Maintaining fish stocks

Sustainable fish stocks are at the heart of the MSC program. Ensuring that the world’s fish stocks remain healthy is vital for marine ecosystems and global food security.

According to the Food and Agriculture Organisation (FAO) 33% of global fish stocks are fished at unsustainable levels with another 60% already being fished at their maximum sustainable level.


MSC requirements for maintaining fish stocks

Principle 1 (sustainable fish stocks) of the MSC Fisheries Standard requires that fisheries do not overfish or deplete their target stock. For stocks that are already depleted but recovering, the fishery must not prevent the stock from recovering.

The Fisheries Standard requires that stocks are around the stock size that produces the maximum sustainable yield (MSY). Stock size is the amount (biomass) of fish that remain in the water. The maximum sustainable yield is the largest catch that fishers can take from a fish stock each year without affecting future years.

When assessing a fishery, certification bodies look at both the stock size and the harvest strategies that control fishing of that stock. A harvest strategy is the combination of monitoring, stock assessment, harvest control rules and management actions taken by a fishery. The harvest strategy needs to maintain stocks at a level that can support the maximum sustainable yield, or help it recover to this level if the stock has dropped below this.

Fish stocks are dynamic. Fluctuating environmental conditions and populations, combined with variation in fishing effort, mean that the size of fish populations, and the potential maximum sustainable yield, will change over time. This is especially true for small pelagic fish (fish that do not feed at the ocean bottom or near the shore) like herring or sprat, or short-lived invertebrates such as squid and octopus. To take variability and uncertainty into account, the MSC Fisheries Standard requires that harvest strategies are robust and precautionary.


Improving our Standards

Every few years we review the MSC Standards so they remain relevant. This allows us to incorporate widely accepted new science and fisheries management best practice, as well as improve  implementation and address stakeholder concerns. 

Stakeholders from all sectors are at the heart of our review, helping identify issues, develop solutions and test proposed changes. Find out more about opportunities to get involved in reviewing our Standards.

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A small boat on the beach in Mexico

Working with mixed fisheries

The MSC is working towards making the MSC program more accessible for mixed fisheries.

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A row of boats in the harbour, the clouds reflect on the water

Improving fisheries management

The MSC seeks to reward best practice in fisheries management and to support fisheries that are working to improve their management systems.

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Clam fisherman standing in silhouette on small boat, India

Our approach to data-limited fisheries

To ensure the MSC program is accessible to all, we developed a methodology for the assessment of data-deficient fisheries: the Risk-Based Framework.

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