WWW.WAS.ORG • WORLD AQUACULTURE • JUNE 2016 25 Acknowledging the high proportion of failures, it is reasonable to ask what went wrong to learn from these experiences and minimize the risk of repeating history. Having spent 30+ years working on RAS projects globally to address operational challenges, I have distilled what I consider to be the ‘big five’ issues that seem to universally plague tightly closed RAS projects and have caused so many to fail. 1. Siting. Inadequate water supply has played a key role in the discipline and engineering specialty. From a farmer’s perspective, modern RAS relies on very highvolume, yet low-cost filtration to maintain excellent water quality that is required to support the health and growth of aquatic animals. That can be a tall order. To meet production targets, the producer must add hundreds or thousands of kilograms of nutrient-dense feed into a tightly closed system. The filtration system must continuously treat water to high standards so that it contains no more than a few parts per million of suspended solids, ammonia, nitrite and typically less than 30 parts per million of CO2. Because this filtration process has to deliver consistent results over the course of an extended production cycle, the systems require a degree of reliability that can be difficult to achieve at a human, mechanical or biological level. Our competitors, who rely on the natural environment to maintain appropriate and suitable conditions, will generally have little to no direct costs to maintain the production environment in a pond, river or net-pen. I often say that RAS are intensive care units for fish. Like patients in the ICU, fish are totally dependent on us for life support, which means mistakes operating the facility are just as unforgiving as they would be in an ICU, except that we have thousands or millions of patients—and relative few doctors and nurses. Perhaps it is for these reasons that so few commercial RAS projects have succeeded. Table 1 summarizes the operational status of the majority of US-based RAS projects that I am aware of that were developed over the past 20 years. This list almost certainly misses numerous smaller projects that also were developed during this timeframe. In aggregate, these projects represent a combined investment likely exceeding $1 billion dollars and a tremendous human effort to bring this new approach to aquaculture production to market. What Went Wrong? Despite the best intentions, knowledge and commitment of the staff and major financial commitment by owners and investors, very few of these projects have been successful over the long run. (CONTINUED ON PAGE 26) TABLE 1. Status of commercial fish farms in the US based on RAS technology.
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