Expansion of strictly protected areas: a strategic step forward or an administrative gesture?
28/05/2026
Discussions about expanding strict protection zones within marine protected areas almost always raise the same question: does it make sense to expand these zones if the existing rules are already not being consistently enforced? The scepticism is understandable. In many cases, both in Croatia and elsewhere, there is a clear gap between regulations on paper and the actual situation at sea.
Still, reducing the entire debate to the conclusion that expansion is therefore pointless would oversimplify and even trivialise a far more complex issue of marine protected area management. Expanding strict protection zones can be a powerful tool for restoring marine ecosystems and improving spatial management, but only under certain conditions: when it is clearly targeted at the real pressures affecting the area and accompanied by consistent enforcement on the ground. With this in mind, the key question is not always whether strict protection zones should be expanded, but rather when such expansion creates genuine value and when other priorities should come first. To explore this issue, we spoke with Nika Stagličić, PhD, Senior Research Associate at the Institute of Oceanography and Fisheries.
When does expansion make sense?
1. When it addresses real pressures
Expanding a strict protection zone is justified when it includes areas exposed to the greatest pressures – from illegal fishing practices and excessive fishing pressure to intensive anchoring and the degradation of sensitive habitats. Additional “justification” exists when these areas contain habitats of exceptional ecological value, including Posidonia seagrass meadows, coralligenous communities, underwater reefs and other vulnerable habitat types. In such circumstances, strict protection is not merely a symbolic measure, but a way of removing the main drivers of degradation from the area. This creates the conditions for habitats to recover and for marine ecosystems to begin functioning in a more natural and stable way.
Experiences from the Mediterranean and other parts of the world show that genuine, effectively enforced no-take zones are among the most effective tools for restoring fish stocks. Within these areas, fish density and biomass increase, as does the average size of individuals. Over time, a more natural balance between species is gradually restored, including the return of larger, ecologically important predators.
This is not only important for nature. A greater share of larger and sexually mature fish also means higher reproductive capacity and stronger population recovery. Over time, a spillover effect occurs as adult fish migrate and eggs and larvae disperse into surrounding areas, extending the benefits of protection beyond the boundaries of the zone itself. In addition to contributing to biodiversity conservation, no-take zones can also generate economic and social benefits through more sustainable fisheries in the wider area. The spillover effect is a key argument for cooperation and partnership with local fishers, as it demonstrates that strict protection is not a measure opposed to fisheries, but rather a tool that contributes to their long-term sustainability. Of course, these effects do not happen automatically or overnight. But where protection is real and long-lasting, the benefits are multiple, both inside the strictly protected zone and in surrounding areas.
2. When it simplifies rules and facilitates enforcement
One of the recurring problems in marine management is the excessive complexity of regulations. Multiple subzones, numerous exceptions and different regimes of use and restrictions can create confusion both for sea users and for those responsible for enforcement.
In this sense, a larger and clearly defined strict protection zone can sometimes be easier to manage than a complex system of partial restrictions. The rule then becomes straightforward: within that zone, there is no extraction of natural resources or activities that damage habitats. Only activities compatible with conservation objectives – such as navigation, monitoring, research and controlled visitation – are permitted.
This makes enforcement easier, as breaches of the rules are simpler to identify. At the same time, the message becomes clearer for users of the area, reducing the potential for conflicting interpretations, misunderstandings and conflicts on the ground. In this context, expansion is not an additional complication, but a rationalisation of the management system. If the goal is long-term conservation and adaptation to accelerating changes in the marine environment, expansion can be a strategic step that contributes to the long-term sustainability of the protection system and improves the efficient use of available human and financial resources.
3. When it connects areas into a coherent ecological unit
Small, isolated and disconnected protected zones often have less impact than larger, spatially connected areas. The sea does not function according to administrative boundaries: species move, habitats are interconnected, and ecological processes take place across wider areas. That is why expansion makes sense when it does not simply create “more protected surface on paper”, but rather forms a logical and connected ecological unit. A larger zone can better protect different habitat types within the same marine area, enable species migration and increase ecosystem resilience to cumulative pressures, including climate change. Such areas serve not only as refuges for individual species, but also as reservoirs of biodiversity and resilience for the wider ecosystem.
4. When it creates value for science and education
Strict protection zones have another important role: they serve as reference areas – natural “laboratories” where scientists can observe how marine ecosystems look and function when human influence is reduced to the minimum possible level. This makes them extremely valuable for scientific research, long-term ecosystem monitoring and climate change studies, as well as for education, interpretation of natural values and the development of programmes for visitors and local communities. For the public, this can mean much more than simply introducing restrictions: it can improve understanding of why protection measures are needed, what they aim to achieve and how healthy marine ecosystems benefit everyone in the long term.
When does expansion not make sense?
1. When there is no real enforcement on the ground
The most common problem in marine protection is usually not the design of the zone itself – in other words, where the boundaries are drawn – but whether the rules are actually enforced. If monitoring is not systematic, if violations are not sanctioned and if rules are applied selectively, expanding the boundaries will not change the reality at sea. Under such circumstances, a larger zone simply means a larger area where rules may potentially be violated. This does not strengthen trust in protection measures; on the contrary, it further undermines it.
Administrative expansion of protected areas without the necessary enforcement capacity is unlikely to produce real ecological benefits. Strict protection therefore only makes sense when there is both the intention and the capacity to enforce it effectively.
2. When it replaces rather than complements stronger management
Expansion makes little sense if it is used as a substitute for strengthening management capacity. Strict protection may simplify the regulatory framework, but it cannot replace the need for fieldwork, scientific monitoring, transparent decision-making and dialogue with stakeholders.
If investment is not made simultaneously in ranger services, monitoring systems, education and communication, expansion remains merely a formal measure. In such cases, the priority should be to make existing protection genuinely effective before considering new boundaries.
3. When the motivation is purely administrative
European and international commitments to increase the share of protected areas are important and beneficial because they encourage countries to take marine protection more seriously and invest more in it. However, increasing the percentage of protected surface alone does not guarantee effective conservation. In this context, there is a risk that the focus shifts towards quantity rather than quality. If the main motivation for expansion is simply to meet a numerical or administrative target, without a clear assessment of where protection is needed, what it should achieve and how it will be implemented, the actual impact may remain very limited. In other words, protection is not successful because it covers a larger area on a map, but because it is well designed and effectively implemented.
Between ambition and feasibility
The dilemma of “expand or make existing protection effective” is ultimately a false one, because these two processes should not be seen as opposites. In an ideal scenario, strengthening management and expanding strict protection would happen in parallel: protection would be improved spatially while also becoming stronger and more effective on the ground. In practice, however, the sequence of actions and the specific context matter greatly.
If the system already demonstrates the capacity for consistent enforcement, if key pressures have been clearly identified and if the proposed expansion creates an ecologically coherent unit, then expansion can represent a major step forward – both for nature and for local communities.
If, however, the basic mechanisms of implementation are not functioning, then the priority should first be to strengthen those foundations. Without that, every new boundary risks remaining merely symbolic. In this context, the ADRIWATCH project seeks to improve monitoring systems and data management in marine protected areas across the Adriatic, strengthening the capacities needed for effective implementation of protection measures.
Strict protection can be the most effective tool for marine recovery, but only when it is real, properly enforced and supported by adequate capacities. Otherwise, the more important question is not how to expand protection, but how to make the existing system more effective.
The boundaries of a protected area are important, but the true value of protection should not be measured by the size of the area on a map, but by the real changes it delivers in the sea itself.
Cover photo credit: Mišo Pavičić.
