Science & Technology (Commonwealth Union) – Drone technology continues to play a crucial role in research. In recent years the agricultural sector has seen increased use of drones for both farmers and researchers with the ability to cover vast areas in a short time period.
Recent research conducted by Monash University and Phillip Island Nature Parks is using drones equipped with thermal and infrared sensors to identify cases where Australian fur seals become tangled in marine debris.
Entanglement in ocean waste is an increasing danger for marine animals such as seals and fur seals. These incidents can lead to injuries, limit their ability to move, and force the animals to expend more energy to survive.
The research, published in Marine Pollution Bulletin, combined drone-mounted colour (RGB) cameras with thermal infrared (TIR) imaging to locate entangled Australian fur seals at Seal Rocks, located southwest of Phillip Island.
Data collected from 54 drone surveys showed that entanglements could be identified in handheld thermal infrared imagery through higher heat levels around the area where debris was wrapped around the animal. Comparable thermal patterns were also detected in 81% of drone observations that used both RGB and TIR imaging, with human reviewers agreeing on the findings in 95% of cases.
Lead researcher Adam Yaney-Keller, a PhD candidate from the School of Biological Sciences at Monash University, said the project represents the first-time drone-mounted thermal infrared imaging has been applied to detect debris entanglement in wildlife.
He pointed out that their results show that entanglements produce a detectable heat signature in thermal imagery. Yaney-Keller further stated that what was significant was, this signature can be identified from drones flying more than 50 metres above the animals, allowing researchers to detect entanglements more easily while minimising disturbance to fur seals at breeding colonies.
He further indicated that what was most significant was that, fishing line entanglements were identified in the dual RGB+TIR drone imagery, when in previous drone-based techniques these types of thin or transparent materials were regularly not detected.
“Fur seals are just one of many species impacted by entanglement. But because they spend time on land and at sea, we can use them as an indicator of the problem for all marine life. By improving detection and rescue techniques, we get a better idea of how bad this problem really is in our oceans.”
Seal Rocks, the largest breeding colony of Australian fur seals in the world, experiences a high rate of entanglement, especially from discarded fishing lines. The introduction of this new technology has significantly enhanced the ability to detect such entanglements, creating more opportunities to rescue wildlife from accidental harm.
Researchers also discovered an unexpected benefit: thermal imaging made it possible to clearly identify other injuries, including shark bite wounds. This suggests the method could be applied to broader monitoring efforts across marine ecosystems.
Phillip Island Nature Parks marine scientist Rebecca McIntosh said the use of thermal drones to survey fur seal colonies represents a significant advancement for conservation.
Dr McIntosh indicated that the technology enables them to detect subtle heat signatures from the air, helping reveal injuries and entanglements that would otherwise be very difficult to spot.
“It means we can detect at-risk seals earlier, intervene with better information and ultimately improve welfare outcomes for individuals and better understand trends in entanglement and impacts on the population as a whole.”
The researchers have already started sharing their method with the broader marine science community. Recently, the same technology was successfully tested in collaboration with the City of Cape Town and the Two Oceans Aquarium in Cape Town, South Africa, focusing on Cape fur seals and producing comparable outcomes.
Dr McIntosh pointed out that by bringing together new technology and their ongoing dedication to protecting marine wildlife, they are developing a better understanding of how marine debris impacts seal colonies and identifying ways to safeguard them.
