Ocean space supplies mankind with a multitude of goods and services and yet it is under severe pressure of pollution and over-extraction of resources. To extract goods and services sustainably and to protect vulnerable ecosystems, we need to manage human activities in the marine domain.
Three essential elements characterize the management of marine resources. First we are dealing with multiple uses. These uses can be conflicting, neutral or complimentary and therefore when we manage one use we should also address the effects on other uses. Second these uses are inherently spatial. Conflicts can at least partly be avoided and complementarities can be improved with careful spatial planning. Therefore we should address the spatial effects of the multiple uses when managing these activities. Third we are dealing with multiple actors. Depending on the spatial scale we look at these actors can be representatives of the several user groups that have conflicting interests, or they can be countries trying to reach agreements over the use of shared resources.
In this thesis I investigate how Marine Spatial Planning and one of its tools, Marine Protected Areas (MPAs), can assist us with the management of ocean space. These instruments and their associated incentives are highly influenced by the regulatory framework, and this framework in turn depends on the spatial scale. I investigate three scale levels: the local level, defined as the Exclusive Economic Zone of a single country, the regional level, defined as a regional sea that is fully claimed by a number of countries, and the global level defined as the High Seas where all countries have access within the limits of the UN Law of the Sea.
On the local level I investigate the spatial planning of offshore wind farms with an optimization model that allocates offshore wind farms under ecological constraints. The model results show that space is an essential element to derive an optimal management plan of the EEZ, because the allocation of offshore wind farms is highly dependent on both spatial economic factors such as location costs and ecological restrictions. The results show that Marine Spatial Planning is necessary, because only in this way can possible synergies between e.g. offshore wind farms and environmental protection be identified and eventually realized. The model can assist with the first steps in Marine Spatial Planning of offshore wind farms; its results can be used as a basis for conversation and consultation with stakeholders.
On the regional scale I investigate how the multiple use nature of MPAs affects the incentives of countries to assign these MPAs. To this end, I develop a game theoretic model in which two specific uses, fisheries and nature conservation, by multiple countries are considered in a strategic framework. The results of the paper suggest that EU marine policy may help to secure the highest possible benefits from these MPAs, but only if policies force countries to cooperate and consider all possible benefits of MPAs. In fact cooperation on a single issue may give a worse outcome than the non-cooperative equilibrium. The results also indicate that cooperation may be hard to achieve because of defector incentives, and therefore policy measures should be strict in enforcing cooperation on all possible uses of MPAs.
At the same scale level I study how species distributions and different ways of accounting for the contributions of others affects MPA assignment as a tool for biodiversity conservation. With a spatial game theoretic model I investigate three different conservation regimes: full cooperation, strategic non-cooperation, and conservation autarky. Under strategic non-cooperation countries anticipate protection by the other, under conservation autarky they ignore these contributions. The main results show that unique species occurring in a single ecosystem are relatively well protected, even when countries are free-riding. Species that occur in multiple ecosystems on both sides of the border in contrast are under non-cooperation under-protected, compared to full cooperation. This is in part caused by location leakage, i.e. protecting a number of species less because they are protected by others. On the one hand conservation autarky eliminates location leakage and generates larger MPAs at the border. On the other hand these MPA sizes are often too high from a global perspective. From this we can conclude that international conservation efforts should mainly focus on transboundary occurring species. Also, although conservation autarky is not a first-best solution, if it occurs, e.g. through social norms, it is certainly better than strategic non-cooperation.
At the third level I study the effect of the assignment of internationally recognized MPAs in the High Seas on the formation of Regional Fisheries Management Organisations (RFMO) with a game theoretic model. MPAs are assigned through a weakest-link game: because everyone has to agree on an MPA before it actually can be protected, it can only be as large as the strongest opposing player wants it to be. I find that if countries have equal costs and benefits MPAs of optimal size are implemented but these have no effect on stability of RFMOs; the only stable coalition is the coalition where everyone acts alone. In the case where countries face different fishing costs, MPAs stabilize a number of extra coalitions such that more and larger coalitions are stable when an MPA is present compared to the no MPA case. Full cooperation, however, is not necessarily reached. A general conclusion is therefore that the assignment of MPAs in the High Seas can not only improve the fisheries through direct effects such as insurance and possible increases in catches, but also indirect by contributing in a positive way to the formation of RFMOs.
Three important conclusions can be drawn from this thesis as a whole. First Marine Spatial Planning and Marine Protected Areas can contribute in a positive way to the management of human activities in ocean space. Second, neither of them is a silver bullet. Both need careful implementation, where all uses are accounted for, and especially the public good aspects of MPAs needs to be addressed. Third the success of MPAs (and as such of Marine Spatial Planning) is not only highly dependent on the incentives and social norms but also on the implementation scale.