Submerged Net Cage with Fish-Dismiss Ceiling for Plankton Protection
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Solution Overview
Problem
Fish in open net cages are exposed to toxic planktonic algae and salmon lice, leading to health issues and regulatory challenges in fish farming, as existing solutions like skirts and tarpaulins require extensive operations and may not be effective in all conditions.
Innovation Solution
A submerged net cage design with a fish-dismissing ceiling and a connection channel that allows fish to swim to the surface while keeping pathogenic plankton out, using a watertight or plankton-dismissing net material, and incorporating a medicament delivery system within the channel for bath treatment, reducing the need for extensive operations and minimizing medicament drift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If open net cages are used for fish farming, then fish can access oxygen-rich surface water, but fish are exposed to toxic planktonic algae and salmon lice
Solution Approach 1:
The water column is segmented into two distinct zones: an upper zone containing toxic plankton and salmon lice, and a lower zone that is relatively free of these harmful organisms. The fish enclosure is positioned in the lower zone while maintaining access to the upper zone through controlled openings, thereby separating the fish from harmful factors while preserving oxygen access.
Solution Approach 2:
A controlled opening or aperture is introduced as an intermediary element between the fish enclosure and the surface water. This opening allows selective exchange of water layers, permitting oxygen-rich surface water to reach the fish while filtering out or limiting exposure to toxic plankton and salmon lice through its specific dimensions and positioning.
2Reliability
If bath treatment with medicaments is performed to treat salmon lice, then fish health is improved, but extensive operations are required and medicament drifts away
Solution Approach 1:
The treatment process is segmented into two phases: prevention phase where the fish enclosure design inherently reduces exposure to salmon lice, and treatment phase where medicaments are applied locally. This segmentation eliminates the need for extensive bath treatment operations by addressing the problem at its source through design rather than through complex treatment procedures.
Solution Approach 2:
The harmful element (salmon lice and toxic plankton) is extracted or removed from the fish environment through the enclosure design that positions fish in a water layer free from these organisms. This extraction eliminates the need for medicament treatment in many cases, and when treatment is necessary, it can be applied more locally and efficiently.
3Quantity of substance
If the net cage depth is reduced for bath treatment, then medicament concentration is increased, but fish access to oxygen-rich surface water is limited
Solution Approach 1:
The water column is segmented into treatment zone and oxygen access zone. The fish enclosure can be positioned or adjusted to allow fish to access oxygen-rich surface water through controlled openings while maintaining the ability to concentrate medicaments in specific treatment areas when needed, thus separating the functions of oxygen access and medicament application.
Solution Approach 2:
The net cage or fish enclosure is made dynamically adjustable, allowing the depth and positioning to be changed based on operational needs. During normal operation, the enclosure allows access to surface water for oxygen. During treatment operations, the enclosure can be adjusted to concentrate medicaments while maintaining fish access to oxygen through controlled openings or temporary repositioning.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively reduces exposure to toxic algae and salmon lice, allows for efficient medicament delivery, and minimizes stress on the fish, while maintaining oxygen levels and preventing escape or predation, thus improving fish health and operational efficiency.
Implementation Method 1
first floating means (4) on a water surface (5) to keep the net cage (1) in a vertical position in a water column
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3B
AI summary
A net cage (1) for farming fish, the net cage (1) including a fish enclosure (3) which is provided with a net (2) which is capable of water throughput, and a first floating means (4) on a water surface (5) for keeping the net cage (1) in a vertical position in a water column, the fish enclosure (3) further being provided with a submerged, fish- dismissing ceiling (22), the fish-dismissing ceiling (22) being provided with at least one opening (28) which is connected to a connection channel (6) which extends from the fish-dismissing ceiling (22) to the water surface (5) and is connected to a second floating means (42; 91, 91'), and the connection channel (6) being arranged for a fish in the fish enclosure (3) to swim spontaneously up to the water surface (5) in the connection channel (6) and back down to the fish enclosure (5), and, in an upper portion (64), the jacket (62) of the connection channel (6) being provided with a swash portion (68) projecting above the water surface (5). A method of farming fish in such a net cage (1) and use of the net cage (1) are described as well.