Technical Note: Animal-borne CTD-Satellite Relay Data Loggers for real-time oceanographic data collection

• Published in: Ocean Science
• Main Authors: Boehme, Lars, Lovell, Philip, Biuw, Martin, Roquet, F., Nicholson, J., Thorpe, S. E., Meredith, M. P., Fedak, Mike
• Other Authors: NERC, University of St Andrews. School of Biology, University of St Andrews. Sea Mammal Research Unit, University of St Andrews. Marine Alliance for Science & Technology Scotland, University of St Andrews. Scottish Oceans Institute
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: Southern-ocean; Elephant seals; Radio-telemetry; In-situ; Temperature; Salinity; Accuracy; Waters; Transport; GC Oceanography; SDG 7 - Affordable and Clean Energy; SDG 14 - Life Below Water; GC; Elephant Seals; Southern Ocean
• Online Access: https://hdl.handle.net/10023/2039; https://doi.org/10.5194/os-5-685-2009

Funded by NERC grants NE/E018289/1 and NER/D/S/2002/00426 The increasing need for continuous monitoring of the world oceans has stimulated the development of a range of autonomous sampling platforms. One novel addition to these approaches is a small, relatively inexpensive data-relaying device that can be deployed on marine mammals to provide vertical oceanographic profiles throughout the upper 2000 m of the water column. When an animal dives, the CTD-Satellite Relay Data Logger (CTD-SRDL) records vertical profiles of temperature, conductivity and pressure. Data are compressed once the animal returns to the surface where it is located by, and relays data to, the Argos satellite system. The technical challenges met in the design of the CTD-SRDL are the maximising of energy efficiency and minimising size, whilst simultaneously maintaining the reliability of an instrument that cannot be recovered and is required to survive its lifetime attached to a marine mammal. The CTD-SRDLs record temperature and salinity with an accuracy of better than 0.005 degrees C and 0.02 respectively. However, due to the limited availability of reference data, real-time data from remote places are often associated with slightly higher errors. The potential to collect large numbers of profiles cost-effectively makes data collection using CTD-SRDL technology particularly beneficial in regions where traditional oceanographic measurements are scarce or even absent. Depending on the CTD-SRDL configuration, it is possible to sample and transmit hydrographic profiles on a daily basis, providing valuable and often unique information for a real-time ocean observing system. Peer reviewed