Marine protection and restoration

Marine protection and restoration can be approached from a geographical angle (area-based approach), from a particular species angle (such as whale conservation), or through more encompassing ecosystem health approaches (reduction of pollution, etc.). 

Key international initiatives have been developed, both globally at EU level (Marine Strategy Framework Directive [3], EU Mission: Restore our Ocean and Waters [4]) that both frame EU actions in terms of marine protection and restoration, and at a more local level (such as the ACCOBAMS).

One of the main tools for area-based marine conservation is Marine Protected Areas (MPAs), but other designations fulfil similar functions (such as Natura 2000 areas). There has been a tenfold increase in MPA designation around the world since 2013.

Governance wise, this hugely diverse sector is divided between a wide range of actors of very different natures: States, NGO’s, local authorities, scientific institutions, international organizations, etc. It is therefore sometimes challenging to identify the relevant players that need to be involved in discussions.

Offshore Renewable Energy

Offshore Renewable Energy (or Marine Renewable Energy - MRE) is a major source of green energy that significantly contributes to the EU’s 2050 Energy Strategy and the European Green Deal. The EU therefore set ambitious objectives for the marine renewables industry, that will need to scale up five times by 2030 and 25 times by 2050 to support the Green Deal’s objectives [5]. 

MRE technologies can be broadly divided into 7 categories [6]:

• Offshore wind power: Electricity is produced by turbines, which harness energy from the wind blowing over stretches of sea;
• Wave power: capturing the movement of sea waves and turning it into electrical energy;
• Tidal power: harnessing energy from tides and converting it into electrical energy;
• Stream Energy: harnessing kinetic energy from currents and turning it into electrical energy;
• Osmotic power: Collecting the energy released by the difference in salt concentrations when a river flows into the sea;
• Ocean energy thermal conversion: using the temperature difference between deep water and the surface to generate electricity;
• Marine biomass: algae could be used to produce fuels.

These technologies have very different degrees of development and maturity: some are already very advanced and widely operated worldwide while others are still at research level. As Offshore Wind Farms (OWF) are the most developed technology when it comes to MRE, they will constitute the main example of OREI in the following pages. 

For more information about EU blue economy sectors please visit the EU Blue Economy Observatory website. 

For more European statistics and data you can also visit the Eurostat website

Locating ORE installations in accordance with ecosystem challenges in the area

Most adverse effects of ORE installations such as OWF, on the marine ecosystems could be prevented by careful placement. A simple way to mitigate the ecological impact is to avoid sensitive habitats, essential habitats for endangered species, or areas with a high abundance of critical species. MSP could encourage the application of such requirements and provide a platform for discussion as positioning must be agreed upon by ORE developers and marine protection and restoration stakeholders. This could also be a solution for areas with a particularly high level of biodiversity. As an example, in the Baie de Saint-Brieuc wind farm in France, the wind farm was built outside the area of the main scallop beds [14].

Consider the possibility of co-locating MPAs with OREI

As explained in the introduction, the “marine protection and restoration” sector is considered here in the broad sense, including area-based initiatives.  As such area-based protection initiatives such as MPA’s should be considered within the context of spatialisation. Within these MPAs, there is a gradation ranging from total prohibition to possible compatibility with ORE installations. The International Union for Conservation of Nature developed a classification of Protected Area Categories, ranging from strictly protected areas (Ia) to simple “protected areas” (VI). Renewable energy generation is not considered desirable within the strictest categories (Ia to III) but could be feasible for the less strict (IV to VI) [15]. A good example of this compatibility is the Parc Marin d’Iroise in France, where the installation of two tidal turbines is planned, as preliminary studies concluded that the turbines will not affect the park's environment [16].

Reducing the noise emitted during the construction phase

As explained in the challenges section, the construction of OWF generates a significant amount of noise, notably through hydraulic piling. This can be reduced using different methods. The first one is using sound barriers, which can include various techniques such as the use of bubble curtains. In the Belgian Nobelwing and Northwester 2 wind farms, a study on harbour porpoise showed that the installation of a double curtain of bubbles was an effective measure for attenuating noise emissions. Experiments showed that porpoise presence within close perimeter of the site was higher when mitigation measures were implemented, demonstrating their effectiveness [17]. Another method is adjusting the parameters of the pile stroke to reduce the sound level and shift the acoustic spectrum to lower frequencies, which are less harmful to marine mammals [18]. Both methods can be used in combination. It should be noted that effective noise mitigation tools are expensive and can account for more than 15% of the total construction expenses [19]. 

Use of acoustic deterrents to protect marine mammals from piling noise

Acoustic deterrents consist of devices which emit sound to scare marine mammals away from the wind farm construction site and to protect them from the noise generated by piling. Uncertainties remain on the efficiency of such devices as limited evidence can be found [20], but studies clearly show evidence of effective deterrence of some species on experimental sites [21]. Research efforts in this field must be further increased.

Using Geographic Information System (GIS) mapping to avoid essential habitats

Sensitivity maps can help to understand the ecological value of marine areas. In 2014, a GIS tool called SeaMaST (Seabird Mapping and Sensitivity Tool) [22], was used to map sensitivity of seabirds to OWF in English territorial waters. These sensitivity maps can inform marine spatial planners by providing information on existing knowledge of seabird distribution and contextualise the significance of potential impacts.

Gather and exploit data on collisions between ORE installations and wildlife to better identify and estimate the level of risk

Precise figures for collisions are difficult to obtain as they often go undetected. The idea is to establish monitoring programmes to register the number of collisions, but also to identify the species involved. This was done notably in the Dutch Offshore Wind Farm Egmond aan Zee (OWEZ), where an automated detection method was installed to measure collision rates with birds[23]. Similarly, in the Saint-Brieuc wind farm in France, radar tracking has been set up to estimate the importance of the area for migratory birds. Results show that migratory bird activity at this location was moderate. It was estimated that 80% of passerines flew at an altitude lower than the height of the blades, which accounted for a reduced risk of collision [24].

Moderatethe lightning of wind farms to reduce the attraction of nocturnal species

Decreasing the number and intensity (and colour) of lights reduces the attraction caused by such lights on sea and air species. 

Timing piling works in accordance with ecologically sensitive periods

As explained in the challenges section, the construction phase of OWF generates a significant amount of noise, notably through hydraulic piling. A common solution is to avoid piling during periods of ecological importance (like spawning). This was for example implemented in the Netherlands where conditions designed to eliminate any significant effects were put in place. Such restrictions require the construction of a maximum of one OWF a year, as well as a seasonal restriction on pilling activitins (construction only permitted between 1 July and 31 December) [25]. In Belgium, similarly, from 2013 onwards, a seasonal piling ban was enforced from January 1st to April 30^th [26]. 

As we consider the “marine protection and restoration” sector in a broad sense, we must also consider initiatives aimed at enhancing ecosystems and wildlife within ORE installations. Therefore, the enablers listed on below will address how such infrastructure can host habitats for marine wildlife. 

For obvious reasons, some elements of the following enablers will also be mentioned on the page dedicated to “ORE and aquaculture”, as they present similarities. 

Enhance Nature Inclusive Design in ORE installations

A suitable enabler to improve ORE installations and marine ecosystems is to design them and especially OWF on the basis of Nature Inclusive Design (NID). This can be defined as “the design of an OWF allowing the creation of suitable habitat for native species or communities whose natural habitat has been degraded or reduced” [27]. The Dutch authorities have been pioneers in stimulating this kind of NID within offshore wind projects through regulations and permitting. For example, for the Borssele and Hollandse Kust wind farm zones, the following regulation states that: “The permit holder must make demonstrable efforts to design and build the wind farm in such a way that it actively enhances the sea’s ecosystem, helping to foster conservation efforts and goals relating to sustainable use of species and habitats that occur naturally in the Netherlands.” [28]. More globally, nature inclusive designs cover a great variety of options that range from biohuts and gabions, to reef balls or reef cubes, etc. [29].

Enhancing multi-use between ORE installations and marine protection & restoration initiatives

• The idea here is to consider the possible synergies between the presence of ORE installations on one hand and their possible utility for marine life on the other hand.  A great example of this is embodied by the possibility of implementing multi-use of offshore wind farms with low-trophic aquaculture. A 2023 article published in Nature showed that allocating 10% of projected wind farm areas to blue mussel and sugar kelp aquaculture in the North Sea and Baltic Sea could yield very significant results in terms of carbon captured, as well as seaweed and mussel shell production[30]. This kind of multi-use technique does not limit itself to research activities and was implemented in several sites. The UNITED project aims at developing multi-use at sea and is based on several multi-use pilot sites. In the Belgian pilot, the objective is to combine OWF with flat oyster aquaculture as part of a restoration process. Flat oysters used to be abundant in the area and formed large reefs, offering a valuable habitat hosting a unique marine biodiversity. However, overfishing and diseases devastated wild oyster reefs, hence the need for this restoration initiative. The hard substrate around the wind turbines constitutes a suitable substrate for oyster larvae to settle on and initiate creation of natural oyster reefs, through the process of bio-colonization [31]. It should be noted that an increasing number of European projects are making significant progress on combining OWF with aquaculture production, both in the areas of research and concrete application [32].