Where are all the marine animals going?

Given the vastness of the oceans, the countless species that live in them, and the lack of a global data set, it’s not easy to figure that out. However, the increasing threats that marine life face mean answering that question is key to protecting animals and their habitats.

A new interactive database and map aims to fill this void.

Scientists from the University of Queensland in Australia and Duke University in the U.S. pulled data from 1,300 studies in the scientific literature from around the world to create a map that shows the comings and goings of 109 species of mammals, birds and fish. Published in May in the journal Nature Communications, their Migratory Connectivity in the Ocean (MiCO) database maps out vital links between crucial marine habitats. The database underscores how marine species transcend political boundaries, highlighting the need for effective cross-border collaboration.

The map comes at a time when countries around the world are discussing several initiatives to protect global biodiversity. The Kunming-Montreal Global Biodiversity Framework, for one, aims to protect 30% of Earth’s lands and oceans by 2030, better known as the 30×30 goal. Another, the “biodiversity beyond national jurisdiction” (BBNJ) treaty, includes a mechanism to designate marine protected areas in the high seas, which are a key migratory route for several species.

“A lot of people across the world are thinking about protected areas now,” Lily Bentley, a movement ecologist and postdoctoral research fellow at the University of Queensland who was involved in developing the database, told Mongabay in a video interview. However, she said, officials engaged in policy discussions often don’t have the time to engage with specific species and locations. “What we’re hoping to do is push a bit of a synthesized version up the chain,” she said.

Work on MiCO started seven years ago and involved researchers manually going through the existing literature to extract information on marine migrations. For each of the 109 species they focused on, the team used a systematic keyword search in databases. MiCO enables users to get a more macro, zoomed-out perspective of marine movements around the world, while also allowing them to key in on specific locations and species.

“If you’re interested in a particular place, you can see what species go through there, or what species have been recorded there,” Bentley said.

Scientists can also download the open-source data and layer it with any spatial data they might have collected during the course of their own research. The database also highlights areas where there are gaps in the knowledge of specific animals and their movements, potentially helping direct focus for future research.

However, historical inequality in funding means there are inevitable gaps in research efforts in some very biodiverse areas of the world, leading to lack of concrete data from these regions. The other big challenge, Bentley said, was to figure out how to visualize the data, given the complicated and interconnected nature of migrations. “There’s someone going somewhere all the time,” she said.

The complex web of migrations also creates a challenge in presenting the data to policy experts. “How do you get all this data into the minds and hands of people who are coming in for a week of meetings on all of global biodiversity?” Bentley said. “How do you keep it high-level enough to get them to think about migratory species?”

While the researchers work to simplify the data, they’re also continuing to pore through more scientific literature in order to fill in the gaps and make the database more robust for policy purposes. Despite the efforts, Bentley said, an insurmountable caveat will always remain.

“This is just measured connectivity that has been studied and published in scientific papers,” she said. “There is so much more going on that we might never know about.”

Banner image: Albatrosses with a rainbow in Ka’ena Point State Park, Hawaiʻi. Scientists pulled data from 1,300 studies to show the comings and goings of 109 species of mammals, birds and fish. Image by Toby Matthews / Ocean Image Bank. 

Abhishyant Kidangoor is a staff writer at Mongabay. Find him on 𝕏 @AbhishyantPK.

Citation:

Bentley, L. K., Nisthar, D., Fujioka, E., Curtice, C., DeLand, S. E., Donnelly, B., … Dunn, D. C. (2025). Marine megavertebrate migrations connect the global ocean. Nature Communications, 16(1). doi:s41467-025-59271-7