Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Heincke	HE584	17.09.2021 - 22.09.2021		North Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Brenner Matthias	Alfred-Wegener-Institut fur Polar- und Meeresforschung	Bremerhaven	Bremerhaven

Ziel der Reise / Objectives of Cruise:

The aims of the cruises are cross disciplinary pilot studies of different wreck sites in the German Bight to assess the risk deriving from munition cargo. To assess the wrecks we will do bathymetry, oceano-graphy/hydrography, marine geophysics, chemistry and marine biology, by applying e.g. multibeam/sonar techniques, sediment/water analysis, CTD, passive sampler and ROV/video missions. Further, we will do fishing and will recover exposed mussels in cages, using remote operating lander to evaluate the biological effects of munition compounds on the health of organisms.RV Heincke left Bremerhaven harbour as planned in the morning of the 17th September and steamed approx. 10 hrs to the reference area at Borkum Riffgrund. Here, Heincke stayed overnight before the sampling campaign started in the morning of the 18th of September with water and sediment sampling. Subsequently three bottom trawls were made to get the necessary 50 dabs (Limanda limandes) for the biological biomarker assessment. After fishing was completed Heincke left Borkum Riffgrund and steamed to the wreck position of SMS Mainz. Here, the first missions of AUV and ROV were conducted, resulting in detailed side scan and multibeam scans as well as subbottom profiles. In addition, the wreck was filmed along its whole length during two subsequent ROV missions. Thereafter, Heincke left the position and steamed to the wreck position of SMS Ariadne. At the wreck site of SMS Ariadne, also sediment and water samples were taken before AUV and ROV mission were conducted. Since light conditions were already bad during afternoon slackwater an additional ROV mission was conducted in the morning of the 20th September. Thereafter, Heincke left the SMS Ariadne and steamed to the wreck position of Sperrbrecher Friesland. Since the wreck position is very close to the pilot vessel surveying the ship traffic towards the river Elbe, the Heincke mission was pre-announced to the water and shipping authorities of Cuxhaven. Similar to the other wrecks water and sediment samples were taken and AUV mission were conducted successfully. ROV mission were also conducted but cancelled later since visibility at the position was too bad for manoeuvring the ROV. In addition, during the last sediment grapping operation the grabber got entangled with the wreck and heavily warped. However, the deck crew managed to fix the grabber, so it could be used at the following day also for the last wreck. In accordance with the captain the search mission for the Torpedoboat S13 was cancelled since an assessment of the wreck can hardly be done safely. The reasons are, that the wreck position is within the waterways towards the river Elbe, in direct vicinity of a big marker buoy and very close to a sandbar with only 1m of water depth. Instead the SMS Hela was approached and investigated similar to the other wrecks. As planned Heincke returned to Bremerhaven at the 22nd of September. Further information are available at: Master track: https://doi.pangaea.de/10.1594/PANGAEA.938570

Messungen / Measurements