Ocean ecosystems and the marine fauna that depend on them are under threat like never before. With overfishing, climate change, plastic pollution and habitat destruction, it is a bad time for shrimp, cod, seabirds and whales.

There is no one-size-fits-all solution to the biodiversity crisis, but in recent years many people in the environmental movement have focused on the “30 x 30” goal: protecting 30% of the planet by 2030. Many countries have made pledges to reach this goal, including the United States, which has translated it into the “America the Beautiful” initiative.

Measurable targets like these give countries clear, quantifiable conservation goals that other members of the international community can track and monitor. They can also use these targets to identify gaps and push for further action.

At the same time, many experts warn that number-based targets such as “protect 30%” create incentives for benevolently viewedsomehow protect as much as possible, rather than protecting the most ecologically important areas. For example, governments can engage in what is euphemistically called “creative accounting” – counting as protected things that really shouldn’t be protected at all.

Two new research papers examine some of these creative accounting practices in the ocean. Together, they highlight important issues to consider when creating protected areas and assessing their usefulness.

To protect a species, you have to protect the areas where it actually lives

A surprisingly common problem in area-based conservation arises when a government declares a new protected area to save an endangered species… without first checking whether the species actually lives within those boundaries.

It happens more often than you might think. A new study published in Journal of Animal Ecology examined 89 marine protected areas in Europe designed to protect diadromous fish species (those that migrate between sea and freshwater, such as salmon or some eels) for which conservation is a concern.

Their results are shocking: many of these areas protect habitats that are not home to these fish species, and very few of them protect the most important core habitat of diadromous fish species.

“A marine protected area should “It should be an area that protects part of the marine environment,” says Sophie Elliott of the Wildlife Conservation Trust, the study’s lead author. “I say ‘should’ because there are many parks that are not thought about enough. Often things are done quickly without thinking or understanding the situation.”

Sometimes that’s because resources for scientific study are limited. In other words, Elliot says, we simply don’t know enough about species’ habitat use to protect their most important habitat, at least not yet. This is known as the rare species paradox: endangered species are often difficult to find and study, especially in the vast oceans. So it can be difficult to understand what habitat qualities they need to thrive, even if we can assume that protecting certain regions will mitigate some of the threats the species face.

Sometimes, in the hope of positive publicity, government officials announce a new protected area that has been studied but does not serve to protect a species.

“We had a number of marine protected areas that were supposed to include measures to protect certain species,” says Elliott. “But then another species was added to the stated objectives of the marine protected area, and it wasn’t effective for that species.” Given the political sensitivity of some of these protected areas, she declined to give examples.

In addition to collecting more data and adopting a strategy that always designates protected areas based on the best available data, Elliott recommends a more holistic approach to designating future protected areas.

“When you think about creating marine protected areas, you should consider all the biodiversity that exists there, because there could be a lot of endangered and protected species living in there,” she says. “You need to know what’s in that marine protected area and do ecosystem-based management” – management that focuses on the whole ecosystem, not just individual species. It’s the difference between protecting cod by setting catch quotas and protecting cod by managing their habitat, their predators and their food and other things that eat that food. “We’ve been calling for that for a long time, but we’re not really working toward it at all,” she says.

What is considered “protected” varies more than you think

Another key question in the management of marine protected areas is what should be considered “protected”.

In some areas, oil and gas extraction is prohibited, but fishing is fully permitted. In others, swimming and other recreational activities are permitted, and in others even scuba diving is prohibited.

In a recent, glaring example, pressure group Oceana UK found evidence that the UK allows bottom trawling in many of its marine protected areas. Bottom trawling is a fishing method that is extremely destructive to sensitive habitats; it has been compared to clearing forests to catch rabbits.

“Ultimately, there is no clear definition of what conservation means worldwide,” says Angelo Villagomez, a senior fellow at the Center for American Progress who has studied the issue. “One of the negative externalities of the global push to protect 30% of the ocean is that some governments are more interested in say that they have protected 30% of the ocean rather than caring about meaningfully protecting biodiversity.”

Villagomez and his colleagues have identified another major problem: According to their new analysis in the journal Conservation certificateA quarter of the 100 largest marine protected areas – as catalogued in the United Nations and IUCN World Database of Protected Areas – are announced but not yet implementedIn many countries, there is no clear timeline for when formal protection measures might be introduced or what these arrangements might look like.

These areas currently exist on paper, but are unprotected in reality. For example, the paper mentions the OSPAR Marine Protected Area, which covers 7% of the North-East Atlantic and currently appears to have no concrete protection.

This wide range of regulations and inconsistent protection measures makes it difficult to protect the oceans – or to include them in the 30×30 targets.

It is traditional for governments not to add to the global database of protected areas until an area is designated, “but they do, and that is the reality,” says Villagomez.

But here lies the biggest problem: As the study found, many of the world’s largest marine protected areas lack the scientific knowledge, funding and political support to be effective.

“We know that marine protected areas work when they are well designed and have the resources to operate them,” Villagomez told me. “But for about a third of the marine protected areas we studied, based on everything we know about the science of protected areas, they will never produce positive outcomes for biodiversity.”

The conclusions of these two studies are clear: too many marine protected areas are poorly designed and located in places where the species they are supposed to protect do not live. And too many marine protected areas allow destructive resource extraction, which limits the benefits of any conservation measures.

Despite these setbacks, Villagomez remains optimistic about the future of MPA-based protection.

“The good news is that about a third of the time, this works really well – if you play baseball and hit the ball 300 times out of 1,000, you’re in the Hall of Fame,” he says. “There’s plenty of scientific evidence that well-designed and well-implemented MPAs work, and a quarter of the MPAs we’ve studied are well-designed and just lack the resources to implement them.”