SeaChoice Methodology

SeaChoice works in collaboration with the Monterey Bay Aquarium’s Seafood Watch program and uses their revised assessment methodology as the basis for our seafood rankings.


Sustainability Considerations for Wild Seafood

Sustainable wild caught fish requires that the fish you eat are from healthy populations and that capturing the fish was not at the expense of damaging other aspects of the ecosystem.

The Criteria SeaChoice Looks at are:

  1. Impacts of the fishery on the target species: Is the stock healthy and abundant? Abundance, size, sex, age and genetic structure should be maintained at levels that do not impair the long‐term productivity of the stock or fulfillment of its role in the ecosystem and food web.
  2. Impacts of the fishery on non-target species (bycatch): What is the fishery’s impact on bycatch?Seafood Watch® defines bycatch as all fisheries‐related mortality or injury other than the retained catch. Examples include discards, endangered or threatened species catch, pre‐catch mortality and ghost fishing.
  3. Effectiveness of Management: The fishery is managed to sustain the long‐term productivity of all impacted species. Management should be appropriate for the inherent resilience of affected marine life and should incorporate data sufficient to assess the affected species and manage fishing mortality to ensure little risk of depletion. Measures should be implemented and enforced to ensure that fishery mortality does not threaten the long‐term productivity or ecological role of any species in the future.
  4. Habitat and Ecosystem Impacts: The fishery is conducted such that impacts on the seafloor are minimized and the ecological and functional roles of seafloor habitats are maintained. Fishing activities should not seriously reduce ecosystem services provided by any fished species or result in harmful changes such as trophic cascades, phase shifts or reduction of genetic diversity.

Sustainability Considerations for Aquaculture

Important factors for sustainable farmed seafood, include:

  1. using production methods that do not harm wild fish or damage ecosystems,
  2. choosing species that are low on the food chain so farms produce more protein than they consume  (i.e. vegetarian-based diets over fish-based), and
  3. ensuring that management and regulations are effective.


  1. Data: All assessments require information. The data criterion is intended to reward those responsible producers that make data on their activities and impacts available, or those that are well researched.
  2. Effluent: Net pens and other systems that discharge untreated waste pollute the surrounding ecosystem, harming marine and freshwater habitats. This criterion considers the risk of impacts beyond the farm boundary. The impact of aquaculture wastes is related to the total amount of pollutants added over time in relation to the sensitivity of the receiving waters.
  3. Habitat: Siting aquaculture operations away from sensitive or ecologically important marine habitats is important. The habitat criterion assesses the risk of impacts within the farm boundary. The degree of impact is ascribed relative to the loss of certain ecosystem processes.
  4. Chemical Use: A wide range of chemicals are used in aquaculture systems for a variety of purposes, but most often they are applied for disease treatment and pest management. The impact of chemicals used is based on a combination of evidence of their use and the risk of their spreading into the environment dictated by the openness of the facilities.
  5. Fish Feed: Feed is a defining factor for aquaculture sustainability, especially in intensive systems that rely entirely on feed coming from external sources. This criterion examines three aspects of feed sustainability. The use of wild fish, net protein gain-loss, and an ecological footprint measure of land/sea area used to produce the feed.
  6. Escapes and Introduced Species: Farming seafood can lead to negative impacts from the escape of some species combined with the threat of introduced non-native species, pathogens or parasites. The escapes criterion provides an estimate of the “biological pollution” and is divided into the risk of escaping combined with the risk of impacting native species and ecosystems.
  7. Disease, Pathogen and Parasite Interaction: All farming operations risk amplifying naturally occurring pathogens and parasites. Depending on the type of production system, these elevated levels of pathogens and parasites can represent a risk to wild species residing in or passing through the vicinity of the farms. Systems that discharge untreated waste cannot prevent the transfer of diseases and parasites to wild stocks. This criterion assesses the risk of disease transmission from the farm to wild populations.
  8. Source of Stock: Some farm operations capture wild brood stock to supply the farm. This criterion evaluates the independence of the farming operation from wild fisheries to source the brood stock.