The Helgoland Underwater Observatory

Fig. 1) Location of the Margate underwater experimental field. (Photo: Alfred-Wegener-Institut)

Fig. 2) Underwater node system with connectors for power and internet. (Photo: Alfred-Wegener-Institut)

Fig. 3) Underwater lander system with various sensors. (Photo: Alfred-Wegener-Institut)

The AWI-COSYNA Helgoland Underwater Observatory was initiated in 2012 by installing a remote operated underwater node system about 500m North of Helgoland in the AWI underwater experimental field Margate at 54° 11.700'N / 7° 52.600'E (WGS84) (Fig. 1)

The observatory was jointly developped by the two Helmholtz centres AWI and HZG in cooperation with the two companies 4HJena and Loth engeneering. Since 2015, the Thünen Institute of Sea Fisheries (Hamburg) is part of the COSYNA node consortium. Since 2016, the Helgoland node system is part of the EU Jericho Next program.

The Underwater Node unit comprises a central lander systems (Fig. 2) with 10 underwater pluggable connectors for power and internet. The lander system is connected via a seacable to a land based server system for remorte control. The central node unit provides power and internet connection to sensor units which can be placed in up to 70m distance to the node (Fig. 3). All sensors are fully remote controlled and data are transferred in realtime to the central server system.

The node system provides up to 5 guest connectors for sensor units from cooperating partners. Sensors of cooperating partners are connected via remote control and are fully accessible from all over the world. Using this system, numerous cooperations with fascinating topics have been established over the last years. A list of ongoing (and previous) projects is provided here.

The Helgoland node system is equipped with a standard sensor unit providing real-time Temperature, Conductivity-Salinity, Oxygen, Chlorophyll A, Turbidity, PAR radiation and a custom made stereoscopic fish observatory (RemOs1) as well as two Webcams. Additionally, an upward looking stationary ADCP (Teledyne, 1200 Hz) is available. The system is complemented by a land based FerryBox in about 500m distance. The sampling intervall of the sensors is 1Hz (1 value per second), the ADCP is configured as single pin ensemble to allow zooplancton biomass estimations. The stereoscopic fish observatory saves one image pair every 30 min. The webcam is permanently online.

Data are automatically transferred every hour to the AWI Near-Realtime-Database (NRT) of the AWI computing center in Bremerhaven where they are shown as averages per hour in the AWI-dashboard for the AWIPEV-UWO for a first check. Data are then post-processed (including quality checks) depending on their use and finally stored as datasets in Pangaea.

Click on the variables (temperature, conductivity etc.) in the above text to have a look on the online data.