Fish Population Dynamic and Stock Assessment

6.3.1. Introduction

For any analytical model of fish stock assessment, qualitative and quantitative database is an essential prerequisite. Holistic models are recommended for the situation when there is limited scope for collecting huge data for particular fishery. Holistic model is simple, less data demanding, and also they do not require age or length structures of the stocks, but consider stock as a homogeneous biomass. Two methods followed in holistic methods are 1) swept area method and 2) surplus production model.

In swept area method, it is assumed that the area swept by the trawl is representative for the entire area over which the fishes are distributed. Surplus production method uses catch per unit of effort (fish caught per hour trawling).