bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Model-Based Evaluation of Active Management of Recreational Fishing Effort
Authors: Cox Sean P. , Walters Carl J. , Post John R. 
Published: June 2004

Abstract
Recreational fisheries are increasingly faced with the dilemma of “too many people chasing too few fish.” Active management of angler effort promises relief from the pressures of overcrowding and declines in angling quality. In this paper, we develop a regional-scale model of recreational fishery dynamics to evaluate how active effort management policies might affect the cumulative value taken over many fisheries. The model incorporates linear increases in satisfaction per angler-day with increases in catch rate to represent demand, declines in catch rate with increasing effort to represent supply limitations, and angler movement among open-access fisheries to represent the presence of uncontrolled, open-access alternatives to effort-managed fisheries. The management control variables were the proportion of fisheries managed under effort control (Pm) and the proportion of open-access effort allowed on managed lakes (Pe). Unmanaged lakes remained open access. Policies that maximized total regional value favored effort management for all combinations of Pm and Pe. The total increases in value over open-access conditions were greatest under conditions of high demand and low effort movement. When effort movement and demand for improved quality were both high, a large proportion (&gt;50%) of fisheries needed to be included under effort control to offset the value losses on open-access fisheries. Because effort management offers promise for creating above-average fishing opportunities, managers should carefully consider regional-scale impacts and the potential demand for high-quality, low-effort angling opportunities.
Biological Performance Indicators for Evaluating Exploitation of Minnesota's Large-Lake Walleye Fisheries
Authors: Gangl R. Scott , Pereira Donald L. 
Published: June 2004

Abstract
We examined the potential for using biological performance indicators (BPIs) to detect the overexploitation of populations of walleye Sander vitreus (formerly Stizostedion vitreum) in Minnesota's large lakes. We developed equations to predict growth (i.e., the von Bertalanffy growth parameter and total length at age 3) and female age at 50% maturity from growing season length and female total length at 50% maturity from growth. Indices of spawning stock age diversity and the variation of population abundance were characterized by means of summary statistics. Thresholds for BPIs were determined by adding a measure of variability to the predicted and mean values. We evaluated the sensitivity of each BPI by comparing observed values with the thresholds for an overexploited population in Upper Red Lake. All six BPIs for Upper Red Lake exceeded the thresholds, demonstrating their potential use for monitoring walleye exploitation. However, the magnitude by which each threshold was exceeded differed by BPI, indicating that some may be more sensitive than others. Managers should integrate the performance of a suite of BPIs with time series analysis to identify the onset of overexploitation of large-lake walleye fisheries.
A Broad-Scale Approach to Management of Ontario's Recreational Fisheries
Authors: Lester Nigel P. , Marshall Terry R. , Armstrong Kim , Dunlop Warren I. , Ritchie Bev 
Published: June 2004

Abstract
Sustainable exploitation of Ontario's aquatic resources calls for a new management approach. This vast resource includes more than 250,000 lakes and offers angling opportunities for many popular species (e.g., walleye Sander vitreus (formerly Stizostedion vitreum), lake trout Salvelinus namaycush, brook trout S. fontinalis, northern pike Esox lucius, smallmouth bass Micropterus dolomieu, largemouth bass M. salmoides, and muskellunge E. masquinongy). In pioneer days, the “apparently inexhaustible abundance of resources” fostered an open-access policy promoting the recreational use of these resources for the benefit of the economy. After World War II, there was a rapid increase in angling effort and by the 1970s many lakes were being overexploited. Clearly, an unrestricted, open-access policy was no longer appropriate. The result has been a rapid proliferation of fishing regulations as exceptions to divisionwide regulations that were created to protect lakes where problems were detected. The growing complexity of these regulations is the result of a management approach that has focused on individual lakes. This complexity is not popular with the angling public, and evaluation of its benefits has proven difficult because a change in regulations on one lake may affect fishing effort on other lakes. We argue that a larger spatial and temporal scale of management is needed when a resource is widely dispersed across a large population of lakes. This new approach should incorporate (1) consensus on biologically achievable objectives, (2) periodic, unbiased assessment of the state of the resource, (3) periodic evaluation to decide whether current management practices are meeting objectives, and (4) adaptive management in choosing among alternative management actions. Recent progress towards establishing this management approach in Ontario is discussed.
Initial Attempts to Actively Manage Recreational Fishery Harvest in Minnesota
Authors: Radomski Paul 
Published: June 2004

Abstract
The theories and management style of commercial fisheries management have recently been applied to recreational fisheries. Several Minnesota recreational fisheries are now managed with target harvest levels based on sustainable yield predictors or quotas based on constant fishing mortality rate strategies. Creel limits and length-based regulations are being used to meet established targets or quotas. Three case histories are described. Both benefits and shortcomings have resulted from applying commercial fisheries management programs directly to recreational fisheries. However, recreational fisheries managers may not be controlling total fish harvest. To effectively manage recreational fisheries for “safe satisfaction returns,” fisheries managers may need to adopt conservative, robust harvest regulations, kill quotas, or aggressive regulations on how people fish. The distribution and mix of those options can be determined by good social science, but the efficacy of managing for safe satisfaction returns will depend on good fisheries data (biological and sociological) and great social skill. The lessons learned from the three case histories reviewed could be used to improve recreational fisheries management.
Active Management of Walleye Fisheries in Alberta: Dilemmas of Managing Recovering Fisheries
Authors: Sullivan Michael G. 
Published: June 2004

Abstract
Managers of the recreational fishery for walleyes Sander vitreus (formerly Stizostedion vitreum) in Alberta, Canada, face an unusual combination of very low productivity (related to the northern climate) and high fishing pressure. Passive management of the large recreational fishery and active management of the smaller commercial fishery failed to prevent declines and collapses of walleye stocks. During the 1990s, extensive consultations with the public resulted in the development of an active recreational fishery management system using set points to classify stocks. Catch and release and large, highly restrictive length limits were used to regulate the harvest. These restrictions on the recreational harvest resulted in a dramatic increase in the catch rates of growth-overfished stocks. Paradoxically, this recovery has created dilemmas and controversies in both the recreational and commercial fisheries. Anglers are now dissatisfied with the low harvest rates and absence of large fish attending the high catch rates of small fish. The total allowable catch, however, is being taken by hooking mortality and illegal harvest of undersize walleyes in the recreational harvest. In commercial gill-net fisheries for lake whitefish Coregonus clupeaformis, increasing bycatch of walleyes restricts the harvest of lake whitefish and has created uneconomical fisheries. Resolving these dilemmas will require dramatic changes to fisheries management techniques in Alberta.
Characteristics of Deep Pools Used by Adult Summer Steelhead in Steamboat Creek, Oregon
Authors: Baigún Claudio R. M. 
Published: June 2004

Abstract
This study examined environmental factors that affect deep-pool use by adult summer steelhead Oncorhynchus mykiss in Steamboat Creek, Umpqua River basin, Oregon. Deep pools (&gt;0.8 m depth) represented only 4% of the available habitat area, and 39% of these pools had a mean bottom temperature not exceeding 19°C. Fish and habitat surveys were conducted in August and the first half of September of 1991 and 1992. The presence of adult summer steelhead in pools was determined by snorkeling and visual inspection, and the physical, chemical, and geomorphic characteristics were measured. Differences in deep-pool use by summer steelhead and their relationship to environmental characteristics were assessed by descriptive canonical discriminant analysis. The canonical function explained 69% of the variation in deep-pool use and defined a gradient from long, shaded deep pools with a coarse substrate and colder bottoms (which fish used) to shorter, shallower, sunny pools with fine particulate substrate, homogeneous water temperatures, and warmer bottoms (which fish did not use). This indicates that pool occupancy by adult summer steelhead in Steamboat Creek is a result of the interaction of geomorphic characteristics, cover, and thermal conditions. Future research should be directed toward understanding how biotic interactions within pools, deep-pool patchiness, and overall riverscape conditions influence summer steelhead distribution and pool use.
Evidence of Handling Mortality of Adult Chum Salmon Caused by Fish Wheel Capture in the Yukon River, Alaska
Authors: Underwood Tevis J. , Bromaghin Jeffrey F. , Klosiewski Steve P. 
Published: June 2004

Abstract
From 1996 to 1998, marked fish from a mark–recapture experiment were used to examine potential effects of fish wheel capture, handling, and tagging on adult chum salmon Oncorhynchus keta in the Yukon River, Alaska. Four fish wheels equipped with live holding boxes were used to capture fish, two at the marking site and two at the recapture site. During the 3 years of the study we annually marked 8,513–18,632 fish with individually numbered spaghetti tags; annual tag returns external to the mark–recapture experiment (not by project fish wheels) ranged from 594 to 1,007. Individual salmon were captured from one to four times in the four project fish wheels used in the mark–recapture experiment. Tag returns, interviews, carcass surveys, and data from other management projects indicated that the proportion of fish with marks decreased as distance from the marking site increased. Nine possible explanations for these observations were considered, but fish mortality associated with capture and handling appeared to be the most likely cause. Tags returned outside of the mark–recapture experiment were used to investigate the relationship between the capture history within the experiment and upriver recapture. Recapture probabilities declined significantly as the number of times a fish was captured increased. Our results raise concern over the relatively common use of fish wheels for gathering in-season management data and for other research purposes. We recommend more definitive investigation of these phenomena, a review of fish wheel construction and operation to minimize potential effects to salmon populations, reexamination of the efficacy of live box capture as a management tool, and development of alternatives to current live box capture practices.
A Comparison of Migration Rates of Radio- and PIT-Tagged Adult Snake River Chinook Salmon through the Columbia River Hydropower System
Authors: Matter Alicia L. , Sandford Benjamin P. 
Published: June 2004

Abstract
Documentation of adult salmonid migration behavior in the Columbia River drainage is critically needed to assess the effects of dams on travel time and passage. In 2000, we compared the upstream travel times of passive integrated transponder (PIT)-tagged and radio-tagged adult chinook salmon Oncorhynchus tshawytscha from Bonneville Dam on the lower Columbia River to Lower Granite Dam on the Snake River. We found no evidence that radio tagging negatively affected chinook salmon behavior. In fact, their median travel time (14.1 d, range = 7.8-44.4 d, N = 113) was actually faster (statistically significant at P = 0.005) than that for PIT-tagged fish (median = 15.9 d, range = 8.9-67.4 d, N = 164) after accounting for temporal effects (i.e., Bonneville Dam passage date). However, we concluded this difference was not biologically significant and was probably related to differences in study design or data complications. This study indicated that radio transmitters weighing less than 2% of chinook salmon body weight and the handling associated with implanting those tags did not negatively affect temporal rates of fish movement from dam to dam.
Scale Pattern Analysis of Selected Scale Characteristics and the First Annulus for Distinguishing Wild and Hatchery Steelhead in the Hood River, Oregon
Authors: Tattam Ian A. , Whitesel Timothy A. , Pan Yangdong 
Published: June 2004

Abstract
Resource managers need an accurate, reliable means of distinguishing hatchery-origin steelhead Oncorhynchus mykiss from wild stocks. We evaluated the effectiveness of scale pattern analysis at distinguishing between wild and hatchery (progeny of wild broodstock) winter steelhead collected at Powerdale Dam in the Hood River basin. The characteristics within the freshwater zone of hatchery (n = 126) and wild (n = 428) scales were quantified to determine whether the improved growth experienced in the hatchery environment would facilitate discrimination between hatchery and wild steelhead. Scale measurements that depended on the location of the first freshwater annulus were the most effective at distinguishing between hatchery and wild steelhead. Linear discriminant function analysis of key scale characteristics correctly classified a maximum of 73.9% of a blind-sampled population (n = 92) of known-stock winter steelhead. On average, estimates of the proportion of wild fish in known-origin test groups differed by 11.7% from the actual proportion of wild fish and had poor precision (mean coefficient of variation (100 · SD/mean), 259.9%). Our results suggest that scale pattern analysis could be an effective tool, but until ponding checks and true annuli can be accurately differentiated managers should not depend on scale patterns to distinguish between wild and hatchery steelhead similar to those from the Hood River.
Influences of Temperature and Environmental Variables on the Distribution of Bull Trout within Streams at the Southern Margin of Its Range
Authors: Dunham Jason , Rieman Bruce , Chandler Gwynne 
Published: June 2004

Abstract
The bull trout Salvelinus confluentus is believed to be among the most thermally sensitive species in coldwater habitats in western North America. We conducted a comprehensive field assessment of thermal habitat associations throughout the southern margin of the species' range. We developed models of thermal habitat associations using two data sets representing a geographically diverse range of sites and sampling methods. In both data sets, maximum temperature was strongly associated with the distribution of bull trout. In spite of the potential biases in these data sets, model predictions were similar. In both cases, the probability of the occurrence of bull trout exceeded 50% when the maximum daily temperature was less than 14-16°C, a result that is consistent with recent laboratory-based thermal tolerances. In one data set, we modeled the association between the distribution of bull trout and environmental variables, including temperature, instream cover, channel form, substrate, and the abundance of native and nonnative salmonid fishes. Only temperature was strongly associated with the distribution of bull trout. Our results and related studies of landscape habitat associations suggest that conservation efforts for bull trout would benefit from a focus on maintaining and restoring large and interconnected coldwater habitats.
Assessment of the Counting Accuracy of the Vaki Infrared Counter on Chum Salmon
Authors: Shardlow T. F. , Hyatt K. D. 
Published: June 2004

Abstract
Vaki, Ltd., of Iceland has designed a system for counting the in-river migration of salmonids via infrared sensors. The Vaki fish counter is used in Iceland, the United Kingdom, and Europe but is much less used in North America partly because of the system's unknown ability to count large populations accurately. In tests in the Big Qualicum River of Vancouver Island, British Columbia, we found the accuracy of the counter to be inversely correlated with migration rate of chum salmon Oncorhynchus keta. The fish counter was very accurate (&gt;95%) for migration rates less than 500 fish/h but accuracy declined to 76% at a rates exceeding 1,500 fish/h. The principal cause for the decline in accuracy was the inability of the infrared sensors to count the passage of more than one fish simultaneously.
Influence of River Conditions on Survival and Travel Time of Snake River Subyearling Fall Chinook Salmon
Authors: Smith Steven G. , Muir William D. , Hockersmith Eric E. , Zabel Richard W. , Graves Ritchie J. , Ross Chris V. , Connor William P. , Arnsberg Billy D. 
Published: June 2004

Abstract
From 1995 to 2000, subyearling fall chinook salmon Oncorhynchus tshawytscha reared at Lyons Ferry Hatchery were PIT-tagged at the hatchery, trucked upstream, acclimated, and released into free-flowing sections of the Snake River weekly from early June to mid-July. We estimated survival probabilities and travel time through the lower Snake River and detection probabilities at dams for each weekly release group. The average median time between release and arrival at Lower Granite Dam was 43.5 d. For each group, we split this time into two nearly equal (on average) periods: one when most fish in the group were rearing and one when most fish had apparently begun active seaward migration. The estimated survival for hatchery fish from release to the tailrace of Lower Granite Dam decreased with release date each year. The estimated survival through this reach was significantly correlated with three environmental variables: survival decreased as discharge (“flow”) decreased, as water transparency increased, and as water temperature increased. Because the environmental variables were highly correlated among themselves, we were unable to determine whether any factors were more important than the others. All three factors have plausible biological consequences for rearing and actively migrating fish, and survival is probably influenced by all of them and possibly by interactions among them as well. Summer flow augmentation will increase discharge and decrease water temperature (provided the additional water is not too warm) and probably increase the speed of seaward migration of smolts, all of which are beneficial to the recovery of threatened Snake River fall chinook salmon.
Evaluating Recent Innovations in Bait Fishing Tackle and Technique for Catch and Release of Rainbow Trout
Authors: Jenkins Thomas M. 
Published: June 2004

Abstract
Since some recent innovations in bait tackle and technique appear to reduce or eliminate the immediate mortality of released rainbow trout Oncorhynchus mykiss, this study tested the hypothesis that they are as effective for hook and release as artificial flies. Hatchery rainbow trout from aquaculture pens were caught using circle hooks, the new Shelton self-releasing hooks, standard J and treble hooks, and artificial flies (all barbless), noting hook location, 26-d weight change, and survival. Except for those caught on artificial flies, the fish were encouraged to swallow the hook, which was baited with a pasty attractant popular in eastern California (Berkley Powerbait). Most Shelton, J, and treble hooks (78, 65, and 63%, respectively) lodged in the esophagus, whereas all artificial flies and at least 70% of the circle hooks lodged in the mouth or jaw. Flies, circle hooks, and Shelton hooks were extracted from the fish, and the lines were cut on the J and treble hooks. The fish caught with flies, J hooks (line cut), and netted controls all survived the observation period. The survival of fish caught on the Shelton, cut-line treble, and extracted circle hooks was 98, 98, and 91%, respectively. The mean growth of cut-line J-hook fish was somewhat below that in other groups. The results from a second experiment showed that the Shelton hooks can be effective (0.7% mortality in 60 d) with no fish handling, and a third study suggested that much larger fish suffer only slightly greater mortality from flies, cut-line circle hooks, and Shelton hooks (0.7, 3.3, and 4.7%, respectively). Since significant differences in the long-term mortality and growth effects of some bait techniques and artificial flies could not be demonstrated, the use of the former should be recommended to anglers and perhaps reconsidered in waters where bait angling is not currently allowed.
Social Aspects of Muskellunge Management in Wisconsin
Authors: Margenau Terry L. , Petchenik Jordan B. 
Published: June 2004

Abstract
Public opinion plays an important part in the successful development of a fisheries management plan. We used a mail questionnaire to survey 1,400 anglers who fish for muskellunge Esox masquinongy in Wisconsin. The survey included defined groups of muskellunge anglers separated by muskellunge club affiliation and geographic location and general anglers selected from a random sample of angler license sales. The survey questions were designed to obtain opinions regarding muskellunge fishery and trophy management in Wisconsin in terms of angling behaviors, regulation options, and perceived problems. All anglers generally preferred fishing with artificial lures and practiced the voluntary live release of legal-length muskellunge. Muskellunge anglers considered a trophy muskellunge to be at least 40 in long, with a preferred length of 50 in or longer. Muskellunge anglers also supported regulations for muskellunge that were based on a water's biological potential, along with increased restrictions on regulations such as minimum length limits. General anglers were less supportive of restrictive regulations and were more likely to keep a legal muskellunge for consumptive purposes. The greatest perceived problems with muskellunge fishing were Native American spearing and conflicts with users of speedboats and jet skis. Opinion surveys such as this can help in formulating management strategies that satisfy most anglers within biological limits.