For several years, MAP has pointed out the potential of recirculating aquaculture systems (RAS) as a better way forward for aquaculture systems. Since aquaculture has actually been around for a thousand years, it is not likely to just disappear as a means of raising marine or fresh water fish, clams, shrimp, crabs and seaweed. Yet we all know and have been struggling against the terrible consequences of what is termed "open, throughput systems" of aquaculture, which in all too many cases lead to environmental and social ills. Both the salmon and shrimp aquaculture industries are representative of some of the worst problems resulting from this "open system" style of aquaculture production, and MAP is committed to opposing these deleterious open production systems.
One important benefit of the "closed system" approach, which is what the RAS involve is that these RAS systems can be located next door to the markets that sell the product, within the countries where the demand exists. This engenders the "eat local, buy local" philosophy that the Slow Food movement promotes, and makes great sense in limiting the international transport costs in terms of fuel and pollution, which contribute to global warming. These RAS systems can feed people, while not causing food insecurity in the process, as happens from "open system" production such as floating salmon pens or excavated shrimp ponds.
Other benefits of these closed systems are mentioned in the article below, but there are still two important points that need to be made to ensure that these are truly "closed systems" that are being promoted, and not still ruinous "open systems." We need to ensure that those promoters of RAS, such as Monterey Bay Aquarium and Seafood Choices, are promoting the following aspects as vital to what closed systems must include before being given this "green" label of their endorsement:
1) FEED- These systems must not rely on wild capture fisheries to feed their farmed species. There needs to be sustainable production of feed for the raised species that does not cause harm to our wild fisheries, as is the case for the fish feed industry today. This "for-farm-feed" production could be from algae, seaweed, mollusks and fish grown within the RAS facility itself, or grown for that facility from a nearby feed production source. Also, plants such as vegetables and grains could supply needed feed nutrients, but must come from organic, non-GMO sources of production.
2) SITING- The RAS facilities must be sited on non-contested lands that are not usurping the land tenure or resource rights of the affected communities living in the area of the RAS facility. Also, the RAS is not damaging surrounding natural resources, such as wetlands or productive farmlands. These restrictions can be realized because one of the major advantages of the RAS is that it can be located just about anywhere, including in deserts or on building rooftops.
3) A SUPPLEMENT, NOT A REPLACEMENT FOR WILD FISHERIES- Aquaculture must be a supplement, not a replacement for our wild fisheries. And, in the process, aquaculture should not damage or destroy wild fisheries habitat or the natural environment that supports wild marine and fresh water fisheries. In other words, no clearing of mangroves, no destruction of coastal wetlands, no wreckage or blockage of fresh waterways, no dumping of pollutants, etc.
It is important that we continue opposing "open system" means of fish, mollusk, or shrimp production, as these can be detrimental to life on our planet. Meanwhile, if there is a better way, then let's take that path. RAS within the limits I have outlined above may be that better way forward. It is, however, still in its early phases of development that needs our careful scrutiny.