Protecting large ocean areas helps biodiversity — and doesn’t harm fisheries, study finds

Five years have now passed since Mexico government established the Revillagigedo National Park, which stands as the largest fully protected marine area in North America.

A new research study reports that there have been no negative impacts on the fishing sector because of this bold conservation effort.

This marks a significant milestone in the ongoing struggle to balance the needs of industry with the crucial imperative to protect our planet's precious marine natural resources.

In 2016, National Geographic's Pristine Seas and Mares Mexicanos initiatives joined forces to carry out a scientific expedition that collected the most extensive data from the Revillagigedo Archipelago to date.

Using cutting-edge technology, including cameras that can dive to 3,000 metres and a three-person submarine that travels to a depth of 500 metres, as well as the satellite tagging of highly migratory species, they were able to demonstrate the importance of fully protecting this archipelago that encompasses four volcanic islands located approximately 700 kilometres west of Manzanillo, Colima, Mexico, in the Tropical Eastern Pacific.

Based on this scientific report, on 24 November 2017, Mexico implemented a decree that formalized the creation of the Revillagigedo National Park.

It became the largest no-take marine protected area (MPA) – which prohibits the removal or significant destruction of natural or cultural resources – in North America, covering an area of 147,000 square kilometres and putting Mexico among the world leaders in marine conservation.

It wasn't easy to convince many sectors of Mexican society to take this significant step, in particular the industrial fishing fleet that used to fish around the islands; but beyond the political will that enabled this achievement, this marine reserve has achieved great undertakings.

In a new study published in the journal Science Advances, researchers reveal that large-scale, offshore and fully protected marine areas (no-take MPAs) protect biodiversity without negatively impacting fishing and food security.

Drawing on data from satellite tracking, fish catches reported by the Mexican Fisheries Commission, and advanced artificial intelligence tools developed by the Allen Institute for AI’s Skylight platform, the authors answered a series of key questions.

First, they determined whether the establishment of this no-take MPA had successfully reduced fishing activities within its bounds; second, they tested whether there had been any discernible impact on fishing catches; and finally, they answer whether the creation of the protected area had led to the displacement of fishing activities onto a larger area, ultimately resulting in a negative impact on marine biodiversity.

Using government-mandated GPS data from some 2,000 fishing vessels, researchers analyzed the fishing behaviours of this fleet in the high seas, in Mexico’s Exclusive Economic Zone and within the Revillagigedo National Park.

With the help of machine learning techniques, they scrutinized patterns of vessel movement to identify any significant changes associated with the creation of the park. Contrary to the Mexican fishing industry's claims of 20% negative impacts on fish landings, the park had not had any adverse effect on the industrial fleet's catches.

Additionally, the no-take MPA creation did not drive fishing vessels to venture further in search of fish, meaning that the park had not increased the area used for fishing. Only a handful of isolated cases of illegal fishing within the no-take MPA had been detected since 2017.

The result of the study challenges a long-held belief by members of industries and academia, dismissing the notion that ocean protection measures pose a threat to fisheries. Instead, it presents a solution to help an industry grappling with the repercussions of overfishing and the ravages of global warming.

Nowadays, with this kind of information, countries can design and implement no-take MPAs that not only restore the vitality and resilience of marine ecosystems, but also benefit fisheries in the long run.

These findings introduce a fresh perspective into the ongoing discussions of ocean protection around the world and, at the same time, highlights the transformative power of data and technology in advancing our collective understanding of the health of the oceans.

Revillagigedo National Park is protecting populations of sharks and giant manta rays that are found nowhere else on Earth. The extraordinary performance of this no-take MPA serves as an example of hope for understanding the intricate workings of marine ecosystems when left undisturbed by human exploitation.

However, the park's impact doesn't end there – it becomes a bustling nursery, offering significant benefits to fisheries. As has happened in other examples of marine reserves of this size, the reserve's borders are "highly productive" areas; where the industrial fishing fleet finds more catches compared to other areas further away from the reserve and those that have been overfished.

The study is published just when nations need to fulfill the global objective of protecting and conserving at least 30% of the ocean by 2030. This ambitious target was part in a historic agreement forged at the UN Global Biodiversity Conference (COP15) held in December 2022.

Recent events have added further momentum, with UN members in March agreeing on a binding instrument to safeguard biodiversity in the high seas – the vast international waters that lie beyond national jurisdictions.

Less than 8% of the ocean has some form of protection, and an insufficient 3% is fully protected from overfishing and other detrimental activities. The world has a window of opportunity to reverse this trend.

By rapidly establishing no-take MPAs in strategically chosen regions of the oceans, countries and societies can collectively safeguard more than 80% of the habitats critical for endangered species.

This new study presents empirical evidence that should resonate deeply, and it is possible that would spark a wider discussion and foster greater collaboration between the fishing industry and conservationists – paving the way for a better future for the oceans.