Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Clupea	254	13.03.2012 - 27.06.2012	RHLS	Baltic Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Polte Patrick	Thunen-Institut fur Ostseefischerei	Rostock	Rostock

Ziel der Reise / Objectives of Cruise:

The German Institute of Baltic Sea Fisheries (vTI-OSF), Rostock monitors the density of herring larvae as a vector of recruitment success within the frame work of the Rugen Herring Larvae Survey (RHLS). It delivers a high-resolution dataset on the herring larvae ecology in the Western Baltic, both temporally and spatially. A sampling grid including 36 stations is sampled weekly using ichthyoplankton- gear (Bongo-net) during the main recruitment period from March to June. If the inshore area is free of ice an additional survey is conducted in February to control for early spawning events. The weekly assessment of the entire sampling area is conducted within two consecutive days. The data collected provide an important baseline for detailed investigation of spawning- and recruitment ecology of Western Baltic spring spawning herring stocks. As a fishery-independent indicator of stock development, the recruitment index is annually incorporated into the HAWG advice.

Messungen / Measurements