For decades, the movements of ocean giants like whales, sharks, turtles, and seals have remained a mystery. These marine megafauna travel vast distances across the world’s oceans to feed, breed, and migrate—largely out of sight. But with nearly one-third of these species now at risk of extinction, mainly due to overfishing, plastic pollution, shipping traffic, and climate change, understanding their hidden pathways is more crucial than ever.
A new global study led by marine scientists has now revealed the largest satellite tracking dataset of marine megafauna ever assembled—tracking 12,794 animals from 111 species over 30 years. The results have uncovered global marine “highways” and biodiversity hotspots critical for survival. This breakthrough could transform how we protect vulnerable marine species.
🌊 30 Years of Tracking the Ocean’s Biggest Animals
Marine biologists have been tagging ocean giants with satellite transmitters since the 1980s. These electronic tags track animal movement, direction, speed, and time spent in specific regions. In this study, 378 researchers from 50 countries collaborated to compile data collected between 1985 and 2018.
The tracking covered a wide range of species, including:
- Whales and dolphins
- Sharks and large fish
- Seals, polar bears, dugongs, and manatees
- Sea turtles and flying seabirds
The project mapped movements across all major oceans, offering a first-of-its-kind global view of marine megafauna behavior.
📍Mapping Marine Megafauna Hotspots
Analysis of the tracking data revealed specific ocean zones that marine megafauna frequent the most, including:
- The central Indian Ocean
- The northeast Pacific Ocean
- The North Atlantic
- Coastal areas around Mozambique and South Africa
These regions represent ecologically and biologically significant areas where megafauna gather to feed, breed, and migrate. Yet, the study found a shocking gap in protection.
🔒 Only 5% of Key Megafauna Zones Are Protected
Although about 8% of the world’s oceans are classified as marine protected areas (MPAs), only 5% of the critical zones identified in this study fall within those protected boundaries.
That means 95% of these vital habitats are unprotected, leaving marine megafauna exposed to serious threats, including:
- High levels of plastic pollution
- Heavy shipping traffic
- Rapid ocean warming
- Industrial-scale fishing
Even more concerning, 75% of these important zones are affected by intense fishing, and over 90% face plastic and climate-related risks.
🌐 National and Global Responsibility
The study also found that 40% of these high-priority areas lie within countries’ exclusive economic zones (EEZs)—a 200-nautical-mile zone from shore where nations have control over marine resources. This gives countries an opportunity to enhance local marine conservation efforts.
However, 60% of critical areas exist in the high seas—international waters with no single country responsible. These areas need strong international cooperation and legal protection.
🛡️ A Global Roadmap for Protecting Ocean Giants
Two major international agreements could help:
- The High Seas Treaty (adopted by the UN and signed by 115 nations) — focuses on protecting biodiversity in international waters.
- The Kunming-Montreal Global Biodiversity Framework — aims to protect 30% of the global ocean by 2030.
Using advanced algorithms, researchers identified the best ocean areas to prioritize for protection. These include places where megafauna gather to feed, breed, migrate, and rest—across all species.
However, even if the 30% protection target is achieved, around 60% of key megafauna zones will still remain unprotected. This makes marine policy reform, targeted conservation planning, and threat reduction essential.
⚠️ Act Now or Lose Marine Giants Forever
Without urgent action, marine megafauna—just like their land-based counterparts—may face irreversible population declines. Effective conservation must focus on:
- Banning destructive fishing practices
- Reducing plastic and chemical pollution
- Limiting shipping-related noise
- Tackling climate change head-on
This landmark study provides a science-backed roadmap to guide national and global efforts to safeguard the ocean’s most majestic creatures.
📚 Citation:
Ana M. M. Sequeira et al. (2025). Global tracking of marine megafauna space use reveals how to achieve conservation targets, Science. DOI: 10.1126/science.adl0239