Feeding the Future
About 70 percent of the world's fisheries are threatened by overfishing - we hit "peak fish" two decades ago. Therefore, if we can't take more wild fish out of the ocean, aquaculture must meet the seafood demands of a growing global population. Terrestrial crops consume precious fresh water resources and require harmful fertilizers; livestock produce an enormous carbon footprint that is unsustainable. That is why aquaculture is the fastest growing form of food production on the planet.
The trophic level of an organism is determined by the position it occupies in the food chain. Ecologically speaking, shellfish are considered low-trophic because animals they are close to the plant base of the marine food web pyramid.
There are three major benefits for the cultivation of shellfish in terms of ecological, social equity and wallet-friendly values. The benefit to the marine environment is based upon an ecological principle: At every step up the marine food web, 10 percent of the biomass is lost. The biomass in the oceans is concentrated at the base of the pyramid, near the plants and those animals that directly feed the plants. As we move up the food web using lower-trophic sardines and anchovies to feed higher-trophic fish and land animals, we are losing protein and value while spending more energy for less protein.
Co-cultivation of shellfish and seaweed is the non-controversial and appropriate approach for large-scale offshore mariculture to feed the future while concurrently sequestering carbon and nitrogen from coastal ecosystems.
Low-trophic mariculture could become the next agriculture, particularly for regions confronted with water shortages and possessing ideal coastal conditions. Species feeding low in the food chain efficiently utilize natural resources. Each level up the food chain inflates costs related to the use of resources, the production of waste and the maintenance of water quality.
