International study shows benefits of monitoring ocean giants for marine conservation

A team of international scientists tracked more than 12,000 individuals from 110 species of marine megafauna for 30 years, identifying the most critical locations in the global oceans to strengthen marine conservation efforts. The research, in which the Faculty of Science and Technology of the University of Coimbra (FCTUC) participates, is part of the “MegaMove” project, led by the Australian National University (ANU) and funded by the United Nations (UN).

This study involves around 400 scientists from more than 50 countries and shows where specific protection can be implemented for the conservation of marine megafauna. André Afonso, Filipe Ceia, Jaime Ramos, José Xavier and Vitor Paiva, researchers at the Centre for Marine and Environmental Sciences (MARE) and Centre for Functional Ecology (CFE) at FCTUC, are five of the co-authors of this research, published in the journal Science.

Currently, marine protected areas cover only 8% of the world's oceans, and the United Nations Treaty on International Waters aims to increase this protection to 30%.

The investigation concluded that the objectives of the current Treaty, signed by 115 countries but yet to be ratified, represent a step in the right direction and will be fundamental to supporting conservation. However, these objectives are insufficient to cover all critical zones used by threatened marine megafauna species, suggesting that additional measures are needed to mitigate threats.

Marine megafauna include seabirds, sharks and whales, typically top predators with essential roles in marine food webs, but face increasing threats resulting from human environmental impact. According to the authors, this study aimed to identify areas used by marine megafauna for important behaviors such as feeding, resting and migrations – areas that can only be detected based on their tracked movement patterns.

“We found that the areas used by these animals significantly overlap with threats such as fishing, maritime traffic, rising water temperatures and plastic pollution. For example, the shearwater, a seabird that breeds in the Azores, Madeira and Berlengas archipelagos, migrates annually to the south coast of Brazil, South Africa or Mozambique, demonstrating an extraordinary capacity to explore the marine environment, being, therefore, exposed to various threats in different ocean basins", reveals Vítor Paiva, CFE researcher.

"The same occurs with countless species of sharks, which travel thousands of kilometres throughout their lives and cross multiple marine areas with different legal regimes, making their conservation difficult due to the heterogeneity of management and protection policies for these resources", declares André Afonso, CFE researcher.

“The objective of protecting 30% of the oceans is seen as useful, but insufficient to safeguard all important areas, which means that additional mitigation strategies are needed to alleviate pressures outside protected areas”, consider the experts. The research is also linked to the United Nations Sustainable Development Goals, namely Goal 14 on marine life, and specifically to Goal A of the Kunming-Montreal Global Framework for Biodiversity, which aims to halt the human-caused extinction of threatened species.

“MegaMove brings together an international network of researchers to provide innovative research that promotes the global conservation of marine megafauna and their habitats. Our research shows that, in addition to protected areas, the implementation of mitigation strategies, such as changing fishing gear, using different lights in nets and traffic schemes for ships, will be fundamental to alleviating the current human pressure on these species", they state.

According to the researchers, 30% of the main areas to protect were identified, classifying them based on their use by species of marine megafauna. “Our analysis identifies which areas of the global ocean these species use as home ranges or migratory corridors. We gave priority to areas used for these important behaviors by a greater number of species", they declare.

“However, ultimately, even if 30% protection were implemented in key areas used by marine megafauna, it would not be enough to conserve them,” they conclude.

The scientific paper “Global Tracking of Marine Megafauna Space Use Reveals How to Achieve Conservation Targets” is available here.