by J.A. GULLAND
Fish Stock Evaluation Branch
Fishery Resources and Exploitation Division, FAO
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
ROME 1969
NOTE
Preliminary English versions of this manual have been issued as FAO Fisheries Technical Papers FIb/40, 1964; FIb/40 (Rev. 1), 1965; FRs/40 (Rev. 2), 1968. They have been based on, or used as lecture notes at various training centres as follows:
|
U.S. Fish and Wildlife Service |
(Beaufort, North Carolina) |
1951 |
|
International Council for the Exploration of the Sea |
(Lowestoft, United Kingdom) |
1957 |
|
FAO/EPTA |
(Bangkok, Thailand) |
1958 |
|
Commonwealth Scientific and Industrial Research Organization |
(Cronulla, Australia) |
1962 |
|
International Council for the Exploration of the Sea |
(Lowestoft, United Kingdom) |
1963 |
|
FAO/EPTA |
(Cronulla, Australia) |
1964 |
|
FAO/EPTA |
(Viña del Mar, Chile) |
1966 |
|
FAO/UNDP |
(Copenhagen, Denmark) |
1968 |
The various revisions of the manual have been based to a large extent on the discussions and experiences of these training centres. Over this period contributions to these notes have been made by E.L. Cadima (who drafted the subsection on mathematics), R.J.H. Beverton, R. Jones, B.B. Parrish, K.P. Andersen, S.J. Holt, L.K. Boerema and others.
A French translation of a preliminary version, Méthodes d'analyse des populations de poissons, translated by F. Baudin-Laurencin and others, was issued by the Office de la recherche scientifique et technique outre-mer, Pointe-Noire, Congo in 1965. Métodos de análisis de poblaciones de peces, a Spanish translation by R. Coyula, N. Cruz and E.L. Cadima, was issued by the Centro de Investigaciones Pesqueras, Cuba, in 1966. These translations included certain amendments and revisions, which have been included in this final version.
© FAO 1969
Printed in Italy
This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.
SECTION 2. MATHEMATICS, STATISTICS AND SAMPLING
2.1.1 Introduction
2.1.2 Functions
2.1.3 Powers and logarithms
2.1.4 Derivatives
2.1.5 Integrals2.3.1 General
2.3.2 Sampling the landings
2.3.3 Sampling the population3.1 Growth by length and weight
3.2 Conversion of length to age
3.3 ExercisesSECTION 4. EFFORT AND CATCH PER UNIT EFFORT
4.1 Introduction
4.2 The mathematical formulation
4.3 Fishing time
4.4 Fishing power
4.5 Distribution of fishing
4.6 Several gears
4.7 Exercises5.1 Introduction
5.2 Estimation of total mortality
5.3 Fishing mortality
5.4 Natural mortality and growth characters
5.5 Special graphical methods
5.6 Exercises6.1 Data for mortality rates and population size
6.2 Varying distribution in space
6.3 ExercisesSECTION 7. RECRUITMENT AND SELECTION
7.1 Trawl selection
7.2 Recruitment
7.3 Size limits
7.4 Gill-net selection
7.5 Exercises
SECTION 8. GENERAL PROBLEMS OF ASSESSMENT
8.1 The need for stock assessment
8.2 The concepts of sustainable yield and potential yield
8.3 The unit stockSECTION 9. THE SIMPLE YIELD CURVE
9.1 Derivation of the equation for yield
9.2 Other forms of the yield equation
9.3 ExercisesSECTION 10. SPECIAL ASSESSMENTS
10.1 Catch and effort statistics
10.2 Schaefer's model
10.3 Changes in selectivity
10.4 Interacting fisheries
10.5 ExercisesSECTION 11. CHANGES IN THE PARAMETERS
Appendix 1. YIELD TABLES FOR M/K = 0.50, 1.00 AND 1.75
Appendix 2. Tables of e-x