SISP 8 - Manual for the International Baltic Acoustic Surveys (IBAS). Version 2.

Abstract

The acoustic surveys have been conducted in the Baltic Sea internationally since 1978. The starting point was the cooperation between Sweden and the German Democratic Republic in October 1978, which produced the first acoustic estimates of total biomass of herring - Clupea harengus and sprat - Sprattus sprattus in the Baltic Proper (Håkansson et al., 1979). Since then there has been at least one annual hydroacoustic survey for herring and sprat stocks mainly for assessment purposes and results have been reported to ICES to be used for stock assessment (Hagström et al., 1991; ICES, 1994a, 1995a, 1995b; 2006; Gasyukov et al., 2009; Grygiel and Orłowski, 2009).

At the ICES Annual Science Conference in September 1997, the Baltic Fish Committee decided, that a manual for the International Baltic Acoustic Surveys (IBAS) should be elaborated. The structure of the manual follows that of the Baltic International Trawl Surveys (BITS). In order to obtain standardization for all ICES acoustic surveys some demands from the Manual for Herring Acoustic Surveys in ICES Divisions 3, 4 and 6 (ICES, 1994b) are adopted. The objective of the Baltic International Acoustic Survey (BIAS) and Baltic Acoustic Spring Survey (BASS) programs are to standardize survey design, acoustic measurements, fishing method and data analysis throughout all national surveys where data are used as abundance indices for Baltic herring, sprat and to some extent cod stocks assessment purposes.