Construction, Assembly and System Deployment of a Fish Cage with Copper Alloy Mesh Pen: Challenging Work Load and Estimation of Man-Power

2014

2013

This document is a practical guide that provides the list and technical details of materials to use in order to construct a hexagonal wooden cage for fish farming, and its mooring system, for the practice of artisanal aquaculture. The instructions for assembling the various components are illustrated in detail, and the technical guidelines for cage placement at the farming site are also described. This manual also offers advice on the choice of cage model and components to be used based on the environmental, logistical and social conditions of the site.

In India, open sea cage culture has been successfully demonstrated and several experimental offshore cages for mariculture were installed along the coast for on-farm demonstration by the Central Marine Fisheries Research Institute, Cochin. In the present study, a model cage was fabricated and tested in a towing tank under different waves and current load conditions. The tension on the mooring chain was measured during the experimental study, besides the towing speed and wave parameters. Based on the experimental data, drag coefficient for the cage net twine was estimated. The tensions in the mooring chain and the cage net twine of the prototype cage were predicted based on the model data. The maximum tension on a single twine of the outer and inner fish net were estimated as 0.15 N and 0.028 N respectively. The force on the net was more than 1.7 times the force on the floating collar and sinker pipe. The tension in the mooring line is mainly due to the force on the net. Further it w...

BIO Web of Conferences

Reservoirs and lakes are widely used for fisheries, both capture fisheries and aquaculture. Aquaculture fisheries that develop in reservoirs or lakes include floating net cages culture (FCC) and pen culture. Besides impacting the economy and employment opportunities, aquaculture activities through FCC can decrease water quality from uneaten feed and fish metabolism residue. For this reason, an environmentally friendly FCC is needed to reduce aquaculture waste. This paper reviews the development of ecologically friendly FCC research in Indonesia. Several studies on environmentally friendly FCC include double net FCC, bio-cages, carpel FCC, windowed, and triple layer FCC. Double net FCC still allows the remaining uneaten feed and feces to settle. Bio-cage research is in the innovation model stage and has no prototype or laboratory tests. Windowed FCC, made with a closed system and a few gaps for circulation, can accommodate aquaculture waste and not spread into the waters, but fish gr...

IOP Conference Series: Earth and Environmental Science, 2018

Fish production is important for the economy in fishing community and for ensuring food security. Climate change will lead a threat to fish productivity. Therefore, a solution offered is to cultivate certain fish, especially those with high economic value by using offshore aquaculture technology. A Sea Station cage is one of the offshore aquaculture cage model that has been used in some locations. As a floating structure, the Sea Station cage need a mooring system to maintain its position. This paper presents the selection analysis of the mooring system designs of the Sea Station cage model that it is suitable with Indonesia Ocean. There are 3 mooring configurations that are linear array, rectangular array, and 4 points mooring type. The nylon mooring rope type has been selected to be used on the 3 mooring configurations and the rope has a diameter of 104 mm with a breaking force of 2.3 MN. Based on results from comparing the 3 mooring configurations, the best mooring configuration is linear array with the tension on the rope of 217 KN and has the safety factor of 0.2 based on DNVGL OS-E301

2012

As more than 71% of the Earth’s surface is covered by water, aquaculture is considered as a formidable alternative to meet rising World population food needs. However, aquaculture is a multi-faceted economic activity requiring scientific expertise from multiple disciplines to bear its successful exploration. This paper deals with the main engineering challenges to be met for sustainable coastal cage aquaculture. In detail, a brief overview of the aquaculture practices is provided, coupled with the main engineering challenges as these apply for the coastal cage aquaculture. Finally, the case of a structured approach development to meet the needs of mooring scenario generation is presented as this applies for the Cyprus’ South Coast aquaculture industry. Key-Words: Coastal aquaculture, Aquaculture Mooring, Sustainable Aquaculture, Aquaculture Engineering.

FAO Fisheries and Aquaculture Technical Paper No. 593, 2015

Global aquaculture production has been steadily growing in recent decades, increasingly contributing fish and other edible aquatic organisms of commercial importance entering national, regional and international markets. The growing demand for such products has stimulated the development and expansion of aquaculture production systems both on land and in all waterbodies, covering technologies ranging from the production of seed material to ongrowing structures and other farming support facilities. In recent decades, the aquaculture industry has also intensified its production output per unit area of space or volume, mainly to compensate, among other things, for the growing competition for land and water surfaces for other uses. The expansion of fish farming in the sea, also referred to as “mariculture”, has happened as a result of several supporting factors. These include the acquisition of reproduction and ongrowing technologies for species of interest, and the development of physical structures to contain the cultured organisms. Modern marine cages, whether floating or submersible, represent one such development. These have evolved significantly from basic and rudimental systems to sophisticated and carefully engineered structures. Many cage designs and models have been developed and are commercially available. Among these, high-density polyethylene (HDPE) cages are widely used, because of the versatility of the materials used, the relative simplicity in the performance of the various farming operations, and the comparatively limited investment capital required. Technological improvements of HDPE cages are evolving with the availability of new materials and the various equipment items needed to service all farming operations. This manual focuses on technical aspects of HDPE cages; however, the introductory chapter covers the importance of proper site selection in terms of site exposure and environmental parameters that affect the well-being of the culture fish and affect farm structures. Proper siting of a cage farm is of paramount importance with regard to the overall technical and economic success of the commercial operation, and for reducing as far as possible the environmental footprint of the farm. Prior to describing the characteristics of HDPE cages and elements making up a culture unit, the handbook describes the grid and mooring systems that support the fish cages. Information is provided on the components of the two systems, their technical specifications in relation to farm size as well as on-land assembling and sea installation procedures. A chapter focuses on the floating collar of the cage, describing the components that make up this key farming structure. The technical specifications and design options are provided for the key elements of the collar readily enabling the construction of structures that meet the needs of the operator and are suitable for the environment in which they will be placed. Technical information is then provided on the ropes, netting and net cage design and on determining the appropriate size and shape. Based on procedures developed over years of field experience, practical information on collar and net installation, net changing, maintenance and inspections technique is provided. The final sections of this publication covers practical procedures related to the stocking of cages with seed material, feeding and managing the fish stock, as well as practical information on pre-harvesting and harvesting methods, fish handling and transportation. Some information is also provided on farm safety procedures, highlighting the potential risks when working on a cage farm either on the floating structures or underwater.

North American Journal of Aquaculture, 1999

We describe the design for a submerged cage that is suitable for aquaculture research and is durable, portable, and affordable. The 1.0-m 3 cages are constructed of galvanized-steel strips and semirigid, high-density polyethylene mesh. The strips are welded together to form panels. The mesh is attached to the panels with an adhesive or silicone before the panels are coupled with self-tapping sheet metal screws. Mesh security is aided by sandwiching the mesh between adjoining panels. As designed, the cage is easy to dismantle for transport and to reassemble on site without sacrificing strength. When disassembled, a cage is 1/10th of its original size. Total weight of a cage is 23 kg. For each cage, total material cost is approximately US$65, and estimated total construction cost is less than $120.

Journal of Marine Science and Engineering, 2020

In Japan, the marine aquaculture net cage has an important role in farming pacific bluefin tuna farming in oceans, and the design of the net cage needs to ensure robustness against hostile oceanic conditions. Accordingly, this study focuses on the drag forces and the cage volume of the net cage, and on their variations induced by different design parameters (netting solidity ratio, netting height, and bottom weight). A series of parametric studies on drag force and deformation of the net cage was conducted using a numerical simulation model. Accordingly, the contribution of each parameter to the drag and volume was analyzed using a generalized additive model. The results indicate that the bottom weight had the highest contribution to the holding ratio of the cage volume, whereas the netting height had the highest contribution to the drag coefficient of the net cage. Finally, a fast prediction model was created by a backpropagation (BP) neural network model and was examined for the a...

Oceanography & fisheries open access journal, 2020