Help screen for
Reference data detail

EMW ref. id
"Estimated mean weight" reference id. References are assigned an id m where m is an integer starting with 1 for each EMW id.
The species for which the mean weight is estimated.
Scientific name
The Scientific name for Species.
Lower (or upper) estimated mean weight (EMW)
The lower (or upper) end of the estimated mean weight range that would be estimated for this Species if based on this reference alone. This shows the value prior to any adjustment to the minimum allowed fish weight (see help notes for EMW set to the min allowed value? on Screen 3).
Used for lower or upper EMW figure?
This indicates whether the fish size data applies to both the lower and upper end of the estimated mean weight range, or just one of them. "Both" means it does e.g. "the average weight is 1-2 Kg". "Upper" means the fish size data applies to the upper end only of the range e.g. "most fish taken in commercial catches are less than 1 Kg". "Lower" means the fish size data applies to the lower end only e.g. "fish exceeding 2 Kg are commonly taken in catches".
EMW method
The derivation of estimated mean weight ranges from different types fish size data are called "methods". Different methods require different types of calculation. For example, estimates based on common lengths require calculations to convert lengths to weights (using length-weight formulae). The type of method used depends on the type of fish size data being used and determines the reliability ranking of the reference.
Similar species EMW id
This applies where the method is to obtain a mean weight estimate based on that for a similar species.
Length-weight calculations
Set to "more info" (a hyperlink to Screen 5) if length-weight calculations were performed for this reference, blank otherwise. Length-weight calculations are performed if the fish size data used is a length and if sufficient length-weight data is available on
*** Fish Size Quote ***
This is the fish size quoted in the reference. This may be blank where the fish size is calculated from data given in the reference, in which case details will be given in *** Explanatory notes ***.
*** Explanatory notes ***
This provides additional information to the *** Fish size quote ***. It also provides explanation of how the fish size was obtained from the information in the reference where some calculation was performed (for example, where a mean weight is derived from tables of capture weight and fish numbers). In such cases, these calculations may be viewed by clicking on the "Calculation detail" link which appears at the bottom of this column.

The scientific and common names of the species referred to in the reference are given in this column, where not given in *** Fish Size Quote *** or Reference document. In cases where this scientific name is not given, or differs from the scientific name displayed for this EMW, then explanation is provided e.g. where the reference scientific name and EMW scientific names are synonyms.
Link to reference
Hyperlink to the reference document if available on the internet.
Reference document
Details the reference document e.g. its title.
Reference URL (or book)
The internet address (if any) from which the reference document was obtained. Gives the book details if Reference document is a book.
Link to Species Summary
Hyperlink to the Species Summary page on for Species. Occasionally this link displays the home page instead of the species summary page. If this happens, enter the scientific name in the "Genus + Species" search field to search for this species.
Species not given ind
The value in this column indicates how the scientific name of the species to which the reference applies was identified (using where it was not given as equal to the scientific name. Some explanation is given in *** Explanatory notes *** when this value is non blank.

S – A scientific name was given in the reference that is a synonym of scientific name.

1 – According to, there is only one scientific name corresponding to the common name given in the reference, which was taken as the scientific name to which the reference applies.

2 – All common names matching the name given in the reference, and that were judged to be for relevant countries, refer to the same scientific name which was taken as the scientific name to which the reference applies. E.g. reference 2 for EMW-338 gives size data for “Wahoo” but does not give the scientific name. According to, all common names, including USA and UK ones, of “Wahoo” correspond to Acanthocybium solandri except for one name for the Phillipines which corresponds to Makaira mazara . Since the reference is a US one, the latter name was judged not relevant, and the reference assumed to refer to Acanthocybium solandri.

3 – The scientific name corresponding to the common name given in the reference could not be uniquely identified. In such cases, the reference is rejected.