RRS Discovery D356
Cruise summary report
|Ship name (ship code)||RRS Discovery (74E3)|
|Cruise period||2010-09-10 — 2010-10-13|
|Port of departure||Walvis Bay, Namibia|
|Port of return||Cape Town, South Africa|
|Objectives||The expedition is planned as the third field phase of the running RTD‐project GENUS (Geochemistry and Ecology of the Namibian Upwelling System) of the German Ministry of Education and Research (BMBF) under the international umbrella of IMBER (Integrated Marine Biogeochemistry and Ecosystems Research).
The first Leg began at the Walvis line at 23S, where a mooring was recovered with 1 year of data. These and further cruise data were useful in a long-term context at this interesting area. From the previous synopsis transect, the Kunene transect at 17-18' S was worked along, next. The cruise track was kept near shore to take samples of fish larvae on the way. At the slope station of the Kunene Transect, the winch system failed and the ship had to return to Walvis Bay roads to pick up a technician who was able to repair the system during the following days. During that time, a subsidiary programme was run, to complete the Walvis Bay Transect using Bongo, Ringtrawl and WP2 nets as well as Microstructure sonde, which could be run independently of the main winch circuit. The outermost deep-sea station could then be worked upon with the main system back in operation. On the way back along the transect, further stations were done. Twelve scientists were exchanged at Walvis Bay on 24 September while the ship was at the Pier.
Leg 2 started at noon, parallel to the coast with Ring Trawl stations and pick up of the short-term mooring. From there, we steamed to the West to start a survey through potential filament heads between 21-19S with Scanfish and Katamaran. When the Rocky Point Transect on the 19S latitude was reached this was begun with a deep station, then worked towards the coast. The ship went W again so that on the 11 00' meridian a further survey with Scanfish and Katamaran due North was done, oriented at Satellite imagery which showed an extensive filament. On the way back to the SSW, Microstructure sonde and CTD were combined with deployments of the full set of nets available. At the end of this transect, the ship moved W to reach the outer margin of the filament under study. CTD, MSS and nets were deployed again to record the hydrography and biotic environment. The survey of the filament was successful and expected to yield valuable data. From the 19th parallel the ship sailed back South towards the position of the third mooring at the Walvis Bay transect (23S). Here a 36h process study with hydrography measurements and net deployments was done. The vertical migration of zooplankton was recorded in parallel with the ship's 150 kHz ADCP. The mooring was released in the end but not recovered.
Six scientists were taken ashore at Walvis Bay on 10 October, among those two Namibian and one S. African colleague to attend this year's Benguela Current Commission Congress at Swakopmund where GENUS was presented. With this, the scientific programme was ended and RRS Discovery steamed to Cape Town, arriving in the evening of 13 October.
|Chief scientist||Friedrich Buchholz (Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research)|
|Coordinating body||Integrated Marine Biogeochemistry and Ecosystems Research (IMBER)|
|Cruise report||(0.96 MB)|
|General||South East Atlantic Ocean (limit 20W)|
|Specific||Southwest African Shelf seas|
|Track charts||(0.14 MB)|