bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal Density Dependence in Atlantic Salmon over Varying Spatial Scales
Authors: Bailey Michael M. , Horton Gregg E. , Letcher Benjamin H. , Kinnison Michael T. 
Published: January 2011

AbstractScale and ontogeny are important in understanding how various ecological processes structure populations. This is expected to be the case for density‐dependent effects (DDE), which influence the population dynamics of many organisms. Our goal was to evaluate stage‐specific DDE on the growth, movement, and survival of Atlantic salmonSalmo salarfrom the individual to the group level over varying spatial scales (20–160 m). We used passive integrated transponder tags and associated technology to assess individual growth, survival, and movement histories in a single stream in Maine undergoing restoration efforts via stocking of fry. We studied six life stages over 18 months for four cohorts of presmolt Atlantic salmon. Our findings show that the DDE on growth can be detected at multiple stages well past the young‐of‐the‐year stage in juvenile salmon. We saw a clear development of decreasing DDE on size and growth as cohorts aged. This trend appears to coincide with a tendency for mean fish size to become more variable in low‐density reaches. Density had limited effects on individual movements and mortality during most of juvenile rearing, with such effects largely being confined to the period from spring through fall of the age‐1 year. Shifting the focus of analysis from individuals to group means spanning larger spatial scales had pronounced effects on both the detection of DDE, the magnitude of apparent density effects, and the amount of variation in fish size explained by density.
Genetic Relationships among Populations of Florida Bass
Authors: Barthel Brandon L. , Lutz‐Carrillo Dijar J. , Norberg Kristen E. , Porak Wesley F. , Tringali Michael D. , Kassler Todd W. , Johnson William E. , Readel Anne M. , Krause Richard A. , Philipp David P. 
Published: January 2011

AbstractFlorida bass Micropterus floridanus are endemic to peninsular Florida and co‐occur with largemouth bass M. salmoides in a natural intergrade zone in the northern portions of the state. In this study, we resolved the genetic population structure among populations of largemouth bass, Florida bass, and their interspecific hybrids from 48 lakes and streams across Florida, and we updated and refined the southernmost boundary of introgression. Nuclear (allozyme and microsatellite) and mitochondrial (restriction fragment length polymorphism) markers produced somewhat different results. Microsatellite genotypes alone and the combination of all nuclear genotypes resolved genetic structure among four regional groups within Florida: (1) northwest, (2) north‐central, (3) central‐west, and (4) south, central‐east, and northeast. Allozyme genotypes alone did not resolve well‐defined groups. The distribution of mitochondrial haplotypes suggested that populations from the St. Johns River drainage should be considered their own distinct group (rather than be included in the south—central‐east—northeast Florida group). Although mitochondrial markers failed to detect introgression throughout much of the intergrade zone, nuclear markers revealed an expected decline in introgression from west to east as well as from north to south. Largemouth bass alleles, however, were detected at low frequencies in 12 populations below the southern boundary of the accepted intergrade zone, some of which are the result of stocking. There was no evidence of nonrandom mating or selection against hybrids in the distribution of nuclear genotypes; however, the rarity of largemouth bass mitochondrial haplotypes suggests either assortative mating or reduced fitness in the progeny of female largemouth bass × male Florida bass crosses.
Mercury Concentration in Two Estuarine Fish Populations across a Seasonal Salinity Gradient
Authors: Farmer Troy M. , Wright Russell A. , DeVries Dennis R. 
Published: January 2011

AbstractMercury (Hg) cycling in estuaries is complex, and little is known about the extent of Hg bioaccumulation in the ecologically diverse fishes that inhabit coastal areas. Using tissue analysis combined with otolith microchemistry, analysis of Hg concentration in common prey species, diet analysis, and age‐and‐growth analysis, we investigated seasonal and spatial trends of Hg accumulation in largemouth bass Micropterus salmoides and southern flounder Paralichthys lethostigma inhabiting the Mobile—Tensaw River Delta, Alabama. The Hg concentrations in largemouth bass (which are known to have high site fidelity) were lowest at downstream, low‐salinity estuarine areas and highest at upstream freshwater areas. Conversely, southern flounder, which have a highly variable migratory life history across salinity gradients, had Hg concentrations that were similar across the study area and lower than those for largemouth bass. Both largemouth bass and southern flounder had negative relationships between individual salinity exposure (as indicated by otolith strontium: calcium ratios) and tissue Hg concentration, although considerable variability existed. Concentrations of Hg in two common prey species, the bluegill Lepomis macrochirus and blue crab Callinectes sapidus, suggested that vertebrate prey had higher Hg concentrations than invertebrate prey. Largemouth bass upstream consumed a higher proportion of vertebrates than those downstream, so differences in prey consumption may partially explain Hg concentration differences across the salinity gradient. However, additional research is required to understand the mechanism responsible for the negative relationship between Hg concentration and salinity exposure.
Use of Statistical Bootstrapping to Calculate Confidence Intervals for the Fall Chinook Salmon Run Reconstruction to Lower Granite Dam
Authors: Steinhorst Kirk , Milks Deborah , Naughton George P. , Schuck Mark , Arnsberg Bill 
Published: January 2011

AbstractMeeting escapement and recovery goals for Pacific salmon Oncorhynchus spp. is greatly facilitated by accurate and precise estimates of run size and stock composition. Although this is particularly important for endangered Pacific salmon runs like the Snake River fall Chinook salmon O. tshawytscha evolutionarily significant unit, few studies provide estimates with confidence intervals (CIs) and standard errors (SEs). We developed a run reconstruction method for fall Chinook salmon returning to Lower Granite Dam on the Snake River. We showed that composition estimates of fish returning to large river systems can be obtained through subsampling. The methods reported here yield CIs around those estimates. We used compound bootstrap methods to derive CIs and SEs on return numbers and composition. In general, if the number of fish returning for a group was 300 or more, we were 90% confident that our return estimate represented the true number within 10%. Estimates for smaller groups were generally imprecise. The analytical technique described here provides fishery managers with information necessary for assessing escapement and recovery goals and addressing conservation and harvest allocations of adult Snake River fall Chinook salmon.
Predicting Yellow Perch Population Responses Using a Density‐Dependent Age‐Structured Matrix Projection Model: How Many Annual Data Points Are Needed?
Authors: Sable Shaye E. , Rose Kenneth A. 
Published: January 2011

AbstractDensity‐dependent matrix projection models are commonly used to simulate fish population dynamics. Much of the data needed to specify the density‐dependent relationships are annual; thus, determining how many years of data are needed to accurately specify these relationships is critical. We used 200 years of simulated output from an individual‐based model (IBM) as “data,” and we estimated density‐dependent age‐0 survival, yearling survival, and adult growth (affected maturity and fecundity) for an age‐structured matrix projection model. We divided the 200‐year baseline simulation into 34 data sequences: three 60‐year sequences, four 40‐year sequences, nine 20‐year sequences, and eighteen 10‐year sequences. We refitted the density‐dependent survival and growth functions to each reduced data sequence and compared their shapes; we then substituted the refitted functions into a matrix model specific to each data sequence. We compared key output variables for the baseline simulations and the responses to decreased egg survival among the IBM, the matrix model based on 200 years, and the 34 matrix models based on the different data sequences. The variation in shape and the number of sequences that resulted in density‐independent survival and depensatory growth increased greatly for the 20‐ and 10‐year sequences. Predicted population dynamics under baseline and predicted responses to reduced egg survival were reasonably similar to those under the IBM and matrix model based on 200 years for the 60‐ and 40‐year sequences but showed increasing divergence for the 20‐ and 10‐year sequences. We suggest that 40 or more years of annual data will allow for reasonable estimation of density‐dependent relationships in age‐structured matrix projection models. Many applications of similar models used in management are based on fewer than 40 years of data, and yet their use is intended to generate predictions with sufficient precision and accuracy to resolve differences between relatively small changes in survival rates.
Correlated Metrics Yield Multimetric Indices with Inferior Performance
Authors: van Sickle John 
Published: January 2011

AbstractMultimetric indices (MMIs) are widely used to assess the ecological health of freshwater ecosystems. An MMI is a sum of several standardized numeric variables or metrics, each representing a different attribute of a biological assemblage. Many researchers believe that highly correlated metrics should not be included in the same MMI because they convey redundant information. To seek evidence for or against this belief, I compared the performance of 1,000 MMIs created for each of eight existing data sets by randomly resampling metrics from sets of previously identified candidates. An MMI's performance was measured by its precision and its ability to detect differences between assemblages sampled in independently assessed reference and impacted streams. Across the 1,000 MMIs, precision decreased with increasing mean correlation magnitude for seven of the eight data sets. For seven of the data sets, multiple linear regressions fitted to each set of 1,000 MMIs predicted a decrease in MMI detection ability as the mean correlation magnitude between metrics increased, after adjusting for the average responsiveness of individual metrics to the difference between reference and impacted conditions. However, similar regressions showed that the size of the largest correlation between any two metrics in an MMI had little or no effect on its detection ability. Thus, minimizing the mean of metric correlations is more effective than the widespread practice of setting an upper correlation limit when optimal MMI performance is desired. Finally, an MMI had originally been built for each data set by selecting one set of individually best metrics. In 23 of 24 assessments, 5–100% of randomly selected MMIs outperformed the original MMIs. Because individually best metrics rarely yielded a best‐performing summed index, I recommend assessing multiple candidate MMIs, rather than just multiple candidate metrics, when developing a new MMI.
Effects of Hurricane Katrina on Freshwater Fish Assemblages in a Small Coastal Tributary of Lake Pontchartrain, Louisiana
Authors: van Vrancken Jeffrey , O'Connell Martin 
Published: January 2011

AbstractHurricane Katrina struck southeastern Louisiana on 29 August 2005 and thereby created an opportunity to examine the effects of a catastrophic storm on fish assemblages in a coastal stream. Bayou Lacombe is a small (46.1 river kilometers), primarily freshwater stream that drains into the northeastern portion of Lake Pontchartrain, a large oligohaline estuary located north of New Orleans. In summer 2005 (prior to the hurricane), three upstream and three downstream reaches of Bayou Lacombe were surveyed by electrofishing. These same six reaches were resurveyed in the summer of 2006 to assess the effects of the hurricane on fish assemblages. There were significant changes in fish assemblages at the downstream and upstream reaches. At the downstream reaches, centrarchid species such as bluegill Lepomis macrochirus, warmouth L. gulosus, and redspotted sunfish L. miniatus increased in abundance after the hurricane, as did inland silverside Menidia beryllina and striped mullet Mugil cephalus, both estuarine‐dependent species. At the upstream reaches, longear sunfish L. megalotis decreased after the hurricane and weed shiners Notropis texanus, goldstriped darters Etheostoma parvipinne, and warmouth were absent from posthurricane samples. Principal components and BEST analyses showed that differences in dissolved oxygen between years were related to fish assemblage changes in the upstream reaches. Salinity and temperature were associated with fish assemblage changes in the downstream reaches. Similar significant changes could occur in other coastal streams prone to increased hurricane activity.
Predation on Early Life Stages of Lake Sturgeon in the Peshtigo River, Wisconsin
Authors: Caroffino David C. , Sutton Trent M. , Elliott Robert F. , Donofrio Michael C. 
Published: January 2011

AbstractMortality of early life stages can limit recruitment of fishes, and understanding the impacts of various sources of mortality has long been a goal of fisheries management. The impacts of predation on lake sturgeon Acipenser fulvescens are not well understood. The objective of this study was to identify and quantify sources of predation that affect lake sturgeon eggs, larvae, and age‐0 juveniles in the Peshtigo River, Wisconsin, during 2006 and 2007. Egg bags were used to assess the rate of lake sturgeon egg consumption by crayfishes Orconectes spp. Potential piscine predators on eggs, larvae, or age‐0 juveniles were captured using fyke nets, gill nets, hoop nets, and electrofishing for analysis of stomach contents. Crayfish consumed lake sturgeon eggs at an average rate of 9.4 eggs/d, and the population of crayfish within the lake sturgeon spawning habitat consumed an estimated 300,000 eggs during the incubation period. Numerous fish species were observed consuming lake sturgeon eggs, and piscine predators likely consumed most eggs that settled on the surface of the substrate. Within 862 predator stomachs, only a single lake sturgeon larva was observed, and there was no evidence of predation on age‐0 juveniles. These results suggest that predation could limit recruitment at the egg stage, but it does not appear to be limiting to the larval and age‐0 juvenile life stages in the Peshtigo River.
Postcapture Survival and Future Reproductive Potential of Ovigerous Blue Crabs Callinectes sapidus Caught in the Central North Carolina Pot Fishery
Authors: Darnell M. Zachary , Darnell Kelly M. , McDowell Ruth E. , Rittschof Dan 
Published: January 2011

AbstractHarvest restrictions by sex or reproductive status are used to protect many spawning stocks. In most U.S. states, fishery regulations for blue crabs Callinectes sapidus require release of ovigerous crabs. Ovigerous crabs caught in pots become stressed by capture and physically damage the egg mass and remove eggs. We conducted a survey to assess the extent of egg mass damage in pot‐caught crabs as well as crabs caught by hand and not subjected to pot stress. Egg mass damage was more prevalent in pot‐caught crabs (>45% during all months) than in crabs caught by hand (<6% during all months). We investigated the postcapture survival, reproductive output, and larval viability of crabs with varying amounts of egg mass damage by collecting ovigerous crabs from the pot fishery and confining them in the field for the duration of their lifetimes. Over 80% of the crabs survived to release the clutch present at capture, and crabs produced up to six clutches of eggs. Of 156 clutches produced in confinement, only 1 was damaged. Crabs confined individually and fed do not experience the stress that causes egg mass damage in pots. The lipid content of early‐stage eggs (77.0 ± 1.3% [mean ± SE]), larval carapace width (269.0 ± 3.34 μm), and larval survival time without food (3.0 ± 0.11 d) were similar for all clutches and levels of egg mass damage. Clutch volume decreased by approximately 20% with each subsequent clutch, and the percentage of embryos developing normally decreased from 97 ± 0.6% for clutch 1 to 79 ± 10.8% for clutch 5. Immediate release of ovigerous crabs could be a viable management strategy, but it would have severe economic consequences for fishermen in high‐salinity areas. Area closures, combined with subsidies for crabbers during critical times, may be the most viable management strategy until crab populations recover from current diminished levels.
Verification of Otolith Identity Used by Fisheries Scientists for Aging Channel Catfish
Authors: Long James M. , Stewart David R. 
Published: January 2011

AbstractPreviously published studies of the age estimation of channel catfish Ictalurus punctatus based on otoliths have reported using the sagittae, whereas it is likely they were actually using the lapilli. This confusion may have resulted because in catfishes (ostariophyseans) the lapilli are the largest of the three otoliths, whereas in nonostariophysean fish the sagittae are the largest. Based on (1) scanning electron microscope microphotographs of channel catfish otoliths, (2) X‐ray computed tomography scans of a channel catfish head, (3) descriptions of techniques used to removed otoliths from channel catfish reported in the literature, and (4) a sample of channel catfish otoliths received from fisheries biologists from around the country, it is clear that lapilli are most often used for channel catfish aging studies, not sagittae, as has been previously reported. Fisheries scientists who obtain otoliths from channel catfish can use the information in this paper to correctly identify otolith age.
Continuous Infusion of Bupivacaine for Pain Control after Anterior Iliac Crest Bone Grafting for Alveolar Cleft Repair in Children
Authors: Meara Daniel Joseph , Livingston Nicholas Ryan , Sittitavornwong Somsak , Ness Timothy , Boyce James , Wang Deli , Daniel Waite Peter 
Published: January 2011

Objective The purpose of this study was (1) to evaluate the analgesic efficacy of continuous infusion bupivacaine, (2) to evaluate the effects of the site-specific catheter infusion on operating room time, narcotic use, ambulatory status, and length of hospitalization, (3) to monitor for adverse outcomes, and (4) to assess patient/family acceptance. Design Randomized, double-blinded, and prospective study of bupivacaine versus saline for pain control after anterior iliac crest bone grafting for alveolar cleft repair. Setting University of Alabama at Birmingham. Patients A total of 65 pediatric patients with alveolar cleft defects treated between 2006 and 2009. Interventions Anterior iliac crest bone grafting for alveolar cleft repair with assignment to either a bupivacaine or a saline infusion group. Main Outcome Measures Physical examination, pain ratings, narcotic use, ambulatory status, operating room time, and length of hospital stay. Results On the blinded physical exam, 71% in the bupivacaine infusion group and 42% in the saline infusion group were assessed as not experiencing pain at the surgical hip site. The experimental group used less narcotics compared with the control group. No significant differences were noted with operating room time, initial ambulatory status, or length of hospitalization (1.09 versus 1.12 days). Satisfaction and acceptance of the catheter treatment was universal. Conclusions These results suggest that postoperative infusion of bupivacaine may be efficacious for enhancing pain relief after bone harvest in pediatric patients and may enhance parental perceptions of postoperative care; however, this patient population is difficult to study accurately.
Association Between Respiratory Disease in Hospitalized Patients and Periodontal Disease: A Cross‐Sectional Study
Authors: Sharma Nikhil , Shamsuddin H. 
Published: January 2011

Background: Recent research indicated that periodontal infection may worsen systemic diseases, including pulmonary disease. Respiratory infections, such as pneumonia and the exacerbation of chronic obstructive pulmonary disease, involve the aspiration of bacteria from the oropharynx into the lower respiratory tract.Methods: A group of 100 cases (hospitalized patients with respiratory disease) and a group of 100 age‐, sex‐, and race‐matched outpatient controls (systemically healthy patients from the outpatient clinic, Department of Periodontics, Government Dental College and Hospital, Calicut, Kerala, India) were selected for the study. Standardized measures of oral health that were performed and compared included the gingival index (GI), plaque index (PI), and simplified oral hygiene index (OHI). Data regarding probing depths and clinical attachment levels (CALs) were recorded at four sites per tooth and compared statistically. The χ2 and Student t tests were used for statistical analyses.Results: The comparison of study‐population demographics on the basis of age, sex, education, and income showed no significant differences between groups. Patients with respiratory disease had significantly greater poor periodontal health (OHI and PI), gingival inflammation (GI), deeper pockets, and CALs compared to controls. In the case group, patients with a low income were 4.4 times more prone to periodontal disease compared to high‐income patients. Smokers had significantly higher CALs compared to non‐smokers in the control group.Conclusion: The findings of the present analysis support an association between respiratory and periodontal disease.
Effect of Enamel Matrix Derivative and Parathyroid Hormone on Bone Formation in Standardized Osseous Defects: An Experimental Study in Minipigs
Authors: Jensen Simon S. , Chen Bo , Bornstein Michael M. , Bosshardt Dieter D. , Buser Daniel 
Published: January 2011

Background: Previous experimental studies have indicated that locally administered enamel matrix derivative (EMD) and parathyroid hormone (PTH) may have a stimulatory effect on bone formation. However, it is not clear if the positive effect of EMD is related to its effect on the periodontium as a whole or directly on the bone‐forming cells. In addition, it is not known if the presentation of PTH by adding the amino acid sequence Arg‐Gly‐Asp (RGD) is essential for its osteopromotive effect. Local delivery of a bioactive substance at the right time and in the right concentration often constitutes a major challenge. Polyethylene glycol–based hydrogel (PEG) is a degradable vehicle developed for delivery of bioactive proteins. To enhance the mechanical stability of the PEG‐bioactive substance complex, an osteoconductive bone substitute material is often needed.Methods: Three standard diameter monocortical bone defects were prepared bilaterally in the mandibles of 18 Göttingen minipigs. The six defects of each animal were grafted with 1) autogenous bone chips, 2) biphasic calcium phosphate bone substitute (BCP), 3) PEG + BCP, 4) EMD + PEG + BCP, 5) PTH + PEG + BCP, or 6) PTH‐RGD + PEG + BCP. A non‐resorbable barrier membrane was used to cover the defects. Three groups of six animals healed for 2, 4, and 8 weeks, respectively.Results: There was no statistically significant effect of EMD, PTH, and PTH + RGD on bone formation compared to BCP and BCP + PEG. Particulated autografts showed the highest amount of new bone formation at all observation periods.Conclusion: The present study fails to demonstrate any stimulatory effect of EMD, PTH, or PTH + RGD in combination with an experimental PEG hydrogel and BCP on bone formation.