Defining Sustainable Seafood: The Use of Life Cycle Assessment (LCA) in Eco-labeling

By Teressa Pucylowski

Seafood has long been a valuable source of food across the globe and, despite concerns about overfishing, global per capita availability of fish for human consumption has actually doubled since 1970 – thanks to the rapid growth of aquaculture. However, amid concerns such as overfishing, pollution, climate change, health hazards, and exploitation of fishworkers [1], the public is demanding more information on where their seafood comes from and how it was harvested or produced. With this surge in demand for responsible seafood harvest and production has come a set of tools to identify and label certain fisheries to be marketed as sustainable. The most commonly used methods include certification programs (or eco-labeling) and consumer awareness programs.

You may notice if you go to your local grocery store that some of the seafood options will have a small blue sticker with a √ on it, labeled “MSC Certified”. The Marine Stewardship Council (MSC), which started in 1992, is a prime example of a certification program that provides a label telling you that it comes from sustainably harvested wild stocks, according to independent certifiers that follow their Principles and Criteria for Sustainable Fishing.

These are aimed at identifying species from fisheries that are well managed, and in which stocks are sustainably harvested. The labels also promote traceability – so you know where the fish came from. What MSC certification fails to do, however, is address the broader environmental impacts related to industrial fishing such as greenhouse gas emissions or pollution runoff [1]. Additionally, the MSC only certifies capture fisheries, hence the Aquaculture Stewardship Council (ASC) was created to address concerns regarding farmed seafood, although the program is still in its early stages of development.

Consumer awareness programs include “fish lists” such as The Monterey Bay Aquarium’s Seafood Watch Program in seafoods are listed and categorized as “best choice”, “good alternative”, and “avoid” options based on scientific information and the opinions of outside research groups. According to the US West Coast consumer guide, Alaskan cod and farmed rainbow trout are listed as best choices. Other similar lists include Blue Ocean Institute’s “Guide to Ocean Friendly Seafood” and guides from World Wildlife Fund (WWF) [1]. As with certification programs, these lists are based on a limited range of considerations.

This is where life cycle assessment (LCA) comes in.

Many concerns regarding seafood harvest are often overlooked. For instance, how much fuel do fishing boats use or how much feed was used to produce farmed salmon? Life cycle assessment has shown these two factors are the largest contributors to greenhouse gas emissions from wild and farmed fish, respectively [2]. Such information is rarely considered by current sustainable seafood sustainability labels or consumption advisories.

LCA can account for more than just greenhouse gas emissions. In fact, this method allows consideration of other broad but significant environmental impacts that are often overlooked in other methods—including toxic emissions released by food production systems such as antibiotics and pesticides, and the use of limited resources such as freshwater and oil.

Life cycle assessment is not a new methodology – it was originally designed to follow a given product from “cradle-to-grave”, beginning with the assemblage of raw materials and resources used for its production and ending with its disposal, thus giving it a holistic analysis [3, 4]. To put this into a seafood perspective: you could, for example, follow the production of one ton of live lobster starting with trap setting and bait selection, continuing through the supply chain, and ending with the lobster served on your dinner plate [5]. As one study mentioned “not even certification, which assesses products, takes a product perspective”; in other words, programs like MSC do not look at the full environmental consequences of actually processing a product [2].

LCA can also be broken down into subsystems like “feed production” or “transport”, identifying all inputs (e.g. electricity use) and outputs (e.g. emissions) within the system. Thus allowing identification of stages within the system with the highest environmental impact [3]. Importantly, this is a standardized method so that impacts can be quantitatively compared between products [2].

With a growing number of LCA studies focused on seafood we are continuing to gain new insights into our current understanding of sustainability. For example, the amount of fuel used to harvest an overfished stock is significantly greater than that for an abundant stock due to the extended amount of time needed to find enough fish. The type of gear used to catch fish can also make a notable difference in fuel use, e.g. using seine nets to collect tuna is three to four times more energy efficient than hook-and-line methods. Even the energy source itself is an important thing to consider, i.e. whether it comes from fossil fuels or renewables. LCA is useful in that it actually takes into account all of these considerations, thus amplifying our understanding of the environmental impacts of seafood production [2].

Given recent press on the use of slave labor in shrimp value chains [6], some of you may be questioning the incorporation of social impacts of seafood harvest and production. Unfortunately, none of the above mentioned methods adequately address social issues. However, as awareness of inequity and social injustices relating to the seafood industry rises, there is increased pressure to include of these elements in sustainability assessments. In recent years, efforts to include social and economic implications have been developed within LCA studies, although there is much progress yet to be made.

The bottom line is that there is a lot to think about when choosing what fish to buy. The number of factors to consider can be overwhelming, but it is important to be aware of the various contemplations. With all this contrasting information, it may also seem nearly impossible to pick a truly sustainable seafood option. You may decide to go with values that matter most to you. Are you mostly concerned with climate change and carbon emissions? Are you worried about chemical use and potential effects on human health? Perhaps high rates of bycatch are the most troublesome to you. Regardless, LCA can help make this information available for consumers to make their own educated choices.

Sources:

[1] Pelletier, N., & Tyedmers, P. (2008). Life cycle considerations for improving sustainability assessments in seafood awareness campaigns. Environmental Management, 42(5), 918-931.

[2] Ziegler, F., Hornborg, S., Green, B. S., Eigaard, O. R., Farmery, A. K., Hammar, L., … & Vázquez‐Rowe, I. (2016). Expanding the concept of sustainable seafood using Life Cycle Assessment. Fish and Fisheries.
[3] Baumann, H., & Tillman, A. (2004). LCA in a nutshell. In The hitch hiker’s guide to LCA: An orientation in life cycle assessment methodology and application (pp.19-41). Lund, Sweden: Studentlitteratur AB.

[4] Pelletier, N. L., Ayer, N. W., Tyedmers, P. H., Kruse, S. A., Flysjo, A., Robillard, G., Ziegler, F., Scholz, A. J., & Sonesson, U. (2007). Impact categories for life cycle assessment research of seafood production systems: review and prospectus. The International Journal of Life Cycle Assessment, 12(6), 414-421.

[5] Driscoll, J., Boyd, C., & Tyedmers, P. (2015). Life cycle assessment of the Maine and southwest Nova Scotia lobster industries. Fisheries Research,172, 385-400.

[6] Ferdman, R. (2015). Don’t eat that shrimp. The Washington Post.
Figures:

Fig 1. https://washunetimpact.wordpress.com/2012/11/07/monterey-bay-aquarium-seafood-watch/

Fig 2. https://blacktieandflipflops.com/2015/07/19/wfm-greenpeace-7-15/

Fig 3. Jameel, F., Daystar, J., & Venditti, R. A. (N.d). Environmental life cycle assessment [Powerpoint presentation]. North Carolina State University