DETERMINING OF OPERATIONAL PARAMETERS FOR TRAWL SYSTEM TAKING INTO ACCOUNT EXPERIMENTAL DATA ON SHAPE OF THE ROPE-NET SHELL OF MIDWATER TRAWLS

• Published in: Izvestiya TINRO
• Main Authors: O. N. Kruchinin, E. A. Zakharov, D. L. Shabelsky
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: Transactions of the Pacific Research Institute of Fisheries and Oceanography 2020
• Subjects: рабочие параметры разноглубинной траловой системы; канатносетная оболочка трала; горизонтальное раскрытие трала; аппроксимирующие уравнения; погрешность расчетов; адекватность моделей разноглубинной траловой системы; Aquaculture. Fisheries. Angling; SH1-691; Okhotsk; okhotsk sea
• Online Access: https://doi.org/10.26428/1606-9919-2020-200-193-209; https://doaj.org/article/04dd9aea8ba24d928aee8e4c044ea625

Calculating of horizontal opening for a trawl mouth using the mathematical model of midwater trawl system developed by V.I. Gabryuk gives the errors 25.4 and 32.9 %, on average, for the trawls RT 57/360 m and RT 80/396 m, respectively. The significant errors cause doubts about correctness of this model equations application for calculation of the catch zone that is necessary for assessment of abundance and biomass of marine biological resources. New empirical equations are proposed on the basis of experimental data on shape of the rope-net shell of a midwater trawl, which allow to calculate the horizontal opening for its certain sections. The errors of the horizontal opening calculation with these new equations are 13.7 and 6.1 %, on average, for the trawls RT 57/360 m and RT 80/396 m, respectively, that is satisfactory for using them for calculating operational parameters of a midwater trawl system. The operational parameters of the midwater trawls RT 57/360 m and RT 80/396 m are calculated using Baranov’s approach with these new empirical equations, and their good adequacy is shown in the experiment with hydroacoustic measurements of the trawls mouth horizontal opening and the distance between the trawl doors conducted aboard RV TINRO and RV Professor Kaganovsky in the Okhotsk Sea in 2012–2015.