Protecting the ocean’s travellers
WHEN it comes to crossing the ocean, lots of large marine animals, from penguins to seabirds, turtles and whales, seem to use the same navigational compass — the sun. Using big data, scientists are also comparing how these animal movements overlap with the global fishing fleet.
Data from more than three million locations is being used to track the movements of over 5000 of the world’s large marine animals all over the world.
An international research team is using cutting-edge data capture techniques to both access the tracking devices mounted on all large fishing vessels and build their understanding of the movements of 50 different species of large marine vertebrates. These megafauna are often the ocean’s apex predators and key to its biodiversity.
The team has assembled huge data sets from the tagged animals. Their first breakthrough has shown that marine mammals, birds and turtles often have similar movement patterns.
Animals in and above the ocean tend to move in long, straight lines, while those in coastal habitats tend to move in more focused search patterns as they forage for prey.
Based within Deakin University’s Centre for Integrative Ecology, Alfred Deakin Professor Graeme Hays — a world expert on turtle behaviour — is working with a core team of 10 other scientists, IT specialists, physicists and mathematicians in the US, Europe and Australia to capture and interpret the data.
“The fact that type of habitat, rather than species, influences movement was unexpected,” Prof Hays said.
“We detected a remarkable similarity in the distribution of speed and turning angles across species, ranging from whales to turtles.
“You would expect that penguins or turtles would have their own ways of navigating through the oceans, but in fact, they may be using the same techniques. They are driven by their habitat.
“This is very different to land-based animals where species often have their own particular patterns of movement. Most probably, these marine species can travel in long straight lines using the sun as their compass.”
Through the international project, called Marine Megafauna Movement Analytical Program (MMMAP), the scientists are seeking to develop measures to conserve marine megafauna by avoiding threats such as fishing, where these animals may be by-catch (nontargeted species), or ship strikes, which particularly affect whales.
Prof Hays said the project would aim to achieve “winwin” solutions. For instance, identifying whale routes would reveal areas that vessels could avoid, so neither whales nor vessels were impacted.
Prof Hays said the tracking technology had been near-perfected over the past 25 years.
“The first tags only lasted a few weeks, but the ones we use now can withstand the rigours of the sea for up to a year,” he said.
“The marine animal tracking information we are collecting now will support evidencebased decisions that will engage the international community. It will be considered by bodies such as the United Nations for improving international conservation polices, which will filter through to individual countries and, hopefully, protect marine biodiversity for coming generations.”
The group’s initial results were published this year in the journal Proceedings of the National Academy of Sciences USA.