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‘Taxonomic reporting quality’ (Tc) was a factor developed by the Ocean Health Index to adjust the Status score for the Fisheries subgoal of Food Provision depending upon the apparent quality and effort of the natiional fisheries statistics system.  

For those years the Status of the Fisheries subgoal represented how closely the biomass of a country’s catch approached 75% of the calculated multispecies Maximum Sustainable Yield (mMSY) available from its waters. If a country supplied the Food and Agriculture Organization of the United Nations (FAO) with poor quality data, calculations of both its catch and mMSY were less certain. Taxonomic reporting quality estimated that uncertainty and modified the sub-goal Status accordingly by using Tc as a factor in the equation status equation.

This component has been replaced by Taxonomic Level of Aggregation, another measure of how accurately the fish caught are identified. Further information is available on this site's Taxonomic Level of Aggregation Web page and in the supplementary information for Halpern et al. (2015)

How Was It Measured?

‘Taxonomic reporting quality’ (Tc) was an index based on the proportion of fished stocks for each country whose taxonomic identities were accurately reported to the Food and Agriculture Organization of the United Nations (FAO).  The method is borrowed and modified from Alder et al. (2009). It assumes that when a commercial species is present within EEZ waters of a country or several countries, this species will be fished by at least one of those countries.

If the taxon does not appear as a separate entity in a given country’s catch reports, then it is likely that it was under-reported or perhaps included in the ‘miscellaneous’ category or a higher-level taxonomic grouping. Countries that under-report their catches are probably not managing their resources as well as they could or should. For example, several countries (e.g. Suriname, Sierra Leone, French Guiana) that are known to have poor overall fish stocks, reported very few stocks, but still had very high status scores, suggesting that their catches contain unreported stocks/taxa that are probably not well managed and hence possibly not in good condition.

Commercial marine taxa of fish and invertebrates are defined here as species, genera, family, order, class, or ISSCAAP grouping that was reported to FAO from 1950 through 2006 in the catch of at least one country. The ISSCAAP grouping is assigned according to codes provided in the FAO 'International Standard Statistical Classification for Aquatic Animals and Plants' (ISSCAAP), which divides commercial species into 50 groups on the basis of their taxonomic, ecological and economic characteristics.

Taxonomic reporting quality (Tc) was measured as an index for each country based on the proportion of taxa that were reported to FAO relative to the number of commercial taxa known to be present according to static range maps produced by the Sea Around Us project showing that their distributions overlap with at least 10% of a country’s EEZ­­. This proportion was weighted based on the level of taxonomic resolution with which the catches were reported. Six levels of taxonomic resolution were identified, from species (weight w= 6) to broad ISSCAAP groups (weight w = 1).  Tc was calculated by finding the weighted sum of the number of taxa reported for each of the 6 taxonomic aggregation levels and dividing it by the weighted sum of the total number of commercial taxa distributions known to be present for each taxonomic aggregation level.  Since Tc ranges from 0 (very low quality) to 1 (all taxa reported), multiplication of the biomass-based portion of the Status score by Tc strongly influenced Status.  

This approach may overestimate the reporting quality for isolated locations such as remote islands, or countries with very extensive EEZs, as these were less likely to have stocks that overlap with neighboring countries.

The reporting coefficient assumes that all unreported stocks are heavily depleted, thus scoring 0. Where this precautionary assumption is not correct, the coefficient will cause Status to be underestimated. 

In any location where catch data are reliable and accurately reported by taxon, Tc could be replaced with a sustainability score that measures the actual status of the harvested stocks (e.g., the proportion of depleted stocks), though that has not been done for Ocean Health Index scores presented here.

What Are The Impacts?


Accurate assessment of Fisheries Status is crucial to avoiding unacceptable harm to fish stocks, habitats, and ecosystems caused by overfishing.


Accurate assessment of Fisheries Status is crucial to maximizing human food benefits both now and in the future. Sustainable food provision from ocean ecosystems is likely to be an increasingly important diet component for the growing human population.    


Accurate assessment of Fisheries Status is crucial for maintaining the long-term economic health of livelihoods in the fishing industry and of the coastal communities providing those livelihoods. 

Get More Information

Food and Agriculture Organization of the United Nations (FAO)

Fishery Fact Sheets Collections. ASFIS List of Species for Fishery Statistics Purposes.      


Developed at the WorldFish Center in collaboration with the Food and Agriculture Organization of the United Nations (FAO) and many other partners, this global information system provides detailed information on almost all of the known world fish species and aquatic living organisms (marine and freshwater), and is searchable by country and species. 

The Sea Around Us Project 

The Sea Around Us project investigates the impact of fisheries on the marine ecosystems of the world, and offers mitigating solutions to a range of stakeholders. The project is a scientific collaboration between the University of British Columbia and the Pew Environment Group that began in July 1999. The Sea Around Us project conducts a catch reconstruction program, the results of which improve the accuracy of estimates of catch, stock exploitation status, and other key factors for fisheries management. 

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