Breaking new ground in larval nutrition

Innovation often comes from unexpected places, and AquaSnow is the perfect example. For us in aquaculture -so used to fish meal/oil, extrusion, pelletising, alternative ingredients from insects, terrestrial farming and crops - it may sound alien that AquaSnow feeds come from dairy and food technology. It definitely took  me some time to get around the idea. 

When I first encountered AquaSnow, it was clear to me that the product had enormous potential. But, I have heard it all before about the topic: micro-diets don't work well, you need to co-feed, larvae don't eat them, they pollute the water, they are kept for emergencies only, and so on. All fair and true, but again AquaSnow was coming from such a different angle that I though that this had to be a good innovation opportunity. In the end, if we were to do the same everyone else was doing, we probably would end having the same results as everyone. 

I challenged AquaSnow to prove me that larvae eat the pellets. They did. So, I was on board. Next, repeated the experiment with difference species - it worked, too. Next: could larvae digest it without succumbing to a polluted tank? That became our small summer adventure. 

I set myself to find the right research center for the job (shameless advertisement to CTAqua in Spain), drafted the experimental design, coordinated the the start of the experiment and stayed around to provide technical support. We were expecting the experiment to end early as our batch of 36.000 European seabass larvae would not be able to digest the feed. We were proven wrong. 

We ran 9 tanks of 120l and 12000 larvae each: 3 fed with AquaSnow, 3 co-fed with live feeds (rotifers+artemia) and 3 fed with live feeds. We monitored gut fill and recorded mortality across the trial. We also monitored turbidity, dissolved oxygen, total ammonia nitrogen and microbial activity through plating. 

At the end of the 10-day trial, the group fed with AquaSnow diets survived just fine, showing similar survival rates to the other two treatments. What is more, the tanks fed with AquaSnow showed considerably less bacterial activity than the others. The rest of the parameters such a dissolved oxygen and total ammonia nitrogen, were also acceptable. 

On the left: a plot showing total mortality for the trial for the three groups with statistically insignificant differences. On the right, agar plates showing vibrio colonies in yellow, one per tank for water samples taken mid-trial. 

To my (limited) knowledge of micro-diet use in larval rearing, this is the first time I see a product being used stand-alone without running into issues. So, we have a diet that the larvae happily eat and they can survive on after yolk-sac absorption. What's next then? We need to see if this feed can be used to take larvae all the way to weaning without affecting growth, survival and quality. For that, we are already laying the ground work. 

What makes this story even more exciting is how it illustrates the concept of the adjacent possible—the idea that innovation often happens by applying ideas from one field to a related, but previously unexplored, area. AquaSnow’s origins in dairy technology provided a set of capabilities and insights that simply we in aquaculture ignore.

This summer's success reminded me that innovation isn’t about messianic eureka moments or reinventing the wheel, but  about finding the wheels that already exist in other domains and putting them to new use. I will continue to look for these intersections, connecting breakthroughs in materials, food science, and process engineering to the unique challenges of aquaculture. I find it incredibly fun. 

If you want to talk more about this project, meet me at Aquaculture Europe in Valencia. I will be presenting a poster on this. 

Until the next one! 

Picture by Marleen Vrij