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Full-Text Articles in Aquaculture and Fisheries
Simulations Of The Effect Of Sample Size On The Maximum Observed Age In A Fish Population, John M. Hoenig
Simulations Of The Effect Of Sample Size On The Maximum Observed Age In A Fish Population, John M. Hoenig
Reports
No abstract provided.
Simulations To Compare The Performance Of Two Length-Based Estimators Of Total Mortality Rate, Amy Y. Then, John M. Hoenig
Simulations To Compare The Performance Of Two Length-Based Estimators Of Total Mortality Rate, Amy Y. Then, John M. Hoenig
Reports
Mean length-based methods to estimate instantaneous total mortality rates, Z, are important assessment tools for data-poor stocks. One commonly used method was developed by Beverton and Holt (1956). The behavior of this method, especially in relation to bias, has been fairly well characterized. Another method by Ehrhardt and Ault (1992) was proposed to "correct" the Beverton-Holt (BH) method for applications to length frequency distributions that are truncated at the upper end. The Ehrhardt-Ault (EA) method has zero bias at equilibrium when there is no variability in length at age but the reliability of the method has not been demonstrated under …
Results Of Evaluating The Performance Of Empirical Estimators Of Natural Mortality Rate, Amy Y. Then, John M. Hoenig
Results Of Evaluating The Performance Of Empirical Estimators Of Natural Mortality Rate, Amy Y. Then, John M. Hoenig
Reports
Natural mortality rate, M, of fish is a highly influential stock assessment parameter. The M parameter is also difficult to estimate directly and reliably. Various empirical estimators have been developed to estimate M indirectly, based on relationships established between M and predictor variables such as growth parameters, lifespan and water temperature (e.g., Beverton and Holt, 1959; Alverson and Carney, 1975; Pauly, 1980; Hoenig, 1983). Despite the importance of these estimators, there is no consensus in the literature on how well they work in terms of prediction error or how their performance may be ranked. Then et al. (2015) evaluated estimators …
Simulated Performance Of Catch Curve Methods For Estimating Total Mortality Rate, Matthew W. Smith, John M. Hoenig
Simulated Performance Of Catch Curve Methods For Estimating Total Mortality Rate, Matthew W. Smith, John M. Hoenig
Reports
This document has been issued as VIMS Data Report 60 and provides additional simulation results for Smith et al. (2012) published in the North American Journal of Fisheries Management. Catch curve methods are a basic tool of population dynamics for estimating total mortality rate from age composition. There are a number of methodological issues which remain unresolved. Smith et al. (2012) attempts to provide guidelines on the use of these methods based on extensive Monte Carlo simulations. This report presents additional simulation results to supplement the results in the journal article. The estimators, evaluation criteria, simulation procedures, and conditions simulated …
Juvenile Finfish And Blue Crab Stock Assessment Program Bottom Trawl Survey Annual Data Report Series, Volume 1991, Christopher F. Bonzek, Patrick J. Geer, James A. Colvocoresses, Robert E. Harris
Juvenile Finfish And Blue Crab Stock Assessment Program Bottom Trawl Survey Annual Data Report Series, Volume 1991, Christopher F. Bonzek, Patrick J. Geer, James A. Colvocoresses, Robert E. Harris
Reports
This report presents a summary page for each tow conducted by the Virginia Institute of Marine Science, Juvenile Fish and Blue Crab Trawl Survey during 1991. The sampling methods and summarized data are presented in Bonzek et al. (1992). Data analysis and calculations of juvenile indices for selected species are presented in Colvocoresses et al. (1991). The purpose of this report is simply to provide a "hard copy" record of trawl results. It also provides a method to retrieve information about one or several particular trawls without consulting computerized archives. · · All data about each tow are presented, except …
License Records Of The Blue Crab Fisheries, Virginia And Maryland, 1898-1960, Willard A. Van Engel, Frank J. Wojcik
License Records Of The Blue Crab Fisheries, Virginia And Maryland, 1898-1960, Willard A. Van Engel, Frank J. Wojcik
Reports
Gear used in the Virginia and Maryland blue crab fisheries have been regulated since 1989. Numbers of fishermen and kinds of fishing devices have been reported in official state publications, in Virginia from 1899 through 1941 and in Maryland from 1916 to date. Unfortunately, these reports have sometimes been incomplete. The fact that Virginia licenses have been reported by fiscal year and Maryland's by calendar year, has made analysis and comparison difficult. The most complete Virginia record was extracted from files of the Commission of Fisheries, and is made available here for the first time, for the calendar years 1920 …
Catch And Value Of Various American Crustaceans 1929-1960, Willard A. Van Engel, Frank J. Wojcik
Catch And Value Of Various American Crustaceans 1929-1960, Willard A. Van Engel, Frank J. Wojcik
Reports
Occasional reference has been made to the relative magnitude of the catch of the blue crab in waters outside Chesapeake Bay, yet comparisons are not easily made unless data are readily available. Both parallel and opposite trends in catch have been observed. These could be reflections of the amount of fishing effort or the size of the crab stocks. Comparable records of other crustacean fisheries are often of interest. Compilations are given here of data on crabs, shrimp and lobsters originally published in "Fishery Industries of the United States" and "Fishery Statistics of the United States".