Sharks, Rays, & MPAs: Evaluating protected area coverage in national waters across species ranges

This study reveals that despite global conservation targets like 30x30, marine protected areas within national waters provide critically insufficient no-take coverage for threatened sharks and rays, with 79% of threatened species having less than 1% of their range protected and significant data gaps further obscuring the true extent of meaningful protection.

The Gist

Imagine the ocean as a giant, bustling city, and the sharks and rays as its most vulnerable residents. Now, imagine the world's leaders have promised to build "safe zones" (Marine Protected Areas, or MPAs) where no one is allowed to fish or disturb the peace. The goal is to protect 30% of this ocean city by 2030, a plan known as "30x30."

This paper is like a reality check. The authors went out and checked the blueprints to see if these safe zones are actually protecting the sharks and rays that need it most. Here is what they found, explained simply:

1. The "Empty Safe Zone" Problem

The researchers looked at 1,158 different species of sharks and rays. They asked a simple question: How much of a shark's home is actually inside a "No-Take" zone (a place where absolutely nothing can be caught)?

The answer is shocking: Almost none of it.

• The Analogy: Imagine you are trying to protect a family of rare birds. You build a giant fence around a park, but you only put a tiny, invisible thread around the specific tree where the birds actually sleep. To the birds, it's as if they have no protection at all.
• The Reality: For 79% of threatened sharks and rays, less than 1% of their home is in a true "No-Take" zone. Even for the most endangered species (the "Critically Endangered" ones), not a single species has more than 5% of its home protected.

2. The "Silent Majority" of Safe Zones

You might think, "Well, maybe there are lots of safe zones, but they just allow some fishing?"

The authors found a bigger problem: We don't even know what the rules are for half the safe zones.

• The Analogy: Imagine a library where half the books have a sign saying "Do Not Touch," but the other half have no signs at all. You walk in and see a book, but you have no idea if you're allowed to read it, borrow it, or if you'll get arrested for touching it.
• The Reality: Nearly half of all the "protected" ocean areas in the world database have no reported rules about fishing. Only about one-third of countries tell the world what their rules actually are. This makes it impossible to know if the sharks are truly safe or just "sort of" safe.

3. The "Wrong Neighborhood" Issue

The paper highlights that even when sharks are in a protected area, it might be the wrong kind of protection.

• The Analogy: Imagine a shark is dying because the water is getting too hot and polluted (like a house with a broken heater). You build a "No-Fishing" fence around the house. The shark is safe from fishermen, but it's still dying because the heater is broken. The fence didn't solve the real problem.
• The Reality: Some sharks, like the Maugean Skate, are protected from fishing, but they are dying because of pollution and bad water quality. A "No-Take" zone stops fishing, but it doesn't stop pollution. We need to fix the specific problem each shark faces, not just draw a circle on a map.

4. The "One-Size-Fits-All" Trap

The world is trying to protect 30% of the ocean, but the paper argues that quantity doesn't equal quality.

• The Analogy: If you are trying to save a specific type of rare flower that only grows in one tiny valley, planting a million trees in a different country doesn't help. You need to protect that specific valley.
• The Reality: Sharks move huge distances. A "No-Take" zone might cover a tiny patch of a shark's massive journey. If the shark spends 99% of its time outside that tiny patch, it's still in danger. The current system is like trying to catch a runaway train with a single speed bump.

The Bottom Line: What Needs to Change?

The authors suggest three main fixes to stop the sharks from sliding toward extinction:

1. Stop counting just the "Area": Don't just say, "We protected 30% of the ocean!" Instead, ask, "How much of the shark's home is actually safe?"
2. Put up the signs: Countries need to be forced to report exactly what the rules are for their protected zones (No-Take, Part-Take, or Unknown). We can't protect what we can't measure.
3. Tailor the protection: Instead of drawing big, generic circles, we need to design protections based on where the sharks actually live and what is killing them (fishing, pollution, or both).

In short: We are building a lot of "safe zones," but for most sharks, they are either too small, in the wrong place, or we don't even know if they are safe inside them. To save these ancient creatures, we need to move from "checking a box" to actually protecting the animals themselves.

Technical Summary

1. Problem Statement

Despite the adoption of the Kunming-Montreal Global Biodiversity Framework (GBF) and its "30x30" target (protecting 30% of marine areas by 2030), there is a critical uncertainty regarding whether current Marine Protected Area (MPA) designations effectively safeguard biodiversity, particularly for threatened species.

• The Gap: Global coverage targets often prioritize politically or economically convenient locations rather than areas critical for species survival.
• The Subject: Chondrichthyans (sharks, rays, and chimaeras) are the most threatened marine vertebrate group, with over one-third at risk of extinction due to overfishing, bycatch, and slow life-history traits (late maturation, low fecundity).
• The Question: How well do existing MPAs within national Exclusive Economic Zones (EEZs) overlap with the geographic ranges of sharks and rays, specifically regarding no-take zones which offer the highest protection against mortality?

2. Methodology

The study employed a rigorous geospatial analysis to quantify the intersection between species ranges and MPA boundaries.

• Data Sources:
  • Species Ranges: IUCN Red List geographic range polygons for 1,158 species of sharks, rays, and chimaeras. Species restricted to high seas or freshwater were excluded.
  • MPA Data: The World Database on Protected Areas (WDPA), retrieved in February 2026.
  • Spatial Boundaries: Flanders Marine Institute EEZ dataset (v12) to restrict analysis to national waters.
• Classification & Processing:
  • MPAs were classified into four take-status categories based on the WDPA NO_TAKE attribute:
    1. No-Take: All extractive activities prohibited.
    2. Part No-Take: Partial restrictions.
    3. Take Permitted: No restrictions.
    4. Not Reported: Take-status unknown.
  • Spatial Analysis: Using DuckDB v1.4.2 (spatial functions) and R (packages sf and terra), the authors:
    1. Clipped species range polygons to EEZ boundaries.
    2. Calculated the area of overlap between species ranges and each MPA category within those EEZs.
    3. Aggregated data globally to determine the percentage of each species' total range protected within national waters.
• Thresholds: The study utilized a 1% coverage threshold to define "gap species" (species with <1% of their range in no-take MPAs), arguing that protection below this level is unlikely to yield meaningful conservation benefits. A 10% threshold was also used as a general benchmark for effective protection.

3. Key Contributions

• First Global Species-Level Assessment: This is the first study to assess MPA coverage for the entire global diversity of sharks and rays (1,158 species) using updated 2021 IUCN range maps and 2026 WDPA data.
• Focus on "No-Take" Effectiveness: Unlike previous studies that often aggregate all MPAs, this analysis specifically isolates no-take zones, which are critical for reducing mortality in species with high post-release mortality rates (e.g., hammerheads, devil rays).
• Identification of Data Gaps: The study highlights a massive transparency deficit in global conservation reporting, specifically regarding the lack of "take-status" reporting in the WDPA.
• Open-Source Tool: The authors developed and released SharkRayMPAexplorer, a Shiny web application allowing users to query MPA coverage by species, region, or taxonomic group.

4. Key Results

• Severe Shortfalls in No-Take Protection:
  • Critically Endangered (CR) Species: 90.6% of CR sharks and 88.5% of CR rays have less than 1% of their range covered by no-take MPAs.
  • Threatened Species: 79% of all threatened species have less than 1% of their range in no-take MPAs.
  • Top Performers: Only six threatened species have more than 10% of their range in no-take MPAs (e.g., Zearaja maugeana at 21.25%).
  • Gap Species: 78% of all analyzed species are classified as "no-take gap species" (<1% coverage).
• The "All MPAs" Illusion:
  • When including all MPAs (regardless of take-status), the median coverage rises to 8.6% and the mean to 15%. However, this masks the reality that most of this "protection" allows fishing, which is insufficient for threatened species.
• Reporting Deficits:
  • 47.8% of the global MPA estate (by area) is classified as "Not Reported" regarding take-status.
  • Only 34% of countries with MPAs in their EEZs report any take-status data to the WDPA.
• Case Studies:
  • Zearaja maugeana (Maugean Skate): High no-take coverage (21.25%), but the primary threat is environmental degradation (hypoxia), not fishing, illustrating that MPAs alone are insufficient without addressing habitat quality.
  • Cephaloscyllium albipinnum (Whitefin Swellshark): Despite having the highest no-take coverage for a CR species (3.5%), the protection is incidental and fragmented, not designed for the species.

5. Significance and Policy Implications

The study reveals a significant "implementation gap" between global area-based targets (30x30) and biodiversity outcomes. The current expansion of MPAs is not strategically aligned with the needs of threatened species.

Key Recommendations:

1. Species-Focused Monitoring: The GBF must integrate species-level indicators. Coverage targets should not just measure area, but the proportion of threatened species ranges protected.
2. Mandatory Reporting: Countries must be required to report take-status for all MPAs submitted to the WDPA to enable accurate functional assessments of protection.
3. Strategic Design: New MPAs should be delineated based on biodiversity-driven decision-making, specifically targeting Key Biodiversity Areas (KBAs) and Important Shark and Ray Areas (ISRA) rather than political convenience.
4. Complementary Strategies: For wide-ranging or habitat-specific species, spatial protection (MPAs) must be combined with fisheries management (e.g., bycatch reduction) and environmental regulations.

Conclusion:
While global MPA coverage is expanding, it is failing to provide meaningful protection for the world's most threatened marine vertebrates. Without a shift toward no-take zones specifically designed for species ranges and improved data transparency, the 30x30 target risks becoming a "paper tiger" that fails to halt biodiversity loss.