Indicator 14.1.b Share of sustainably fished stocks of fish in the North and Baltic Seas

14.1.b Share of sustainably fished stocks of fish in the North and Baltic Seas

A fish stock is considered to be sustainably managed when the actual annual catch per stock does not exceed the scientifically recommended catch level based on the Maximum Sustainable Yield (MSY) approach, or complies with a long-term management plan based on the MSY approach that is deemed sustainable. A fish stock refers to a self-reproducing population of a fish species. Accordingly, a single species may consist of multiple stocks, each subject to different catch reference levels. The stock reference values are calculated by the International Council for the Exploration of the Sea (ICES).

Data collection for calculating the indicator encompasses the entire North Sea and Baltic Sea; therefore, a separate reporting for German territorial waters or the German exclusive economic zone is not possible. The annual determination of sustainable catch limits is based on stochastic forecasting models that rely on the historical development of the stocks. Data on landed quantities are derived from reported catches. Additionally, samples provide information on demographic parameters of the stock, such as the age and size of fish. These are supplemented by fishery-independent scientific surveys conducted on research vessels. The underlying time series is updated annually; the fish species considered may also be retrospectively adjusted, which can lead to revisions of indicator values for previous years.

In 2023, the proportion of sustainably fished stocks among all stocks assessed according to the MSY approach in the North and Baltic Seas combined was 71.4%. In the North Sea, the proportion was 70.4%, and in the Baltic Sea, 75.0%. Between 2018 and 2023, an overall positive trend is evident. The politically established target is to sustainably manage all economically exploited fish stocks in accordance with the MSY approach by 2030. However, if the current trend continues, this target is likely to be narrowly missed.

The evaluation of the indicator is challenging for several reasons. Besides the actual stock development, the selection of stocks under assessment influences the indicator values. This complicates comparability between years, as the basis for evaluation may change. Not all fish stocks are examined for sustainable management. Therefore, the proportion of sustainably managed stocks should always be considered relative to the total number of economically exploited fish stocks. While the aim is to include as many stocks as possible in the assessments, a complete coverage – particularly of economically less relevant or lightly fished stocks – is unrealistic due to the high effort and costs involved.

Currently, 58 stocks are economically exploited in the North Sea and 20 in the Baltic Sea. Of these, 27 stocks in the North Sea and eight in the Baltic Sea are assessed based on the MSY approach – accounting for approximately 45% of the exploited stocks. Stocks for which sufficient data for an MSY analysis are lacking are excluded from the indicator. It should also be noted when interpreting the indicator that the recommended catch limits apply across borders and can only be indirectly influenced by individual states.