Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Solea	794	30.06.2021 - 20.07.2021	NHAS	Skagerrak Kattegat North Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Schaber Matthias	Thunen-Institut fur Seefischerei	Cuxhaven	Cuxhaven

Ziel der Reise / Objectives of Cruise:

The survey was part of an international hydroacoustic survey providing information on stock parameters of small pelagics (Acoustic Survey in the Skagerrak and Kattegat, the North Sea, West of Scotland and the Malin Shelf area, HERAS) coordinated by the ICES Working Group of International Pelagic Surveys (WGIPS). Denmark, Ireland, the Netherlands, Norway and Scotland also participated in the survey. In general, this survey provides the most important fisheries independent contribution to the assessment of herring stocks in the North Sea, Western Baltic Sea, Skagerrak/Kattegat as well as areas west of Scotland and the Irish Sea. The total survey area largely covers ICES Divisions IIIa, IVa, IVb and VIa. The survey design has been standardized across participants and the survey area is partitioned into 23 strata out of which four strata comprising the southern North Sea have been allocated to Germany and were covered during this survey. Main focus was set on herring (Clupea harengus) and sprat (Sprattus sprattus), whereas distribution patterns and abundance of anchovy (Engraulis encrasicolus) as well as sardine (Sardina pilchardus) were another objective of the survey. Altogether, 1612 nautical miles of hydroacoustic transects were covered, which is slightly less than planned. Adverse weather conditions during the survey led to the loss of a few survey days which had to be compensated through an adapted survey design. Accordingly, transect spacing was increased and transects were dropped in stratum 131 reducing the amount of transects covered in that stratum from four (planned) to three. In general, the whole survey area was covered and all strata were sampled.

Messungen / Measurements