Does aquaculture add resilience to the global food system?

Abstract

Aquaculture is the fastest growing food sector and continues to expand alongside terrestrial crop and livestock production. Using portfolio theory as a conceptual framework, we explore how current interconnections between the aquaculture, crop, livestock, and fisheries sectors act as an impediment to, or an opportunity for, enhanced resilience in the global food system given increased resource scarcity and climate change. Aquaculture can potentially enhance resilience through improved resource use efficiencies and increased diversification of farmed species, locales of production, and feeding strategies. However, aquaculture's reliance on terrestrial crops and wild fish for feeds, its dependence on freshwater and land for culture sites, and its broad array of environmental impacts diminishes its ability to add resilience. Feeds for livestock and farmed fish that are fed rely largely on the same crops, although the fraction destined for aquaculture is presently small (∼4%). As demand for high-value fed aquaculture products grows, competition for these crops will also rise, as will the demand for wild fish as feed inputs. Many of these crops and forage fish are also consumed directly by humans and provide essential nutrition for low-income households. Their rising use in aquafeeds has the potential to increase price levels and volatility, worsening food insecurity among the most vulnerable populations. Although the diversification of global food production systems that includes aquaculture offers promise for enhanced resilience, such promise will not be realized if government policies fail to provide adequate incentives for resource efficiency, equity, and environmental protection.

Keywords: crop resources; diversity; food portfolio management; global change; shocks.

Fig. 1.

Comparison of growth of aquaculture and main food commodities/groups (based on refs. and 2): Growth expressed as annual percentage for the period 1990–2009 and production for 2009. Data on meat from animals obtained from Tacon and Metian (3) and FAO/FAOSTAT (2). Similar sources (1, 2) for data on production of cereals, fruits, and vegetables.

Fig. 2.

(A) Trends in food prices by sector from 1990 to 2013. The y axis is a normalized average (typically, a weighted average) of price relativity for a given class of goods or services in a given region over time (19). (B) Matrix showing the correlations between the sectors and the coefficients of variation. The data are based on global volumes.

Fig. 3.

Global amount of (A) major crop feed ingredients used in aquaculture in compound feeds for fed species, (B) their relative plant equivalents (estimates from ref. 21), and (C) major agriculture products used in all terrestrial animal feeds (3).

Fig. 4.

Five major agriculture items used for animal feeds (for both terrestrial and aquatic culture) and human food according to FAO (1) for feed/food data and aquafeed-plant equivalents (21).