This phenomenon is particularly prevalent in coastal areas, as 8 of the 10 global megacities are located on shores, such as Lagos, Tokyo, Jakarta and New York. The global maritime infrastructure footprint was approximately 32,000 km2 in 2018 (Bugnot et al. 2021). It is expected to reach 39,400 km2 by 2028, a territory equivalent to the state of Bhutan! However, the area of seascapes impacted by these structures was also estimated to be between 1 and 3.4 million km2 in 2018, with an increase of 50–70% expected by 2028, which is comparable to the global extent of urbanized areas (estimated at 0.02–1.7% of the land mass (Bugnot et al. 2021)). On the French coast, the rate of occupation doubled between 1965 and 19801. Between 2000 and 2006, no less than 6,809 ha were destroyed for the construction of harbors, dikes, embankments and other structures2. For example, in Hérault, a department in the Occitanie region, close to the Mediterranean Sea (southern France), the level of urbanization in 2015 on a narrow coastal strip of 15 km was close to 70%, with no less than three-quarters of the population concentrated there (DREAL Occitanie). In the international literature, we speak of a global “coastal squeeze”. This phrase, introduced by Doody (2004), is based on the threat to coastal development caused by the dual effect of rising sea levels and the explosion of human activities. There is an incoherence between human and the needs of our planet, especially in the urgent matter of the artificialization of natural environments, notably coastal ones. Urbanization remains the result of a development that is still too predatory of space.
Faced with the enormous challenge of a renaturation of culture (Pelt 1977), for a livable future of humankind, it becomes crucial to improve the consideration of biodiversity in territorial planning projects. We will focus here on the potential for nature-friendly planning, trying to integrate its functional needs as a fully-fledged objective in the design of infrastructures.
1.1. Principles of maritime eco-design
The actions taken to allow for the “natural” environment (we will use this term here in relation to the word “ecosystem”) for the operation of maritime works are varied. In the case of ports, these include the control and reduction of discharges, energy, sediment, waste and water management, environmental management plans (compliant since 2013), natural infrastructure master plans – including a natural heritage master plan – and Natura 2000 operators within the port perimeter (e.g. the Grand Port Maritime of Dunkirk).
At the same time, several tools designed to provide (voluntary) environmental certification are also available to project owners: AFAQ Clean Ports, ISO 14001, Blue Flag and the latest “Clean Port” certification active in biodiversity3, in March 2018. These certifications are often accompanied by communication programs, such as the “Green Port”4, “Year of Biodiversity” and “Port Biodiversity Index”, or information panels and stands proposed by the ports’ sustainable development departments, suppliers of “eco-” equipment or operators (Figure 1.1).
Figure 1.1. Public presentation panel on port biodiversity in the port of Kernével, one of the first two ports in Brittany to be certified “Clean Ports Active in Biodiversity”5 in 2018 (photo: ©APPB)
Political actions or the dissemination of good environmental practices have been strengthened in recent years. At the international level, for example, we can cite the Working with Nature program (from the International Association of Ports and Canals, 2008), based in particular on the experience of Port 2000 in Le Havre and the numerous guides produced PIANC6 (2011a, 2019, 2020); the World Harbour Project7 (Steinberg et al. 2016), which brings together 15 ports around the issues of ecological engineering, nature-based solutions and the resilience of natural port environments; at the European level, the CWA 16987 (Clean Harbour Guidelines); and at the national level, the reflections initiated as part of the Grenelle mission on the “Port of the Future” (led by CEREMA8), or regional variations, such as for the major seaport of Marseilles and the “GIREL” 9 research program, which was carried out in 2010.
In spite of these virtuous impulses, in the field, during the first design phases of a project, the objectives are primarily to propose a structure that meets technical constraints (resistance, durability) with a controlled cost, aligned with socio-economic objectives that meet a functional need: a marina or a commercial port, an offshore wind turbine, a breakwater, an offshore wastewater treatment plant, etc. The environmental question is applied to justificatory and secondary considerations which are dealt with once the technical and socio-economic choices have been made, under regulatory “constraint” (Airoldi et al. 2021).
This is where the purpose of eco-design, or oekodesign10, takes root, for its objective is to design a project, from sketch or feasibility phases (within the meaning of Act no. 85-704 of July 12, 1985, on public contracting and its relationship with private contracting, known as the MOP Act), according to ecological performance or co-benefit objectives. The aim is not to “wipe the slate clean” for the past but, based on technical engineering knowledge, to introduce biophysical considerations, in connection with the need to protect and develop the natural environment in the project to develop the sea.
1.2. Definition of eco-design of marine infrastructures
The eco-design of marine infrastructures is the result of recent cultural evolutions, as mentioned above. It is part of the interdisciplinary field of ecological engineering, which includes human sciences (geo-planning, law), engineering sciences (civil engineering, materials science) and natural sciences (biology, ecology). It responds to a major challenge for responsible human societies and biodiversity managers.
For Francis and Lorimer (2011), reconciling human and non-human in the project of developing urban territories, by integrating the conservation of nature, is undoubtedly the greatest challenge of the 21st century. For these same authors, the contribution of ecological engineering, a discipline that is still in its infancy in terms of the solutions it proposes, is a decisive factor in ecodevelopment. It was Odum, in 1962, in the context of his work on energy flows in marine ecosystems, who proposed the term “ecological engineering” (Odum et al. 1963). The most widely accepted definition today is that of B. Mitsch, a student of Odum, associated with S.E. Jørgensen (Mitsch and Jørgensen 1989): “Ecological engineering uses ecology and engineering to predict, design, construct or restore, and manage ecosystems that integrate human society with its natural environment for the benefit of both.”
The intimate link between ecology, land use planning and civil engineering is underlined by Van Bohemen (2004) who makes it the key to its diffusion and application. According to Bergen et al. (2001), the design of development projects must integrate the issues of human societies in an ecological approach, for a mutual human–nature benefit, following steps that ratify its application, the first three of which are:
1 1) design in accordance with ecological principles;
2 2) design adapted to the environmental specificity of each site;
3 3) maintaining the functional requirements of the structures, regardless of environmental requirements.
While ecological engineering includes eco-design in its definition, this term seems important to us because it underlines a crucial aspect in the success of a project benefiting human and nature; that is, to apply ecological concerns at the feasability step, to guide the project design from the beginning. Indeed, all too often, so-called eco-designed infrastructures take into account environmental aspects once the technical-economic