Recommendations on estimating krill escape mortality during fishing operations: the problems and approaches

The task to estimate the escape mortality of krill during the fishing operation assigned by Scientific Committee requires assessment of the total krill passed through the rope and netting parts of trawl and krill amount appeared unviable in the process of escapement. The recommendations presented are the first attempt to develop the method of instrumental assessment of the «escape mortality». Estimation of the total amount of krill escaped from the rope and netting parts of the trawl is proposed to carry out on the basis of the complex application of fine-meshed chafers and acoustic method. The method of fine-meshed chafers allows obtaining the quantitative assessment of krill killed during escapement from the trawl. However, the practical implementation of fine-meshed chafers requires special investigation on methodical and technological issues of estimating krill escape mortality. The problems and approaches to elaboration of the efficient method for «escape mortality» study by standardizing data collection and processing, including a standard chafer design, are discussed. Keywords: escape mortality, method of fine-meshed chafers, acoustic methods, krill injury rate, krill viability.