Methodological guidelines on the assessment of trawl catchability of krill by means of statistical modelling
This paper offers an approach to the assessment of the relative effectiveness of krill fishing gear by means of statistical modelling. The Monte-Carlo method, which is described in the works by Metropolis, N., Ulam, S. (1949) and Sobol, I.M. (1978), is used as a basis. The Monte-Carlo method is useful for solving problems related to the quantitative assessment of complex stochastic systems, including the assessment of the effectiveness of trawl nets used in krill fishing. However, on its own the Monte-Carlo method does not provide a complete solution to the set problem. This paper sets out a method of comparative assessment of the effectiveness of trawl nets of various configurations. The algorithm for solving this problem is constructed in such a way that it can be applied without alteration for the assessment of the effectiveness of trawl nets of any configuration and affects only the input information.
The paper formulates axioms describing the ideal situation for the process of entrapment of krill by the net; this permits the rigorous mathematical formulation of the problem and the development of an algorithm for its solution. A detailed description is given of the algorithm for the assessment of the effectiveness of krill trawl nets, which includes a principal module and the module RESOLV (i.e. the resolution of several systems composed of two linear equations and two double inequalities).
The proposed algorithm can be realised by computer in algorithmic languages ALGOL, FORTRAN or PL-l; for this utilisation of a rapid-operation computer is recommended.