As one of their WorkPackages for Integrated Coastal Zone Management (ICZM), INCOFISH provides materials to aid in the use of simple size indicators (see Froese 2004) to ensure the sustainability of a catch. Depending on the regulations present in a given fishery, these indicators may be set as lower limits (i.e. a length/ age below which it's assumed the fish has not had a chance to spawn yet, and should not be caught) or upper limits (i.e. a length/ age above which fish are assumed to be "megaspawners", and should not be caught). Among these resources, they provide worksheets to calculate maturity indicators from length-frequency data and length at maturity (Lm), a set of downloadable rulers for consumers and fishers to use to measure a given species of fish against scientifically defined lengths that indicate age/ maturity, and worksheets for calculating the global costs of overfishing.
