bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecology and Life History of Coaster Brook Trout and Potential Bottlenecks in Their Rehabilitation
Authors: Huckins Casey J. , Baker Edward A. , Fausch Kurt D. , Leonard Jill B. K. 
Published: August 2008

Abstract
Lake Superior once supported abundant lake-dwelling brook trout Salvelinus fontinalis called coasters; however, only scattered remnant populations remained by the early 20th century. Owing to their early decline, there is little information about their ecology and life history, yet such information is vital for the ecologically based rehabilitation and management of coasters. This study reviews the ecology of coaster brook trout from a life history perspective and presents quantitative data on the biology and status of the few populations that have been studied. Within the Lake Superior basin, some brook trout are stream residents while others are lacustrine or adfluvial. Although the variation in migratory behavior may be related to individual energetics, the role of evolution and the proximate factors triggering specific life histories remain uncertain. Comparisons of recent biological data from populations in the Lake Superior basin show that the northern populations have longer lengths at age and length frequency distributions skewed toward longer individuals. The degrees to which this difference is driven by variation in individual growth rates and size-selective mortality are unknown. All known populations around the Lake Superior basin appear to have a small number of individuals and are thus of conservation concern. We believe that biotic interactions such as competition with introduced salmonines (in particular coho salmon Oncorhynchus kisutch) have a strong negative influence on the individual and population performance of coasters. Coupled with high past and recent mortality from fisheries, these factors may create bottlenecks limiting the growth and rehabilitation of the remnant populations. Lake Superior coaster brook trout are persisting, albeit uncertainly, under conditions different from those in which they once thrived. Management focused on native ecosystem rehabilitation may foster the return of these fish as abundant members of Great Lakes food webs, and recent basinwide restrictions on length and catch limits are a positive step toward enhancing their rehabilitation and evolution.
Tracking Coaster Brook Trout to Their Sources: Combining Telemetry and Genetic Profiles to Determine Source Populations
Authors: D'Amelio Silvia , Mucha Jamie , Mackereth Rob , Wilson Chris C. 
Published: August 2008

Abstract
Radiotelemetry and genetic analysis are potent tools for informing fisheries management. Although they are usually applied independently, combining them can provide insights on fish origins, movement, and reproduction that could not otherwise be achieved. We applied these two techniques in two separate studies to resolve the origins and habitat use of coaster brook trout Salvelinus fontinalis in Nipigon Bay, Lake Superior. Telemetry of adult fish was used to determine the habitat use of coaster brook trout and microsatellite DNA genotyping to determine the relatedness of coasters to river-resident brook trout. Both studies indicated that coaster brook trout utilize multiple tributaries within Nipigon Bay for spawning. In terms of philopatric homing, however, the tracking data suggested that coasters show site fidelity between years, whereas the genetic data indicated substantial gene flow among tributaries. For individual tracked fish, the genetic data supported the homing hypothesis for 10 of 11 fish but also conclusively showed straying for 1 individual. The complementary insights from these combined data sets significantly clarify the behavior and habitat use of coaster brook trout and provide an example of the power of these combined methodologies for fisheries management.
Development and Evaluation of Condition Indices for the Lake Whitefish
Authors: Rennie Michael D. , Verdon Richard 
Published: August 2008

Abstract
Despite frequent use of length-based condition indices by fisheries managers and scientists to describe the overall well-being of fish, these indices are rarely evaluated to determine how well they correlate with more direct measures of physiological or ecological condition. We evaluated common condition indices (Fulton's condition factor KF, Le Cren's condition index KLC, and two methods of estimating relative weight Wr) against more direct measures of physiological condition (energy density, percent lipid content, and percent dry mass) and ecological condition (prey availability) for lake whitefish Coregonus clupeaformis in Lake Huron. We developed four standard weight (Ws) equations using the regression length percentile (RLP) method: one for the species as a whole, and three separate equations describing immature, mature male, and mature female lake whitefish from 385 populations in North America. Species RLP-Ws showed less length-related bias and more closely matched empirical quartiles of lake-specific mean weight than did maturity- or sex-specific RLP-Ws equations. Significant length-related bias was detected in EmP-Wr. No biologically significant length-related bias was detected in KLC, but this index was specific to a single population of fish. Species RLP-Wr showed no significant length-related bias, and KF was significantly size dependent. All length-based condition indices were significantly correlated with energy density, percent lipid content, and percent dry mass. The index most strongly correlated with all three measures of physiological condition was KF, likely because both the physiological measures and KF exhibited positive relationships with body size. Across two Lake Huron sites, RLP-Wr was significantly correlated with density of prey (amphipods Diporeia spp.). Of the two condition indices developed in this study, RLP-Wr was consistently more strongly correlated with physiological condition indices than was EmP-Wr.
Effects of Reservoir Operations on Hatchery Coastal Rainbow Trout in Lake Roosevelt, Washington
Authors: McLellan Holly J. , Hayes Stephen G. , Scholz Allan T. 
Published: August 2008

Abstract
It is suspected that reservoir operations limit the mitigation fishery for coastal rainbow trout Oncorhynchus mykiss irideus in Lake Roosevelt, Washington. Entrainment through Grand Coulee Dam has been suggested as the primary impact of reservoir operations. However, the causal mechanisms and effects of entrainment have been difficult to quantify. A logistic regression model was used to examine the effect of reservoir operations on the coastal rainbow trout tag return probability. Eight independent variables were studied: release location, presence–absence of a tag reward, minimum reservoir elevation (m above mean sea level (msl)) during a sample year, reservoir elevation on the fish release date, mean daily water retention time (d) 2 weeks postrelease, mean daily retention time 4 weeks postrelease, mean annual water retention time, and water year type (associated with shallow, average, or deep drawdown events). Models were selected on the basis of likelihood ratio tests, odds ratio confidence intervals (CIs), and predictive ability. Analyses indicated that the significant independent variables were release location, water year, release elevation, and mean water retention time at 4 weeks postrelease. Angler return of tagged fish was 1.86 times more likely after a shallow drawdown event than after a deep drawdown event (95% profile likelihood CI = 1.15–3.03). The effect of mean water retention time was dependent on reservoir elevation at the time of release. When release elevation was low (366–381 m above msl), increasing mean water retention time increased the probability of tag return. However, when release elevation was high (381–393 m above msl), increasing mean water retention time did not increase the probability of tag return. The logistic regression model can be used by fisheries managers to predict the impacts of hydropower operations on the coastal rainbow trout fishery in Lake Roosevelt, thereby allowing for annual adjustments to release strategies that would maximize harvest potential.
A Modified Drop Net for Sampling Fish Communities in Complex Habitats: A Description and Comparison with Other Techniques
Authors: Beesley L. S. , Gilmour J. P. 
Published: August 2008

Abstract
A modified drop net (area = 19.3 m2) was constructed to enhance the collection of fish from within complex freshwater habitats. The net was evaluated in three pools located within the Pilbara region of north Western Australia. The net's efficiency was determined by comparison with gillnetting and beach seining; accuracy of the net was investigated using the toxicant rotenone. In terms of efficiency, the modified drop net and beach seine generated similar descriptions of the fish community (relative abundance, species richness, ordination of a species–abundance matrix); panel gill nets collected a diminished subset of the community. Efficiency of the drop net remained relatively constant among pools, whereas the seine became increasingly easy to use as habitat complexity decreased. In terms of accuracy, the drop net produced estimates of total fish abundance similar to those obtained by use of rotenone and adequately depicted site-related differences in fish community structure (multivariate ordination in space). The drop net and rotenone collected similar numbers of species, but the drop net missed some species that were present in very low abundance. The drop net also underestimated the abundance of one benthic species. We recommend use of the drop net when studying ephemeral pools where habitat complexity changes through time or when precise estimates of density are required. Beach seining, which has minimal gear requirements, is recommended for situations in which only a general description of the community (species–abundance matrix) or species richness information is required. When the drop net is used, gill nets should also be used to collect large size-classes that are in low abundance.
Redd Site Microhabitat Utilization and Quantitative Models for Wild Large Brown Trout in Three Contrasting Boreal Rivers
Authors: Wollebæk Jens , Thue Roy , Heggenes Jan 
Published: August 2008

Abstract
Riverine spawning areas are important but restricted source habitats for large brown trout Salmo trutta (≥40 cm total length). In hydrophysically different reaches within three contrasting boreal rivers, redds larger than 100 cm in length were located by direct underwater observation in 1998 and 2001 (n = 157 redds; range = 10–60 redds per reach and year) and were characterized based on 29 habitat variables. The microhabitat of utilized redd sites (total redd length: mean ± SD = 206 ± 83 cm, range = 100–615 cm) was typified by a mean total water depth of 103 ± 39 cm with a wide optimum (range = 23–215 cm) and a mean water velocity of 47 ± 32 cm/s (range = 2–124 cm/s). Mean velocity measured at 5 cm above the substrate was 29 ± 20 cm/s (range = 0–82 cm/s). Mean substrate particle size was 7 ± 6 cm and demonstrated a narrower optimum (range = 2–37 cm) than the other variables. Substantial differences among the three rivers, particularly in water depth and velocity measures, largely reflected size and gradient differences and indicated some flexibility in spawning microhabitat utilization. The use of substrate particle size was less variable. Multivariable analysis indicated that water velocity (except velocity measured just above the substrate) and water depth explained most of the variation. Depths and substrates utilized were larger than previously reported, probably reflecting the in situ habitat availability in the relatively large study rivers.
Novel Tools for Analyzing Proportional Size Distribution Index Data
Authors: Brenden Travis O. , Wagner Tyler , Murphy Brian R. 
Published: August 2008

Abstract
Proportional size distribution (PSD) indices are convenient measures for numerically summarizing size structure of fish populations. Several novel methods for analyzing PSD index data were examined as a means for potentially improving inferences of size structure: generalized linear mixed modeling, calculation of location quotients, and simultaneous construction of 100(1 − α)% confidence intervals for PSD indices through multinomial modeling. The methods are demonstrated using simulated and previously published PSD index data. Generalized linear mixed modeling was used to (1) conduct a model selection analysis of PSD index data relative to a change in harvest regulation for walleyes Sander vitreus, (2) partition the variance of PSD index data among spatial, temporal, and environmental attributes, and (3) nonlinearly relate PSD data to adult density for largemouth bass Micropterus salmoides. The location quotient, which is an index for describing relative concentration of proportional data, was used to describe spatial and temporal localization of largemouth bass and walleye PSD index data. Finally, a modified method of constructing simultaneous 100(1 − α)% confidence intervals for multinomial proportions was used to produce 95% confidence intervals for traditional and incremental PSD indices based on length frequency data from muskellunge Esox masquinongy. The approaches described herein can assist fishery biologists in size structure assessments of fish populations and ultimately aid in cost-effective fisheries management.
Effect of Artificial Sunlight on the Retention of External Calcein Marks on Lake Trout
Authors: Honeyfield Dale C. , Kehler Tom , Fletcher John W. , Mohler Jerre W. 
Published: August 2008

Abstract
When choosing a fish marking technique to address fishery related questions, it is important to consider factors that affect mark retention. Calcein, a chemical marking agent, is under investigation for potential use on fish. Two laboratory trials were conducted with calcein-marked lake trout Salvelinus namaycush to determine the effect of artificial sunlight on calcein mark intensity. In trial 1, fish exposed to 18,000 lx for 7 d lost 90% or more of the calcein mark intensity (relative to the colorimetric key, mg/L) on the head, body, ventral region, and pectoral fins relative to mark intensity in fish that were maintained in darkness. In trial 2, light intensity was reduced 2.5–3.0-fold. After 7 d of light exposure, calcein mark intensity on the head was reduced by 40–45% relative to mark intensity in fish that were held in darkness; by day 14, calcein mark intensity on the head was reduced by 55–60% relative to that of dark-treated fish. No further decline was observed in light-exposed fish, and head mark intensity values did not differ among days 14, 21, and 28 for this treatment group. Of the four areas evaluated, the head and pectoral fin were more easily read using a colorimetric key than the lateral or ventral regions of the fish. The concentration of calcein spotted on filter paper to devise the colorimetric key ranged from 1 to 100 mg/L. A difference of approximately 7 mg/L in apparent calcein mark intensity means for the head region could be detected using the colorimetric key. These trials showed that calcein mark intensity on lake trout declined when fish were exposed to artificial sunlight, and the use of a colorimetric key improved the objectivity of calcein mark intensity assessment.
Genetic Identification of Hatchery-Released Red Drum in Texas Bays and Estuaries
Authors: Karlsson S. , Saillant E. , Bumguardner B. W. , Vega R. R. , Gold J. R. 
Published: August 2008

Abstract
The stock enhancement program for red drum Sciaenops ocellatus in Texas annually releases from 25 to 30 million fingerlings into Texas bays and estuaries and represents one of the largest such programs for marine fishes worldwide. We used 16 nuclear-encoded microsatellites and a 370-base-pair fragment of the mitochondrial DNA (mtDNA) D-loop to assign red drum sampled from two bays along the Texas coast to either hatchery or wild origin. A total of 30 hatchery-released fish were identified among 321 red drum belonging to three year-classes sampled from Galveston Bay, while a total of 11 hatchery-released fish were identified among 970 red drum belonging to four year-classes sampled from Aransas Bay. Allelic richness (microsatellites) was significantly lower among hatchery-released fish than among hatchery broodfish and wild fish. Similarly, the expected number of mtDNA haplotypes in hatchery-released fish (based on simulation analysis) was significantly lower than that expected in a random sample of both brood and wild fish. The contribution of brood dams, sires, and dam × sire combinations to the hatchery-released fish was nonrandom, as was the distribution of hatchery-released and wild fish with respect to sampling stations (localities) within each bay. The possibility of a Ryman–Laikre effect is discussed.
Genetic Effective Size in Populations of Hatchery‐Raised Red Drum Released for Stock Enhancement
Authors: Gold John R. , Ma Liang , Saillant Eric , Silva Paul S. , Vega R. R. 
Published: August 2008

AbstractGenetic analysis of progeny from 13 spawning events occurring over a 2‐week period in a Texas Parks and Wildlife Department (TPWD) hatchery for red drum Sciaenops ocellatus during the spring of 2002 and hatchery spawning and release records over the 2003 spawning season were used to estimate the average genetic effective size of an average spawn and an average hatchery‐released population. The purpose of this study was to assess the potential for a Ryman‐Laikre effect in the TPWD red drum stock enhancement program. Genetic analysis revealed that 16 of 27 dams (59.2%) and 16 of 18 sires (88.9%) spawned at least once. The average effective size (Ne) for a single spawn was 2.59, approximately 43% less than the maximum Ne (4.55) predicted if all possible mating (dam × sire) combinations had occurred and family size per mating combination had been equivalent. The reduction in Ne stemming from the actual number of mating combinations was approximately 34% and appeared to be due primarily to nonspawning dams; the reduction in Ne generated by the actual variation in family size was approximately 9%. Spawning and release records at the TPWD hatchery indicate that in 2003 the number of released populations per bay or estuary ranged from 7 to 27. Using the average effective size (Ne) estimate for a single spawn (2.59), the estimated average effective size of all released fish per bay or estuary (NeR) in 2003 ranged from about 28.5 to about 46.6. These values of NeR are less than the averages estimates of about 272 and 263 for the long‐term (NeI) and contemporaneous (NeV) effective size, respectively, of red drum in bays and estuaries in the northern Gulf of Mexico and indicate a reasonable potential for a Ryman‐Laikre effect. Approaches that might be employed to increase the NeR of TPWD‐released fish and decrease the probability of a Ryman‐Laikre effect are discussed.
Drill Collar with Auto Release Sleeve—A New Approach for Preventing Stuck Pipe Problems
Authors: Agarwal Navin Ashok 
Published: August 2008

Abstract
Drilling Industry is exploring various ways of reducing costs through multitude of initiatives. One of the major area where there is potential for cost reduction is downtime due to drill string failures. Losing a bottom hole assembly (BHA) is one of the most costly unplanned drilling events that can occur for an operator. Time spent on fishing for the lost assembly, the rig time wasted waiting on the mobilization of equipment and people, as well as the additional costs of whip stocks, cement, and directional tools significantly increase the cost of a well and often results in exceeding the approval for expenditure. Even though this is an old problem, with new drilling technology, especially related to the use of drill collars (larger OD), which is one of the main component of the drill string which in 60% of cases get stuck, therefore there is a need to redesign the drill collar which can be able to drill ahead even in case of stuck pipe situations. In this paper, a new solution to prevent stuck pipe problems and to retrieve stuck BHA is proposed. A drill collar is designed in such a way that during stuck situations, it can be released and we can continue drilling ahead and/or retrieve drill string easily. This is achieved by use of expandable techniques on drill collar. This proposed technique will allow us for continuous and easier drilling, thus saving rig time and ultimately economics of the entire operation at a fraction of increased cost in new drill collar.
This paper explains the causes and solution for stuck pipe problems and then presents a new designed drill collar with its design and operating concept. Finally conclude that use of this drill collar can be a viable tool for Drilling industry.
Parametric Analysis of Stress Reduction in the Cap Rock above Compacting Reservoirs
Authors: Morita Nobuo , Fuh Giin-Fa 
Published: August 2008

Abstract
It is well known that the fracture gradient is significantly reduced when drilling through depleted reservoirs, hence, mud density must be adjusted or a casing must be set before drilling through depleted reservoirs. However, the magnitude and extent of fracture gradient reduction in the cap rock above depleted reservoirs has not been well characterized. Several casing shoe tests performed in the cap rocks showed that fracture gradients in the cap rock above depleted reservoirs also significantly declined with reservoir depletion. This gives rise to the problem of determining a safe casing shoe set position without inducing lost circulation problems.
To answer the above questions, parametric analysis of stress reduction in the cap rock above compacting reservoirs were performed using a finite element structural model with fluid flow from cap rocks. It was found that two factors dominate the in-situ stress change in cap rocks. One factor is pore pressure change due to dehydration from shale to reservoir sections as reservoir pressure is depleted and the other factor is the horizontal stress reduction due to the roof effect of cap rocks. Although cap rock permeability is generally very low, shale pore fluid can drain over time into reservoir sections due to large pressure differences after reservoir pressure depletion. The loss of pore fluid causes a fracture gradient reduction in shale sections. By contrast, if the shear modulus in the shale section is high compared to the shear modulus of reservoir formation, the horizontal stress in the cap rock reduces due to the roof effect. Using the correlations of shale elastic modulus and permeability with respect to shale porosity, a practical method to estimate the extent and magnitudes of stress reduction in the cap rock above depleted reservoirs is proposed in this paper.