In the vast expanse of our planet’s oceans, the challenge of safeguarding large, wide-roaming marine species has long vexed conservationists and policymakers alike. Recent research emerging from a collaboration involving the University of Exeter, Heriot-Watt University, and the Zoological Society of London (ZSL) provides compelling evidence that the creation and maintenance of very large Marine Protected Areas (MPAs) can offer substantial protection to some of the ocean’s most iconic megafauna. By tracking the movements of sea turtles, manta rays, and multiple seabird species, the study highlights how expansive conservation zones like the Chagos Archipelago MPA in the Indian Ocean can effectively encompass the critical habitats these animals depend upon throughout their life cycles.
Marine species such as hawksbill turtles, reef manta rays, and seabirds including red-footed boobies, brown boobies, and wedge-tailed shearwaters exhibit extensive spatial use patterns driven by foraging, breeding, and migratory behaviors. Such broad-ranging movements inherently expose them to fragmented protections if MPAs are too small or poorly located. This research utilized advanced biologging and satellite tracking technologies to capture precise location data on these species across a significant time frame. Intriguingly, an impressive 95% of all recorded locations fell within the bounds of the Chagos Archipelago MPA, a protected area spanning an immense 640,000 square kilometers. This finding signifies that the MPA is sufficiently large to encompass the ecological needs of these highly mobile megafauna, underscoring the strategic value of very large MPAs (VLMPAs) for marine biodiversity conservation.
The scientific community has debated the effectiveness and ecological merit of VLMPAs, typically defined as protected zones exceeding 100,000 square kilometers. Critics argue that the sheer size of such areas could be impractical to manage or could fail to address the specific spatial needs of certain species. However, this study presents data-driven counterarguments, emphasizing how the VLMPA model can deliver robust protection by capturing the majority of habitat use patterns of vulnerable marine taxa. Dr. Alice Trevail of the University of Exeter’s Environment and Sustainability Institute elucidates that such MPAs also align closely with international conservation targets, such as the goal to protect 30% of the world’s oceans by 2030, helping bridge policy ambitions with ecological realities.
Expanding on ecological functions, the study recognizes the critical ecosystem services provided by the megafauna inhabiting the Chagos region. For instance, seabirds contribute essential nutrients to coral reefs and adjacent marine environments through guano deposition, which acts as a natural fertilizer enhancing reef productivity and resilience. This biogeochemical linkage illustrates the complex interdependence between mobile species and their habitats, reinforcing the rationale for spatially extensive protection schemes that maintain ecosystem integrity across multiple trophic levels.
Beyond assessing the current MPA, researchers also modeled a hypothetical scenario involving a significantly smaller MPA of 100,000 square kilometers. The results indicated that while protection would remain high for manta rays (97%) and turtles (94%), seabird species would be disproportionately exposed, with only 59% of their movements covered. These findings spotlight differential spatial ecology among taxa and suggest that smaller MPAs might insufficiently protect species with broader ranges or those exhibiting complex migratory behaviors. Such nuanced understanding advocates for careful MPA design and sizing based on empirical tracking data tailored to target species’ ecological requirements.
The study gains further relevance considering geopolitical shifts in the region. The Chagos Archipelago is transitioning towards sovereignty under Mauritius, prompting urgent conservation dialogues about the future governance and stewardship of this ecologically vital area. As Dr. Ruth Dunn from Heriot-Watt University remarks, the research not only validates the current MPA’s protective value but also identifies priority zones for continued and enhanced conservation efforts to ensure the long-term viability of the megafauna community. This highlights how science can inform policy during politically sensitive junctures, reinforcing evidence-based decision-making.
Methodologically, the integration of high-resolution biologging data represents a significant advance in marine conservation science. Satellite telemetry allowed for continuous, fine-scale tracking of individual animals, revealing both spatial overlap with the MPA boundaries and critical habitat hotspots. These insights provide concrete spatial benchmarks for conservation planners, enabling adaptive management that can respond dynamically to species’ movements and changing oceanographic conditions. In addition, such tracking approaches foster cross-disciplinary collaborations between ecology, technology, and marine policy, embodying a holistic framework for addressing complex conservation challenges.
The global significance of this study resonates strongly with international conservation funding bodies. The Bertarelli Foundation, which supported the research, emphasizes how multidisciplinary scientific endeavors can unlock profound discoveries that bolster protection for vulnerable oceanic species. As ocean ecosystems confront mounting anthropogenic pressures—from overfishing to climate change—the scaling up of protected areas emerges as an indispensable strategy. This research elevates empirical evidence that robust, large-scale MPAs not only safeguard species breadth-wise but also temporally by encompassing key life-history stages critical to population persistence.
Moreover, the findings stimulate broader considerations about the design principles underlying protected area networks worldwide. While many MPAs are sited close to coastlines or encompass relatively small territorial waters, this study advocates for incorporating vast offshore zones that mirror the movement ecologies of pelagic and migratory species. Incorporating the behavior and ecology of multiple species into spatial conservation planning enhances the functional representativeness of MPAs and mitigates risks associated with conservation gaps. Consequently, fostering resilient ocean ecosystems capable of withstanding environmental perturbations necessitates visionary marine spatial planning informed by cutting-edge scientific data.
This research also underscores the value of marine megafauna as umbrella species—organisms whose protection indirectly conserves broader ecological communities. Understanding how these animals use vast marine landscapes enables conservationists to implement protections that cascade habitat benefits across diverse taxa. Thus, maintaining connectivity within and between MPAs supports genetic diversity, population dynamics, and ecosystem processes, critical aspects for sustaining healthy and productive ocean environments in the Anthropocene era.
In summation, the evidence from tracking data within the Chagos Archipelago MPA illustrates unequivocally that very large MPAs can deliver comprehensive protection for a range of large and mobile marine species. These insights strengthen calls for the establishment and careful stewardship of expansive marine reserves as keystones in global biodiversity conservation strategies. Upholding the ecological integrity of our oceans through such visionary measures is indispensable if humanity is to preserve the natural heritage and ecosystem services of planetary marine realms for future generations.
Subject of Research: Conservation efficacy of very large Marine Protected Areas for wide-ranging marine megafauna in the Chagos Archipelago.
Article Title: Large marine protected areas can encompass movements of diverse megafauna.
News Publication Date: 7-Aug-2025
Web References: http://dx.doi.org/10.1111/1365-2664.70117
Image Credits: Leila Scheltema / Manta Trust
Keywords: Marine protected areas; Marine conservation; Megafauna; Aquatic animals; Marine biodiversity
