Peter Tyedmers

Sustainability and Global Seafood

Tight coupling to ecosystems and dependence on common-pool resources threaten fisheries and aquaculture. Although seafood is the most highly traded food internationally, it is an often overlooked component of global food security. It provides essential local food, livelihoods, and export earnings. Although global capture fisheries production is unlikely to increase, aquaculture is growing considerably. Sustaining seafoods contributions to food security hinges on the ability of institutions, particularly in developing countries, to protect and improve ecosystem health in the face of increasing pressures from international trade.

Fueling Global Fishing Fleets

Abstract Over the course of the 20th century, fossil fuels became the dominant energy input to most of the worlds fisheries. Although various analyses have quantified fuel inputs to individual fisheries, to date, no attempt has been made to quantify the global scale and to map the distribution of fuel consumed by fisheries. By integrating data representing more than 250 fisheries from around the world with spatially resolved catch statistics for 2000, we calculate that globally, fisheries burned almost 50 billion L of fuel in the process of landing just over 80 million t of marine fish and invertebrates for an average rate of 620 L t−1. Consequently, fisheries account for about 1.2% of global oil consumption, an amount equivalent to that burned by the Netherlands, the 18th-ranked oil consuming country globally, and directly emit more than 130 million t of CO2 into the atmosphere. From an efficiency perspective, the energy content of the fuel burned by global fisheries is 12.5 times greater than the edible-protein energy content of the resulting catch.

Forecasting potential global environmental costs of livestock production 2000–2050

Food systems—in particular, livestock production—are key drivers of environmental change. Here, we compare the contributions of the global livestock sector in 2000 with estimated contributions of this sector in 2050 to three important environmental concerns: climate change, reactive nitrogen mobilization, and appropriation of plant biomass at planetary scales. Because environmental sustainability ultimately requires that human activities as a whole respect critical thresholds in each of these domains, we quantify the extent to which current and future livestock production contributes to published estimates of sustainability thresholds at projected production levels and under several alternative endpoint scenarios intended to illustrate the potential range of impacts associated with dietary choice. We suggest that, by 2050, the livestock sector alone may either occupy the majority of, or significantly overshoot, recently published estimates of humanity’s “safe operating space” in each of these domains. In light of the magnitude of estimated impacts relative to these proposed (albeit uncertain) sustainability boundary conditions, we suggest that reining in growth of this sector should be prioritized in environmental governance.

Not All Salmon Are Created Equal: Life Cycle Assessment (LCA) of Global Salmon Farming Systems

We present a global-scale life cycle assessment of a major food commodity, farmed salmon. Specifically, we report the cumulative energy use, biotic resource use, and greenhouse gas, acidifying, and eutrophying emissions associated with producing farmed salmon in Norway, the UK, British Columbia (Canada), and Chile, as well as a production-weighted global average. We found marked differences in the nature and quantity of material/energy resource use and associated emissions per unit production across regions. This suggests significant scope for improved environmental performance in the industry as a whole. We identify key leverage points for improving performance, most notably the critical importance of least-environmental cost feed sourcing patterns and continued improvements in feed conversion efficiency. Overall, impacts were lowest for Norwegian production in most impact categories, and highest for UK farmed salmon. Our results are of direct relevance to industry, policy makers, eco-labeling programs, and consumers seeking to further sustainability objectives in salmon aquaculture.

Does aquaculture add resilience to the global food system

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.

Scenario Modeling Potential Eco-Efficiency Gains from a Transition to Organic Agriculture: Life Cycle Perspectives on Canadian Canola, Corn, Soy, and Wheat Production

We used Life Cycle Assessment to scenario model the potential reductions in cumulative energy demand (both fossil and renewable) and global warming, acidifying, and ozone-depleting emissions associated with a hypothetical national transition from conventional to organic production of four major field crops [canola (Brassica rapa), corn (Zea mays), soy (Glycine max), and wheat (Triticum aestivum)] in Canada. Models of these systems were constructed using a combination of census data, published values, and the requirements for organic production described in the Canadian National Organic Standards in order to be broadly representative of the similarities and differences that characterize these disparate production technologies. Our results indicate that organic crop production would consume, on average, 39% as much energy and generate 77% of the global warming emissions, 17% of the ozone-depleting emissions, and 96% of the acidifying emissions associated with current national production of these crops. These differences were almost exclusively due to the differences in fertilizers used in conventional and organic farming and were most strongly influenced by the higher cumulative energy demand and emissions associated with producing conventional nitrogen fertilizers compared to the green manure production used for biological nitrogen fixation in organic agriculture. Overall, we estimate that a total transition to organic production of these crops in Canada would reduce national energy consumption by 0.8%, global warming emissions by 0.6%, and acidifying emissions by 1.0% but have a negligible influence on reducing ozone-depleting emissions.

Fisheries and Energy Use

active fishing gear Equipment used for fishing in which the aquatic organisms being targeted encounter the gear primarily through movement of the gear itself. Examples include cast nets, dredges, harpoons, jigs, and all forms of seine and trawl fishing. animate energy Energy dissipated through the application of human or animal muscles to do work. artisanal fisheries Small-scale fisheries that are typically executed by members of fishing households (as opposed to commercial companies) in which relatively small amounts of capital and energy and relatively small, if any, fishing vessels are employed. culturally mediated energy All forms of energy dissipated through the application of technologies in the process of human activities. energy intensity The amount of culturally mediated energy required to provide a given quantity of a product or service of interest. In the current context, energy intensity is expressed either as the total joules of energy required to land a live weight or ‘‘round’’ tonne of fish or shellfish harvested, or in terms of fuel use intensity, the total liters of fuel burned directly on fishing vessels per tonne of fish or shellfish landed. energy return on investment (EROI) ratio A dimensionless ratio calculated by dividing the amount of useful energy provided by a given activity by the culturally mediated energy dissipated in providing it. In the case of food production systems, a common energy output used to calculate the EROI is the edible protein energy yield from the system being evaluated. fishing Any activity that results in the catching, collecting, or harvesting of fish, and or aquatic invertebrates for any purpose other than scientific research. In the current context, the harvesting of aquatic plants and mammals is not considered as fishing, nor is aquaculture. industrial fisheries Those fisheries typically undertaken by commercial companies in which relatively large quantities of capital and energy are deployed. net primary productivity (NPP) The difference between the total amount of carbon taken up by plants via photosynthesis and the amount of carbon lost by living plants via respiration. passive fishing gear Equipment used for fishing in which the aquatic organisms being targeted encounter the gear primarily through their own movement or as a result of the movement of the surrounding waters. Examples include all forms of hook and line gears, drift nets, gillnets, traps, and weirs.

An Ecological Economic Critique of the Use of Market Information in Life Cycle Assessment Research

The rising prominence of life cycle assessment (LCA) and similar environmental accounting frameworks reflects increasing awareness of the pressing necessity of managing both for eco‐efficiency and with respect to the macroscale, environmental dimensions of the material/energy flows and emissions that underpin all economic activity. However, by relying on environmentally myopic market signals to inform evaluations of the biophysical dimensions of economic activity through the widespread use of market information (in particular, via economic allocation) in LCA, we are concerned that researchers greatly compromise the value of their work to furthering these objectives. In response to this problem, we provide a systematic critique of the use of market information in attributional LCA and present the case for an ecological‐economic approach to the execution, interpretation, and application of biophysically consistent LCA research specifically intended to elucidate the environmental dimensions of meeting human needs. We further argue that, although LCA has historically been limited to informing eco‐efficiency considerations, it can and should also be used to manage for sustainable scale, which is the first condition of sustainability.

Life cycle considerations for improving sustainability assessments in seafood awareness campaigns.

It is widely accepted that improving the sustainability of seafood production requires efforts to reverse declines in global fisheries due to overfishing and to reduce the impacts to host ecosystems from fishing and aquaculture production technologies. Reflective of on-going dialogue amongst participants in an international research project applying Life Cycle Assessment to better understand and manage global salmon production systems, we argue here that such efforts must also address the wider range of biophysical, ecological, and socioeconomic impacts stemming from the material and energetic throughput associated with these industries. This is of particular relevance given the interconnectivity of global environmental change, ocean health, and the viability of seafood production in both fisheries and aquaculture. Although the growing popularity of numerous ecolabeling, certification, and consumer education programs may be making headway in influencing Western consumer perceptions of the relative sustainability of alternative seafood products, we also posit that the efficacy of these initiatives in furthering sustainability objectives is compromised by the use of incomplete criteria. An emerging body of Life Cycle Assessment research of fisheries and aquaculture provides valuable insights into the biophysical dimensions of environmental performance in alternative seafood production and consumption systems, and should be used to inform a more holistic approach to labeling, certifying, and educating for sustainability in seafood production. More research, however, must be undertaken to develop novel techniques for incorporating other critical dimensions, in particular, socioeconomic considerations, into our sustainability decision-making.

Life Cycle Assessment of Frozen Tilapia Fillets From Indonesian Lake‐Based and Pond‐Based Intensive Aquaculture Systems

We used life cycle assessment to evaluate a subset of the cradle-to-destination-port environmental impacts associated with the production, processing, and transportation of frozen, packaged Indonesian tilapia (Oreochromis niloticus) fillets to ports in Chicago and Rotterdam. Specifically, we evaluated the cumulative energy use; biotic resource use; and global warming, acidifying, and eutrophying emissions at each life cycle stage and in aggregate. We identify the importance of least environmental cost feed sourcing for reducing supply chain environmental impacts. We also highlight the need for more effective nutrient cycling in intensive aquaculture. The environmental trade-offs inherent in substituting technological inputs for ecosystem services in intensive pond-based versus lake-based production systems are discussed. We further call for more nuanced considerations of comparative environmental advantage in the production and interregional trade of food commodities than has been characteristic of historic food miles discussions. Significant opportunities exist for improving environmental performance in tilapia aquaculture. This product compares favorably, however, with several other fishery, aquaculture, and animal husbandry products, according to the suite of impact categories considered in this study.