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Indicator summary

 Summary of indicator structure and function

IndicatorAttributePurposeIf restricted to taxa, list which onesEcosystem applicabilityIdentified capabilityBiological classification levelResponse variableDriversRobustness
Temporal variability of total biomassTropic shifts; community Community structurefisheriesFisheries Should be applicable to all ecosystemsDemonstrableCommunity; Ecosystem

Species-based; trophodynamicsTrophodynamics

TrophodynamicsPotentially medium to high

Examples of how the indicators is used for ecosystem management and ecosystem status and trends

Indicator examplesCurrent status and trendsManagement objective/directionStakeholder/Public acceptability
Examples of how the indicator is used.

Pick one of the following:

  • decreasing
  • increasing
  • stable
  • unclear
or should it be deteriorating, improving, stable, unclear

Pick one of the following: 

  • Conservation and Biodiversity
  • Ecosystem Stability and Resistance to perturbations
  • Ecosystem Structure and Functioning
  • Resource Potential

Pick one of the following: 

  • Widely accepted
  • Good public awareness
  • Weak public awareness
  • No public awareness
  • Unknown
    
    
    


Definition and/or background

The following is from Fulton et al (2004a) -

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The index is calculated as follows:

                                                                                                  need to add equation 5.2 

where CVi  is the coefficient of variation for species i, σi is the standard deviation and x (need to have a line over the top of the x) is the and  is the mean of the measured variable (biomass landings, CPUE and biomass) for species i. CVt is the sum of all the CVi.

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fisheries, birds and mammals

Taxa

Data required

The following is from Fulton et al 2004a -

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Should be applicable to all ecosystems, and has been applied to comparisons of fish communities in the Bay of Biscay and Gulf of Lions (Blanchard and Boucher 2001).

Identified capability

Biological classification level

Response variable

Drivers

Is there any additional information that would be of interest in regards to ecological drivers?

If not can leave this section blank and just fill in the table instead.

Robustness

The following is from Fulton et al 2004a -

Potentially medium to high: The main limitations relate to the use of CPUE data, which can be highly variable and inconsistent. As a result, accurate data on total biomass may not be recorded. Moreover, market forces, rather than just the ecological effects of fishing, can influence the catches (so catch shifts to planktivores from piscivores without a concomitant shift in the underlying system). It is also worth remembering that if a species goes extinct its CVi will be zero and any fluctuation in overall biomass will be greater than it. Thus, to be truly robust, this indicator requires testing on data sets derived from research surveys that are not linked to effort, and/or from data collected in unfished reference areas. It could also be useful to examine time series data of target species (which tend to be large piscivores), as this could give a measure of the total biomass variability over time in established fisheries and provide a snapshot of how the higher trophic levels, which regulate the energy flow, have varied. Lastly, estimating variability can require a lot of data, especially if it is to be separated from time trends in the data sets used (Rochet and Trenkel 2003).

Current status and trends

what was it like in an undisturbed/unexploited system?

how would it be expected to change?

which way is the indicator showing a population is going in?  decreasing or increasing ??

Management strategies and/or objectives

define a standard set of management objectives?? ie from Indiseas

  • Conservations biodiversity
  • Ecosystem stability and resistance to perturbations
  • ecosystem structure and functioning
  • resource potential

has it been used in a management strategy? if so how?

relationship to management strategies/ objectives

Stakeholder/public acceptability

Acceptability with stakeholders

  • by all stakeholder
  • by the public
  • understandable to the stakeholders

Hyperlinks to organisations, databases, webportals, and ID books, that are associated with this indicator, if appropriate.

References

Fulton, E.A., Smith, A.D.M., Webb, H., and Slater, J. (2004a) Ecological indicators for the impacts of fishing on non-target species, communities and ecosystems: Review of potential indicators. AFMA Final Research Report, report Number R99/1546.

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Fulton, E.A., Fuller,M., Smith, A.D.M., and Punt, A. (2004) Ecological indicators of the ecosystem effects of fishing: Final report. AFMA Final Research Report, report Number R99/1546.

Possible references for updating this indicator

 

Citation

Please cite this page as:

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Citethis

 

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