the contemporary period, results of models that split all 3 species into separate groups were similar to results of models that combined the 2 suckers but not the chub. Collectively, these results confirmed that declines in these fishes were strongly associated with water development and that relative to their historic distribution all 3 species have declined dramatically. Further, the chub was distinct in that it declined the most dramatically and therefore may need to be managed separately. Our modeling approach may be useful in other situations in which targeted data are sparse and conservation status and best management approach for multiple species are uncertain.
© 2015 Society for Conservation Biology.
We offer suggestions to avoid misuse of information-theoretic methods in wildlife laboratory and field studies. Our suggestions relate to basic science issues and the need to ask deeper questions (4 problems are noted), errors in the way that analytical methods are used (7 problems), and outright mistakes seen commonly in the published literature (5 problems). We assume that readers are familiar with the information-theoretic approaches and provide several examples of misuse. Any method can be misused-our purpose here is to suggest constructive ways to avoid misuse.
Regression models allow us to isolate the relationship between the outcome and an explanatory variable while the other variables are held constant. Here, we introduce an R package, visreg, for the convenient visualization of this relationship via short, simple function calls. In addition to estimates of this relationship, the package also provides pointwise confidence bands and partial residuals to allow assessment of variability, outliers, and deviations from modeling assumptions. The package also provides several options for visualizing models with interactions, including lattice plots, contour plots, and both static and interactive perspective plots. The implementation of the package is designed to be as generic as possible, allowing visualization not only of linear models, but of generalized linear models (glm), proportional hazards models (coxph), generalized additive models (gam), robust regression models (rlm), and more.
Variability is a hallmark of animal behavior and the degree of variability may fluctuate in response to environmental or biological gradients. For example, diel activity patterns during reproductive migrations often differ from those in non-breeding habitats, reflecting trade-offs among efficient route selection, reproductive phenology, and risk avoidance. In this study, we tested the hypothesis that diel movements of anadromous fishes differ among freshwater migration habitats. We analyzed diel movement data from ~13 000 radio-, PIT-, and acoustic-tagged adult fishes from five Columbia River species: Chinook salmon, Oncorhynchus tshawytscha; sockeye salmon, O. nerka; steelhead, O. mykiss; Pacific lamprey, Entosphenus tridentatus; and American shad, Alosa sapidissima. All five species were active during most of the diel cycle in low-gradient, less hydraulically complex reservoir and riverine habitats. Movement shifted to predominantly diurnal (salmonids and American shad) or nocturnal (Pacific lamprey) at hydroelectric dam fishways where hydraulic complexity and predator density were high. Results suggest that context-dependent behaviors are common during fish migrations, and that diel activity patterns vary with the degree of effort or predation risk required for movement.
Prespawning adult Chasmistes cujus congregate off the mouth of the Truckee River in Pyramid Lake from mid-March to early June. Spawning runs have been largest during years when spring flows in the Truckee River were relatively high. The fish spawned over predominately gravel substrate depths of 21-110 cm, where water velocities were 21-140 cm/s. Most cui-ui larvae emigrated downstream to Pyramid Lake soon after swim-up, primarily at night. Eleven year classes that were identified included fish from 1-41 yr old. In 1983, c92% of the fish in the reproductive population were from the 1969 year class and 5% were from the 1950 or earlier year class; the rest were divided among 6 year classes (1967, 1971 and 1973-76). Males and females grew at the same rate until 6 yr of life, the age at which they first entered the spawning run; thereafter, females grew faster and lived longer than males. Estimated numbers of cui-ui in the prespawning aggregation off the mouth of the Truckee River were 187 000 in 1982 and 103 000 in 1983. Larvae in the Truckee River fed primarily on chironomids and zooplankton; yearlings near the mouth of the Truckee River and adults in the prespawning aggregation off the mouth of the river ate mostly zooplankton. Predation by American white pelicans Pelecanus erythrorhynchos caused substantial mortality of adult cui-ui during their spawning migration in 1982 and 1983.-from Authors
Abstract – The efficiency of a Passive Integrated Transponder (PIT)-tag detection system was tested during a 23-day experiment using a permanent digital video to record the passage of fish through multiplexed antennas. Coupling video to the PIT system allowed the detection of error sources and the correction of erroneous data. The efficiency of the detection system and its variation were investigated according to fish swimming speed, direction of movement and individual fish behaviour. Influence of time and environmental conditions on detection results were also checked. The PIT tag system was 96.7% efficient in detecting fish. Upstream movements were better detected (99.8%) than downstream movements (93.7%). Moreover, results showed that efficiency rate was not stable over the experiment; it was reduced on stormy days. Several sources of errors were identified such as sub-optimal orientation of the PIT tag relative to the antenna plane, the influence of fish swimming speed, individual fish behaviour and influence of environmental conditions.
Detection of PIT-tagged juvenile salmonids migrating in the Columbia River estuary 2016. National Oceanic and Atmospheric Administration Northwest Fisheries Science Center
- M S Morris
- A J Borsky
- P J Bentley
- L N Webb
Population fragmentation and White Sucker introduction affect populations of Bluehead Suckers Flannelmouth Suckers and Roundtail Chubs in a headwater stream system Wyoming
- R I Compton
Compton, R. I. (2007). Population fragmentation and White
Sucker introduction affect populations of Bluehead Suckers,
Flannelmouth Suckers, and Roundtail Chubs in a headwater stream system, Wyoming [Unpublished master's thesis].
A review of fish sampling methods commonly used in Canadian freshwater habitats(Canadian Technical Report of Fisheries and Aquatic Sciences 2604). Fisheries and Oceans Canada
- C B Portt
- G A Coker
- D L Ming
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freshwater habitats (Canadian Technical Report of Fisheries
and Aquatic Sciences 2604). Fisheries and Oceans Canada.
Migration timing, return patterns, and tradeoffs for the early life stage of tributary spawning Flannelmouth Sucker (Catostomus latipinnis) [Doctoral dissertation
- S M Bonjour
Bonjour, S. M. (2024). Migration timing, return patterns, and tradeoffs
for the early life stage of tributary spawning Flannelmouth
Sucker (Catostomus latipinnis) [Doctoral dissertation, Kansas
State University].
Detection of PIT-tagged juvenile salmonids migrating in the Columbia River estuary
- M S Morris
- A J Borsky
- P J Bentley
- L N Webb
- B P Sandford
Morris, M. S., Borsky, A. J., Bentley, P. J., Webb, L. N., & Sandford,
B. P. (2017). Detection of PIT-tagged juvenile salmonids migrating in the Columbia River estuary, 2016. National Oceanic and
Atmospheric Administration, Northwest Fisheries Science
Center. https:// www. webap ps. nwfsc. noaa. gov/ assets/ 26/ 9090_
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Pacific States Marine Fisheries Commission. (2024). Columbia
basin PIT tag information system (PTAGIS) [Online database].
Feasibility of using implantable passive integrated transponder (PIT) tags in salmonids
- E F Prentice
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using implantable passive integrated transponder (PIT) tags in
salmonids. In N. C. Parker, A. E. Giorgi, R. C. Heidinger, D. B.
Jester, Jr., E. D. Prince, & G. A. Winans (Eds.), Fish-marking
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The spring migration of the Common White Sucker, Catostomus c. commersonnii (Lacépède)
- E C Raney
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the Common White Sucker, Catostomus c. commersonnii
(Lacépède), in Skaneateles Lake Inlet, New York. Copeia,
1942(3), 139-148. https:// doi. org/ 10. 2307/ 1438203
The spring migration of the Common White Sucker, Catostomus c. commersonnii (Lacépède), in Skaneateles Lake Inlet, New York
- Raney