WOBEC SOP SUIT

Weddell Sea Observatory of Biodiversity and Ecosystem Change – WOBEC Standard Operating Procedures Technical Documentation December 2025 To be cited as Schaafsma, Fokje, Nils Van den Steen, Anton Van de Putte, and Hauke Flores. ‘WOBEC SOP SUIT’. Zenodo, 15 December 2025. https://doi.org/10.5281/zenodo.17936316 Co-funded by the European Union (c) The authors This report is licensed under the Creative Commons Attribution International license Versions Date Comment Responsible Approved April 2025 First Draft H. Flores/F. Schaafsma 12/12/2025 Formatting N. Van den Steen Table of Contents 1 Description of sampling gear .......................................................................................................... 5 2 Sampling gear deployment .............................................................................................................. 5 2.1 Sensor preparation ............................................................................................................................... 7 2.1.1 CTD ............................................................................................................................................................ 7 2.1.2 ADCP ......................................................................................................................................................... 7 2.1.3 GoPro ........................................................................................................................................................ 7 2.1.4 RAMSES (at the last moment possible) ....................................................................................... 7 2.2 Sensor retrieval ..................................................................................................................................... 8 2.2.1 Aquadopp ............................................................................................................................................... 8 2.2.2 CTD ............................................................................................................................................................ 8 2.2.3 RAMSES ................................................................................................................................................... 8 2.2.4 GoPro ........................................................................................................................................................ 8 3 Sample sorting-collection-preservation procedure ............................................................... 9 4 Annex ........................................................................................................................................................ 9 4.1 Annex 1. Station protocol ................................................................................................................ 10 4.2 Annex 2: Explanatory example catch processing protocol ................................................ 11 4.3 Annex 3: Detailed sensor protocols ............................................................................................ 12 4.3.1 3.1 Aquadopp (second priority to remove, download and/or turn off) ..................... 12 4.3.2 3.2 CTD.................................................................................................................................................. 12 4.3.3 3.3 RAMSES (this should be the first priority to remove from SUIT) .......................... 13 4.3.4 3.4 GoPro.............................................................................................................................................. 14 Method responsible: Hauke Flores/Fokje Schaafsma 1 Description of sampling gear A Surface and Under Ice Trawl (SUIT) will be used to sample the upper two meters of the water column. The SUIT has a steel frame with a 2x2 net opening and floats attached to the top to keep the net at the surface or directly under the ice. The SUIT shears out to the side of the ship, sampling away from the ship’s wake. To achieve good shearing and sufficient distance from the ship, between 100 and 150 m of cable length should be set out. The frame contains a 7-mm half-mesh commercial shrimp net over 1.6 m width, and a 0.3-mm mesh plankton net over 0.4 m width. The frame is equipped with an Acoustic Doppler Current Profiler (ADCP), Ramses radiance and irradiance measurement devices (including datalogger), a CTD probe and a GoPro camera. To ensure that the towing cable does not get entangled in the ice, there is a 1000 kg weight attached to keep it emerged directly behind the stern of the ship. 2 Sampling gear deployment Before the SUIT is lowered into the water, the sensors are installed in the net’s frame and the cod ends are attached. The SUIT net and the weight is brought into position, according to the gear operation instructions of RV Polarstern and the technical documentation “SUIT Figure xx: The SUIT in the water (left) (© Jan Andries van Franeker). Schematic overview of SUIT deployment from the side (top right) and from above (bottom right). protocol”. Safety guidelines should be followed carefully during this operation. The deployment is performed by the ship’s crew and may be assisted by specifically trained staff from the science team. GPS, station protocol sheet (Annex 1) and fish boxes are ready on deck. Hose for rinsing the net after deployment is open on deck to ensure that the water is cold when the net has been retrieved. The length of the towing cable when sampling is approximately 120 m. In open water it may be decided to extend the towing cable to 200 m. The ship’s speed during sampling is ~2.5 - 3 kn. The standard towing duration is 30 minutes. The cod ends are retrieved on deck, after the crew lifted up the rear end of the nets and these are both rinsed out with the sea water hose. When the cod ends are overflowing, the remainder will be collected in a large fish box. This box will also be used to collect specimens Figure xx: The SUIT sensor array. From top to bottom: Ramses radiance and irradiance sensors, data logger, CTD probe and ADCP (© Fokje Schaafsma). Figure xx: Left: the SUIT nets are hoisted up to enable net rinsing during hauling in. Right: cod end are retrieved after net rinsing to be transported to the wet lab for processing the catch (© Jan Andries van Franeker). from rinsing the net. Both the cod ends and the fish boxes will be brought to the wet laboratory. 2.1 Sensor preparation 2.1.1 CTD • Connect to the PC and follow the instructions for calibration of pressure sensor • Activate auto-recording mode • Disconnect • Put into protection cap at SUIT frame • Attach altimeter • Remove fluorometer cap • Magnet in your pocket • Activate with magnet just before launch 2.1.2 ADCP • Connect to PC and follow the instructions • Disconnect • Put into protection cap at SUIT frame • Ready to go! 2.1.3 GoPro • Check that the battery is charged and the memory empty • Put in protection case • Ready to go! • 2.1.4 RAMSES (at the last moment possible) • Connect sensors and PC following the instructions • Activate auto recording mode • Disconnect • Put sensors into protection cap at SUIT frame • Ready to go! A detailed sensor preparations guide can be found in Annex 3. 2.2 Sensor retrieval 2.2.1 Aquadopp • Rinse sensor with fresh water • Connect to sensor-pc via usb-serial adapter • Download data • Check battery status – if necessary, change batteries (when down to ca. 9 v) • Check memory – if necessary, erase memory • Convert data and save as .csv files • Prepare for next measurement • Disconnect sensor • Store safely in case • Copy data on external hard disk and on ship’s network server 2.2.2 CTD • Rinse CTD with fresh water • Connect to sensor-pc via usb-cable • Download data • Check battery status – if necessary, change batteries • Check memory – if necessary, erase memory • Prepare for next measurement • Disconnect sensor • Store safely in case, or mount back in SUIT protection case for next use • Copy data on external hard disk and on ship’s network server 2.2.3 RAMSES • Rinse all parts with fresh water • Consecutively connect SUIT and ship sensors to PC and download data • • • Prepare for next measurement • Store safely in case, or mount SUIT sensor and ISP back in SUIT protection case for next use • Copy data on external hard disk and on ship’s network server 2.2.4 GoPro • Open Camera housing and check for leakages • Bring Camera to drylab • Download video files from sd card • Prepare for next measurement • Mount back in SUIT protection case • Copy data on external hard disk and on ship’s network server A detailed sensor retrieval guide can be found in Annex 3. 3 Sample sorting-collection-preservation procedure Process the catches from the shrimp and plankton net separately. Use a separate catch sheet for each net. Details on further sample processing can be found in the SOP for mesoand macrozooplankton net sample processing. 4 Annex 1. Explanatory example station protocol 2. Explanatory example catch processing protocol 3. Detailed sensor protocols