Solo human casts fishing line into sea from a rocky cliff

Can a little bit of a good thing be worse than nothing at all?

Research reviewed: Turnbull, J. W., Johnston, E. L., & Clark, G. F. (2021). Evaluating the social and ecological effectiveness of partially protected marine areas. Conservation Biology, cobi.13677.

Two kayaks in a wide, flat ocean
MPAs can protect recreation opportunities, like kayaking the seas off Adelaide, Australia. (Credit: Magdalena Love on Unsplash.

There’s a range of “protection” in marine protected areas

Let’s travel for a moment to the shores of southern Australia, where big swells crash into rocky headlands, tides seep through mudflats and mangroves, and waves lap gently on beaches dotted with surfers and sunbathers.

These dynamic seas are increasingly managed as marine protected areas, or MPAs. MPAs are an important marine conservation tool, in Australia and around the globe. These are stretches of the ocean where human activities are regulated, in the hopes of helping to preserve a healthy ocean ecosystem and support the human communities that rely on it.

MPAs can be created for different reasons, but typically stem from a desire to protect marine biodiversity and ecosystem processes from extractive activities, like commercial fishing or oil drilling. But, as MPA proponents point out, these areas do more than limit extraction. MPAs can also improve opportunities for marine recreation, from boating to fishing to SCUBA diving. They can offer schools and universities places for education and research. They can protect cultural resources, from traditional fishing grounds to shipwreck sites.

The term MPA covers a wide range of regulations, as areas are managed differently to allow for all of these uses. At the highest level of protection, human activity in the MPA is extremely limited: no fishing, no aquaculture, no oil exploration, no boating allowed. At the other end of the protection spectrum, MPAs allow these activities. Many MPAs sit between the two extremes, allowing certain types of fishing, boating, and other human activities.

In southern Australia, the ocean is dotted with MPAs that vary in their level of protection. Fully protected MPAs disallow fishing, while partially protected MPAs allow recreational fishing or collection of marine organisms. Those allowances have made partially protected MPAs attractive in the eyes of ocean managers and the public; as a result, partially protected MPAs are three times as common as fully protected MPAs in southern Australia. That has led some to wonder about whether partially protecting the ocean is an effective way to meet social and ecological goals.

Some amount of protection should be better than no protection at all, right?

That’s exactly the question a team of researchers set out to answer.

Map depicting Australian waters with some areas partially and fully protected
This map, courtesy of MPAtlas, shows some of the fully (dark blue) and partially protected (teal) MPAs across Australia’s waters. (Credit: MPAtlas.)

Scoping the social and ecological scene

In assessing the impact of full versus partial protection, researchers wanted to understand both the social and ecological promises of marine protection. Their assessment included both biological metrics— like measuring coral health, fish populations, and biodiversity— as well as metrics that capture human use and values— like the prevalence of recreation activities, perceived beauty of the area, or general awareness of the area. They analyzed data across these metrics for a set of fully protected and partially protected areas across Australia’s Great Southern Reef. To make sure they had a fair comparison, they included non-MPAs, or open sites, in their study as well.

To gather data for the study, researchers spent time on the coast at each of their study sites, observing human activities. They counted the number of people they saw taking part in fishing, walking, SCUBA diving, and the like. Researchers stopped some of these fishers and recreators for interviews, querying them about their perception of the area. Did they think fishing was allowed here? Why did they come to the site? Did they think it had a healthy ecosystem? In their opinion, how had the site changed in their lifetimes?

They buttressed this with ecological data on the sites. One important source of data came from the Reef Life Survey, a project in which volunteer divers and scientists work together to gather observations on ocean habitats, including fish counts and habitat assessments.

In pulling together these various social and ecological data sources, researchers were able to ascertain a holistic assessment of Australia’s protected areas. They found promising outcomes in the fully protected areas, where both social and ecological indicators showed that marine protection was achieving its conservation promises. But in partially protected areas? The story wasn’t so rosy.

Surfers catching waves in a teal sea
As part of the study, researchers counted the number of people engaged in different ocean activities– like these surfers in Sydney, Australia. (Credit: Kevin Bosc on Unsplash.)

Partially protected areas as a “red herring” in ocean conservation

When researchers assessed the ecological state of all three types of sites, they found that the partially protected areas score no higher than unprotected, open sites on any ecological metric. Partially protected areas fared worse on fish and invertebrate biomass and diversity, telling indications of a poorer marine environment.

When interviewed, ocean users at the partially protected areas tended to believe they were in a fully protected area. Because of that, they assumed fish populations, biodiversity, and habitats would be healthier in these partially protected sites. The data shows that’s not the case. Somehow, people are led astray by the idea of protection, and ready to see healthy ecosystems where they don’t exist.

Partially protected MPAs, the researchers argue, are a distraction from effective ocean conservation. People assume some protection is better than nothing, so they support this approach and devote resources to creating more partially protected MPAs. As a result, already-slim budgets for ocean conservation are siphoned away on these ineffective measures, leading researchers to dub them the “red herring” of ocean conservation.

Given that, should we eschew partially protected areas forever? Not so fast, researchers say. There’s still a place for these quasi-protected areas. Allowing some extractive activities can be important in supporting the needs of particular ocean user groups. By designing partially protected areas that allow some fishing, for example, space can be made for recreational or subsistence fishing communities.

But when it comes to delivering on ecological metrics of ocean health? Partial protection is worse than no protection at all.

Solo human casts fishing line into sea from a rocky cliff
Partial protection still has a role in ocean management, especially in supporting the needs of recreational or subsistence fishing communities. (Credit: Britt Gaiser on Unsplash.)

Leave a Reply

Your email address will not be published.