This indicator shows changes in the proportion of commercial fish and shellfish stocks that are within safe biological limits and fished sustainably. The indicator is derived from assessments of individual stocks. Where available, the assessment of stocks against their Maximum Sustainable Yield (MSY) will be incorporated into the overall indicator. The indicator is linked to UK Marine Strategy Descriptor 3 (Commercial Fish and Shellfish) and the Convention on Biological Diversity sustainable fisheries indicators and is derived from International Council for the Exploration of the Sea and national stock assessments. The data presented in this indicator for the proportion of marine fish quota stocks of UK interest exploited above or below maximum sustainable yield were presented as part of indicator E9 Percentage of our seafood coming from healthy ecosystems, produced sustainably in 2019. These data are now presented here in C10 because they are specific to fish and shellfish rather than reflecting the health of the marine ecosystem as a whole.
Readiness and links to data
This indicator is not available for reporting in 2021 in a finalised form. An interim indicator is presented here that shows: the percentage of stocks fished at or below the level capable of producing Maximum Sustainable Yield (FMSY); and the percentage of stocks with biomass above the level capable of producing Maximum Sustainable Yield (MSY Btrigger). The assessments used for this interim indicator have been reported under the UK Marine Strategy Part One (2019) using data from 1990 to 2015 for FMSY and from 1990 to 2016 for MSY Btrigger. Data on commercially exploited fish and shellfish, analytical methods and assessment are available. Data are also published annually in the UK Biodiversity Indicators. National shellfish stocks assessments are updated on a 3-year cycle. These data are not included in the interim indicator but were published as part of the UK Marine Strategy Part One (2019) and will be included in the final indicator. Once population age and size distribution assessments are developed, they will be included to provide further detail for this indicator.
a) Marine fish (quota) stocks of UK interest harvested sustainably
Overall, there is evidence of a positive trend towards a greater proportion of stocks fished sustainably and within safe biological limits. The percentage of fish stocks (including Nephrops) fished at or below levels capable of producing maximum sustainable yield (FMSY) has increased from 9% in 1990 to 51% in 2018. The percentages fished above FMSY and at unknown levels relative to FMSY have both decreased over the same time period. In the most recent year of assessment (2018), there was an 11 percentage point increase in the percentage of stocks with fishing pressure below FMSY.
b) Marine fish (quota) stocks of UK interest with biomass at levels capable of maintaining full reproductive capacity
To maintain the reproductive capacity of stocks, each stock’s spawning biomass (SSB) should be at or above the level capable of producing maximum sustainable yield (MSY Btrigger). The percentage of stocks subject to quota management and achieving this goal has increased from 32% in 1990 to 61% in 2018. The percentages of stocks below MSY Btrigger and the percentage of stocks with unknown SSB have both decreased over the same time period, the latter by considerably more than the former.