Click this link to display all EMWs in numerical order.
"Estimated mean weight" id. An EMW id which is numeric, e.g. EMW-2, indicates the estimated mean weight is for an FAO species category. An EMW id ending with 'a' or 'b' indicates the estimated mean weight is for a species that is not an FAO species category. E.g. EMW-2a is the EMW id for Gilled lungfish which is not an FAO species category but which is used to estimate the mean weight for EMW-2 African lungfishes.
|FAO species category
A species or group of species reported in FAO fisheries capture statistics.
|A multi-species category?
Y indicates the FAO species category includes more than 1 species.
|Lower (or upper) estimated mean weight (EMW)
The lower (or upper) end of the estimated mean weight range.
|Smallest (or largest) species in group EMW id
For categories that include more than 1 species, the estimated mean weight range is (usually) based on an estimated mean weight for the smallest and largest relevant species, combined to give a range.
|Same species EMW id
Sometimes there is more than one FAO species category for the same species. These may be different subspecies. In such cases, the estimated mean weight range is derived for one of the FAO species categories, and the estimated mean weight ranges of the other FAO categories are based on this.
|Reliability ranking for Lower (or upper) EMW
This number indicates the type of data used to calculate the lower (or upper) end of the estimated mean weight range. The lower this number, the better the data is likely to be. For single species categories, the reliability rankings for the lower and upper end of the estimated mean weight range are usually the same because they are usually based on the same fish size data. However, it is possible for them to be different for a single species category. Some fish size references apply to only the lower or upper end, resulting in different references being used for each. For example, "most fish caught in commercial catches weigh less than 1000g" gives an upper end but not a lower end.
|Overall reliability ranking
This number indicates the type of data used to calculate the estimated mean weight range as a whole. If the reliability ranking of the lower end of the estimated mean weight range differs from that of the upper end, the overall reliability ranking will be the higher figure (i.e. the lower ranking).
For example, suppose we have a multi-species FAO species category "A" for which the smallest and largest species are species "S" and species "L" respectively. Suppose, in this example, that the estimated mean weight range for species S and L are respectively 100-150g and 1000-1200g, giving an overall estimated mean weight range of 100-1200g. In this example, the estimated mean weight of 100-150g for species S is obtained from average weight data. The estimated mean weight of 1000-1200g for species L is obtained from converting common lengths to weights. The reliability ranking for average weight data is 1 and that for common lengths is 3 (lengths being less reliable than average weights). The reliability rankings for the lower and upper ends of the estimated mean weight range for FAO species category A are therefore 1 and 3 respectively. The overall reliability ranking is therefore 3
|Max weight (g)
Maximum weight for this species. This is the maximum published weight obtained from fishbase.org, unless a reference citing a larger size has also been obtained. This is not shown for multi-species categories.