February 10, 2026
Cabrera National Park: what to do when a National Park loses marine life
Cabrera National Park is often presented as the flagship of marine conservation in the western Mediterranean Sea. The popularity of the waters around the Spanish island of Cabrera grew in 1977, after Jacques Cousteau turned his attention here and filmed its turquoise waters and rich marine life. Then, in 1991 it was designated as a national park – granting it, at least on paper, the highest level of legal protection, and making it the first such park in Spain to include marine ecosystems.
Despite its long-protected status, a new study has documented a significant decline in marine biodiversity in Cabrera over the last decade. The findings should alert us and, particularly, the authorities that protection on paper does not automatically translate into protection at sea.
DNA study unveils biodiversity decline
The research, published in the scientific journal Diversity and Distributions in 2025, analysed changes in marine life in Cabrera between 2014 and 2022, using cutting-edge genetic techniques. Instead of relying only on visual surveys to identify traditional species, researchers used an approach known as DNA metabarcoding. This method allows scientists to identify a very large number (thousands) of marine species from seawater samples – including those that tend to be undetectable using traditional equipment and survey methods. This approach therefore provides much more complete information on the presence of different species than conventional monitoring.
The methodology applied was based on collecting water samples from different seabed habitats and areas, extracting the DNA from traces of organic material in these samples, and comparing how marine communities changed over time.
The results speak for themselves. In Cabrera, the researchers found:
- A loss of around 40% in species richness over the study period (more than a decade).
- A decline in genetic diversity (i.e. variability within the same species, which is essential for them to adapt to environmental changes).
- Clear changes in the structure of benthic (seafloor) communities.
Importantly, these trends were detected inside a national park that is widely recognised for its ecological value, a key factor underlying its designation.
At the same time, scientific evidence from other marine protected areas (MPAs) shows that when MPAs are effectively managed with adequate protection, they can generate clear biodiversity benefits in the medium and long term. In Spain, there are multiple examples of such MPAs, like Cabo de Palos-Islas Hormigas or Illas Medas Marine Reserves – well managed zones that have shown increases in species diversity, biomass, and abundance following their designation. However, this positive outcome is not just a given. For MPAs to deliver significant benefits, they must be of a sufficient size, include no-take zones where no fishing is permitted, and have adequate management and surveillance in place. Without these elements, science has shown that MPAs are unlikely to bring significant ecological improvements; insufficiently protected areas risk becoming what are known as “paper parks”.
The authors of the research in Cabrera point to global pressures – such as ocean warming and other human impacts – as potential causes of the observed decline in marine life. But the findings also highlight that marine protected areas cannot deliver results without effective, fit-for-purpose management. That is why Cabrera’s management history becomes highly relevant.
A national park without a proper management plan
Since its designation in 1991, Cabrera has experienced long gaps in its planning and governance. Its first management plan (PRUG) was approved in 1995 and was only valid for six years. The second PRUG was adopted in 2006, already four years late, and expired in 2012. For more than a decade after that, the park operated without a valid management plan.
During this period, the adoption of a new plan was repeatedly postponed, due to opposition from certain parts of the fishing sector, political delays, and a lack of park staff. Moreover, the size of the park was expanded tenfold in 2019, considerably increasing the marine protected area concerned and the complexity of managing it. Despite this significant expansion, the management plan was not updated to incorporate the new area and the occurrence of non-compatible activities, such as industrial and non-selective fishing, continues to date.
Even when the local Balearic government took over responsibility for the park in 2020, the third PRUG continued to face delays. A first attempt to initiate a new management plan started in December 2021 but expired in 2023 without being approved. A second attempt began in April 2024 and is now valid until April 2026, with a new draft plan having only recently been published. Throughout this period, Oceana has been tirelessly advocating to secure a management plan, as a member of the park board.
Without adequate monitoring, funds, and effective enforcement, even the best-designed protected areas are at risk of becoming paper parks. Cabrera is a good case in point: the continuous lack of a proper, fully implemented management framework has left it vulnerable to activities which are incompatible with its protection status.
Key management needs – before it’s too late
The recent research findings from Cabrera should be a call to act. Cabrera’s biodiversity loss shows that proper management is essential for protection, especially in a rapidly changing Mediterranean Sea. A new management plan is needed urgently, and as a minimum should contain:
- A zoning scheme aligned with conservation priorities, including no-take or strictly protected zones where appropriate, with explicit rules for each zone.
- Timely and science-based regulations to ensure that all activities are compatible with the conservation and restoration goals, and which are subject to adaptation by means of periodic reviews.
- Clear conservation objectives and measurable outcomes, to be assessed through regular and robust biodiversity monitoring, using standardised protocols to track ecological changes and management effectiveness.
- A well-defined enforcement and compliance strategy, with adequate staffing, surveillance capacity, sanctions, and coordination mechanisms across competent authorities.
- A structured stakeholder participation and communication process, to ensure meaningful engagement and shared governance.
Cabrera still has the potential to be an international model for marine conservation, but the Spanish and Balearic government authorities must ensure that protection is not just declared but delivered effectively before its waters lose even more of the richness once documented by Jacques Cousteau.
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