C10: Productive seas: fish and shellfish stocks fished sustainably
Short Description
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 (ICES) and national stock assessments.
Readiness and links to data
This indicator is not available for reporting in 2023 in a finalised form. A revised interim indicator is presented here that shows: C10a, the percentage of stocks of UK interest fished at or below the level capable of producing MSY (FMSY); and C10b, the percentage of stocks with spawning stock biomass (SSB) above the level capable of producing MSY (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 from1990 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 Indicator B2 – Sustainable fisheries. 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.
Indicator components
Figure C10a: Marine fish (quota) stocks of UK interest harvested sustainably, 1990 to 2019
Table C10a: Marine fish (quota) stocks of UK interest harvested sustainably, 1990 to 2019
| Year | Percentage above fmsy | Percentage in fmsy range | Percentage less than or equal to fmsy | Percentage unknown |
|---|---|---|---|---|
| 1990 | 42.11 | 0.00 | 8.77 | 49.12 |
| 1991 | 43.86 | 1.75 | 8.77 | 45.61 |
| 1992 | 42.11 | 3.51 | 10.53 | 43.86 |
| 1993 | 52.63 | 3.51 | 7.02 | 36.84 |
| 1994 | 52.63 | 1.75 | 10.53 | 35.09 |
| 1995 | 56.14 | 3.51 | 3.51 | 36.84 |
| 1996 | 59.65 | 1.75 | 5.26 | 33.33 |
| 1997 | 54.39 | 3.51 | 5.26 | 36.84 |
| 1998 | 59.65 | 3.51 | 3.51 | 33.33 |
| 1999 | 63.16 | 1.75 | 3.51 | 31.58 |
| 2000 | 59.65 | 3.51 | 5.26 | 31.58 |
| 2001 | 61.40 | 3.51 | 7.02 | 28.07 |
| 2002 | 54.39 | 5.26 | 12.28 | 28.07 |
| 2003 | 50.88 | 5.26 | 19.30 | 24.56 |
| 2004 | 52.63 | 5.26 | 15.79 | 26.32 |
| 2005 | 56.14 | 7.02 | 12.28 | 24.56 |
| 2006 | 56.14 | 8.77 | 10.53 | 24.56 |
| 2007 | 56.14 | 3.51 | 15.79 | 24.56 |
| 2008 | 54.39 | 3.51 | 17.54 | 24.56 |
| 2009 | 54.39 | 3.51 | 19.30 | 22.81 |
| 2010 | 47.37 | 3.51 | 24.56 | 24.56 |
| 2011 | 42.11 | 8.77 | 24.56 | 24.56 |
| 2012 | 42.11 | 5.26 | 29.82 | 22.81 |
| 2013 | 31.58 | 8.77 | 38.60 | 21.05 |
| 2014 | 40.35 | 5.26 | 33.33 | 21.05 |
| 2015 | 35.09 | 7.02 | 36.84 | 21.05 |
| 2016 | 29.82 | 8.77 | 40.35 | 21.05 |
| 2017 | 35.09 | 8.77 | 35.09 | 21.05 |
| 2018 | 22.81 | 8.77 | 47.37 | 21.05 |
| 2019 | 26.32 | 7.02 | 43.86 | 22.81 |
Trend description for C10a
Overall, there is evidence of a positive trend towards a greater proportion of stocks fished sustainably in both the long term and in recent years. There is also a decreasing percentage of stocks with unknown status, from almost 50% in 1990 to 23% in 2019. The percentage of fish stocks (including Norway lobster, Nephrops norvegicus) fished at or below FMSY, and/or within acceptable mortality range levels, has increased from 9% in 1990 to 51% in 2019. The percentage fished above FMSY has decreased over the same time period, from 42% of UK quota-fish stocks assessed being fished at levels of fishing pressure above FMSY in 1990 to 26% in 2019.
Assessment of change
Assessments of change are made for the short term, as well as medium and long-term periods. In every case there has been an improvement recorded.
Change since 2018 has also been assessed. Marine fish harvested sustainably decreased (a deterioration) in 2019. However, this is based on two data points so should be considered as indicative and not evidence of a clear trend.
The assessment results reported here are not directly comparable with other analyses published elsewhere that use different methodologies to explore these indicator components.
Further information on this assessment, along with details on the methodology, is provided in the Assessment background page. Summaries by 25 Year Environment Plan goal and information on indicator links are presented in the Assessment results pages.
Table C10a: Assessment of change
| Component | Subcomponent | Period | Date range | Percentage change | Smoothing function | Assessment of change |
|---|---|---|---|---|---|---|
| C10a | below FMSY or in FMSY range | Short term | 2013 to 2018 | 39.33 | Loess | Improvement |
| C10a | below FMSY or in FMSY range | Medium term | 2008 to 2018 | 113.73 | Loess | Improvement |
| C10a | below FMSY or in FMSY range | Long term | 1990 to 2018 | 327.05 | Loess | Improvement |
Note that assessment categories for the short, medium and long term were assigned based on smoothed data, so percent change figures in Tables C10a may differ from unsmoothed values quoted elsewhere. Percent change refers to the difference seen from the first to last year in the specified date range.
Figure C10b: Marine fish (quota) stocks of UK interest with biomass at levels capable of maintaining full reproductive capacity, 1990 to 2019
Table C10b: Marine fish (quota) stocks of UK interest with biomass at levels capable of maintaining full reproductive capacity, 1990 to 2019
| Year | Percentage below msybtrigger and below blim (where available) | Percentage greater than or equal to msy btrigger | Percentage less than msy btrigger but greater than blim | Percentage unknown |
|---|---|---|---|---|
| 1990 | 10.53 | 29.82 | 12.28 | 47.37 |
| 1991 | 12.28 | 31.58 | 12.28 | 43.86 |
| 1992 | 8.77 | 33.33 | 15.79 | 42.11 |
| 1993 | 12.28 | 36.84 | 15.79 | 35.09 |
| 1994 | 12.28 | 40.35 | 14.04 | 33.33 |
| 1995 | 15.79 | 35.09 | 14.04 | 35.09 |
| 1996 | 12.28 | 33.33 | 22.81 | 31.58 |
| 1997 | 12.28 | 36.84 | 17.54 | 33.33 |
| 1998 | 12.28 | 42.11 | 15.79 | 29.82 |
| 1999 | 12.28 | 42.11 | 17.54 | 28.07 |
| 2000 | 14.04 | 35.09 | 22.81 | 28.07 |
| 2001 | 15.79 | 42.11 | 15.79 | 26.32 |
| 2002 | 17.54 | 38.60 | 17.54 | 26.32 |
| 2003 | 19.30 | 45.61 | 10.53 | 24.56 |
| 2004 | 15.79 | 42.11 | 17.54 | 24.56 |
| 2005 | 17.54 | 40.35 | 17.54 | 24.56 |
| 2006 | 19.30 | 42.11 | 14.04 | 24.56 |
| 2007 | 19.30 | 38.60 | 17.54 | 24.56 |
| 2008 | 14.04 | 45.61 | 17.54 | 22.81 |
| 2009 | 17.54 | 49.12 | 10.53 | 22.81 |
| 2010 | 14.04 | 54.39 | 8.77 | 22.81 |
| 2011 | 10.53 | 59.65 | 7.02 | 22.81 |
| 2012 | 15.79 | 54.39 | 7.02 | 22.81 |
| 2013 | 10.53 | 56.14 | 10.53 | 22.81 |
| 2014 | 14.04 | 59.65 | 3.51 | 22.81 |
| 2015 | 14.04 | 57.89 | 5.26 | 22.81 |
| 2016 | 12.28 | 57.89 | 7.02 | 22.81 |
| 2017 | 15.79 | 57.89 | 3.51 | 22.81 |
| 2018 | 15.79 | 57.89 | 3.51 | 22.81 |
| 2019 | 15.79 | 57.89 | 3.51 | 22.81 |
Trend description for C10b
Overall, there is evidence of a positive trend for fish stocks remaining within safe biological limits in the long term, but a negative trend in recent years. There is also a decreasing percentage of stocks with unknown status, from almost 50% in 1990 to 23% in 2019. 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 (that is, MSY Btrigger). The percentage of stocks subject to quota management and achieving this goal has increased from 30% in 1990 to 58% in 2019. A further 4% of stocks were at low risk of reproductive impairment (that is, with a SSB below MSY Btrigger but above Blim) in 2019 and 16% more were at high risk of reproductive impairment (that is, with SSB below MSY Btrigger and Blim).
Assessment of change
Assessments of change are made for the short term, as well as medium and long-term periods. In every case there has been an improvement recorded.
Change since 2018 has also been assessed. There was little or no change in marine fish stocks with biomass at levels capable of maintaining full reproductive capacity. However, this is based on two data points so should be considered as indicative and not evidence of a clear trend.
The assessment results reported here are not directly comparable with other analyses published elsewhere that use different methodologies to explore these indicator components.
Further information on this assessment, along with details on the methodology, is provided in the Assessment background page. Summaries by 25 Year Environment Plan goal and information on indicator links are presented in the Assessment results pages.
Table C10b: Assessment of change
| Component | Subcomponent | Period | Date range | Percentage change | Smoothing function | Assessment of change |
|---|---|---|---|---|---|---|
| C10b | Percentage greater than or equal to MSY Btrigger | Short term | 2013 to 2018 | 5.61 | Loess | Improvement |
| C10b | Percentage greater than or equal to MSY Btrigger | Medium term | 2008 to 2018 | 24.38 | Loess | Improvement |
| C10b | Percentage greater than or equal to MSY Btrigger | Long term | 1990 to 2018 | 89.11 | Loess | Improvement |
Note that assessment categories for the short, medium and long term were assigned based on smoothed data, so percent change figures in Tables C10b may differ from unsmoothed values quoted elsewhere. Percent change refers to the difference seen from the first to last year in the specified date range.