bluuebunny/crossref_metadata_2025 huggingface dataset:
Undegradable dietary protein in alpaca diets affects fibre diameter and time spent urinating
Authors: Lund K. E. , Milton J. T. B. , Maloney S. K. , Glover K. M. M. , Vaughan J. L. , Blache D.
Published: July 2012

There is evidence that alpacas derive most of their glucose for energy from the deamination of amino acids. Consequently, they may have an insufficient supply of amino acids to meet their requirements for fibre growth. To optimise fibre production, it may be necessary to supply alpacas with supplemental protein to meet their requirement for extra amino acids. In this study, we examined if the proportion of rumen-degradable dietary protein (RDP) to undegradable dietary protein (UDP) from canola meal influenced the fibre growth of alpacas. We hypothesised that alpacas fed at maintenance a diet containing canola meal protein high in UDP would produce more fibre and spend less time urinating than peers fed a similar amount of canola meal protein with a low proportion of UDP. Four groups of eight alpacas were fed diets with the following ratios of UDP : RDP: 0 : 100, 30 : 70, 60 : 40 or 100 : 0 from canola meal protein. The fibre growth of the animals was measured over 2 months and the behaviour of the animals in the two extreme groups (0 and 100% UDP) was measured over 5 days. The alpacas fed the 0% UDP diet produced fibre of finer diameter than the alpacas fed diets containing higher levels of UDP (P = 0.039) and the 0% UDP group also spent more time urinating (P = 0.027). This result suggests that alpacas may have a limited ability to recycle nitrogen to the fermentative chambers of their stomach when fed a diet low in UDP. Consequently, microbial protein synthesis in the fermentative chambers may have limited the supply of amino acids available to the alpacas.
Effect of 1,3,5,8-tetrahydroxyxanthone on carcass characteristics and meat quality traits in pigs
Authors: Xiao Hong-Bo , Jun Fang , Sun Zhi-Liang
Published: July 2012

Angiopoietin-like protein 3 (Angptl3) may promote adipose formation. The present study investigated the beneficial effect of 1,3,5,8-tetrahydroxyxanthone (Xan), a naturally occurring polyphenol agent, on carcass characteristics and meat quality in pigs and the mechanisms involved. Forty-eight Duroc × Landrace × Yorkshire pigs (65.3 ± 7.8 kg) were randomly divided into four groups: control group, untreated high lipid diet (HLD) group and two groups of HLD with Xan (1 or 3%). Forty-two days later, Xan (1 or 3%) treatment significantly increased percentage lean, loin eye area, colour, expression and activity of adipose tissue lipoprotein lipase activity and decreased percentage fat, backfat thickness, total cholesterol concentration, triglyceride concentration, and Angptl3 mRNA expression. The present results suggest that the beneficial effect of Xan on carcass characteristics and meat quality may be related to decreased expression of Angptl3 in pig.
A mutation in the chicken lipoprotein lipase gene is associated with adipose traits
Authors: Han Wenpeng , Ze Xiaolei , Xiong Dan , Li Jingyi , Li Junying , Zhao Chunjiang
Published: July 2012

Lipoprotein lipase (LPL), which consists of an N-terminal catalytic domain and a C-terminal binding domain, is a crucial enzyme in the metabolism of lipids. Binding in the presence of cofactors or receptors on the cell surface, LPL catalyses the hydrolysis of triglycerides in the lipoprotein. To investigate the correlation between the LPL gene and adipose traits, single nucleotide polymorphisms in the exons of LPL in two breeds, Tibet chicken and E-white recessive rock (EWRR) chicken were investigated. The two breeds have significantly different levels of obesity. They were screened with single-strand conformation polymorphism and its effect on adipose traits was analysed. The results showed that a missense mutation G–C in the seventh exon of LPL changed alanine 377 to proline at the C-terminal binding domain, which is involved in the binding activity of LPL. Association analysis showed that the intermuscular adipose tissue width of Tibet chicken with the CC genotype decreased significantly (P < 0.05), while abdominal adipose weight of EWRR chicken of the CC genotype increased markedly (P < 0.05) compared with the individuals of other genotypes. Although the mutation correlated with very low-density lipoprotein in Tibet chicken, it did not demonstrate significant association with the lipoprotein in EWRR chicken (P > 0.05). Neither the glucose or triglyceride levels of chickens with different genotypes differed significantly (P > 0.05). As very low-density lipoprotein content and fat mass were upregulated by LPL, we concluded that the A377P mutation may enhance the binding activity of the LPL C-terminal domain to very low-density lipoprotein receptors, which promoted triglyceride metabolism in very low-density lipoprotein.
Evaluating seasonal risk and the potential for windspeed reductions to reduce chill index at six locations using GrassGro
Authors: Broster J. C. , Robertson S. M. , Dehaan R. L. , King B. J. , Friend M. A.
Published: July 2012

The death of newborn lambs is a major factor influencing the reproductive efficiency of sheep enterprises. Adverse weather conditions (wind, precipitation and low temperature), either alone or in combination (chill index), can increase the level of newborn lamb mortality to over 50% of births for short periods through increased heat loss. The provision of shelter to reduce wind speed and therefore chill index (heat loss) has been shown to reduce lamb mortality; however, the reduction in mortality has been variable. This study used the decision support tool GrassGro to determine the likelihood of adverse weather conditions occurring at six locations across south-eastern Australia which varied widely in climate. Data were extracted for 24 consecutive weekly periods between May and October over 39 years (1968–2006) to evaluate daily precipitation, temperature, radiation, wind speed and chill index. The minimum, maximum and median values were calculated for all climatic factors for every week and year combination. The effectiveness of reducing wind speed to reduce the occurrence of a high chill index was also evaluated. The severity of these weather events varied between locations with the median weekly chill index rarely exceeding 1000 kJ/m2.h at Temora, but at both Hamilton and Orange this occurred in over two-thirds of the weeks examined. Reducing wind speed by 50% reduced the number of weeks with a median chill index exceeding 1000 kJ/m2.h in twice as many weeks at Hamilton and Yass compared with Orange. These results show that the potential for shelter to reduce chill index will vary according to the location and time of year. In locations where another climatic factor, such as low temperature or rainfall, has a greater influence on the chill index, shelter which only reduces wind speed, will be less effective than at locations where wind speed is the driver of chill index.
Increasing platform speed and the percentage of cows completing a second rotation improves throughput in rotary dairies
Authors: Edwards J. P. , Lopez-Villalobos N. , Jago J. G.
Published: July 2012

This study sought to improve milking efficiency in rotary dairies by modelling the effect of increasing platform speed on the percentage of cows requiring multiple rotations to complete milking, i.e. ‘go-around’ cows, and cow throughput. Milking data, including 376 429 milking event records from 44 530 cows, were collected from 62 commercial farms with rotary dairies in New Zealand. Average rotation time, a function of platform speed and rotary size, was 10.0 ± 1.5 min, mean milking duration 383 ± 129 s, and mean milk yield 11.9 ± 3.8 kg per milking session. Milking duration data were normalised using a log10 transformation. An estimate of the percentage of ‘go-around’ cows and potential throughput over a range of platform speeds were made using the NORMDIST function of Microsoft Excel 2010. Results indicate that throughput continues to increase with increasing platform speed, despite a greater number of ‘go-around’ cows. If a potential shadow effect (whereby a ‘go-around’ cow may cause the following bail to be unoccupied) is considered, the optimum percentage of ‘go-around’ cows was ~20%. Accordingly, a change of operating practices in many rotary dairies is justified as the current target of 10% ‘go-around’ cows may limit throughput. In order to achieve greater cow throughput, platform speed should rather be set based on the capability of the operator attaching clusters. The difference between the current average rotation time and milking duration indicates that many dairies can increase platform speed and thus throughput. Furthermore, many work routines can be accelerated so faster platform speeds can be achieved without increasing labour requirements. The increased throughput potential of larger dairies is only realised when operated at fast platform speeds.
Gold/Palladium Bimetallic Alloy Nanoclusters Stabilized by Chitosan as Highly Efficient and Selective Catalysts for Homocoupling of Arylboronic Acid
Authors: Sophiphun Onsulang , Wittayakun Jatuporn , Dhital Raghu Nath , Haesuwannakij Setsiri , Murugadoss Arumugam , Sakurai Hidehiro
Published: July 2012

Aerobic oxidative homocoupling of arylboronic acid under acidic aqueous conditions (pH 4.0) using bimetallic Au/Pd alloy nanoclusters stabilized by chitosan has been investigated. It was found that a Au0.81Pd0.19 catalyst (3.1 ± 0.8 nm) exhibited superior catalytic activities as compared to monometallic Au (2.3 ± 0.3 nm) and other series of bimetallic nanoclusters, giving the corresponding biaryls in nearly quantitative yield.
A Perspective on Perspectives: Methods to Reduce Variation in Shape Analysis of Digital Images
Authors: Muir A. M. , Vecsei P. , Krueger C. C.
Published: July 2012

We present digital imaging methods for geometric morphometric analysis of shape, and we describe issues associated with improper image acquisition by using lake troutSalvelinus namaycushas an example. The choice of imaging equipment, the configuration of that equipment, and the orientation of the specimens with respect to the camera lens can lead to inaccurate imaging and ultimately to error in landmark placement during morphometric analysis. Lake trout that were imaged at 15‐mm focal length and 0.5‐m focal distance (treatment 1) were distorted in comparison with fish that were imaged at 50‐mm focal length and 2‐m focal distance (treatment 2). Deformation grids showed dramatic variation in the horizontal plane along the length of the fish, especially midbody, suggesting that barrel distortion was occurring at the 15‐mm focal length. Partial warp scores resulting from geometric analysis of body shape differed for all fish on all 18 warps as a result of the different focal length and distance treatments for image capture. To minimize perspective (orientation) and distortion (equipment) errors, we recommend using a digital single‐lens reflex camera (>5 megapixels) with a lens that has a focal length exceeding 35 mm, a horizontal tripod to position the lens directly over the specimen, a mesh cradle to create a planar imaging surface, and dissection pins to display the fish in a standard orientation. The method presented herein will aid in reducing measurement error associated with landmark homology and will promote comparability of geometric shape data among studies.
Work–family interface from a life and career stage perspective: The role of demands and resources
Authors: Demerouti Evangelia , Peeters Maria C. W. , van der Heijden Beatrice I. J. M.
Published: July 2012

Work–family conflict and enrichment are experiences that occur daily and have substantial consequences for employees, their families, and the organizations that employ them. The aim of the current review is to make a link between life and career stage, work and family conditions, and the work–family interface. The basic proposition is that life stages partly determine career development, and consequently the specific working conditions (job demands and job resources) and family conditions (family demands and family resources) that individuals are exposed to. As a result, the specific demands and resources in the work and family domains determine to what extent individuals experience that work and family are conflicting or enriching life domains. In this review we suggest that individuals in early adulthood will experience high inter‐role conflict and low facilitation due to high demands and low resources in both life domains, while individuals in late adulthood will experience the opposite pattern; that is, low conflict and high facilitation due to low demands and high resources in both domains. Individuals in middle adulthood will experience high work–family conflict but also high family–work facilitation due to the presence of high job demands and resources in both life domains. Integrating life and career stage perspectives and the experience of work–family interface is of notable practical utility because it provides a mechanism to make more informed decisions about the relative need for and corresponding benefits of work–family programs.
Effects of a health‐promotion programme in sixth grade German students' physical education
Authors: Höner Oliver , Demetriou Yolanda
Published: July 2012

The aim of the study was to assess the effects of a school‐based health‐promotion programme in physical education (PE) on sixth grade German students' motor performance, BMI and health‐related quality of life (HRQOL). In a quasi‐experimental design, 516 students (54.7% girls) were assigned to either the intervention group (IG) that received eight 90‐minute health‐promoting PE lessons or the control group (CG), which continued regular PE. Outcome variables were assessed at baseline, immediately after, and three months after the intervention in order to explore significant short‐ and middle‐term intervention effects, respectively. The intervention programme had gender specific effects in motor performance with girls reaching higher levels. Positive short‐term intervention effects were found in girls' sideways jumps (η 2=0.17) and negative effects were measured in the 20‐meter sprints (η 2=0.05) and the standing long jump (η 2=0.04). Positive middle‐term effects were measured on the motor performance score (η 2=0.05), sideways jumps (η 2=0.08) and stand‐and‐reach flexibility (η 2=0.04). In boys, short‐term positive intervention effects were found in 20‐meter sprints (η 2=0.04). In the middle‐term, differences in favour of the CG were found in press‐ups (η 2=0.03) and sideways jumps (η 2=0.06). Concerning BMI the IG had significantly lower levels compared to the CG in the short‐term (η 2=0.04) and in the middle‐term (η 2=0.03), respectively. There were no significant differences between the groups in HRQOL. In conclusion, the results demonstrate the feasibility of promoting health related parameters in PE, but also raise the question whether gender‐specific tailored interventions would result in higher intervention effects concerning motor performance especially in boys.
More consistent, yet less sensitive: Interval timing in autism spectrum disorders
Authors: Falter Christine M. , Noreika Valdas , Wearden John H. , Bailey Anthony J.
Published: July 2012

Even though phenomenological observations and anecdotal reports suggest atypical time processing in individuals with an autism spectrum disorder (ASD), very few psychophysical studies have investigated interval timing, and the obtained results are contradictory. The present study aimed to clarify which timing processes function atypically in ASD and whether they are related to the ASD diagnostic profile. Visual, auditory, and cross-modal interval timing was assessed in 18 individuals with ASD using a repeated standards version of the temporal generalization task. The use of two different standard durations (600 and 1,000 ms) allowed for an assessment of the scalar property of interval timing in ASD, a fundamental characteristic of interval timing. The ASD group showed clearer adherence to the scalar property of interval timing than the control group. In addition, both groups showed the normal effect that auditory stimuli had longer subjective durations than visual ones. Yet, signal detection analysis showed that the sensitivity of temporal discrimination was reduced in the ASD group across modalities, in particular for auditory standards. Moreover, response criteria in the ASD group were related to symptom strength in the communication domain. The findings suggest that temporal intervals are fundamentally processed in the same way in ASD and TD, but with reduced sensitivity for temporal interval differences in ASD. Individuals with ASD may show a more conservative response strategy due to generally decreased sensitivity for the perception of time intervals.
The role of numerosity in processing nonsymbolic proportions
Authors: Fabbri Sara , Caviola Sara , Tang Joey , Zorzi Marco , Butterworth Brian
Published: July 2012

The difficulty in processing fractions seems to be related to the interference between the whole-number value of the numerator and the denominator and the real value of the fraction. Here we assess whether the reported problems with symbolic fractions extend to the nonsymbolic domain, by presenting fractions as arrays of black and white dots representing the two operands. Participants were asked to compare a target array with a reference array in two separate tasks using the same stimuli: a numerosity task comparing just the number of white dots in the two arrays; and a proportion task comparing the proportion of black and white dots. The proportion task yielded lower accuracy and slower response, confirming that even with nonsymbolic stimuli accessing proportional information is relatively difficult. However, using a congruity manipulation in which the greater numerosity of white dots could co-occur with a lower proportion of them, and vice versa, it was found that both task-irrelevant dimensions would interfere with the task-relevant dimension suggesting that both numerosity and proportion information was automatically accessed. The results indicate that the magnitude of fractions can be automatically and holistically processed in the nonsymbolic domain.
Use of a Novel Cage System to Measure Postrecompression Survival of Northeast Pacific Rockfish
Authors: Hannah Robert W. , Rankin Polly S. , Blume Matthew T. O.
Published: July 2012

We used a caging system designed to minimize the adverse effects of caging fish in marine waters to evaluate the discard mortality of seven species of rockfish Sebastes with barotrauma. Altogether, 288 rockfish were captured, scored for barotrauma, evaluated behaviorally at the surface, and caged individually on the seafloor for 48 h to determine survival. With the exception of three blue rockfish S. mystinus, the condition of surviving fish after cage confinement from 41 to 71 h was excellent. At capture depths up to 54 m, survival was 100% for yelloweye rockfish S. ruberrimus (n = 25) and copper rockfish S. caurinus (n = 10) and 78% for blue rockfish (n = 36). At capture depths up to 64 m, survival was 100% for canary rockfish S. pinniger (n = 41) and quillback rockfish S. maliger (n = 28) and 90% for black rockfish S. melanops (n = 144). Black rockfish survival was negatively associated with capture depth (m) and the surface–bottom temperature differential (°C). Blue rockfish survival was negatively associated with capture depth. Barotrauma signs and surface behavior scores were not good indicators of survival potential across species but were useful within species. In black and blue rockfish, severe barotrauma was negatively associated with survival, while higher scores on reflex behaviors at the surface were positively associated with survival. The high survival rates and excellent condition of some species in this study suggest that requiring hook-and-line fishers to use recompression devices to help discarded rockfish return to depth may increase survival for some species.

Received April 14, 2011; accepted July 30, 2011
Microsatellite Mixed-Stock Identification of Coho Salmon in British Columbia
Authors: Beacham Terry D. , Candy John R. , Wallace Colin , Wetklo Michael , Deng Langtuo , MacConnachie Cathy
Published: July 2012

Variation at 17 microsatellite loci was analyzed for about 50,000 coho salmon Oncorhynchus kisutch sampled from 274 locations ranging from Russia to California (but largely from British Columbia), and the variation was applied to estimate stock composition in mixed-stock fishery samples. High resolution of mixed-stock samples was possible; accurate estimates of stock composition were available for coho salmon originating from 39 regions (Russia, 1 region; Yukon River, 1; southeast Alaska, 1; British Columbia, 28; Washington, 5; Columbia River, 1; Oregon, 1; California, 1). The power of a locus in providing accurate estimates of stock composition of simulated single-population mixtures was related to the number of alleles observed at the locus. Approximately 800 alleles were observed across the 17 microsatellites. Analysis of known-origin samples indicated that accurate regional estimates of stock composition were obtained; estimates from 37 of 39 regions had accuracy greater than 90%. Estimated stock compositions of five mixed-fishery samples collected in British Columbia and the San Juan Islands (Washington) reflected the presence and timing of migration of the local populations. Microsatellites provided accurate estimates of stock composition from many locations in the British Columbia distribution of coho salmon.

Received July 5, 2011; accepted October 22, 2011
Using Ecopath with Ecosim to Explore Nekton Community Response to Freshwater Diversion into a Louisiana Estuary
Authors: Mutsert Kim , Cowan James H. , Walters Carl J.
Published: July 2012

Current methods to restore Louisiana's estuaries include the reintroduction of Mississippi River water through freshwater diversions to wetlands that are hydrologically isolated from the main channel. The reduced salinities associated with freshwater input are likely affecting estuarine nekton, but these effects are poorly described. Ecopath with Ecosim was used to simulate the effects of salinity changes caused by the Caernarvon freshwater diversion on species biomass distributions of estuarine nekton. A base model was first created in Ecopath from 5 years of monitoring data collected prior to the opening of the diversion (1986–1990). The effects of freshwater discharge on food web dynamics and community composition were simulated using a novel application of Ecosim that allows the input of salinity as a forcing function coupled with user-specified salinity tolerance ranges for each biomass pool. The salinity function in Ecosim not only reveals the direct effects of salinity (i.e., increases in species biomass at their optimum salinity and decreases outside the optimal range) but also the indirect effects resulting from trophic interactions. Through multivariate analyses we determined that the simulated species biomass distributions in the estuary change significantly with distance from the diversion. However, the simulations do not show a significant difference estuarywide between the modeled distributions (with pooling of the data from different distances) before and after the opening of the diversion. This indicates a redistribution of species in the estuary rather than the replacement of species within the estuarine nekton community. The salinity function is a useful addition to the Ecopath with Ecosim software for estuarine ecologists and fisheries managers.

Received January 31, 2011; Acceptdate November 30, 2011
Assessment of Genetic Diversity for American Shad in the Santee–Cooper River Basin of South Carolina prior to Hatchery Augmentation
Authors: Moyer G. R. , Williams A. S.
Published: July 2012

American shad Alosa sapidissima once supported large commercial fisheries along the Atlantic coast, but by the early 1980s many of these fisheries had declined precipitously. In contrast to most Atlantic coastal rivers, the abundance of American shad in the Santee–Cooper River basin of South Carolina has grown substantially; still, much of their upstream spawning habitat in this watershed has been restricted or adversely affected by impoundments. In an effort to rebuild populations in upstream river reaches of the Santee–Cooper basin, state and federal agencies developed an approach relying on hatchery augmentation, the relocation of prespawning adults, and the construction of permanent fish passage structures. Genetic monitoring was adopted to ensure that the genetic integrity of the population remains intact during the rebuilding process. Our study provided an initial assessment of genetic diversity for the genetic monitoring program. There were three components to the study: an assessment of within-basin genetic stock structure, a comparison of genetic diversity (the number of alleles and observed heterozygosity) between hatchery and wild stocks, and an evaluation of molecular tags for monitoring hatchery returns. The estimation of genetic diversity and the assessment of molecular tags were based on 10 microsatellite loci. We found no apparent stock structure in the Santee–Cooper basin and no difference in genetic diversity between broodstock and their wild counterparts. Eight microsatellite markers provided enough resolution to successfully (>95% assignment success) match returning American shad with their respective hatchery parents. Our results highlight the utility and importance of integrating genetic information in supportive breeding programs in an effort to evaluate the programs’ effectiveness (both in terms of increasing the census size and in terms of maintaining the long-term viability of a population).

Received March 18, 2011; accepted August 8, 2011
Alosine Restoration in the 21st Century: Challenging the Status Quo
Authors: Hasselman Daniel J. , Limburg Karin E.
Published: July 2012

Despite the expenditure of millions of dollars on restoration efforts for depleted North American stocks of alosine fishes, rangewide abundance levels for multiple species have declined to historic lows. Stocking practices aimed at rebuilding spawning runs are deemed successful when numerical abundance levels are shown to increase in response. However, these practices may only yield short-term gains in abundance at the ultimate expense of population genetic integrity and do not ensure the long-term persistence and evolutionary potential of a species. Although molecular methods are now widely employed in fisheries management and provide a suite of powerful management tools, these approaches have not been well integrated into alosine management strategies. We review the net effects of stocking practices on population genetic integrity and species’ long-term persistence as it is currently understood and highlight what is known in this regard for alosines in North America, with particular focus on American shad Alosa sapidissima. We find that stocking practices carry a substantial risk to the persistence of genetically distinct alosine spawning populations and suggest that future restoration efforts proceed by providing access to historical spawning grounds, either through dam removal or through providing effective fish passage, followed by natural recolonization of reclaimed habitat. We also identify important areas of research relevant to future alosine restoration that require exploration and identify recent developments that may alter future restoration decisions in an adaptive management framework.

Received March 18, 2011; accepted October 6, 2011
Demographic Population Model for American Shad: Will Access to Additional Habitat Upstream of Dams Increase Population Sizes?
Authors: Harris Julianne E. , Hightower Joseph E.
Published: July 2012

American shad Alosa sapidissima are in decline in their native range, and modeling possible management scenarios could help guide their restoration. We developed a density-dependent, deterministic, stage-based matrix model to predict the population-level results of transporting American shad to suitable spawning habitat upstream of dams on the Roanoke River, North Carolina and Virginia. We used data on sonic-tagged adult American shad and oxytetracycline-marked American shad fry both above and below dams on the Roanoke River with information from other systems to estimate a starting population size and vital rates. We modeled the adult female population over 30 years under plausible scenarios of adult transport, effective fecundity (egg production), and survival of adults (i.e., to return to spawn the next year) and juveniles (from spawned egg to age 1). We also evaluated the potential effects of increased survival for adults and juveniles. The adult female population size in the Roanoke River was estimated to be 5,224. With no transport, the model predicted a slow population increase over the next 30 years. Predicted population increases were highest when survival was improved during the first year of life. Transport was predicted to benefit the population only if high rates of effective fecundity and juvenile survival could be achieved. Currently, transported adults and young are less likely to successfully out-migrate than individuals below the dams, and the estimated adult population size is much smaller than either of two assumed values of carrying capacity for the lower river; therefore, transport is not predicted to help restore the stock under present conditions. Research on survival rates, density-dependent processes, and the impacts of structures to increase out-migration success would improve evaluation of the potential benefits of access to additional spawning habitat for American shad.

Received March 19, 2011; accepted August 22, 2011
Findings on American Shad and Striped Bass in the Hudson River Estuary: A Fish Community Study of the Long-Term Effects of Local Hydrology and Regional Climate Change
Authors: O'Connor Megan P. , Juanes Francis , McGarigal Kevin , Gaurin Steven
Published: July 2012

It has been hypothesized that climate change is an underlying factor in determining fish abundances in the Hudson River estuary (HRE). To study the effects of hydrology and climate on the HRE fish community, we applied multivariate statistical methods to data on 20 species–life history stages collected from 1974 to 2005. We confirm that the HRE fish community has changed over this period. These changes are correlated with local hydrology (freshwater flow and water temperature) and regional climate (the Atlantic Multidecadal Oscillation [AMO] and North Atlantic Oscillation). We found that the abundances of striped bass Morone saxatilis larval stages are positively correlated with high freshwater flows and those of juvenile American shad Alosa sapidissima negatively correlated with the AMO or warmer sea surface temperatures. Our findings suggest that climate-related variability affects HRE juvenile shad abundances and that management strategies for this declining species should include the implications of climate change.

Received March 19, 2011; accepted January 10, 2012
Evaluating Changes in Diadromous Species Distributions and Habitat Accessibility following the Penobscot River Restoration Project
Authors: Trinko Lake Tara R. , Ravana Kyle R. , Saunders Rory
Published: July 2012

The Penobscot River basin, covering approximately 22,265 km2, is the largest river wholly within Maine and the second largest river system in New England. The Penobscot River Restoration Project (PRRP) is a multimillion-dollar endeavor that aims to restore native sea-run fish through the removal of two main-stem dams and improved fish passage at a third dam on the Penobscot River. We used geographical information systems, accounts of historic ranges, and barrier survey data to estimate species-specific distributions and habitat accessibility for 11 diadromous species before and after the proposed restoration. We predict a range of outcomes in terms of expected distribution and accessibility that are largely based on habitat use and life history differences. For 4 out of 11 species (Atlantic sturgeon Acipenser oxyrinchus, shortnose sturgeon A. brevirostrum, Atlantic tomcod Microgadus tomcod, and striped bass Morone saxatillis), the PRRP is anticipated to provide access to 100% of their historic freshwater habitat. However, for alewives Alosa pseudoharengus, approximately 69% of the historic spawning and rearing habitat will remain inaccessible due to the presence of other passage barriers. Our results demonstrate that the PRRP is an important step toward ecosystem recovery in the Penobscot River basin but that other restoration activities will be needed to realize the full potential of the PRRP, particularly for alosines. Further, our results provide the first spatial analysis of diadromous fish distribution and access following the PRRP and serve as the baseline for developing a guiding image for expected diadromous fish population responses following the dam removals.

Received March 21, 2011; accepted August 21, 2011
Striped Bass Consumption of Blueback Herring during Vernal Riverine Migrations: Does Relaxing Harvest Restrictions on a Predator Help Conserve a Prey Species of Concern?
Authors: Davis Justin P. , Schultz Eric T. , Vokoun Jason C.
Published: July 2012

Anadromous blueback herring Alosa aestivalis are declining throughout much of their range, and fishery closures in some systems have failed to produce population recovery. A potential contributing factor is increased predation pressure from sympatric striped bass Morone saxatilis. We integrated data on the predator–prey interaction between striped bass and blueback herring during vernal migrations into the Connecticut River with data on the in-river striped bass fishery to assess the potential for mitigation of blueback herring mortality via increased striped bass harvest. Striped bass abundance, size structure, diets, and angler catches were assessed within a river segment during spring 2005–2008. We estimate that striped bass consumed 400,000 blueback herring (90% confidence interval = 200,000–800,000) annually in our study area during the spring migration season. The predator–prey interaction between striped bass and blueback herring was predator size dependent. Blueback herring were most commonly found in the stomachs of striped bass between 650 and 999 mm total length. Intermediate size-classes (650–799 mm) made the greatest contribution to population-level consumption. Highly abundant small striped bass (400–549 mm) consumed herring infrequently, yet still made substantial contributions to population-level consumption. Anglers caught 17,000 striped bass in our study area during March–June 2008; only 11% of these fish could be harvested under the current 28-in (710-mm) minimum length limit. Allowing anglers to harvest up to 15,000 sublegal striped bass from a “bonus harvest” slot limit would reduce annual predatory losses of blueback herring by up to 10%. Alternatively, a smaller bonus harvest of legal-sized striped bass could achieve reductions in consumption of up to 7%. The recreational fishery in our study area, however, may not be intense enough to realize such harvest levels.

Received March 21, 2011; accepted October 18, 2011
Use of a Natural Isotopic Signature in Otoliths to Evaluate Scale-Based Age Determination for American Shad
Authors: Upton Sally A. , Walther Benjamin D. , Thorrold Simon R. , Olney John E.
Published: July 2012

We used δ18O signatures in otoliths as a natural tag for hatch year to evaluate the scale-based age determination method used for adult American shad Alosa sapidissima in the York River, Virginia. Juveniles of the 2002 year-class exhibited high δ18O values in otolith cores that identified adult members of the cohort as they returned to spawn. Recruitment of the 2002 cohort was monitored for three consecutive years, identifying age-4, age-5, and age-6 individuals of the York River stock. The scale-based age determination method was not suitable for aging age-4, age-5, or age-6 American shad in the York River. On average, 50% of the individuals from the 2002 year-class were aged incorrectly using the scale-based method. These results suggest that the standard age determination method used for American shad is not applicable to the York River stock. Scientists and managers should use caution when applying scale-based age estimates to stock assessments for American shad in the York River and throughout their range, as the applicability of the scale-based method likely varies for each stock. This study highlights a promising new direction for otolith geochemistry to provide cohort-specific markers, and it identifies several factors that should be considered when applying the technique in the future.

Received March 21, 2011; accepted August 18, 2011
Comparison of Juvenile Alewife Growth and Movement in a Large and a Small Watershed
Authors: Turner Sara M. , Limburg Karin E.
Published: July 2012

The freshwater behaviors of juvenile alewives Alosa pseudoharengus and the variables affecting their survival to recruitment are relatively unknown, even though recruitment to marine populations is critical to sustaining and restoring populations. Fish were collected in fall 2009 from a large watershed (the Hudson River, New York; N = 10) and a small watershed (the Peconic River, New York; N = 14), otolith chemistry was used to associate the fish to groups, and growth rates were compared both within and between rivers. Otolith Sr:Ca and Ba:Ca were measured along growth transects, and significant changes in these values were determined. In many instances, changes in these values are associated with changes in daily otolith growth increments. More variation was observed in the Ba:Ca ratios and daily growth rates of Hudson River alewives, possibly because they had more available nursery habitats. While there was variation in otolith chemistry and daily growth within Peconic River fish, fewer otolith chemistry patterns were observed in this group. Comparison of cumulative daily growth rates between the two groups showed that Hudson River alewives were smaller at younger ages but that their growth rate increased and their size at age eventually surpassed that of the Peconic River alewives. The results presented here provide the foundation for future work investigating the abiotic and biotic variables influencing juvenile alewife growth, behavior, and survival in different-size watersheds.

Received March 21, 2011; accepted September 26, 2011
Spatial and Temporal Variability in Instantaneous Growth, Mortality, and Recruitment of Larval River Herring in Tar–Pamlico River, North Carolina
Authors: Overton Anthony S. , Jones Nicholas A. , Rulifson Roger
Published: July 2012

We estimated the variation in the instantaneous rates of growth and mortality between cohorts of larval alewife Alosa pseudoharengus and blueback herring A. aestivalis in the Tar–Pamlico River, Pamlico Sound, North Carolina. The age of larvae captured by push net was estimated by counting the daily rings on sagittal otoliths. Weight-at-age and abundance-at-age data were used to generate instantaneous daily growth (G) and mortality rates (M) for 7-d cohorts. The instantaneous daily growth rate was relatively constant between cohorts, ranging from 0.103 to 0.277 for alewives and from 0.105 to 0.200 for blueback herring. The instantaneous daily mortality rate was more variable between cohorts, ranging from 0.064 to 0.270 for alewives and from 0.100 to 0.251 for blueback herring. All but one blueback herring cohort had an M/G value exceeding 1.0, indicating that these cohorts were losing biomass during the early larval stage. For alewives, M/G values were more variable, with 50% of the cohorts having values less than 1.0. The effect of habitat was consistent between species, with M/G values being higher and closer to 1.0 at sites in tributary creeks and backwater areas of Tar River. The overall M/G values were 0.57 for alewives and 1.60 for blueback herring from both backwater and main-channel sites, indicating that the environmental conditions in the Tar–Pamlico River are more favorable for alewives.

Received March 25, 2011; accepted November 10, 2011
Foraging Potential of Larval Alosines in the Lower Roanoke River and Albemarle Sound, North Carolina
Authors: Binion Samantha M. , Overton Anthony S. , Riley Kenneth L.
Published: July 2012

Zooplankton composition and abundances were quantified in the lower Roanoke River and Albemarle Sound, North Carolina. The spatial and temporal overlap between larval alosines, including American shad Alosa sapidissima, river herring (alewife A. pseudoharengus and blueback herring A. aestivalis), hickory shad A. mediocris, and zooplankton were examined to determine whether larval alosines in this system are food limited. Samples were collected weekly at 19 stations from March through June 2008–2009 in three habitats: River, Delta, and Sound. Spatial differences in zooplankton were observed, with the abundance in the Sound (16,546 ± 14,678 [number/m3 ± SD]) being significantly higher than those in the River (4,934 ± 3,806) and Delta areas (4,647 ± 2,846). Zooplankton composition was dominated by Daphniidae, Bosminidae, calanoid and cyclopoid copepods, copepod nauplii, and rotifers. The spatial patterns in alosine abundance were the opposite of those for zooplankton, being highest in the River (21.0 ± 127.6) and lower in the Delta (7.5 ± 35.5) and Sound (4.6 ± 24.8). Mouth gape models for each alosine species showed that copepod nauplii and rotifers are the most suitable-sized prey for the first feeding after yolk sac absorption. There was a high degree of spatial and temporal overlap between larval alosines and size-appropriate prey items, suggesting that the larval alosines are not food limited in Albemarle Sound.

Received March 25, 2011; accepted January 24, 2012
Estimating the Food Requirements and Prey Size Spectra of Larval American Shad
Authors: Riley Kenneth L. , Binion Samantha M. , Overton Anthony S.
Published: July 2012

Widespread declines in American shad Alosa sapidissima along the Atlantic coast have been attributed to overfishing, a decrease in water quality, and loss of habitat. Recent surveys along the Roanoke River and Albemarle Sound, North Carolina, suggest that stocks are continuing to decline despite extensive management and stock enhancement efforts. Laboratory experiments were conducted to evaluate the effect of prey density on the growth and survival of American shad and to determine whether larvae can survive and grow in a riverine environment with a limited forage base. Larvae were reared from 11 to 20 d posthatch in one of five treatments: (1) no food; (2) low food (1 prey/L), which simulated the prey densities in the Roanoke River; (3) medium food (50 prey/L), which simulated the prey densities typical of coastal watersheds; (4) high food (500 prey/L); and (5) Artemia spp. (500/L). Larval survival was 35 ± 7% (mean ± SE) and was not significantly different among treatments. Treatments with starved fish had the lowest survival (22 ± 12%), while the highest survival was observed in treatments with high densities of wild zooplankton (46 ± 18%) and Artemia (40 ± 16%). Length-specific growth rates were 0.017 mm/d for the starved treatments and 0.024, 0.029, 0.034, and 0.039 mm/d for the low-prey, medium-prey, high-prey, and Artemia treatments, respectively. Larval growth as a function of length was not significantly different between the Artemia and high-prey treatments; however, growth in these treatments was significantly higher than in those with lower prey densities. Weight-specific growth rates (Gw) were significantly higher for the Artemia treatment (Gw = 0.129) than for all the other treatments (Gw = 0.081). Analysis of stomach contents indicated that American shad were selectively feeding on the smallest zooplankton (80–250 μm) and that larvae exhibited a strong preference for copepod nauplii and rotifers. These results suggest that spatial and temporal overlap between larvae and zooplankton is important for larval growth and survival.

Received March 31, 2011; accepted September 12, 2011
Assessing Freshwater Habitat of Adult Anadromous Alewives Using Multiple Approaches
Authors: Mather Martha E. , Frank Holly J. , Smith Joseph M. , Cormier Roxann D. , Muth Robert M. , Finn John T.
Published: July 2012

After centuries of disturbance, environmental professionals now recognize the need to restore coastal watersheds for native fish and protect the larger ecosystems on which fish and other aquatic biota depend. Anadromous fish species are an important component of coastal ecosystems that are often adversely affected by human activities. Restoring native anadromous fish species is a common focus of both fish and coastal watershed restoration. Yet restoration efforts have met with uneven success, often due to lack of knowledge about habitat availability and use. Using habitat surveys and radio tracking of adult anadromous alewives Alosa pseudoharengus during their spring spawning migration, we illustrate a method for quantifying habitat using multiple approaches and for relating mobile fish distribution to habitat. In the Ipswich River, Massachusetts, measuring habitat units and physical conditions at transects (width, depth, and velocity) provided an ecological basis for the interpretation of landscape patterns of fish distribution. Mapping habitat units allowed us to efficiently census habitat relevant to alewives for the entire 20.6 river kilometers of interest. Our transect data reinforced the results of the habitat unit survey and provided useful, high-resolution ecological data for restoration efforts. Tagged alewives spent little time in riffle–run habitats and substantial time in pools, although the locations of pool occupancy varied. The insights we provide here can be used to (1) identify preferred habitats into which anadromous fish can be reintroduced in order to maximize fish survival and reproduction and (2) pinpoint habitat types in urgent need of protection or restoration.

Received April 3, 2011; accepted January 9, 2012
Relative Sensitivity of New England American Shad to Fishing, Discard Mortality, and Dam Passage Failure or Mortality
Authors: Kahnle Andrew , Hattala Kathryn
Published: July 2012

American shad Alosa sapidissima in Atlantic coastal rivers of the New England states are affected by anthropogenic sources of mortality, such as discards of immature fish (bycatch) in various fisheries, directed fishing on prespawning adults, and the passage failure or mortality of mature fish at migratory barriers. We evaluated the relative importance of these factors, independently and in combination, by modeling the predicted lifetime spawning stock biomass of an age-1 female recruit (SSBR) with an assumed constant rate of natural mortality. Discard losses had the greatest impact on the SSBR, followed by directed fishing and upstream passage mortality, upstream passage failure (the fish survived but did not pass the barrier or spawn), and downstream losses of postspawning adults. Fishery managers strive to keep mortality rates below those that reduce SSBR to less than 30% of that of a stock with no anthropogenic mortality. In our modeling, SSBR dropped below that benchmark when bycatch rates exceeded 0.21, directed fishing or upstream passage mortality exceeded 0.45, and upriver passage failure without mortality exceeded 0.70. Since the downriver passage mortality of adults occurred after spawning, SSBR did not decline below the benchmark even at 100% downriver loss. The impacts of upstream passage mortality always exceeded those from comparable downstream passage mortality. Fishing and discard losses seriously reduced any gain in SSBR from reduced fish passage mortality or failure. The results in this paper suggest that among the anthropogenic factors evaluated, American shad in New England are most sensitive to discard losses of immature shad in ocean fisheries and that fish passage improvements at dams are most effective when they are developed in combination with reductions in fishery-related losses.

Received April 25, 2011; accepted November 29, 2011