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Por: Salvador Meza *
RAS systems that use renewable energies such as wind, solar, or geothermal are outlined to ensure aquaculture’s environmental and financial sustainability. Not so much because of an increase in production per unit area, but because of the decrease in resources waste from the feed not consumed in cages and ponds.
In a world that is getting smaller every day, where the limit of the exploitation of many natural resources, which previously seemed infinite, is already in sight, the challenge of any economic activity is the possibility of remaining sustainable and financially viable on a predictable timescale.
In this sense, the perennial potential that we have always wanted to see in aquaculture also draws its limits on that timescale, and although it has not exploited all its desired growth, its development could be caught between the challenges of climate change, the increase of greenhouse gases, the availability of water, the viability of agriculture, and the disorder of fishing.
Aquaculture expansion depends not only on the environmental and financial sustainability of its farms and production centers but also on the sustainability of the entire supply chain that makes fish and shellfish production possible. And in this sense, aquafeeds bear the greatest responsibility.
It is difficult to imagine, in a world limited by all these environmental and economic factors, the situation of feeding shrimp in a pond, where we know in advance that the cultured shrimp will not ingest a greater percentage of this feed. We use 10 grains or pellets of feed so that perhaps a shrimp consumes one or two entirely. And what happens to the rest of the pellets? Although the rest of the pellets can become part of the feed of a zooplankton chain, which is later assimilated by the shrimp or colonized by bacteria, and becomes a floc rich in nutrients to be later ingested by the shrimp, it is, in reality, a waste.
In this wasted feed, or expensive fertilizer and floc, there are a few tons of fishmeal, soybean meal, rice, oil, canola, and a few kilos of other high-tech and high-value inputs, such as vitamins, minerals, probiotics, and even peptides, free amino acids, organic acids, essential oils, etc. We should not waste one gram of such a wide variety of inputs, coming from a technological development supported by other resources and a considerable financial investment. This makes the uneaten feed a true waste of valuable agricultural, livestock, and fishing resources.
“In this sense, aquaculture in general and especially shrimp and salmon aquaculture, which demand the most significant amount of specialized feeds with a composition of high-value ingredients, must urgently evolve towards technological production systems that minimize resources waste.”
This is the great challenge that we all have and that aquafeed companies must lead. It is no longer about making extruded foods that last longer in water without leaching, with attractive additives to be consumed in less time, or feeding on demand with automatic feeders. Although all these technologies have given aquaculture an important advance, they still do not limit the waste of resources of uneaten feed, which, in a world convulsed by the availability of resources, will not be possible.
What is the way forward, then? Production in RAS systems where there is maximum control of all the crop variables, but especially of the feeding. Production systems in which the species will certainly consume each pellet that is put into the water. Thus limiting, on the one hand, the over-formulation of additives to ensure that they will arrive in quantity and form at the organisms in culture. On the other hand, the amount of food that went to waste in traditional systems.
Finally, to reflect on. If we consider that 10% of the feed that is used in shrimp ponds and pools in the world is not consumed by organisms in culture (which is a conservative percentage) and that the average FCA is 1.3 (** which is conservative as well), we could well speak of 650 thousand tons per year of uneaten feed that is a total waste. If we multiply these 650 thousand tons by USD 850.00 per ton of shrimp feed, we would have $552 billion annually dumped into the culture ponds that the shrimp will not consume until they become zooplankton or bacteria flocs.
An alliance of global shrimp feed manufacturers that constitutes an Investment Fund with these 552 billion dollars per year for the feasible development of RAS technologies with renewable energies could be better than throwing them away in shrimp ponds.
** (Figures based on 2020 production, according to GOAL.)
