September 2, 2025 — Fish and other marine organisms, though deeply affected by human activities, don’t respect human borders. The ranges of many commercially important species in fact straddle the borders of countries’ exclusive economic zones (EEZs) and international waters, known as the high seas. This arrangement, which makes fisheries management difficult, is set to get even more complicated as climate change continues to heat up the ocean, a new study says.
The study, published July 30 in the journal Science Advances, found that more than half of the world’s straddling stocks will shift across the maritime borders between EEZs and the high seas by 2050. Most of these shifts will be into the high seas, where fisheries management is much more challenging and stocks are more likely to be overexploited.
“It’s an important issue and an important paper that I think should make anyone concerned about fisheries or the seafood on their plate sit up and pay attention,” Malin Pinsky, an associate professor of biology at the University of California, Santa Cruz, who wasn’t involved with the study, told Mongabay.
“The shift towards the high seas that they document would have some really serious consequences, in part because fisheries management tends to be much less effective in the high seas,” added Pinsky, an expert on climate-driven fisheries distribution shifts. “Climate change is sending a whole bunch of fisheries out into the lion’s den because the high seas doesn’t have a great reputation for sustainable fisheries management.”
Among the most serious potential consequences is a loss of fisheries resources for many tropical countries that did little to create the climate crisis, Pinsky and other experts said.