Study of swimbladder morphometry of Baltic herring and sprat (development of measurement methodology)

Jakub Idczak; Natalia Gorska; Bartłomiej Arciszewski

Study of swimbladder morphometry of Baltic herring and sprat (development of measurement methodology)

Abstract

Effective management of Baltic clupeids, which are valuable commercially and ecologically,
requires the biomass control. The acoustical techniques are recognized as effective in fish
stock assessment. The study of Baltic herring and sprat individual backscattering
characteristics is required for the accurate biomass estimation using acoustical techniques.
The previous measurements demonstrated significant dependence of the backscattering
properties of Baltic clupeids on their geographical location. For southern Baltic Sea the properties
are not recognized sufficiently yet. Accounting for that fish swimbladder morphometry
effectively impacts on the backscattering, it is important to study the morphometry of southern
Baltic herring and sprat. It motivated the paper study. The paper is addressed to the
development of the methodology of the analysis of the accurate shape of the swimbladder. The way
of the fish catch, transport and storage, the X-ray irradiation and the X-ray image analysis
was developed.