Polar Sharks And Rays Are Losing Their Safe Haven As Sea Ice Declines

Standing on the edge of a polar sea, looking out across an expanse of ice, cold water, it is easy to imagine that the marine life beneath the surface remains largely untouched by humanity's fingerprint. Far from cities, ports and the bustle of everyday life, these remote waters can seem almost pristine. But sea ice is retreating, meaning fishing vessels can now reach places that were once difficult, if not impossible, to access. The very conditions that once made these ecosystems feel so remote are changing, opening the door to greater human activity. And suddenly, those seemingly untouched habitats risk becoming covered in our fingerprints, much like a toddler's sticky handprints smeared across a freshly cleaned window.

Researchers recently examined sharks, rays and chimaeras (collectively known as Chondrichthyans) across Arctic and Antarctic waters and identified 35 Important Shark and Ray Areas, or ISRAs, in a new assessment of the region. ISRAs are places considered especially important for Chondrichthyans because they may serve as reproductive areas, feeding grounds, movement corridors or habitats for species with restricted ranges. The team also found 86 Chondrichthyan species in Polar Waters, yet only 15 had enough evidence to qualify for an ISRA, meaning information was insufficient for more than 80% of the species in the region. This is particularly concerning because many polar Chondrichthyans are not exactly built for rapid recovery; about 72% of the region's species are deepwater animals and many have the familiar combination of slow growth, late maturity and relatively low reproductive output of those Chondrichthyans in warmer waters. Lose too many adults and populations may struggle to bounce back… same story as their relatives around the rest of the world, just in a tad bit colder setting. The conservation assessment also found that 28 of the 86 species are threatened with extinction. The Arctic had considerably more species than the Antarctic, with 73 compared with 19, and the proportion considered threatened was also higher in the Arctic.

Much of what scientists know about polar Chondrichthyans comes from scientific fishing surveys or commercial fisheries, where we have gotten valuable information about where animals occur, their size and sometimes their reproductive condition. But getting information like this about animals here has created a major blind spot: we tend to know the most about animals and places that are already being sampled. It's a bit like trying to map a city by studying only the streets where taxis travel — you might learn a lot about those roads, but you could completely miss what is happening in the neighborhoods between them. This problem is especially obvious in the Antarctic, since most Antarctic ISRAs were identified because species have highly restricted ranges rather than because researchers had detailed evidence about nurseries, feeding grounds or other important life-history habitats. The Greenland shark provides a glimpse of what is possible when more information exists, with the species being associated with 10 different Arctic ISRAs; this is because it has been studied using a much broader mix of methods (including electronic tracking, underwater cameras, fishing surveys and local ecological knowledge) while other species have nowhere near that depth of information.

Meanwhile, fishing is already reaching many of the areas that researchers identified as important, with fishing activity overlapping with 22 of the 27 Arctic ISRAs and all eight Antarctic ISRAs. Between 2013–2018 and 2019–2024, the geographical footprint of both trawling and longlining expanded at the two poles, even when the total number of fishing hours for some fleets stayed level or declined. But it's important to remember that a fleet does not necessarily need to fish more hours to affect more habitat: it can simply spread out.

And then there is the ice…

Across both polar regions, areas experiencing significant sea-ice decline were much larger than areas experiencing significant increases, yet the researchers found surprisingly little direct overlap between places where sea ice was declining and places where fishing effort was significantly increasing. At first glance, that might sound reassuring, but that's not exactly the case. Yes, fishing does not automatically rush into every newly ice-free patch of ocean! Where vessels go depends on where commercially valuable fish are found, regulations, economics and whether conditions are practical for fishing. As ocean temperatures change, however, fish communities can shift toward higher latitudes and fisheries may follow, creating a potential moving-target problem for conservation. A habitat that seems relatively safe today could become much more exposed tomorrow, and if scientists have not yet identified its ecological importance, protection may arrive only after fishing activity has already established itself.

Polar Waters are not entirely unprotected, though, as marine protected areas cover about 9.6% of the region. But that protection is unevenly distributed; only 8.2% of the area contained within Arctic ISRAs overlaps with MPAs and just 0.8% overlaps with no-take protection. Antarctic ISRAs fare better, with 43.8% overlapping MPAs and 14.8% overlapping no-take areas.

We are in a pivotal decade for ocean conservation, with the UN Decade of Ocean Science for Sustainable Development and the global 30×30 initiative , which aims to conserve at least 30% of the world's ocean by 2030. But that ambition raises the important question of what does protecting 30% of the ocean actually accomplish if those protected areas do not include the habitats that vulnerable species depend on? Reaching a percentage target matters, but so does making sure the right places are protected for the right reasons. That is where ISRAs could become especially useful, since they aren't themselves marine protected areas but instead provide a scientific map of where sharks, rays and chimaeras have important habitat. Those "maps" could then inform fisheries rules, marine protected areas, environmental impact assessments and emerging high-seas conservation measures. The new High Seas Treaty and the Global Biodiversity Framework provide mechanisms through which this information could feed into broader spatial planning.

But there is still a basic problem to solve first: we need to know more. The 35 ISRAs identified here are not a complete map of polar Chondrichthyan habitat, but they are the first pieces of a much larger puzzle. The challenge now is making sure conservation does not wait for every piece to be found before protecting the picture that is already emerging.

This article was originally published on Forbes.com