New research: We're not protecting our oceans as well as we think

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Not so long ago, we thought the ocean was an inexhaustible resource . There would always be plenty more fish in the sea.

We now know this isn't true. A growing proportion of the world's oceans are overfished . And even though we're fishing more intensively and using more advanced gear than ever, the total number of fish caught has plateaued . There simply aren't as many left to catch.

On top of this, climate change and other human-driven pressures are placing even more stress on marine species.

Globally, governments are working to prevent further damage to ocean systems by establishing marine protected areas . However, our new research suggests these aren't as effective as they seem.

Governments and communities are increasingly aware of the various threats our oceans face, including fishing, marine heat waves and overabundant species .

These compounding threats have prompted countries around the world to rapidly expand the coverage of marine protected areas —places where fishing and other destructive activities are restricted—over the past three decades. Protected areas are designed to help fragile ecosystems recover or, in some cases, prevent damage before it begins.

The international push to meet ambitious conservation targets has fueled this expansion. The " 30 by 30 " target is one example. In 2022, 196 countries adopted the Kunming-Montreal Global Biodiversity Framework and committed to protect at least 30% of the ocean by 2030.

Currently, about 10% of the ocean is officially "protected." On the surface, this is a major win for ocean life. But an area with this label on paper might not actually be protected in practice.

Until now, we've judged how well the world's marine protected areas are working based on data we can collect from the surface . This includes how many square kilometers these areas collectively cover or how strict their rules seem to be.

As a result, we don't know what is happening underwater at a global scale. That's where our new research comes in.

To find out whether marine life is actually recovering, we analyzed underwater biodiversity data from thousands of shallow coral and rocky reefs worldwide, both inside and outside marine protected areas. These data enabled us to measure how much fish biomass —the total weight of fish on a reef—has bounced back. This is an indication of true recovery, not an assumption based on whether an area is protected on paper.

Our results suggest less than 2% of the ocean falls inside marine protected areas where ecosystems are actually recovering. That's an optimistic estimate, which assumes people are following the fishing rules in each area. In reality, many don't . On a global scale, this low compliance means the share of the ocean that is effectively protected is likely much smaller.

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It's worth noting that marine protected areas can be an effective conservation tool. Research shows they deliver significant and lasting benefits for marine life, such as restoring fish and shark populations.

However, there are various reasons why a marine protected area can fail. Fishing is a major one. If any amount of fishing is still happening, it's difficult for marine communities to fully recover .

Research shows most of the world's marine protected areas fail to safeguard marine life in practice. The reasons for this are complex and vary from place to place. What's worrying is that even a low level of noncompliance may put pressure on marine populations and undermine conservation efforts.

To ensure marine protected areas actually work, we need to improve protection on paper and in practice by strengthening fishing rule compliance . We must also ensure stakeholders are both aware of and actively engaged in marine stewardship.

But we can't manage what we can't see. We need an ongoing, coordinated strategy for monitoring how marine species are faring by tracking them underwater, both inside and outside protected areas.

Otherwise, we risk overestimating how well the world's protected areas are doing while ocean ecosystems beneath the surface continue to deteriorate.

Swati Mestri holds a bachelor's degree in Electronics Engineering and has worked as a content editor since 2019. She has experience editing research documents across technology, health care, and materials science, and has a particular interest in technology and space.

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Master's in physics with research experience. Long-time science news enthusiast. Plays key role in Science X's editorial success.

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This article is republished from The Conversation under a Creative Commons license. Read the original article .