FW 324 - Seafood Guide: Indicator and Rating Development
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With a mission of identifying seafood choices that would nourish human health, support resilient fisheries, and contribute to ecologically sound practices, the following indicators were developed in order to assess each of the three overarching goals:
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Indicator #1 – omega-3 fatty acid content (Human Health): Omega-3 fatty acid content was chosen as an important indicator for human health because these polyunsaturated fatty acids (in particular eicosapentaenoic acid or EPA and docosahexaenoic or DHA) are thought to play important roles in cell function, brain and eye development, reducing risk of heart disease, and potentially even in decreasing behavioral problems, depression, and inflammatory conditions (Ruxton 2004). While more recent data have indicated some uncertainty around some omega-3-related health claims, there is still conclusive evidence for health benefits associated with EPA and DHA, of which seafood is the only dietary source (US FDA 2019). The omega-3 fatty indicator was approached from a simple quantitative standpoint, utilizing grams of EPA and DHA in a standard 100-gram serving to generate a rating for each seafood item.
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Indicator #2– risk of mercury and other toxins (Human Health): Just as omega-3 fatty acids are a primary health benefit of seafood, the risk of mercury contamination from both marine and freshwater organisms is a primary public health concern, with seafood being the most common source of human exposure to mercury (Karimi et al. 2014). High levels of exposure are associated not only with adverse neurodevelopmental effects, but also with cardiovascular and immunological risks (Karimi et al. 2014). Mercury concentration in parts per million (ppm) was used as a simple quantitative assessment for this indicator. For some species, these values were not available, and literature on the species in question was consulted to generate a rating based on available information. Mercury concentrations for the selected species were compared using a bar graph. Additionally, each species on this guide was researched for other toxins or health concerns associated with its consumption. Health concerns that are relatively easily mitigated (e.g., risk of pathogens that can be killed with proper preparation such as cooking or deep freezing) were not used to weight this indicator. An assessment of the presence and relative weight of these additional concerns was also factored into the score for this indicator.
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Indicator #3– distance traveled (Resilient Fisheries): This indicator is used as a proxy for an important consideration when assessing the relative resilience of a fishery: damage to coastal communities and economies The human dimensions of seafood do not always explicitly feature in seafood guides, though many of the assessed indicators are indirectly related to human variables. Fisheries are closely woven into the fabric of coastal communities and economies, and I believe that even the most ecologically sustainable fishery in the world should not be considered sustainable if it does cultural and socioeconomic damage.
Because I was unable to locate an established metric by which to assess these interwoven impacts, this indicator was assessed by comparing the relative distance a given seafood item traveled from its source, under the basic assumption that seafood bought closer to its source is providing more support for local (or at least regional or national) economies, which in turns drives relatively more benefits to the coastal communities. For all of the seafood assessed in this guide, no specific origin (i.e., town or city) was known or specified, so this necessitated using the basic proximity of the country of origin to generate a rating – for example, because this guide was made for use in the United States, seafood sourced from the U.S. was given a rating of 5, while seafood from a neighboring country (e.g., Canada) received a rating of 4, and countries farther abroad were given lower ratings based on approximate distance.
This indicator is far from perfect. It does not adequately reflect the complexity of this issue, and it does not encapsulate the full range of variables involved in assessing damage to coastal communities and economies. However, it does allow for a simple comparison of seafood choices in a way that acknowledges the important role of local seafood in increasing the resilience of fisheries as social-ecological systems (Stoll et al. 2015).
Because I was unable to locate an established metric by which to assess these interwoven impacts, this indicator was assessed by comparing the relative distance a given seafood item traveled from its source, under the basic assumption that seafood bought closer to its source is providing more support for local (or at least regional or national) economies, which in turns drives relatively more benefits to the coastal communities. For all of the seafood assessed in this guide, no specific origin (i.e., town or city) was known or specified, so this necessitated using the basic proximity of the country of origin to generate a rating – for example, because this guide was made for use in the United States, seafood sourced from the U.S. was given a rating of 5, while seafood from a neighboring country (e.g., Canada) received a rating of 4, and countries farther abroad were given lower ratings based on approximate distance.
This indicator is far from perfect. It does not adequately reflect the complexity of this issue, and it does not encapsulate the full range of variables involved in assessing damage to coastal communities and economies. However, it does allow for a simple comparison of seafood choices in a way that acknowledges the important role of local seafood in increasing the resilience of fisheries as social-ecological systems (Stoll et al. 2015).
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Indicator #4 – sustainability certifications (Resilient Fisheries): Many seafood brands claim sustainability on their packaging, and it can be difficult to assess when a brand is merely making a strategic (and ethically questionable) marketing choice versus when a brand is truly committed to conservation and sustainable harvest. Overall sustainability is a vital component of resilient fisheries. Similar to Indicator #3, Indicator #4 acts as a proxy measurement for the commitment to conservation and sustainable harvest of a given fishery and/or brand; again, this likely does not encompass the full spectrum of seafood sustainability – particularly because the concept of sustainability in fisheries, while ubiquitous, has been plagued by a lack of formal definition and vague operationalization (Standal & Utneb 2011).
However, a brand or fishery that has been certified as sustainable by a reputable third party does meaningfully reflect the relative sustainability of a seafood item. Seafood Watch recognizes a number of certifying bodies, including the Marine Stewardship Council and the Aquaculture Stewardship Council (Monterey Bay Aquarium 2020). Using Seafood Watch, each of the seafood items were assessed with a rating of “certified” (+2 points), “unclear” (0 points), or “uncertified” (-2 points). Because some of the seafood items were difficult to assess for exact capture or culture method – which is often necessary to determine whether or not a fishery is certified – a zero rating was used in unclear cases to avoid heavily impacting the overall score. |
Indicator #5 – damage to habitats and other species (Ecologically Sustainable Practices): This indicator was chosen as a way to merge into a single rating the many indicators used in Seafood Watch, the Monterey Bay Aquarium’s authoritative guide to sustainable seafood. The Seafood Watch uses the following indicators to evaluate seafood: (1) data, (2) effluent, (3) habitat, (4) chemical use, (5) feed, (6) escapes, (7) disease, pathogen, and parasite, (8) source of stock – independence from wild fisheries, (9) wildlife mortality, and (10) introduction of secondary species (Monterey Bay Aquarium n.d.). The cumulative rating generated from these extensively researched indicators is considered reflective of the overall damage to habitats and other species associated with a given seafood item.
Items that Seafood Watch rates “Avoid” were given a 1 for this category, items rated “Good Alternative” were given a 3, and items rated “Best Choice” were given a 5. If there were a mixture of ratings and the exact origin of the seafood item, method of harvest, or method of farming could not be determined, the ratings were averaged (e.g., 2 for a mixture of “Avoid” and “Good Alternative”). If the only rating that could be identified for a given item was “Certified” (which the Monterey Bay Aquarium states is equal to a “Good Alternative” rating or better) the same rating for “Good Alternative” (3) was utilized. This is because the certification of the product automatically conferred an additional 2 points via Indicator #4, as noted above.
Items that Seafood Watch rates “Avoid” were given a 1 for this category, items rated “Good Alternative” were given a 3, and items rated “Best Choice” were given a 5. If there were a mixture of ratings and the exact origin of the seafood item, method of harvest, or method of farming could not be determined, the ratings were averaged (e.g., 2 for a mixture of “Avoid” and “Good Alternative”). If the only rating that could be identified for a given item was “Certified” (which the Monterey Bay Aquarium states is equal to a “Good Alternative” rating or better) the same rating for “Good Alternative” (3) was utilized. This is because the certification of the product automatically conferred an additional 2 points via Indicator #4, as noted above.
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Indicator #6 – carbon footprint (Ecologically Sustainable Practices): With escalating climate change, the relative carbon footprint of food systems (e.g., red meat vs. seafood) has come increasingly to the forefront of food security and sustainability conversations. While aquatic species tend to have a lower overall footprint than many terrestrial species, the impacts of climate change on the ocean (including rising temperatures, ocean acidification, and changes in species distribution) are expected to be particularly hazardous to aquatic species and the humans who depend upon them, lending an extra layer of importance to identifying seafood choices associated with low carbon emissions (Brierly & Kingsford 2009, Petsko 2021). This indicator was assessed quantitatively using the Seafood Carbon Emissions Tool developed by the Monterey Bay Aquarium and Dalhousie University, and the range of CO2 eq/kg of fish for each species in this guide was compared graphically to generate ratings. For some species, a CO2 eq/kg of fish value was not available; in these cases, literature on the species in question was consulted to generate a rating based on available information.
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Scoring Methods: With the exception of Indicator #6, which was assessed as described above, each indicator was ranked on a scale from 1-5, with 1 being the worst score and 5 being the best. With five indicators ranked from 1 to 5 and one indicator ranked as either +2, 0, or -2 points, the highest possible total score for any seafood item was 27, and the lowest possible score for any item was 3. Originally, items scoring 20-27 were classified as “best choice,” items scoring 11-19 were classified as “acceptable choice,” and items scoring 3-10 were classified as “poor choice.” However, after further consideration and comparison of seafood items falling in the middle and low ranges, these categories were fine-tuned to differentiate between high-scoring alternatives and low-scoring alternatives within those wider ranges. “Acceptable choice” was split into two ranks: items scoring 11-14 retained the “acceptable choice” label, and items scoring 15-19 were classified as “good choice.” “Poor choice” was also split into two sections: items scoring 3-6 were classified as “avoid,” and items scoring 7-10 retained the “poor choice” label.
Final Rating Matrix
References
Brierly, S. & Kingsford, M. J. (2009). Impacts of climate change on marine organisms and ecosystems. Current Biology 19(14):R602-R614. https://doi.org/10.1016/j.cub.2009.05.046
Karimi, R., Silbernagel, S., Fisher, N. S., & Meliker, J. R. (2014). Elevated blood Hg at recommended seafood consumption rates in adult seafood consumers. International Journal of Hygiene and Environmental Health 217(7):758-764.
Monterey Bay Aquarium. (2020). Seafood Watch recommendations. https://www.seafoodwatch.org/recommendations
Monterey Bay Aquarium. (n.d.). Our standards. https://www.seafoodwatch.org/recommendations/our-standards
Petsko, E. (2021). Wild seafood has a lower carbon footprint than red meat, cheese, and chicken, according to latest data. Oceana. https://oceana.org/blog/wild-seafood-has-lower-carbon-footprint-red-meat-cheese-and-chicken-according-latest-data/
Ruxton, C. (2004). Health benefits of omega-3 fatty acids. Nursing Standard 18(48):38-42.
Seafood Carbon Emissions Calculator. (n.d.). CO2 eq kg of fish. Monterey Bay Aquarium, Dalhousie University. http://seafoodco2.dal.ca/
Standal, D. & Utneb, I. B. (2011). The hard choices of sustainability. Marine Policy 35(4):519-527. https://doi.org/10.1016/j.marpol.2011.01.001
Stoll, J. S., B. A. Dubik, & L. M. Campbell. (2015). Local seafood: Rethinking the direct marketing paradigm. Ecology and Society 20(2): 40. http://dx.doi.org/10.5751/ES-07686-200240
US FDA. (2019). FDA announces new qualified health claims for EPA and DHA omega-3 consumption and the risk of hypertension and coronary heart disease. https://www.fda.gov/food/cfsan-constituent-updates/fda-announces-new-qualified-health-claims-epa-and-dha-omega-3-consumption-and-risk-hypertension-and
Karimi, R., Silbernagel, S., Fisher, N. S., & Meliker, J. R. (2014). Elevated blood Hg at recommended seafood consumption rates in adult seafood consumers. International Journal of Hygiene and Environmental Health 217(7):758-764.
Monterey Bay Aquarium. (2020). Seafood Watch recommendations. https://www.seafoodwatch.org/recommendations
Monterey Bay Aquarium. (n.d.). Our standards. https://www.seafoodwatch.org/recommendations/our-standards
Petsko, E. (2021). Wild seafood has a lower carbon footprint than red meat, cheese, and chicken, according to latest data. Oceana. https://oceana.org/blog/wild-seafood-has-lower-carbon-footprint-red-meat-cheese-and-chicken-according-latest-data/
Ruxton, C. (2004). Health benefits of omega-3 fatty acids. Nursing Standard 18(48):38-42.
Seafood Carbon Emissions Calculator. (n.d.). CO2 eq kg of fish. Monterey Bay Aquarium, Dalhousie University. http://seafoodco2.dal.ca/
Standal, D. & Utneb, I. B. (2011). The hard choices of sustainability. Marine Policy 35(4):519-527. https://doi.org/10.1016/j.marpol.2011.01.001
Stoll, J. S., B. A. Dubik, & L. M. Campbell. (2015). Local seafood: Rethinking the direct marketing paradigm. Ecology and Society 20(2): 40. http://dx.doi.org/10.5751/ES-07686-200240
US FDA. (2019). FDA announces new qualified health claims for EPA and DHA omega-3 consumption and the risk of hypertension and coronary heart disease. https://www.fda.gov/food/cfsan-constituent-updates/fda-announces-new-qualified-health-claims-epa-and-dha-omega-3-consumption-and-risk-hypertension-and
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