Conversion coefficients are the factors used in estimating the live-weight equivalent of fish caught. Live weight is the only measure used in catch statistics, being the basis in particular for monitoring the drawdown of quotas and estimates of the state of stocks. The study looked first at how figures on catches in live-weight equivalent are gathered, validated and calculated in three Member States, namely Denmark, France and the United Kingdom. These three countries employ related methods involving the database storage of sales data together with details of the presentation of the fish. The information in logbooks is mainly used as a cross-check on the sales data. If sales data are not available, logbook details are entered raw in the catch databases.... |