Indicator 14.4.1 Proportion of fish stocks within biologically sustainable levels

Indicator 14.4.1: Proportion of fish stocks within biologically sustainable levels

Target 14.4: By 2020, effectively regulate harvesting and end overfishing, illegal, unreported and unregulated fishing and destructive fishing practices and implement science-based management plans, in order to restore fish stocks in the shortest time feasible, at least to levels that can produce maximum sustainable yield as determined by their biological characteristics

Food and Agriculture Organization of the United Nations (FAO)

Definition:

The indicator, "Proportion of marine fish stocks within biologically sustainable levels", measures the sustainability of the world's marine capture fisheries by the abundance of the exploited fish stocks with respect to MSY levels.

For each level of reporting (National, Regional, Global) the indicator is calculated as the ratio between the number of exploited fish stocks classified as "within biologically sustainable levels" and the total number of stocks in the reference list that were classified with a determined status (within/not within "biologically sustainable levels").

$P_s=\frac{N_s}{N}x100=\frac{N_s}{N_s+N_u}x100$

where Ps is the percentage of stocks classified as "within biologically sustainable levels" for the reference list of stocks. Ns is the number of stocks in the reference list classified as "within biologically sustainable levels", Nu is the number of stocks in the reference list classified as "outside biologically sustainable levels" and N = Ns + Nu is the total number of stocks in the reference list that have been classified as within or outside "biologically sustainable levels".

Classifying individual stocks as within/outside "biologically sustainable levels":

In order to keep consistency with the 14.4 target ("at least to levels that can produce maximum sustainable yield as determined by their biological characteristics" and other earlier international agreements, including the United Nations Convention on the Law of the Sea (UNCLOS), a fish stock is classified as "within biologically sustainable levels" if its abundance is estimated (considering uncertainty) to be equal to or greater than the level that can produce the Maximum Sustainable Yield (MSY). In contrast, when abundance falls below the MSY level, the stock is classified as "outside biologically sustainable levels".

A wide array of methods and approaches (including documented expert opinion) is used to classify stock status relative to the abundance producing MSY. This varies among countries, regions and stocks. Nevertheless, the reliability of the classification is assessed by FAO as part of the process of producing the index.

Maximum Sustainable Yield (MSY) is commonly defined as the greatest average amount of catch that can be harvested in the long-term from a stock under constant and current environmental conditions (e.g., habitat, water conditions, species composition and interactions, and anything that could affect birth, growth, or death rates of the stock), without affecting the long-term productivity of the stock. A stock can produce MSY if its abundance is above a certain level, usually around 50% of its unexploited abundance (but actual value can vary around that level, depending on the biological characteristics of the stock). See more at https://www.fao.org/faoterm/en/?defaultCollId=21

MSY-based reference points are the most common type of reference points used in fisheries management today. This is primarily because, for decades, reference points from surplus production models have most often been set based on the concept of MSY and they are the basic benchmarks for the sustainability of fisheries set by the UN Convention on the Law of the Sea (UNCLOS, Article 61(3)). For more on Reference Points in Fish Stock Assessment, see Caddy and Mahon (1995), Cadima (2003) or Haddon (2011).

BMSY: Biomass corresponding to Maximum Sustainable Yield from a production model or from an age-based analysis using a stock recruitment model. Often used as a biological reference point in fisheries management, it is the calculated long-term average biomass value expected if fishing at FMSY.

A population is: “A group of individuals of the same species living in the same area at the same time and sharing a common gene pool, with little or no immigration or emigration.”

A biological stock is: “A subpopulation of a species inhabiting a particular geographic area, having similar biological characteristics (e.g. growth, reproduction, mortality) and negligible genetic mixing with other adjacent subpopulations of the same species." (FAO, 2004-2021).

The reference list of Stocks: it is not possible to classify the sustainability of exploitation for all the exploited stocks from a country, region or the world. Therefore, the indicator must be calculated based on a subset of these stocks. The list of the stocks that are classified for status and used to calculate the indicators is called the "reference list of Stocks".

The reference list of Stocks is built differently for the Regional/Global and the National levels. The process of building the reference list of Stocks for regional and global level are described in FAO (2011). At National level, countries are requested to define a list of stocks, based on an agreed set of criteria (Appendix 1). National and shared stocks can be included, but not straddling stocks (stocks that are distributed both in national EEZ and Areas Beyond National Jurisdiction).

At this moment, there is not a direct correspondence between the national level reference lists (that are defined by each country) and the regional and global Reference lists (that are defined by FAO).

FAO is working on an update of its methodology at global/regional level (FAO, 2024) which also addresses needs for convergence with the national level. Full results of the application of this updated methodology are planned to be published in 2026.

The detailed description of all necessary concepts can be found in the e-learning course (FAO 2019-2021).

Percent (%)

The classification of the status of exploited stocks relative to the abundance that can produce MSY is often established through a formal stock assessment process. The data to inform stock assessments can come from many different sources, including fishery-dependent and fishery-independent sources. Fishery-dependent data are collected from the fishery itself, using both commercial and recreational sources through reporting or sample-based surveys at sea, at landing sites, or within fishing communities. They can include information on removals of fish from the sea, which can include landings and discards, and information on the fleet such as number of boats, number of tows, time spent on the sea, as well as economic and social information like fish prices, fuel expenditures, total sales, employment or other.

Fishery-independent data are obtained in ways not related to any fishing activity and are typically collected by scientists via surveys (often scientific cruises) designed to estimate species abundance and biomass over long time series, and over consistent seasons and geographic areas. Typically, fisheries-independent data also include biological information on the species (age, length, weight, maturity, etc.), and habitat and environmental information (temperature, salinity, depth, etc.).

These data and other information are used by stock assessment scientists to classify the stock status. References on the methods most commonly used can be found in Cadima (2003), Haddon (2011), Sparre and Venema (1998) and other publications dealing with the methods of stock assessment.

The information used for the indicator at the Global/Regional level is based on a different process and data sources than that used for the national level.

Global/Regional:

Because of the high data demands of classical stock assessment methods, only a limited number of fish stocks have been assessed. These species account for ca 50 percent of the global catch (Hilborn et al., 2020), and most are caught by industrial fisheries in developed countries. To balance the global representativeness of the assessment results and the goal of using the best available information, FAO uses a wide spectrum of data and methods to extend its assessment to the fish stocks that account for the majority (70-80 percent) of the global catch (FAO, 2011).

National:

The national level indicator, on the other hand, is based exclusively on the stock status reported by countries. A multiplicity of methods are used to classify the stock status, including model-based estimates, empirical indicators and documented expert opinion.

For country reporting, a questionnaire is sent out to all FAO member states with marine boundaries (i.e. 165 states, 11 territories, and three Caspian Sea border countries) on a two-year basis. For the most recent and complete list of questions used to inform this indicator, please visit https://www.fao.org/fileadmin/user_upload/faoweb/statistics/questionnaires/SDG_14.4.1_questionnaire_2022_en.xlsx .

FAO provides global and regional data. National-level data are generally reported by the National Statistics Office or the Ministry of Fisheries and/or Agriculture.

The indicator measures the sustainability of fishery resources, and as an end-result, is a measure of Target 14.4. Its derivation requires catch and fishing effort data and/or other biological or technical data and parameters together with the scientific expertise necessary to correctly perform stock assessment. The indicator at the global level is estimated by FAO based on methodology developed in the 1980s. Although regular updates were carried out to incorporate technical advances and changes in major fish species, some discrepancies between regions may occur in the representativeness of the reference list. However, this will not pose a large impact on the reliability of the indicator’s temporal trends.

For the national level, the composition of stocks within the reference list of stocks and the selection criteria used to develop the list will vary between countries, making the indicator suitable for checking countries’ own progress over time.

FAO currently reports the global and regional indicators calculated from FAO’s assessment of a selected reference list of fish stocks around the world. The methodology is described in FAO Technical Paper (FAO 2011).

FAO has been developing the new approach for country-level reporting since 2017, and has consulted with countries in three dedicated expert consultation workshops: in November 2017, FAO convened a workshop to exchange views with national practitioners on the proposed new analytical methods to produce Indicator 14.4.1 at country level^[1]. In February 2019, FAO convened an expert consultation workshop^[2] on development of the methodologies for the global assessment of fish stock status, with participants from countries and regional fisheries organizations. In order to help countries reporting on the indicator, FAO then organized a series of capacity development workshops on stock status assessment and estimation methods of SDG Indicator 14.4.1 for most regions.

In November 2019, FAO dispatched the first SDG14.4.1 questionnaire calling countries to report on their national indicator. Eighty-three countries submitted their questionnaire and three reported independently.

For each level of reporting (national, regional, global) the indicator is calculated as the ratio between the number of exploited fish stocks classified as "within biologically sustainable levels" and the total number of stocks in the reference list that were classified with a determined status (within/not within "biologically sustainable levels").

$P_s=\frac{N_s}{N}x100=\frac{N_s}{N_s+N_u}x100$

where Ps is the percent of stocks classified as "within biologically sustainable levels" for the reference list of stocks. Ns is the number of stocks in the reference list classified as "within biologically sustainable levels", Nu is the number of stocks in the reference list classified as "outside biologically sustainable levels" and N = Ns + Nu is the total number of stocks in the reference list that have been classified as within or outside "biologically sustainable levels".

To classify individual stocks as within/outside "biologically sustainable levels":

To keep consistency with the 14.4 target ("at least to levels that can produce maximum sustainable yield as determined by their biological characteristics" and other earlier international agreements, including the United Nations Convention on the Law of the Sea (UNCLOS)), a fish stock is classified as "within biologically sustainable levels" if its abundance is estimated to be (considering uncertainty) at or greater than the level that can produce the Maximum Sustainable Yield (MSY). In contrast, when abundance falls below the MSY level, the stock is classified as "outside biologically sustainable levels".

A wide array of methods and approaches (including documented expert opinion) is used to classify stock status relative to the abundance producing MSY. This varies among countries, regions and stocks. Nevertheless, the reliability of the classification is assessed by FAO as part of the process of producing the index.

Global/Regional:

Global and regional estimates of stock sustainability have been performed for 584 fish stocks around the world since 1974, representing 70% of global landings. The status of each stock is estimated using the methodology described in FAO Technical Paper (FAO, 2011).

National:

Countries are requested to report the status of a reference list of fish stocks defined by each country on the basis of the criteria presented in Appendix 1.

2024-03-28

Food and Agriculture Organization of the United Nations (FAO)

Indicator 14.7.1: Sustainable fisheries as a percentage of GDP in small island developing States, least developed countries and all countries

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