Massive animals of the ocean go about their days largely hidden from view. Scientists know this marine megafauna – reminiscent of whales, sharks, seal, turtles and birds – journey huge distances to feed and breed.
However virtually a 3rd at the moment are susceptible to extinction due largely to fishing, transport, air pollution and international warming.
Defending them might be troublesome, as a result of we don’t typically know the place these animals are.
New analysis I led sought to make clear the difficulty. My colleagues and I gathered 30 years of satellite tv for pc monitoring knowledge to map hotspots of megafauna exercise across the globe.
We tracked 12,794 animals from 111 species to search out out the place they go. The outcomes reveal underwater “highways” the place megafauna crisscross the worldwide Ocean. Additionally they present the place megafauna dwell for feeding and breeding. Now we all know the place these particular locations are, we’ve a greater probability of defending them.
Satellite tv for pc monitoring reveals marine megafauna migration pathways and locations of residence.
Sequeira et al (2025) Science
Pulling all the information collectively: a mega process
For greater than 30 years, marine biologists have tagged massive animals within the sea with digital units and tracked their actions through satellite tv for pc. The trackers seize knowledge on every part from pace of journey, to course of motion and the place the animals spend most of their time.
I put a name out to the worldwide analysis group to deliver collectively the monitoring knowledge. I hoped it might assist scientists higher perceive the animals’ actions and establish their favorite locations.
Some 378 scientists from 50 international locations responded. We assembled the world’s largest monitoring dataset of marine megafauna. It contains species of flying birds, whales, fishes (largely sharks), penguins, polar bears, seals, dugongs, manatees and turtles. They had been tracked between 1985 and 2018, all through the world’s oceans.
Ana Sequeira swimming with a whale shark in Ningaloo Reef, Western Australia, to gather samples.
Australian Institute of Marine Science
Mapping reveals an absence of safety
Once we began analysing the information, it confirmed the tagged animals used some components of the ocean extra ceaselessly than others. Most of them travelled to the central Indian Ocean, northeast Pacific Ocean, Atlantic north, and waters round Mozambique and South Africa.
It’s possible this displays an absence of information from elsewhere. Nonetheless, these species are recognized to go to locations the place they’re most certainly to search out meals, so we anticipate some areas for use greater than others (together with the areas we detected).
Then we had been in a position to establish the world’s most “ecologically and biologically significant areas” for the tracked animals.
At the moment solely about 8% of the worldwide ocean is protected. And solely 5% of the necessary marine megafauna areas we recognized happen inside these present marine protected areas.
This leaves all the different necessary marine megafauna areas we recognized unprotected. In different phrases, the species utilizing these areas are more likely to endure hurt from human actions happening at sea.
Greater than 90% of the necessary marine megafauna areas we recognized are uncovered to excessive plastic air pollution, transport site visitors or to intensifying international warming. And about 75% are uncovered to industrial fishing.
We additionally discovered marine megafauna are likely to spend most of their time inside unique financial zones. This space lies past the territorial sea or belt of water 12 nautical miles from the coast of every nation, extending 200 nautical miles from shore. The presence of megafauna in these unique financial zones means particular person international locations might improve the safety afforded inside their jurisdictions.
About 40% of the necessary marine megafauna areas had been situated in these zones. However about 60% had been on the excessive seas.
The way forward for marine megafauna conservation
The Excessive Seas Treaty, just lately adopted by the United Nations and signed by 115 international locations, governs the conservation and sustainable use of marine organic biodiversity on the open ocean.
Working alongside this treaty, the Kunming-Montreal World Biodiversity Framework goals to guard 30% of the worldwide ocean by 2030. This presents a possibility to make sure necessary marine megafauna areas are properly represented.
We used an optimisation algorithm to establish the most effective areas to guard, in the case of marine megafauna. We gave precedence to areas which can be probably used for feeding, breeding, resting and migrating throughout all of the totally different species.
However even when necessary marine megafauna areas are chosen when 30% of the ocean is protected, about 60% of those areas would nonetheless keep unprotected.
Important dangers from human actions will stay. Administration efforts should additionally give attention to decreasing hurt from fishing and transport. Combating local weather change and slicing down noise and plastic air pollution also needs to be key priorities.
Like for many megafauna on land, the reign of marine megafauna would possibly come to an finish if humanity doesn’t afford these species higher safety.
