SMRU > Research > Instrumentation
Marine mammals may travel to remote regions of the ocean and may spend a high proportion of their time underwater. The opportunity for direct visual observation is limited, so we need to use instruments attached to animals to collect and relay data. These generally record depth and location but instruments may also record physiological, oceanographic or other behavioural parameters (even the sound and visual field of animals). An alternative approach is to detect and record the sounds made by the animals themselves.
Sascha Hooker uses Time Depth Recorders (TDR’s) that incorporate cameras so that the type and abundance of prey can be estimated.
Oceanographer Lars Boehme uses data from SMRU CTD tags depolyed mainly on Southern Elephant Seals in his work on projects such as SEaOS, SAVEX and MEOP. (See also the page on Oceanographic Research.)
Patrick Miller uses “D Tags” that can be deployed with suction cups to study the fine scale behaviour of a number of cetacean species, including sperm whales, killer whales, and humpback whales. Miller is also working with the Instrumentation group to develop a new generation of higher-resolution archival tags for seals. These tags will be able to record detailed behaviours, such as swimming movements, over 8-months. This will allow us to study the critical period between the moult and breeding seasons.
Doug Gillespie and Jonathan Gordon develop and use passive acoustic detection systems to estimate the presence and abundance of cetaceans. Marine mammals can be difficult to spot at the surface except in the calmest conditions. Passive acoustic monitoring (PAM) allows us to detect the sounds marine mammals make while they are submerged, at night and during inclement weather. PAM data can be used to measure animal distribution and abundance and can also be used to find animals for other studies such as photo-id. Specialist software, such as PAMGUARD, can be used to automatically detect sounds which are too low or too high to be heard by the human ear and also to estimate the location of vocalising animals. (See also the page on Acoustics Research.)