Report of the Workshop on Collecting Quality Underwater Acoustic Data in Inclement Weather (WKQUAD

The Workshop on Collecting Quality Underwater Acoustic Data in Inclement Weather (WKQUAD), chaired by Michael Jech (USA) and Matthias Schaber (Germany), met on 31 March – 2 April 2017 at the National Institute of Water and Atmospheric Research (NIWA) in Nelson, New Zealand. Seventeen representatives from seven countries par-ticipated in the workshop. The participants addressed the terms of reference (TORs) with focus on developing standard procedures and methods for identifying unsuitable survey conditions, proposing methods for dealing with degraded data, and comparing procedures and methods on selected datasets.The goal was to develop diagnostics and metrics that are independent of a specific vessel, i.e. criteria based on effects on the acoustic data. Each vessel responds differ-ently to wind and sea state, rendering it difficult to derive absolute criteria that can be applied to every vessel. Instead, diagnostics and criteria were developed that can be applied broadly, in relative terms. The priority was single-beam narrow-bandwidth echosounders operating at 18, 38, 70, 120, and 200 kHz on vessels with the transducers mounted on the hull or in a retractable keel. Single-beam wide bandwidth, multibeam water column systems, or multibeam bathymetric systems were not addressed, because they are not currently used for abundance estimates.