Large-scale static acoustic survey of a low-density population—Estimating the abundance of the Baltic Sea harbor porpoise

• DOI: 10.1121/1.4900114
• Publication Date: 2014-10-18T00:33:39Z
• Authors: Jens C. Koblitz; Mats Amundin; Julia Carlström; Len Thomas; Ida Carlén; Jonas Teilmann; Nick Tregenza; Daniel Wennerberg; Line Kyhn; Signe Svegaard; Radek Koza; Monika Kosecka; Iwona Pawliczka; Cinthia Tiberi Lj...; Katharina Brundiers; Andrew Wright; Lonnie Mikkelsen; Jakob Tougaard; Olli Loisa; Anders Galatius; Ivar Jüssi; Harald Benke
• Keywords: Phocoena; Baltic sea; Hydrophone; Aerial Survey

SAMBAH (Static Acoustic Monitoring of the Baltic Sea Harbor Porpoise) is an EU LIFE + -funded project with primary goal estimating abundance and distribution critically endangered harbor porpoise. From May 2011 to April 2013, members in all countries around undertook a static acoustic survey using 304 porpoise detectors distributed randomly positioned systematic grid waters 5–80 m deep. In recorded data, click trains originating from porpoises have been identified automatically algorithm developed specifically for conditions. To determine train C-POD detection function, series experiments carried out, including tracking wild free ranging hydrophone arrays area moored C-PODs playbacks porpoise-like signals at during various hydrological Porpoise has estimated by counting number individuals detected short time interval windows (snapshots), then accounting false positive detections, probability animals being silent, non-silent within specified maximum range. We describe method detail, how auxiliary enabled us estimate required quantities.