Ecosystem-based approach and sustainable development are key principles of MSP, and require appropriate consideration of ecological implications throughout the MSP process, to ensure sustainable expansion of marine sectors. The MSFD is intended to provide a mechanism of ensuring ecological protection at an ecosystem scale, and is seen as a complementary pillar to MSP, to reconcile growth in marine activities with minimal negative impact on the marine environment.
Although the environment is a key consideration throughout planning, special attention is also required to those ecological features which are afforded specific protection under conservation legislation, including primarily the Habitats and Birds Directive (Council Directive 92/43/EEC). The Habitats Directive requires the protection of key species and habitats through a 2-pillar approach of designation of marine protected areas (MPAs) and specific measures addressing the species listed on Annex IV(a) of the Directive (see question “How are mobile species with conservation status considered in MSP?”).
As a defined spatial element of conservation, much emphasis is placed on the primary pillar, i.e. designation and inclusion of MPAs in planning processes in order to achieve conservation objectives. In most cases, MPAs have already been designated and are therefore incorporated into the MSP process when allocating areas for other activities (for example in Germany). Their status would not be expected to change through MSP, and the objectives of the MPA will be a consideration in planning activities which may interact with the site or its’ conservation features. Where MPAs are established MSP can support their designation and understanding of objectives in relation to other interests. In any case, it is important to note the great variety of types of different MPAs as recognised by IUCN’s 7 different categories  of protection, and that all may need to be considered within developing MSP. In fact, different synergies can be identified between the various MPA categories and the other maritime sectors.
 Dudley, N. (Editor) (2008). Guidelines for Applying Protected Area Management Categories. Gland, Switzerland: IUCN. x + 86pp. WITH Stolton, S., P. Shadie and N. Dudley (2013). IUCN WCPA Best Practice Guidance on Recognising Protected Areas and Assigning Management Categories and Governance Types, Best Practice Protected Area Guidelines Series No. 21, Gland, Switzerland: IUCN. Available at https://portals.iucn.org/library/sites/library/files/documents/PAG-021.pdf
How can conservation measures be planned?
A multi-criteria assessment framework, integrating environmental accounting with MSP, can be pursued to allow a broad and interdisciplinary approach to nature conservation and spatial planning. This approach was applied to the case of the Egadi islands (Italy) where the biophysical and non-market monetary value of natural capital was assessed through the emergy accounting method. In addition, by using the Marxan software, the results of the environmental accounting were integrated with spatial data on main human uses to identify key areas for natural capital conservation, taking into consideration the trade-offs between protection measures and human exploitation.
From an operational point of view, the combined use of the Marxan software and a cumulative impact decision support tool can help to analyse areas suitable for conservation measures. This has been applied to the MSP process in Portugal, focusing on marine waters off the mainland of Portugal . For practical applications, the Cumulative Impact Model, developed by Fernandez et al. (2017) would need to be adapted to a different context in order to be used as a surrogate for ecological condition, input as “costs” in Marxan.
 Fernandes M., Esteves T. C., Oliveira E. R., Alves F. L., 2017. How does the cumulative impacts approach support Maritime Spatial Planning?,Ecological Indicators 73: 189-202. https://doi.org/10.1016/j.ecolind.2016.09.014.
How is the functionality of MPA networks assessed and what is its relevance for MSP?
The objective of networks of MPAs are that they are ‘ecologically coherent’ which is fundamental to understanding the contribution of MPAs to an ecosystem-based approach, but ‘ecological coherence’ is a challenging concept to define and evaluate. Most definitions envisage MPA networks that maintain ecosystem processes, functions and structures and where individual MPAs function synergistically with others in the network. Criteria used to judge ecological coherence include representativity, replication, adequacy, viability and connectivity.
Understanding ecological functioning is a critical basis for ecosystem-based MSP, hence knowledge and analysis of such systems would be beneficial to developing a shared understanding of the system and the effects of proposed activities. Relating ecosystem functioning from a conservation perspective to the ecosystem services framework would improve communication of the potential for maritime activities to negatively affect ecosystem processes, functions and structures in MSP. It would also build understanding of the reliance of such activities on healthy ecological networks (in terms of benefits and services) such as fisheries and sustainable tourism.
Essential Fish Habitats (EFH) (those waters and substrates necessary to fish for spawning, breeding, feeding or growth to maturity) and fish migration patterns can be used to assess the ecological coherence of Marine Protected Areas (MPAs) and eventually plan additional MPAs. In the BALANCE project, analyses of ecological coherence of the Natura 2000 network in relation to EFHs was performed using existing maps of designated Natura 2000 sites, and maps of Natura 2000 habitat types. For a preliminary assessment of how well Natura 2000 habitat types may be representative of potential EFHs, the expected association of different fish species with defined Natura 2000 habitat types was estimated. Explicit analyses of connectivity and other aspects of ecological coherence (for example representativity) may be performed based on those fish species and life stages for which maps of potential EFH are currently available. This indirect approach can be used for broad, preliminary descriptions of the distribution of EFHs, but should be replaced by maps based on statistical models as soon as enough information is available for predictive modelling.
 U.S. Magnuson-Stevens Fishery Conservation and Management Act (1998)
How can mobile species with conservation status be considered in MSP?
In the second pillar of the Habitats Directive, animal species listed on Annex IV(a) present a further aspect for consideration, particularly as this includes the majority of mobile species (all marine mammals and many seabird species). Where possible, the areas of high sensitivity for such species should be represented spatially for inclusion within MSP mapping processes; for example, migratory bird routes or marine mammal foraging areas. However, data is often limited in being able to specifically define these, hence MSP processes would need to consider the potential for these to occur and enable subsequent planning to account for them.
Given the migratory nature and extensive range of these species, trans-boundary co-operation is necessary to manage issues at an appropriate scale in order to understand effects at a population level (a key determinant in evaluating the ‘significance’ of particular effects under the Habitats Directive). In this context, initiatives such as the Trilateral Wadden Sea Plan, reviewed through the ARTWEI project, addressing transboundary policy and management of the Wadden Sea are a fundamental starting point, since they enable development of a shared vision for a healthy environment and set the basis for co-operation in addressing shared ecological challenges.
How are activities within MPAs managed? Are activities excluded?
MPAs generally do not mean exclusion of all marine activities. Depending on the features for which the sites are designated, the conservation status and conservation objectives for the site (i.e. are they in good condition? Is the aim to maintain condition or improve?), and the likely interactions between activities, the management measures for the MPAs will state what restrictions on particular activities are appropriate. This may include seasonal restrictions only (e.g. seal haul-out sites), or restrictions on certain activities (e.g. bottom-trawling in areas of sensitive seafloor habitats). The risk of adverse effect of proposed activities on a particular feature or site is therefore of critical interest, and will be location specific.
Reference documents exist which support understanding around environmental implications of proposed activities in an MSP context, including through the PartiSEApate project, which hosted a number of cross-sectoral workshops between sea users, including addressing environmental issues.
Given the likelihood of compatibility between marine activities and MPAs, a zoning approach to inclusion of MPAs in MSPs is therefore not always relevant (or at least not the only relevant one), as activities may overlap, in space and time, and innovative models of management may be appropriate, including seasonal controls on activities or promoting co-location of activities which promote and enhance environmental features, (e.g. sustainable tourism, artificial reefs at wind farm sites, etc.). Guidelines and regulation for the spatial and temporal management of marine activities must be therefore integral part of the MSP approach, in particular when dealing with MPAs,
How can conflicts with other sea uses be managed?
As experienced within the PlanCoast project in the Wismar Bay case (Germany), conflicts between tourism and nature protection can be solved through a process of spatial and seasonal differentiation. In fact, zoning for spatial and seasonal differentiation allows for flexibility and can be coupled with other forms of resource management. This is particularly important where ecological resources are concerned. Reserve areas or human activities may need to be shifted, limited or adapted. Use demands from commercial sectors should be as focussed as possible, in order to limit the impacts caused by undifferentiated demands.
Spatial and seasonal restrictions and other solutions to conflicts between nature conservation and commercial uses can be reached through voluntary agreements, a powerful tool that represent a practical, operational alternative to the formal process of creating a new protected site (very long and complex process). In the Greifswalder Bodden case - also within the PlanCoast project - the German WWF facilitated dialogue between nature conservation NGOs, the state Ministry for the Environment, and a wide range of local user groups and associations. Actual negotiations then took five years, with the last agreement signed in 2005.
How MPAs can be integrated into MSP?
In the planning process for the Gulf of Gdańsk (Poland), separate planning of areas with a specific environmental protection need was adopted in order to link to MPAs issue. Since the plan covers environmentally valuable areas subject to many economic pressures, it was decided that the whole planned area should be divided into smaller sea areas (basins) in order to properly reflect their specificities. The maritime spatial plan covering West Part of the Gulf of Gdańsk (pilot plan) has to consider some MPAs located adjacent to the densely populated terrestrial areas and thus subject to numerous pressures. Ecological considerations strongly influenced the definition of objectives for the Plan. The inclusion of ecologically valuable areas into the plan was done in three steps. First, an inventory of ecological value was carried out. Second, the types of human activity that might pose a threat to that value were assessed. Third, this knowledge was translated into concrete provisions and solutions within the plan.
How can MPA zoning contribute to marine conservation?
Zoning is a spatial management tool particularly relevant to MPAs as it divides MPAs in different sub-areas where different activities are allowed or restricted with the aim to reduce competition for space among users (IUCN, 2004). MPA zoning usually include an internal no-take zone, where only minimal human activities are permitted (e.g. diving and swimming), a second surrounded area where more activities are permitted (e.g. diving and swimming as well as sailing with small boats, etc.), and a third surrounded area, where also fishing activities are allowed (European Commission, 2018). MPA zoning can effectively provide benefits to fisheries since the establishment of a no-take area can improve size, diversity, and abundance of fish stock in the surrounding areas (Spillover effect). Nonetheless, it should be noted that the size of the no-take zone as well as the fish species targeted and their level of mobility are all factors that influence the benefits generated by the establishment of a restricted area (European Commission, 2018). MPA zoning, if done by taking into account the different uses and by involving stakeholders in the design processes can minimise conflicts between different users and benefit biodiversity and fisheries by restoring fish stocks (Makino et al., 2013). Hence, MPA zoning can be indented as a valuable tool for conservation purposes.