Best practice of using air-bubble curtains as part of complex fish protection structures

Приведены результаты исследований работы комплексных рыбозащитных сооружений с использованием воздушно-пузырьковых завес. Дано описание механизма работы комплексных рыбозащитных сооружений и принципа работы воздушно-пузырьковой завесы. На основе гидравлического расчета разработана методика проектирования и применения воздушно-пузырьковой завесы в составе комплексных рыбозащитных сооружений. Приведены результаты исследований по оценке функциональной эффективности построенных комплексных рыбозащитных сооружений. Комплексные рыбозащитные сооружения, имеющие в своем составе запани и воздушно-пузырьковые завесы и работающие в эрлифтном режиме, достаточно эффективно защищают молодь рыб. При правильно подобранных параметрах работы оборудования и выбранном створе размещения сооружений, с учетом гидравлических и технических особенностей водозабора, их эффективность гарантированно превышает нормативные значения. The results of studying the operation of complex fish protection structures with the use of air-bubble curtains are presented. A description of the operating mechanism of complex fish protection structures and the principle of operation of the air-bubble curtain is given. On the basis of a hydraulic calculation, a method for designing and using an air-bubble curtain as part of complex fish protection structures has been developed. The results of estimating the functional efficiency of the built complex fish protection structures are presented. The complex fish protection structures that include debris deflectors and air-bubble curtains and operate in an air-lift mode, effectively protect fish fry. Provided the operating parameters of the equipment and the selected alignment of the structures with account of the hydraulic and technical features of the water intake have been correctly chosen, their efficiency is guaranteed to exceed the standard values.

DEVELOPMENT OF A FICH PROTECTION DEVICE DESIGN

The water intake structure is a functional element of the water supply system, but it must also be a fish protection object. The following basic requirements are imposed on the devices of modern fish protection devices at water intakes: prevention of ingress and death of young fish and larvae, prevention of injury to young fish and larvae, removal of protected fish from water intake, reliability of operation under specific conditions and means. According to the principle of operation, the most effective is the active scheme, with the forced formation of the hydraulic flow structure. The design of a universal combined type device with the use of a jet generator as a flow-forming element that creates a reactive hydraulic movement designed to protect fish and juveniles with a body size of less than 15 mm is proposed.

Efficiency of Sonar Fish Protection Device at the Kokaral Dam of the Small Aral Sea

The study aimed to assess the efficiency of the pilot hydro-acoustic (sonar) fish protection device (SFPD) installed at the Kokaral Dam of the Small Aral Sea. For this purpose, between August 27 and September 5, 2020 experimental and control fish catching was carried out using fixed fishing nets (30×60 mm mesh). The SFPD’s effectiveness was assessed based on the amount and species diversity of the caught fish with and without the SFPD operating. Fish behavior and distribution were monitored using an echo sounder. In terms of quantity, 173 fish were caught with the SFPD off, and 94 with the SFPD on. In terms of biomass, the values were 37.5 kg and 27.6 kg, respectively. With the SFPD off, the ichthyofauna composition was represented by 12 fish species: carp, crucian carp, roach, ide, bream, common rudd, saber carp, snakehead, pike perch, perch, pike, and asp. With the SFPD on, roach and ide were absent in the catch, and the quantity of common rudd significantly decreased. In both catches, the quantity of carp and crucian carp was similar; bream and saber carp specimen were sporadic. The number of predatory fish (pike, perch, snakeheads, and pike perch) in the catches increased. Asp was absent in the net catches also; however, this fish species represents the main object of amateur hook and line fishing. Based on the catch-per-effort unit, it can be concluded that whereas the SFPD observed efficiency for small non-predatory fish like ide, roach, and common rudd was 95%, it was 0% for large non-predatory fish (carp and crucian carp); and negative for predatory fish.

Ammonia Monitoring in Aquarium for Fish Protection and Alert Generation

Fish is an important species that benefits human life in several ways. Fisheries are the best food provider and also aquarium is used at home and public places which becomes decoration cum mind relaxing item. There are lot of attack to fish which goes unnoticed. Large number fish die due to the ammonia (NH3) produced as a by product of protea metabolism and is the most common waste product of fish. There is a given level of ammonia that becomes dangerous and leads to death of the fish. One of the solutions to this issue is to monitor ammonia in aquarium for fish protection and alert generation. A prototype is developed for monitoring the ammonia in the fish tank using Intern is used for protection and alert generation. Ammonia is monitored by measuring pH values. In this project a prototype model is developed that is connected through Internet of Things (IoT) such that it can be monitored in a remote station through mobile app. The prototype model includes an LCD display for local readout. The project will reach the benefit to many engaged in fisheries industry and also who are using Aquarium.

Changes in the Methodology for Determining the consequences of Negative Impacts on the State of aquatic biological resources and their Habitat

On March 17, 2021, Rosrybolovstvo Order No. 238 of May 6, 2020 "On Approval of the Meth-odology for Determining the Consequences of Negative Impacts during Construction, Recon-struction, and Major Repairs of Capital Construction Facilities, the Introduction of New Techno-logical Processes and other Activities on the State of Aquatic Biological Resources and their Habitat, and the development of measures to eliminate the consequences of Negative Impacts on the State of Aquatic Biological Resources and their Habitat, aimed at Restoring their Disturbed State" (Methodology) [1]. This document is not only a normative act, but also a practical guide to the independent calculation of damage when planning economic activities. Earlier, the Order of Rosrybolovstvo No. 1166 of November 25, 2011 was used to assess the damage [2]. Due to the exceptional importance of the Methodology in the field of fish protection and impact assessment on aquatic biota, we have prepared a brief overview of the significant changes that have affected the text of the document. References in the text, unless otherwise specified, point to the points of the new Methodology.

WATER INTAKE FROM A SURFACE WATER SOURCE FOR FISH BREEDING AND RECLAMATION COMPLEXES

Purpose: development of a layout-design solution for water intake from a surface water body, excluding the entry of harmful aquatic organisms into fish-breeding reservoirs. In accordance with modern ideas about water intakes that meet the requirements of fish protection and prevent the ingress of aquatic organisms into water supply system of fish-breeding complexes, filtering water intakes are the most effective. Materials and Methods. The water intakes structures development is based on the materials of the fish and water body surveys and the results of the analysis of developments in this area. Results. As part of water nutrition system of the fish-breeding complex, it is proposed to use a water intake with a two-chamber water inlet equipped with filtering panels and regulating screens. Filtering panels located at the head of each of the chambers ensure the retention of harmful, weed and predatory aquatic organisms, and the screens ensure the water inlet shutdown at replacing the filtering panels. Various modes of water inlet chambers operation are considered for intake of various water flows, replacement of filter cassettes and shutdown of water intake operation. It is proposed to use a filtering panel with impervious chambers, which make it possible to simplify the cleaning of its filler as a filtering element. Conclusions. A layout solution for a filtering water intake as part of water nutrition system of the fish-breeding complex has been proposed and developed. The design of a two-chamber water intake based on the use of filter panels and impervious screens, providing fish protection functions and preventing harmful, weed and predatory species of aquatic organisms from entering the water supply system is developed. A technology for water inlet functioning under various operating modes of the water intake has been developed. It is proposed to use a filtering panel with a simplified scheme for cleaning it from colmatation products as a water inlet element of the water intake.