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Indicator Specification

Status of marine fish stocks

Indicator Specification
  Indicator codes: CSI 032
Published 28 Apr 2005 Last modified 04 Dec 2019
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This page was archived on 03 Mar 2015 with reason: Other (New version data-and-maps/indicators/status-of-marine-fish-stocks-2 was published)
The indicator tracks the ratio of the number of over-fished stocks to the total number of commercial stocks per fishing area in European seas. Fish species rarely reproduce randomly with con-species throughout their geographical range, but form a series of stocks that are reproductively isolated in space and time. Cod for instance form a stock in the North Sea and another one in the Iceland area. These are isolated from each other and one can potentially be fished out while the other is thriving. European eel is an example of an extreme situation where there is only one stock as all mature eel migrate to the Sargasso Sea to spawn in random mixture with each other.  It should be noted that in the Northeast Atlantic area stocks are generally defined based on biological criteria and knowledge of population migration, mixing and spawning areas, while in the Mediterranean due to lack of biological knowledge, stocks are defined largely by area and not in general on the basis of well established biological knowledge on population units.   Commercial stocks are the stocks of economic importance on which the fishing effort is focused upon in each area aiming at a profit, i.e. a subset of exploited stocks. It is a broader term encompassing target species, by-catches and industrial species that are of economic importance to the market. Overfished stocks are stocks outside safe biological limits Safe stocks are stocks inside safe biological limits Non-assessed stocks are stocks for which no assessment has been carried out. The indicator also contains information on: 1. Numbers of commercial, assessed and over-fished stocks by sea area; 2. The state of commercial stocks (over-fished stocks per area), safe stocks, stocks for which an assessment has not been carried out. 3. Fish catch in specific seas from assessed and unassessed stocks. 4. Status of stocks by species and seas.

Assessment versions

Published (reviewed and quality assured)
  • No published assessments
 

Rationale

Justification for indicator selection

EU policies, and in particular the Common Fisheries Policy (CFP), aim for sustainable fishing over a long period through appropriate management of fisheries within a healthy ecosystem, while offering stable economic and social conditions for all involved in the activity.

An indication of the sustainability of fisheries in a particular area is the ratio of the number of over-fished stocks (those that are outside safe biological limits) to the total number of commercial stocks (for which an assessment of status has been carried out). A high value of this ratio identifies areas under heavy pressure from fishing.

In general, a stock becomes over-fished when mortality from fishing and other causes exceeds recruitment and growth. A fairly reliable picture of stock development can be derived by comparing trends over time in recruitment, spawning stock biomass, landings and fish mortality. Hence not only the quantity of fish taken from the sea is important, but also their species and size, and the techniques used to catch them.

Scientific references

Indicator definition

The indicator tracks the ratio of the number of over-fished stocks to the total number of commercial stocks per fishing area in European seas.
Fish species rarely reproduce randomly with con-species throughout their geographical range, but form a series of stocks that are reproductively isolated in space and time. Cod for instance form a stock in the North Sea and another one in the Iceland area. These are isolated from each other and one can potentially be fished out while the other is thriving. European eel is an example of an extreme situation where there is only one stock as all mature eel migrate to the Sargasso Sea to spawn in random mixture with each other. 

It should be noted that in the Northeast Atlantic area stocks are generally defined based on biological criteria and knowledge of population migration, mixing and spawning areas, while in the Mediterranean due to lack of biological knowledge, stocks are defined largely by area and not in general on the basis of well established biological knowledge on population units.

 

Commercial stocks are the stocks of economic importance on which the fishing effort is focused upon in each area aiming at a profit, i.e. a subset of exploited stocks. It is a broader term encompassing target species, by-catches and industrial species that are of economic importance to the market.
Overfished stocks are stocks outside safe biological limits
Safe stocks are stocks inside safe biological limits
Non-assessed stocks are stocks for which no assessment has been carried out.

The indicator also contains information on:
1. Numbers of commercial, assessed and over-fished stocks by sea area;
2. The state of commercial stocks (over-fished stocks per area), safe stocks, stocks for which an assessment has not been carried out.
3. Fish catch in specific seas from assessed and unassessed stocks.
4. Status of stocks by species and seas.

Units

Landings and spawning stock biomass are given in thousand tonnes, recruitment in million tonnes; fishing mortality is expressed as the proportion of a stock that is removed by fishing activities in a year.

 

Policy context and targets

Context description

The sustainable exploitation of fish stocks is regulated through the EU Common Fishery Policy (OJ C 158 27.06.1980). Regulatory arrangements, identifying harvesting levels  based on the CFP, the precautionary principle and multi-annual fisheries plans, were set through the Cardiff European Council (COM (2000) 803). Total Allowable Catches (TACs) and quotas for the stocks in the NE Atlantic and the Baltic Sea are set annually by the Fisheries Council. In the Mediterranean Sea, where no TACs have been set except for the highly migratory tunas and swordfish, fisheries management is achieved by means of closed areas and seasons to keep fishing effort under control and make exploitation patterns more rational. The General Fisheries Council for the Mediterranean (GFCM) attempts to harmonise the process.

 

The latest Action Plan on Fisheries management as part of the CFP reform was presented to the Fisheries Council in October 2002, and Council Regulation (EC) No 2371/2002 of 20 December 2002 on the conservation and sustainable exploitation of fisheries resources under the Common Fisheries Policy is now in force. A new set of regulations has since been adopted on specific issues.

Targets

Sustainable exploitation of fish stocks is a target of the EU common fishery policy (CFP).

Total Allowable Catches (TACs) and quotas for the individual stocks in the NE Atlantic and the Baltic Sea are set annually by the Fisheries Council. In the Mediterranean Sea, where no TACs have yet been set (except for the highly migratory tunas and swordfish), fisheries management is achieved by means of closed areas and seasons that are designed to keep fishing effort under control and make exploitation patterns more rational.

Related policy documents

Key policy question

Is the use of commercial fish stocks sustainable?

 

Methodology

Methodology for indicator calculation

Number of commercial stocks = 12
Number of assessed stocks = overfished +safe = 1+11= 12
Stock are regarded as within safe biological limits if the stocks size with a high probability is high enough to secure average future recruitment (in technical terms if SSB is above Bpa as defined by ICES). The numbers of overfished and safe stocks have been extracted from the relevant sources. Their ratio has been calculated and presented in pie charts per fishing area.

The above data are from ICES Advice 2006 (section 1.5.1.1 supplemented by Icelandic, Faroese and Barents Sea stocks).  The definition used here is the sum of the stocks listed as overfished and within safe biological limits. Shell fish are not included.

Fish species rarely reproduce randomly with con-species throughout their geographical range, but form a series of stocks that are reproductively isolated in space and time. Cod for instance form a stock in the North Sea and another one in the Iceland area. These are isolated from each other and one can potentially be fished out while the other is thriving. European eel is an example of an extreme situation where there is only one stock as all mature eel migrate to the Sargasso Sea to spawn in random mixture with each other. 


 

Methodology for gap filling

In the case of the Mediterranean since yearly assessment focuses only on four species with limited geographical coverage ( or 6 out of the new 27 units ) it was decided to use the old geographical units and include assessments of species that were presented (ad hoc) in the 2001 assessment.

Methodology references

  • ICES Advice Further details on the way ICES formulates advice in precautionary terms.
  • Fisheries in the Mediterranean Papaconstantinou, C., and Farrugio, H., 2000, 'Fisheries in the Mediterranean', Mediterranean Marine Science, 1/15-18.
 

Data specifications

EEA data references

  • No datasets have been specified here.

External data references

Data sources in latest figures

 

Uncertainties

Methodology uncertainty

All international fisheries organisations use almost the same principles to determine the state of the stocks, and ICES has fine-tuned the methodology used. However decisions are based on safety margins usually set at 30 % above safe limits which in turn bears a degree of uncertainty since estimates of fishing mortality (F) and Spawning Stock Biomass (SSB) are themselves uncertain; the decision on the reference points is then a task for managers, not scientists.

Species and spatial coverage for the Mediterranean is limited. No reference points have been defined for the Mediterranean stocks. The detailed stock assessments for the NE Atlantic and Baltic are obtained through ICES. In the Mediterranean, stock assessments are carried out by the General Fisheries Council for the Mediterranean (GFCM) and, in the absence of complete or independent information on fishing intensity or fishing mortality, are based mainly on landings. Stock assessment is thus based mainly on analysis of landing trends, biomass surveys, and analysis of commercial catch per unit effort (CPUE) data. On the Mediterranean supplementary work is being carried out by DG Fisheries, and a number of internationally funded bottom trawl surveys (MEDITS, SAMED).

Shellfish and cephalopodes are not included in this assessment. It cannot be assumed that fish indicators represent the status of these two groups in relation to sustainable fishing, because they are mainly prey for fish species and will therefore often show the opposite stock development of the fish.

Data sets uncertainty

In the Mediterranean, fisheries management is considered to be at an early stage compared with the NE Atlantic. Catch and effort statistics are not considered to be fully reliable and much effort is directed at estimation of corrective factors (Papaconstantinou & Farrugio, 2000).
Unreported landings are still considered to be a major problem.

Rationale uncertainty

Slightly different approaches are being used in the Mediterranean and the NE Atlantic to determine whether a stock is outside safe biological limits.

Further work

Short term work

Work specified here requires to be completed within 1 year from now.

Work description

 

Resource needs

No resource needs have been specified

Status

In progress

Deadline

2008/12/31 00:00:00 GMT+1

Work description

Future assessments will also include 1. Temporal trends of total catch by groups of species will be developed and combind with temporal trends in fishing pressure or intensity. The methodology will be based on Sparholt, H., Bertelsen, M. and Lassen, H. 2007. A meta-analysis of the status of the ICES fish stocks in the past half century.  ICES Marine Science Symposium Series. Vol 64, 2007.  2. A focus on stocks which are really seriously in trouble, so-called ”Redlist” fish species/stocks. Examples of this are: Blue fin tuna Eel Some salmon stocks Some other diadromous fish   3. Comparison of TACs and scientific advice to address to which extent the scientific advice has been followed by managers and to which extent have the fishery been restricted by TACs and other management measures. An analysis has shown that for the EC the TAC have on average been 40% higher than the advice. Illegal catches have in some cases resulted in realised catches being more than 50% higher than the TAC. Appropriate indicators will be explored.    

Resource needs

No resource needs have been specified

Status

In progress

Deadline

2008/12/31 00:00:00 GMT+1

Long term work

Work specified here will require more than 1 year (from now) to be completed.

General metadata

Responsibility and ownership

EEA Contact Info

Constança De Carvalho Belchior

Ownership

European Environment Agency (EEA)

Identification

Indicator code
CSI 032
Specification
Version id: 1

Frequency of updates

Updates are scheduled once per year

Classification

DPSIR: State
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)

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