Softened Seawater Treatment for Ectoparasite Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for treating ectoparasites in fish farms, such as sea-lice and amoebic gill disease, face challenges including environmental concerns, resistance development, and logistical limitations due to the need for large amounts of freshwater and high energy consumption in desalination processes.

Innovation Solution

Softened seawater with a salinity range of 1.0 to 15 g/kg and a Ca2+ content of ≤100 mg/kg is used to treat marine fish, specifically targeting calcium-sensitive ectoparasites like Neoparamoeba perurans and Lepeophtheirus salmonis, by creating a treatment zone within fish farms using nanofiltration to reduce calcium ion concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If antiparasitically active substances are added to water to kill ectoparasites, then ectoparasite populations are reduced, but environmental contamination and resistance development occur

Engineering Contradiction:
Improveectoparasite control effectivenessVSAvoidenvironmental contamination and resistance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the physical-chemical parameters of the water environment by reducing salinity to create a hypertonic stress condition that is lethal to ectoparasites but tolerable to fish. This parameter change (salinity reduction) replaces chemical substance application, avoiding environmental contamination and resistance development while maintaining effective ectoparasite control

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the harmful effect of osmotic stress, which is normally detrimental to marine organisms, into a beneficial selective treatment mechanism. By creating a controlled hypertonic environment through salinity reduction, the treatment exploits the greater osmotic tolerance difference between fish and ectoparasites, turning osmotic stress from a harmful factor into a selective killing mechanism

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If freshwater bathing is used to treat ectoparasites, then treatment effectiveness is achieved, but large amounts of freshwater and high energy consumption are required

Engineering Contradiction:
Improveectoparasite treatment effectivenessVSAvoidenergy consumption in desalination
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of completely desalinating seawater to produce freshwater (excessive action), the invention applies partial desalination to achieve a intermediate salinity level (1-15 g/kg) that is sufficient to create hypertonic stress on ectoparasites while avoiding the high energy costs of complete desalination. This partial action approach maintains treatment effectiveness while significantly reducing energy consumption

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The invention changes the salinity parameter to an optimal range (1-15 g/kg) that balances treatment effectiveness with energy efficiency. This parameter optimization avoids the extreme energy consumption associated with producing complete freshwater from seawater, while still achieving sufficient osmotic stress to kill ectoparasites

Inventive Principle:
Principle #35Parameter changes

3Productivity

If dense fish populations are maintained in fish farms, then economic efficiency is improved, but risk of infectious diseases and parasitic infestations increases

Engineering Contradiction:
Improvefish farming economic efficiencyVSAvoidinfectious diseases and parasitic infestations
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention applies preliminary treatment action by regularly exposing fish to softened seawater conditions before severe parasitic infestations or disease outbreaks occur. This preventive approach maintains dense fish populations economically while proactively controlling ectoparasite buildup, avoiding the need to reduce stocking densities as a preventive measure

Inventive Principle:
Principle #10Preliminary action

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 approach effectively kills or detaches ectoparasites, reducing treatment costs and environmental impact while providing a prophylactic solution for fish farms, enhancing fish health and reducing ectoparasite populations.

Implementation Method 1

a treatment zone (3) in the form of a volume of softened seawater contained in a floating container (4), wherein the softened seawater is produced by nanofiltration of seawater

Methodology Applied
Scientific EffectNanofiltration: Nanoporous Material

Implementation Method 2

Protozoa living in water need to obtain, or at least be relatively close to, isotonic equilibrium with the surrounding water to cope with the osmotic pressure in their cytosol

Methodology Applied
Scientific EffectOsmotic pressure: Osmotic Pressure

Data Source

PatentEP3629738B1Method and system for treating fish in fish farms
Publication Date: 2021.07.21 AKVAFRESH AS
  • EP3629738B1 patent drawingFigure 1
  • EP3629738B1 patent drawingFigure 2
  • EP3629738B1 patent drawingFigure 3

AI summary

The present invention relates to a method and system for treating fish for calcium sensitive ectoparasites by containing the fish for a period in softened seawater having a salinity in the range from 0.5 to 15 g/kg, determined as the total mass of Na+, K+, Ca2+, Mg2+, Cl-, HCO3 -, CO3 2-, and SO4 2- ions being present in a sample of one kg of the softened seawater, and a Ca2+ content of ≤ 100 mg/kg, determined as the mass of Ca2+ ions in a sample of one kg of the softened seawater.