By Allan Hirsch
When it comes to running a profitable ocean-based fish farm, two of the biggest obstacles are fish loss and poor growth rates. While there are many possible causes for each of those challenges, environmental conditions often play a key role.
Fortunately, there are ways to help combat both of those problems through aeration and oxygenation.
Both processes use a system of valves and supply hoses that are connected to diffuser assemblies at the bottom of each fish pen. Operators can then pump either air or oxygen into the water in each pen to achieve their desire results.
Although the two systems have much in common, they are used for different purposes.
Aeration systems use an air compressor to distribute diffused air at the bottom of the fish pen. This creates upward water movement that brings colder, cleaner, oxygen-rich water to the fish in the pen.
Aeration is used to fend off harmful algae blooms, improve poor water quality caused by tarps/lice skirts and help regulate fluctuating water temperatures.
Similar to an aeration system, oxygenation uses an oxygen generator to distribute diffused oxygen into a fish pen. Oxygenation is mainly used when there are low levels of dissolved oxygen in the water or when dissolved oxygen has rapidly dropped to the point where fish will not feed, which can lead to starvation and mortality. Adding pure oxygen directly into the pens can quickly improve fish health and stimulate feeding and growth.
Strategies for Aeration and Oxygenation
The best way to ensure healthy fish through aeration and/or oxygenation is by following 3M approach of monitoring, mitigation and management.
- Monitoring: An effective aeration or oxygenation strategy begins with proper environmental monitoring. Farm operators need to closely track key fish health factors such as dissolved oxygen, water temperature, plankton levels and currents.
- Mitigation: Once farm personnel understand the environmental conditions in their fish pens, they can begin developing a mitigation strategy. The amount of air or oxygen sent into a pen is determined by what operators are seeing from their environmental sensors, and operators continue adjusting levels based on the data they see. System adjustments are important to find the right technique for each period within the grow out cycle and for different water conditions.
- Management: Addressing long-term environmental conditions requires a detailed response plan to combine and analyze monitoring data with mitigation results. Having this data and properly analyzing it enables users to make adjustments to their strategy for future improvement.
Taking the 3M approach to aeration and oxygenation at the start – and then sticking with it to fine tune your operations – will help greatly improve fish health and maximize growth for the highest returns at harvest.
A New Breakthrough
While aeration and oxygenation systems have been in use on fish farms for more than a decade and have remained largely unchanged, last week Innovasea was excited to announce a revolutionary advancement: our new aquaControl autonomous aeration and oxygenation system, which enables operators to quickly react to environmental events whether they’re present at the farm or off-site.
Having an adaptable, end-to-end solution gives operators the ability to observe and respond in real time to various site conditions.
Although aeration and oxygenation systems have many similar components, they differ greatly in application. Both technologies, however, require a data-driven management to effectively combat the challenges faced by ocean-based fish farms. This data-driven approach to mitigation provides farmers with the ability to make the right decisions each day to maximize fish health, ensure strong growth and boost productivity.
About the Author
Allan Hirsh is a global product manager at Innovasea and has more than 10 years of experience developing innovative monitoring and control solutions for the aquaculture industry.