Two major studies arrive at seemingly opposite conclusions about the effectiveness of Marine Protected Areas (MPAs), creating a complex but crucial picture for the future of ocean conservation in the polar regions. One finds that industrial fishing is rampant in protected zones, while the other concludes they are highly effective sanctuaries. The truth, it turns out, is in the details, and it holds important lessons for the planned MPAs in the Arctic and Antarctic.
The debate over the effectiveness of MPAs is as heated as the waters along the Antarctic Peninsula. Are they genuine safe havens for marine life, or simply lines on a map—”paper parks”—that do little to stop the march of industrial fishing fleets? A pair of studies recently published in the journal Science offers a detailed, data-driven look into this question, and their findings could be vital for the future of the polar oceans.
The first study, led by Raphael Seguin, paints a concerning picture. Analyzing thousands of coastal MPAs worldwide, it found that industrial fishing vessels were detected in nearly half of them. By combining public vessel tracking data with satellite radar imagery that can spot “dark” vessels operating without a tracker, the researchers found a substantial hidden problem. A staggering 67% of vessel detections within MPAs were from these untracked vessels.
Perhaps most alarmingly, the study concluded that the official protection level of an MPA had little to do with the amount of fishing taking place. Instead, “the presence and density of fishing vessels were mainly driven by the size and remoteness of MPAs rather than their management category itself”. This supports the long-held suspicion that many MPAs are “residual» – placed in areas of little interest to fisheries to meet conservation targets without affecting the industry.
However, a second study, led by Jennifer Raynor, tells a very different story. This research team took a more focused approach, looking specifically at MPAs where industrial fishing is explicitly banned by clear, fully implemented regulations.
Their conclusion was starkly different: “We find little to no activity in most cases”. In these strictly protected areas, the density of fishing vessels was nine times lower than in unprotected waters. The study directly challenges “the commonly held view that industrial fishing is widespread in MPAs”.
Two Sides of the Same Coin
How can both of these findings be true? The answer lies in what was being measured. The study by Raphael Sequin looked at a broad collection of MPAs, many of which have weak regulations or legally permit certain types of industrial fishing. The study by Jennifer Raynor, by contrast, filtered for only the “best-in-class” MPAs with the strongest, unambiguous rules.
Together, they show that the label “MPA” can be misleading. Many are indeed failing to stop industrial fishing, as Seguin’s team found. But, as Raynor’s research demonstrates, when an MPA is designed with clear, strict, and enforced regulations, it works. The problem isn’t the concept of an MPA itself, but the weak design and implementation of many existing ones.
Lessons for the Polar Regions
This detailed understanding is critical as the world looks to protect the fragile Arctic and Antarctic ecosystems. The Central Arctic Ocean (CAO), where a multinational agreement prevents unregulated commercial fishing, seems to align with the successful model from the Raynor study. It is a clear, proactive ban on industrial fishing. Its effectiveness will depend entirely on the commitment of signatory nations to robustly monitor this vast, remote area for any illegal, untracked vessels—the very type highlighted by the Seguin paper.
The situation is more complex for the planned MPAs around Antarctica in the Weddell Sea, East Antarctica, and the Antarctic Peninsula. For years, their creation has been stalled by geopolitical disagreements within the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).
Global efforts like the Third UN Ocean Conference, held in Nice in June 2025, have sought to build the political momentum needed to ratify the High Seas Treaty and accelerate the creation of just these types of MPAs. Still, these proposed Antarctic sanctuaries face two major risks outlined in the studies. First is the risk of becoming “residual” parks. To gain the consensus needed for their approval, there is a danger that the final boundaries will be drawn to exclude the most valuable fishing grounds, limiting their real-world conservation impact. Second, until they are fully implemented with clear regulations, they remain true “paper parks,” offering no protection at all.
A Final, Crucial Complication: The Animals Don’t Read the Maps
Even if the polar regions were to get perfectly designed and enforced MPAs, a fundamental challenge remains, one that is increasingly highlighted by modern animal tracking studies: the animals themselves are highly mobile and pay no attention to lines drawn on a map. The effectiveness of a static protected area is inherently limited when the species it is meant to safeguard spends most of its life elsewhere.
This issue was starkly illustrated in a recent comprehensive study that compiled tracking data for 20 species of polar marine megafauna, including whales, seals, and penguins. The findings revealed that on average, these animals spent only 26% of their time within the boundaries of existing MPAs. Even the best-covered species in the study, the chinstrap penguin, was only protected for 55% of its time. For critically important species like the southern blue whale, this figure dropped to a mere 3%.
Another study published 2022 in Frontiers in Marine Science reinforces this point, identifying significant “data gaps” in the Southern Ocean where the movements of 17 predator species are concentrated, often far outside of established protected zones. This research emphasizes that the locations of current MPAs may not align well with the actual, year-round habitats these animals depend on for foraging and breeding. Together, these findings present a clear and urgent message: static MPAs alone are not a silver bullet for conserving highly mobile polar wildlife.
The future of polar conservation, therefore, could depend on a three-part strategy: establishing MPAs with the clear, strict, and enforceable regulations proven to work; ensuring these areas are placed in ecologically critical locations, not just convenient “residual” zones; and recognizing that for migratory species, a network of protected areas will be needed to safeguard them throughout their epic journeys. The science is clear: it is known how to make protection work. The question is whether there is the political will to implement it.
Link to the studies:
Jennifer Raynor et al., Little-to-no industrial fishing occurs in fully and highly protected marine areas. Science 389, 392-395 (2025) DOI:10.1126/science.adt9009