Fish farming for our future

Given the triple threat of population growth, habitat destruction, and changing ocean temperature and chemistry, we have to be ever more cautionary in our approach to taking wild fish out of the sea.

Mark Spalding-150x150Editor’s note: Ecotrust does not currently engage in work related to aquaculture, but we recognize that there is valuable dialogue to be held around this topic.  As always, we welcome discussion in the comment section below.

By Mark J. Spalding

Earlier this year, headlines trumpeted the fact that 2013 is the year that more than half the world’s global seafood consumption needs will be met by aquaculture.  This is no surprise—the United Nations Food and Agriculture Organization estimates that aquaculture needs to expand by about 10% every year in order to fill demand for fish and other aquatic species—especially since 1 in 7 people rely on them as their primary source of protein.  We reached “peak fish” in wild catch from the ocean in the late 1980’s, and ever since, global food security relied on the expansion of aquaculture.

Food insecurity causes political and social instability, and even environmental instability in the sense that the pursuit of food at any cost promotes short-term thinking and reduces community commitment to a shared vision of a more stable, sustainable future.  Continued population growth places additional stress on wild resources.

The author at Guolian Zhanjiang Group’s shrimp aquaculture facility in China. Courtesy of The Ocean Foundation.

As the human population grows, the stress on the wild population of animals in our ocean increases and the system cannot keep up.  The oceans have suffered from decades of industrial overfishing, loss of habitat to development, destructive fishing gear such as bottom trawls, and changes in ocean chemistry and temperature.  The work to rebuild fish stocks and promote more precautionary thinking in managing wild fish stocks proceeds slowly.  As the UNFAO and the World Fish Centre each predict, it is aquaculture that can and should be expanded to meet the food security needs of a growing population.

Aquaculture has been practiced for thousands of years.  In Asia, fish were often raised in rice paddies and harvested when the rice crops were harvested and the paddies drained.  Other systems co-produced fish and vegetables—the waste from one nourishing the other.  Emerging technology allows us to produce diverse species on land in recirculating systems that can allow for local food security and small scale economic development far from the sea.  To be successful as a support for global food security, the deployment of aquaculture methods, the species grown, and the intended customers must both be sensitive to local resource protection and responsive to local demand.  Different contexts demand different solutions.

For example, in regions where refrigeration is scarce, fish must be grown to a smaller size so that they can be consumed without the need for storage, and at a lower cost.  Such fish operations can also supply institutional needs such as hospitals, schools, prisons, and other entities.

In regions where local wild fisheries are a key source of both economic and food security, outside fishers must be discouraged from adding to the pressure on wild fisheries.   Local communities can be assisted in the design of community-owned fishery management schemes.  To maintain commercial fisheries to supply demand, we need to reduce wild fishing effort, allow fish biomass to recover and maintain total catch at a level that is sustainable.

Two major aquaculture industries are less about supporting food security than filling consumer demand in North America and elsewhere—farmed salmon and farmed shrimp.  Most of the farms that produce these animals are in nearshore open waters or in (former) mangrove forests.  It is Atlantic salmon that can be farmed—and often are—far from their home waters.  Atlantic salmon escapees are now competing with Pacific salmon in the upper Northwest and British Columbia.  In Chile, outbreaks of disease have moved the salmon industry to different places along the coast as areas have become too polluted to support the salmon pen.  Feeding them in their cages requires conversion of millions of tons of small prey fish into fish meal—anchovies from Peru, pogies from the Gulf of Mexico, and menhaden from the Atlantic Coast, among them—in addition to antibiotics,  other drugs, and a special dye to make them pink, as though they had had the same diverse diet as their wild cousins.

We have plenty of terrestrial examples from bison to passenger pigeons that showed we were unable to take “wild-caught” animals to a global commercial scale for consumption without driving them to extinction. For most wild prey species, we stopped hunting them, or domesticated them before they disappeared.

Eating carnivorous fish such as tuna or salmon is like feeding cows to lions so we can eat the lions. First, both the tuna and the salmon have to be fed a large volume of fish products to become a marketable size and flavor for the wealthy country markets where they are sold.  Second, their feed is derived from other wild fish populations such as anchovies, herring, pollock, and menhaden that play a significant role IN the water as prey for larger animals.  Third, the prey fish are a significant source of protein for people in all poor, coastal regions.

Thus, we predict we will move toward eating more herbivorous fish — tilapia, carp, and catfish, among others — via recirculating aquaculture systems because of global population growth and feed conversion ratios.  This prediction is not without debate, and it may be on a long time scale that we see it play out in wealthy nations like the United States, but worldwide it may be unavoidable if we wish to avoid a continued downward trend in biomass in the ocean.

Obviously, we need new technologies and new ideas. The good news is they are emerging and being implemented; now, we need to implement them even faster.

New Trends on the Horizon

New Technologies: Recirculating aquaculture systems combined with hydroponic agriculture forms the new space of aquaponics, which  enables the growing of both plants and fish together in one highly efficient system. Aquaponics can provide controls that allow production with lower contaminant loads, and may be an organic alternative. These are especially beneficial if powered by renewable energy, and are designed to prevent loss of water via evaporation.

Focus on Herbivores: Successful herbivore aquaculture could take pressure off the use of wild animals to feed humans or other animals destined for human consumption. Also, farming is an alternative way to produce marine species for the home and commercial aquarium trade and to reduce pressure on vulnerable reef systems

Better Fishmeal:  When we do farm carnivores, such fish farms increasingly are consuming a significant percentage of the “reduction” wild catch made into fishmeal.  Aquaculture thus plays a role in continuing and increasing demand for wild fish.  However, another trend is in the improvements in feed content modifications to reduce the ratio of protein from meat.

Global Unemployment Problems: Aquaculture can provide viable local jobs requiring a variety of skill sets and education levels; although these jobs are not necessarily alternative livelihoods for local fisher communities who don’t want to work in an industrial setting.

Changes in Market Demand: Sustainable aquaculture can meet and encourage the “locavore” movement, while addressing legitimate concerns that global commercial scale aquaculture is the enemy of sustainability.

Rise of Community-Based, Grassroots, Diverse Constituency:  In the United States for example, many recirculating farms are grassroots oriented; the farms are often run by lower-income and traditionally socially disadvantaged individuals and communities in blighted urban areas and food deserts. These grassroots groups often support high quality standards to prevent new entrants who undercut them on quality and price, which would change the industry from overwhelmingly sustainable to something more like factory farming.

At the end of the day, we know that we now have less than 10 percent of the fish that were in the oceans in the 1950’s, while the world’s population has grown from fewer than 3 billion to more than 7 billion people.  Great management and habitat protection can help rebuild fish stocks globally.  Sensible wild fisheries management strategies can help those coastal communities with few alternatives.  Given the triple threat of population growth, habitat destruction, and changing ocean temperature and chemistry, we have to be ever more cautionary in our approach to taking wild fish out of the sea. Cautious starts to look a lot like deploying these new aquaculture technologies on land, with an eye toward managing energy, water, and transportation demands. That approach will ensure food security, to underpin social and economic security, and to allow the ocean stocks to replenish themselves.

Mark J. Spalding is president of The Ocean Foundation.