Deep Water Hydroacoustics - Advances, What Must be Standardized, and Where Is Flexibility Allowed?

Hydroacoustics is a dynamic field that evolves as technology advances and methods are conceived and tested. Most researchers use acoustic methods to study fish and invertebrates to inform fisheries management and advance the understanding of lentic ecosystems. Still there is need for standardization so that results of different studies can be compared, especially those dealing with routine fish density and biomass estimation in lakes and reservoirs. Recently, researchers have made good progress towards standardization of collection and processing methods for assessing pelagic fish in North America and Europe.  Standard operating procedures (SOPs) for Great Lakes were finalized in 2009, and the European Standard (CEN) Water Quality – Guidance on the Estimation of Fish Abundance with Mobile Hydroacoustic Methods was accepted in 2014.  The procedures are being evaluated with subsequent field studies, some of which are in different stages of completion.  The primary goal of our presentation is to recommend a pathway to global standardization. To meet this goal we will compare the North American Great Lakes and European SOPs for similarities and differences, and use results of the recent field studies to 1) formulate a path forward and 2) recommend further research as needed.