Title: Biomass survey manual: a proposed standard guide for conducting annual monkfish biomass survey in Namibian waters.

To keep consistency in data collection and comparability of data time series in fisheries research, gear and sampling methods should be standardized. A full standard trawl system and sampling procedures have not been documented for the annual monkfish biomass survey in Namibia. Furthermore, the old research vessel (RV) Welwitchia was replaced with RV Mirabilis in 2014. Different trawl doors were used on RV Mirabilis resulting in poor catches of monkfish on the new vessel during a series of parallel trawling surveys. The purpose of this study is to standardize the trawl system and sampling procedures based on the methods used during the most recent biomass survey of November 2016. Blueprints for the trawl doors, sweep lines, trawl net and ground gear were developed to provide standard details of the trawl system configuration. Standard operating procedures were also expounded.