Protecting 30% of the ocean may not be enough to help large marine animals

Despite plans to protect large areas of our ocean, it seems that many species may still be in hot water.

Many large marine animals will often travel hundreds of kilometres, crossing multiple national boundaries and areas that lie outside the jurisdiction of any country. This can make small, local protections alone ineffective in conserving these animals.

To gain a deeper understanding into how large animals known as megafauna use our oceans, a United Nations-endorsed research project called MegaMove is tracking species to identify the areas they use for essential behaviours such as foraging, resting and migrating.

The project has recently had their research published in the journal Science, where hundreds of scientists from around the world tracked nearly 16,000 animals across 121 species of marine megafauna.

The results of their study suggest that while the current target to protect 30% of land and sea by 2030 goes some way to aiding conservation efforts, it may be insufficient to protect some of the important habitats used by these iconic species.

Professor Ken Norris, Research Leader in Biodiversity Change at the Natural History Museum was a co-author of the report. He helped set up a large tacking programme for the Round Island petrel off the coast of Mauritius. The data from this was used in the study.

“This is a wonderful example of a genuine global collaboration to help protect marine biodiversity, with over 400 scientists from 50 countries working together with a common aim,” says, Ken.

“The research reinforces the view that simply designating 30% of the oceans as protected areas won’t be enough to cover all those habitats critical to marine megafauna – from sharks, whales and turtles to seals and seabirds such as albatrosses.”

“We urgently need to ensure that wider conservation strategies take into account the integral role these marine areas play in ocean ecosystems, so that we are working towards a future where life in our oceans can thrive.”

Why are currently planned ocean protections insufficient?

In 2022, the Kunming-Montreal Global Biodiversity Framework (GBF) was adopted at the 15th Conference of the Parties to the Convention on Biological Diversity.

One of the targets of this international agreement is to protect 30% of land, waters, and seas by 2030, known as 30 by 30.

Currently, there is still a long way to go as just 8% of the world’s oceans are protected. But this is hopefully going to change as the United Nations High Seas Treaty aims to protect areas that fall outside the boundaries of any single country to meet the 30% target.

The MegaMove project found that, based on the movements of tracked species, 66% of the space they use is dedicated to critical behaviours, including migratory behaviour and residency behaviours such as mating, foraging, and resting.

They suggest that the 30% target will protect up to 40% of critical habitats for these animals, which leaves the remaining 60% of habitats exposed to threats.

Professor Ana Sequeira, lead author of the research said, “We found that the areas used by these animals overlap significantly with threats like fishing, shipping, warming temperatures, and plastic pollution.”

“The 30 per cent protection goal is seen as helpful but insufficient to protect all important areas, meaning that additional mitigation strategies are needed to alleviate pressures beyond areas that will be protected.”

How can we save species outside marine protection areas?

Approximately one-third of marine megafauna are believed to be at risk of extinction. Many of these species are top predators and play a crucial role in regulating the numbers of their prey. Identifying and protecting the areas used by marine megafauna is therefore essential to prevent the decline of these animals and the degradation of ocean ecosystems.

But over 75% of the critical habitats used by marine megafauna currently overlap with areas affected by fishing, shipping, pollution, or warming. This means that outside of protected areas, additional measures will likely be needed to help protect these important species.

This could include modifications to fishing gear, such as the use of circle-shaped hooks in long-line fishing. These hooks circle round into a sharp, inward-facing point, as opposed to the upward-facing point of a J-shaped hook. Circle hooks are wider and so are less likely to fit in a turtle’s mouth and may also increase the survival of accidentally caught turtles and sharks.

Turtle Excluder Devices could also be used to prevent turtles from becoming trapped in shrimp trawling nets. This device is a metal grid that fits into a trawl net. Smaller shrimp pass through the grid to the back of the net, while the larger animals that accidentally become caught are able to escape through an opening.

Traffic Separation Schemes, which force ships to adhere to approved routes in busy shipping areas, along with vessel speed limits in key regions, could help reduce the number of collisions between ships and large marine animals, such as whales. These schemes are already used in some high-traffic areas, such as the Gulf of Panama, where a large number of ships approach the Panama Canal.

There is no single, simple solution to helping marine megafauna. But tracking these species and identifying important areas is a helpful step in addressing this complex problem.

“MegaMove brings together an international network of researchers to provide innovative research to advance the global conservation of marine megafauna,” Says Ana.

“Our research shows that, in addition to protected areas, implementing mitigation strategies like changing fishing gear, using different lights in nets, and traffic schemes for ships will be key to alleviating current human pressure on these species.”