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Catfish farm using RAS

‏‏‎ ‎Farming Catfish in RAS - Looking behind the scenes

In this Catfish RAS-special, you will read Niels Jeuken’s first-hand account of diving into the world of farming African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS) at Van Melis Catfish Farm, operated by Rick van Melis and his wife, Wendy.

Please note that this visit took place before social distancing and other restrictions were put in place due to the COVID-19 outbreak.

At Alltech Coppens, we firmly believe that working closely with our customers enables us to thoroughly research, develop and produce tailored aquatic feeds. Being driven by key market insights at a customer level (on-farm) makes Alltech Coppens stand out in the industry.

First, I feel very proud to work with a firm that strongly values training and developing its staff, equipping them with the experience and knowledge they will need in their future career. Second, it is unique to have the opportunity to join a farmer’s weekly routine, experiencing the daily life of a fish farmer. Because it is simply impossible to learn how to farm fish in just a week, we decided the approach would be to learn to understand the mindset and way of working of a fish farmer. While doing so, I would immerse myself in the daily farm activities on Van Melis Catfish Farm, overcome challenges and learn to understand key facets at a farm level.

Farming catfish in RAS

Early on my first day, I experienced Rick’s pragmatic approach and his unruffled attention to detail. The first lesson was the importance of biosecurity and respecting hygiene rules — wearing appropriate clothes and disinfecting my hands/arms every single time I entered or left the farm. Second, he explained that the most important aspect of farming fish is to keenly observe fish behaviour and condition, monitor water quality and system parameters and provide good quality, constant feed, free of dust and adapted to RAS. In that respect, Special Pro, specifically developed for African catfish in RAS, is the perfect product.

the world of farming African catfish (Clarias gariepinus)

We start every day by doing a round through the facility, where we check every tank, first observing the fish behaviour and condition. Then we check the self-feeder, clean it and adjust the feed level (if necessary). Finally, we remove the occasional dead fish from the tank. All information regarding feed rate, quality of feed and water, fish behaviour and mortality is collected and logged, indicating the farm’s performance. Next, we conduct an essential check of the RAS-system, where the sedimentation filter is first flushed and then cleaned thoroughly. We then reopen the inlet that allows the system water to flow.

“Over the years, we noticed that this procedure slightly disturbs the peace in the farm, causing minimal stress for the fish,” explains Rick.
“So, we add a fraction of salt to the system, ensuring the fish copes optimally with this routine.”

Catfish farm using RAS

Optimal conditions

In a RAS, an impressive 550 kg of African catfish can be produced per m3, under the optimal conditions, as Rick explained. In order to do so, it is an absolute necessity to stay on top of how the system operates. Comprehensive control, adequate maintenance and keen observation are crucial to success, Rick elaborates.

Van Melis Catfish Farm has its own hatchery and grow-out farm. The grow-out facility consists of three farms, each holding 18 tanks with a maximum capacity of 3,000 kg of fish (2,000 individuals). In the hatchery, you will find 40 aquarium tanks. Having this many tanks allows for frequent grading. It is by grading that you can ensure that each batch is made up of a homogenous group of fish. Here it is again vital to tailor your feed protocol according to the nutritional need, depending on the life stage of the fish.


The foundation

In 1986, Rick’s parents laid the foundation for what later became Van Melis Catfish Farm, which now produces over 300 tonnes of African catfish per year. At that time, Wageningen University was only beginning to develop research and experience in RAS farming in the Netherlands. Since the early 90s, Alltech Coppens has been involved in specialised feed formulation for what was then a new method of farming fish. Over the past decades, we have built a deep understanding of the essentials in RAS feeds, and it is exciting to see the potential of RAS in the aquaculture industry first-hand.

Want to learn more about Catfish in Recirculating Aquaculture System (RAS)?

Good knowledge of management practices and feeding routines are fundamental to the success of both your fish and your farm.