Working with mixed fisheries

The MSC is working towards making the MSC program more accessible for fisheries that catch multiple species.

Fisheries that catch more than one species at a time, often called mixed fisheries, require a different kind of management than fisheries that target and catch a single species.

In a single-species fishery, management is based on the amount of fish that can be harvested from a given population without overfishing. This concept is known as Maximum Sustainable Yield (MSY). There are many fisheries in the MSC program that are managed using MSY, such as certified tuna fisheries.

In a mixed fishery, management based on the MSY of just one of the caught species does not necessarily maintain all caught species at sustainable levels. The more species in the catch, the more costly and difficult it is to monitor and manage each one. Species in the catch can have different population numbers, breeding rates and some species might be more impacted by fishing than others.

In addition, different species often interact with each other. For example, if one species is the predator or prey of another then harvesting one will probably affect the abundance of the other.

MSC requirements for mixed fisheries


Currently the MSC Fisheries Standard requires every species that is caught to be assessed. For some fisheries this can involve over a dozen species.

In the light of scientific developments and advances in fisheries management we are looking to develop a modified Standard for mixed fisheries, as part of the Fisheries Standard Review.

We are looking at whether it would also be acceptable to focus assessments on only the highest risk species. Fisheries would still be required to evaluate the risk to all species, but not managed each one directly.

We believe this could make the program more accessible to mixed-species fisheries who cannot afford multiple species assessment. We do not think it would weaken the Standard because the precautionary approach involved results in lower allowable yields than those produced with full data.

This approach is called index-species based management, and has been used to assess Western Australian Fisheries.

Developing our Standards

To evaluate the benefit of a modified Standard for mixed fisheries we undertook a global best practice review of science and management practices for managing mixed fisheries. We compiled case studies from around the world and listened to experts in an international workshop.

This resulted in a draft index-species Standard. With the support of the Walton Family Foundation we conducted feasibility trials of this in mixed stock demersal (deep sea) fisheries in Indonesia and Mexico. We found that there is a need for a modified Standard that offers an alternative management approach to meeting the stock status outcome requirements in Principle 1 (sustainable fish stocks).

We'll be consulting stakeholders in the industry and environmental experts to develop requirements and guidance for multi-species fisheries. The proposed modifications will provide an assessment framework based on the index-species management approach.

When would changes to the Standard happen?

If any part of the Standard is revised, a new version will be released in March 2022.The MSC Board of Trustees will make the final decision on implementation of any change, with the development process set out in the Fisheries Standard Review.

Get involved

To be notified when consultation opens, please register your interest in the Fisheries Standard Review. Information about future events, such as targeted consultations and workshops, will also be posted here.

For other questions on mixed fisheries requirements please email us at

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