scholarly journals Variability in the relationship between sea scallop shell height and meat weight

2009 ◽  
Vol 66 (9) ◽  
pp. 1972-1977 ◽  
Author(s):  
Brian J. Rothschild ◽  
Charles F. Adams ◽  
Christopher L. Sarro ◽  
Kevin D. E. Stokesbury
Keyword(s):  
Shell Height ◽  
Spatial And Temporal Variability ◽  
Commercial Fishing ◽  
Regression Equations ◽  
Placopecten Magellanicus ◽  
Scallop Shell ◽  
Linear Mixed Effects ◽  
Meat Weight ◽  
Sea Scallop ◽  
The Relationship

Abstract Rothschild, B. J., Adams, C. F., Sarro, C. L., and Stokesbury, K. D. E. 2009. Variability in the relationship between sea scallop shell height and meat weight. – ICES Journal of Marine Science, 66: 1972–1977. We investigated the spatial and temporal variability in the relationship between shell height and meat weight (SHMW) of the sea scallop (Placopecten magellanicus) from Georges Bank (GB) and the mid-Atlantic. Data for the study were collected collaboratively during normal commercial fishing operations. A one-way random-effects ANOVA revealed that 19–44% of the variance in MW was at the batch level. A linear mixed-effects model was used to explain the variability in SHMW regression equations across batches. There was a significant effect of month and year on the SHMW relationship for GB from June through December, and a significant effect of area and year on the SHMW relationship for the mid-Atlantic from January through May. The SHMW relationships presented reflect those of the fishery year-round rather than an estimate of the biological population at a specific point in time. Failure to include intra-annual, interannual, and regional variations in the SHMW could result in continually over- or underestimating the allowable catch in areas open to fishing for short periods. The techniques used are applicable to length–weight studies in general.

scholarly journals The Influence of Temperature - Food Availability on the Shell Growth of Sea Scallop Placopecten magellanicus (Gmelin, 1791)

2016 ◽  
Vol 19 (1) ◽  
pp. 1 ◽  
Author(s):  
Adi Santoso
Keyword(s):  
Food Availability ◽  
Shell Growth ◽  
Shell Height ◽  
Culture Conditions ◽  
Outer Edge ◽  
Placopecten Magellanicus ◽  
Surface Sites ◽  
Sea Scallop ◽  
Key Words Temperature ◽  
Culture Site

A study of the growth of the sea scallop, Placopecten magellanicus, under suspended culture conditions was carried out over a seven month period at a culture site in Graves Shoal, Mahone Bay,Nova Scotia – Canada. Scallop spat were cultivated in pearl nets at a density of 30-35 per net set at four locations corresponding to the surface (7 m) and bottom (14 m) at the outer edge and the center of the site. Shell height was measured at monthly intervals. Environmental conditions represented as temperature and food availability at the surface and bottom over the same period were also monitored. Shell Height growth rate was slightly greater at the surface than at the bottom. At the surface sites growth was greater at the outside (SUROUT) than at the center locations, but at the bottom growth was greater at the centre location (BOTIN). The only significant relationship between shell growth and temperature - food variables was chlorophyll a concentration.  Key words: temperature, food availability, shell height, sea scallop

scholarly journals Shell growth of sea scallops (Placopecten magellanicus) in the southern and northern Great South Channel, USA

2006 ◽  
Vol 63 (5) ◽  
pp. 811-821 ◽  
Author(s):  
Bradley P. Harris ◽  
Kevin D.E. Stokesbury
Keyword(s):  
Shell Growth ◽  
Shell Height ◽  
Management Strategies ◽  
Height Distribution ◽  
Placopecten Magellanicus ◽  
Geographic Scale ◽  
Sea Scallop ◽  
Asymptotic Size ◽  
The Usa ◽  
Sea Scallops

Abstract Shell growth of sea scallops in two commercially productive regions of the Great South Channel (GSC) (41°4′N 69°16′W) was studied using tag–recapture experiments. Commercial fishers captured and returned 9.7% of the 11 704 sea scallops tagged in the southern GSC study area, and 7.9% of the 18 274 sea scallops tagged in the northern GSC study area. Scallop density and shell height distribution were sampled with underwater video in the two study areas. In the southern GSC tagged scallops grew faster, reached larger asymptotic size, and had higher growth performance (Φ′) than in the northern GSC study area. Mean sea scallop density in the southern GSC was 0.117 scallops m−2 (s.e. = 0.01), and 2.601 scallops m−2 (s.e. = 0.28) in the northern GSC. Environmental factors, fishing pressure, and sea scallop density all influence shell growth on a fine geographic scale (1–100 km2) and should be considered in area-specific management strategies, such as that currently used in the USA sea scallop fishery.

Verification of Atlantic sea scallop (Placopecten magellanicus) shell growth rings by tracking cohorts in fishery closed areas

2009 ◽  
Vol 66 (5) ◽  
pp. 751-758 ◽  
Author(s):  
Deborah R. Hart ◽  
Antonie S. Chute
Keyword(s):  
Shell Growth ◽  
Shell Height ◽  
Annual Growth ◽  
Transition Matrices ◽  
Placopecten Magellanicus ◽  
Sea Scallop ◽  
Growth Increments ◽  
Repeated Sampling ◽  
The Mean ◽  
Shell Rings

We tracked the growth of large cohorts of sea scallops ( Placopecten magellanicus ) at four sites located in areas closed to scallop fishing and compared the observed growth with that inferred from rings on sea scallop shells collected at the same sites. Stochastic growth transition matrices were constructed for each site based on the shell growth increments, assuming annual ring formation. These matrices were used to predict the annual growth of the scallops, which were compared with direct observations of growth obtained by repeated sampling. Additionally, the observed growth of the scallops was used to estimate the parameters of a stochastic von Bertalanffy model for each site, which were used to estimate the mean annual growth increments as a function of starting shell height. These were compared with the mean growth increments on the shells. There was a close correspondence, in most cases, between the observed growth and the growth inferred from the shell rings, implying that the shell rings were formed annually. The lack of fishing mortality in the areas meant that there was no confounding of size-selective fishing with growth and allowed us to track cohorts longer than would otherwise have been possible.

scholarly journals The Changing Relationship between Surface Temperatures and Indian Monsoon Rainfall with the Phase of ESI Tendency

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
S. B. Kakade ◽  
Ashwini Kulkarni
Keyword(s):  
Temporal Variability ◽  
Monsoon Rainfall ◽  
Summer Monsoon Rainfall ◽  
Relative Strength ◽  
Negative Phase ◽  
Spatial And Temporal Variability ◽  
Regression Equations ◽  
Winter Time ◽  
Effective Strength Index ◽  
The Relationship

Effective Strength Index (ESI) is the relative strength of NAO and SO. ESI tendency is the algebraic difference between April-ESI and January-ESI and it represents the simultaneous evolution of NAO and SO from winter to spring. During positive (negative) phase of ESI tendency, NAO restores positive (negative) phase and SO restores negative (positive) phase before the beginning of summer season. Thus during contrasting phases (positive and negative) of ESI tendency, the evolution of NAO and SO is out of phase. In this paper we have studied the spatial and temporal variability of winter-time temperature field over Europe, Arabian Sea and Bay of Bengal during contrasting phases of ESI tendency. The study reveals that during positive (negative) ESI tendency, smaller (larger) region of Europe is showing significant winter-time cooling (warming) at surface. The relationship between winter-time surface temperature over above regions and Indian summer monsoon rainfall (ISMR) also shows spatial and temporal variability. The probable explanation for this change in the relationship is discussed in the paper. Two sets of temperature parameters for two different phases of ESI tendency are found out. Multiple regression equations are developed for the prediction of ISMR in each phase of ESI tendency. The performance of these equations is also discussed in this paper.

scholarly journals Estimating von Bertalanffy growth parameters from growth increment data using a linear mixed-effects model, with an application to the sea scallop Placopecten magellanicus

2009 ◽  
Vol 66 (10) ◽  
pp. 2165-2175 ◽  
Author(s):  
Deborah R. Hart ◽  
Antonie S. Chute
Keyword(s):  
Growth Parameters ◽  
Growth Increment ◽  
Mixed Effects ◽  
Mixed Effects Model ◽  
Von Bertalanffy ◽  
Georges Bank ◽  
Placopecten Magellanicus ◽  
Linear Mixed Effects Model ◽  
Linear Mixed Effects ◽  
Sea Scallop

Abstract Hart, D. R., and Chute, A. S. 2009. Estimating von Bertalanffy growth parameters from growth increment data using a linear mixed-effects model, with an application to the sea scallop Placopecten magellanicus. – ICES Journal of Marine Science, 66: 2165–2175. We introduce a novel linear mixed-effects method for estimating von Bertalanffy growth parameters from growth increment data that lack explicit age information. The method is simple to implement and can incorporate and estimate variability in both the asymptotic size L∞ and the Brody growth coefficient K. Simulations indicate that estimates from the method are accurate over a range of conditions. The method is applied to growth data from more than 6000 Atlantic sea scallop (Placopecten magellanicus) shells from the Mid-Atlantic Bight and Georges Bank. Sea scallops grow to a larger asymptotic shell height on Georges Bank than on the Mid-Atlantic Bight and in areas closed to fishing on Georges Bank than on the fished portions. Depth and latitude had significant effects on scallop growth in both the Mid-Atlantic and Georges Bank, with smaller asymptotic shell heights in deeper water and at higher latitudes.

Cadmium in Sea Scallop (Placopecten magellanicus) Tissues from Clean and Contaminated Areas

1987 ◽  
Vol 44 (1) ◽  
pp. 91-98 ◽  
Author(s):  
J. F. Uthe ◽  
C. L. Chou
Keyword(s):  
Digestive Gland ◽  
Soft Tissues ◽  
Shell Height ◽  
Cadmium Concentration ◽  
Predictor Variable ◽  
Adductor Muscle ◽  
Placopecten Magellanicus ◽  
Tissue Concentrations ◽  
Sea Scallop ◽  
Sea Scallops

Over 90% of the total cadmium in the soft tissues of sea scallops (Placopecten magellanicus) was in the digestive gland with less than 1% in the adductor muscle. The amount of cadmium in the digestive gland was significantly related to shell height. Shell height was superior to age as an independent (predictor) variable due to difficulties in ageing scallops. Based on these relationships, scallops of approximately 100 mm shell height were selected to study interregional differences. Neither cadmium concentration nor burden could be used to identify contaminated areas. The ratio of digestive gland cadmium to that in the adductor muscle was lowest for scallops from Chaleur Bay, which had received substantial anthropogenic cadmium input, and for scallops that had been starved for approximately 14 mo. We suggest that the high tissue cadmium levels in scallops from Georges Bank and Browns Bank are not due to contamination from anthropogenic or natural sources but rather reflect feeding and the nutritional inadequacy of the diets. Conversely, the high levels of cadmium input to Chaleur Bay were not reflected in high tissue concentrations or burdens in scallops.

THE MODEL FOR MANAGING INVESTMENTS IN THE MOSCOW ENVIRONMENT BASED ON A POWER REGRESSION EQUATION

2020 ◽  
Vol 2 (7) ◽  
pp. 91-99
Author(s):  
E. V. KOSTYRIN ◽  
◽  
M. S. SINODSKAYA ◽  
Keyword(s):  
Solid Waste ◽  
Influencing Factors ◽  
Pair Correlation ◽  
Approximation Error ◽  
Regression Equation ◽  
Regression Equations ◽  
The Impact ◽  
The Relationship ◽  
Average Approximation ◽  
Average Approximation Error

The article analyzes the impact of certain factors on the volume of investments in the environment. Regression equations describing the relationship between the volume of investment in the environment and each of the influencing factors are constructed, the coefficients of the Pearson pair correlation between the dependent variable and the influencing factors, as well as pairwise between the influencing factors, are calculated. The average approximation error for each regression equation is determined. A correlation matrix is constructed and a conclusion is made. The developed econometric model is implemented in the program of separate collection of municipal solid waste (MSW) in Moscow. The efficiency of the model of investment management in the environment is evaluated on the example of the growth of planned investments in the activities of companies specializing in the export and processing of solid waste.

scholarly journals Sodium Metasilicate Cemented Analogue Material and Its Mechanical Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Songlin Yue ◽  
Yanyu Qiu ◽  
Pengxian Fan ◽  
Pin Zhang ◽  
Ning Zhang
Keyword(s):  
Complex Geometry ◽  
Sodium Metasilicate ◽  
Raw Material ◽  
Fine Aggregate ◽  
Regression Equations ◽  
Deformation And Failure ◽  
Orthogonal Experiments ◽  
Low Modulus ◽  
New Type ◽  
The Relationship

Analogue material with appropriate properties is of great importance to the reliability of geomechanical model test, which is one of the mostly used approaches in field of geotechnical research. In this paper, a new type of analogue material is developed, which is composed of coarse aggregate (quartz sand and/or barite sand), fine aggregate (barite powder), and cementitious material (anhydrous sodium silicate). The components of each raw material are the key influencing factors, which significantly affect the physical and mechanical parameters of analogue materials. In order to establish the relationship between parameters and factors, the material properties including density, Young’s modulus, uniaxial compressive strength, and tensile strength were investigated by a series of orthogonal experiments with hundreds of samples. By orthogonal regression analysis, the regression equations of each parameter were obtained based on experimental data, which can predict the properties of the developed analogue materials according to proportions. The experiments and applications indicate that sodium metasilicate cemented analogue material is a type of low-strength and low-modulus material with designable density, which is insensitive to humidity and temperature and satisfies mechanical scaling criteria for weak rock or soft geological materials. Moreover, the developed material can be easily cast into structures with complex geometry shapes and simulate the deformation and failure processes of prototype rocks.

PSVI-8 Meta-regression Analysis to Determine the Relationship Between Growing Pig Body Weight and Variation

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 218-219
Author(s):  
Andres Fernando T Russi ◽  
Mike D Tokach ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
Robert D Goodband ◽  
...  
Keyword(s):  
Body Weight ◽  
Regression Analysis ◽  
Sample Size ◽  
Polynomial Regression ◽  
Data Sets ◽  
Regression Equations ◽  
Prediction Equations ◽  
Data Set ◽  
Rate Of Increase ◽  
The Relationship

Abstract The swine industry has been constantly evolving to select animals with improved performance traits and to minimize variation in body weight (BW) in order to meet packer specifications. Therefore, understanding variation presents an opportunity for producers to find strategies that could help reduce, manage, or deal with variation of pigs in a barn. A systematic review and meta-analysis was conducted by collecting data from multiple studies and available data sets in order to develop prediction equations for coefficient of variation (CV) and standard deviation (SD) as a function of BW. Information regarding BW variation from 16 papers was recorded to provide approximately 204 data points. Together, these data included 117,268 individually weighed pigs with a sample size that ranged from 104 to 4,108 pigs. A random-effects model with study used as a random effect was developed. Observations were weighted using sample size as an estimate for precision on the analysis, where larger data sets accounted for increased accuracy in the model. Regression equations were developed using the nlme package of R to determine the relationship between BW and its variation. Polynomial regression analysis was conducted separately for each variation measurement. When CV was reported in the data set, SD was calculated and vice versa. The resulting prediction equations were: CV (%) = 20.04 – 0.135 × (BW) + 0.00043 × (BW)2, R2=0.79; SD = 0.41 + 0.150 × (BW) - 0.00041 × (BW)2, R2 = 0.95. These equations suggest that there is evidence for a decreasing quadratic relationship between mean CV of a population and BW of pigs whereby the rate of decrease is smaller as mean pig BW increases from birth to market. Conversely, the rate of increase of SD of a population of pigs is smaller as mean pig BW increases from birth to market.

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