GPS suction tracker puts whales on the radar

A worldfirsttrialof tracking migrating humpback whalesusing a novel methodhasbeen successfuland paved the way for less invasive devices to be deployed in future tracking studies.

Dr OlafMeyneckefrom Griffith University’s Coastal and Marine Research Centre (CMRC) led the study, which has been published inJournal of Marine Science and Engineering.

Using a CATS(Customised Animal Tracking Solutions)suction cup tag, whichtemporarily adheres to the whale’s skin, DrMeyneckewas able to deploy the tagsin theGold Coast bayregionsand track the whalesin real timeusing Global Positioning System/Global Systems for Mobile Communication (GPS/GSM).

During the two deployments – one on a suspected male and another on a female humpback whale – the tags provided location points with relatively high accuracy for both individuals albeit different swim behaviour and surface intervals.

In combination with an integrated archival data logger, the tag also provided detailed information on finescale habitat use, such as dive profiles.

“Using a GPS/GSM module on whalescommonly used for fleet trackingis a first and it’s a method that hasa lot ofpotential,” he said.

Normally, satellite relay tags are usedto transmit location data, simply because they work in remote locationsbut they are very expensive. However, because migrating whales stay close to shore most of the time, our tag workswell.

“These tags are amore cost-effective method and capture more data locationsanddata points over time.The principle is the sameasother suction cup tags– thetag sucks onto thewhalesskin and just falls off.The whales dontseem tonoticethemat all.

Suction cup tags do not have to penetrate the animals’ skin and can be used for shortterm deployments (hours to days), which make them applicable for fine-scale habitat use studies such as this,whichinvestigated movements within the range of metrestokilometres.

The tags measured about 20cm long and 10cm wide, were specially designed in a hydrodynamic shape for minimal resistance,and werewatertight and pressure safe to several hundred metres.

DrMeyneckesaid information on fine-scale habitat use of cetaceans(aquatic mammals)couldprovide important insights into habitat preferences and sensitivity to environmental drivers (hydrodynamics, temperature gradients, salinity, bathymetry) as well as anthropogenic impacts.

“Ideally for future studies we would like to modify the tag so that the antennaeisout of the water enough to transmit after the tag comes off the whale, and extend the tagging time and focus on resting whales in the bays to study their behaviourfurther,” he said.

The study ‘Asset Tracking Whales – First Deployment of a Custom-Made GPS/GSM Suction Cup Tag on Migrating Humpback Whales’ has been published inJournal of Marine Science and Engineering.