tried to advance the notion that the human can play the role of positive creator for their environment, improving the biosphere with new symbioses of humans in nature.
In this work, we propose to focus on marine structures. Indeed, coastal structures, although not specifically designed for this purpose, generate new biotopes that are particularly attractive for coastal species at the juvenile stage: for example, 30–109 times more juveniles are welcomed on dikes and harbors than on natural rocky habitats in the western French Mediterranean (Pastor 2008).
However, these ecological potentialities are ignored, or at best incidentally recognized and very rarely enhanced by specific eco-designed and nature-inspired infrastructures. Marine works are generally designed with regard to functional, technical, economic or hydro-sedimentary marine environment considerations, not as supports to maintain or increase marine biodiversity.
The objective is now to develop their functional aspects from an ecological point of view so that the structure becomes a proactive element for the environment. It becomes part of a dynamic ecosystem by creating habitats and ecological functions: shelter for juveniles, feeding areas, habitats for fixed fauna and flora, etc.
This book first offers the reader two chapters related to the developments in the fields of environmental regulation and maritime civil engineering, increasingly expressing a social expectation towards the prefix “eco-”. Indeed, every planner must design a facility in response to a functional and technical need, meeting regulatory standards.
However, beyond this “classic” approach to marine development projects, the eco-design approach presented in Chapter 3 allows environmental impacts to be taken into account from the technical definition of the works. The authors illustrate this approach in Chapter 4 with practical examples that they have dealt with, complemented by feedback from projects carried out according to these principles and attempting to avoid running the risk of justifying avoidable projects by their “green” appearance. It is always preferable to abandon a project if its negative effects on the environment are unavoidable, because offset is a Trojan horse for the development that is thus facilitated, as denounced by Firth et al. (2020): “Greening of grey infrastructure should not be used as a Trojan horse to facilitate coastal development.”
Sylvain Pioch
Jean-Claude Souche
July 2021
1 1 The work of McHarg in the area of landscape architecture, gathered in his famous Design with Nature, served as a basis for our extrapolation to the submerged, underwater marine domain.
Acknowledgments
This book is dedicated to our families: Élise, Guilhem, Céleste, Raphaëlle and Julianne, and Sophie, Juliette, Rémi, Éloïse and Alexis, who are the driving force of our lives. We would also like to thank all those who, through their lives, actions and convictions, seek to build a fairer and more beautiful world where humankind will be able to consider all the other forms of life on the planet of which it is only the host.
This book is the compilation of 30 years of professional practice acquired as an environmental engineer in planning and impact studies (S. Pioch) and as a civil engineer (J.-C. Souche), then as lecturers and researchers in University Montpellier 3 and Mine Telecom Institute of Alès or simply as divers.
Beyond our common passion for the sea, it seemed unavoidable to merge our experiences as the need to design and build marine structures differently is urgent. It is also with modesty that we propose this work to readers, without claiming it to be exhaustive or the absolute truth. We simply provide a testimony and methodological tracks that we have tested in the field, with actors involved in development.
We would like to thank Régis Dumay, Marie Salgues, Jean Bougis, Philippe Saussol and Jean-Marie Miossec for their active help in the elaboration of this book, as well as the company Beuchat for the diving equipment. A special thought for Françoise Gaill for her constant support. We would also like to thank all the contributors who shared their testimonies with us in order to make this book a moment of sharing of experiences in France and abroad, which we hope the readers will appreciate:
– Alexandra Agostini, Anne Rioux, Aurore Léocadie, Osanne Paireau, Katherine A. Dafforn (Australia), Louise Firth (UK) and Shimrit Perkol-Finkel (Israel);
– André Grosset, Bernard Sigros, Cyril Giraudel, Cyrille Taioni, Etienne Cunge, Fabrice Javel, Frédéric Martarèche, Jean-Louis Gaziello, Jean-Michel Cathala, Michel Fons, Patrick Guiraud, Pierre Roy, Romaric Vicente, Marcel Stive (Netherlands), Jean-Luc Nguyen (Monaco) and Richard Spieler (USA).
May this modest work inspire us to think differently and to eco-design marine works, for the mutual benefit of the sea and humankind.
1
Principles and Genesis of Maritime Eco-design
The global ecological crisis is concomitant with the Anthropocene, this new geological era in which humans have become the central actors of pressures on the planet (Crutzen 2006). Indeed, the recent IPBES report (IPBES 2019) makes a damning assessment of the state of biodiversity since the beginning of the industrial era two centuries ago: 75% of the land has been altered by humans (one-third of the land consuming three-quarters of the available water resources is agricultural), 66% of the oceans are threatened by humans and more than 85% of wetlands have been destroyed. It is therefore our actions on this unique planet that are holding back our own future. The logic of this observation would lead us to stop, or at least to slow down, the well-known causes of this disaster (in decreasing order): (1) artificialization and land use; (2) resource exploitation (fishing, forestry, etc.); (3) climate change; (4) pollution (plastics, chemical residues, etc.); and (5) invasive species (IPBES 2019). Thus, artificialization and land use would be our main problem. In addition to agriculture, it is the issue of urbanization and its consequences (cities, ports, mines, industries and roads) that is the most important because it leads to an artificialization of environments that is difficult to reverse. If we look at the forecasts, we can see not only a continuity but also an acceleration of global urbanization, both on the continents and at sea. No less than 60,000 billion US dollars will be invested in infrastructure between 2019 and 2040 (in the 56 countries representing 88% of the world’s GDP (Global Infrastructure Hub and Oxford Economics 2017)), more than 1.2 million km2 will be urbanized by 2030, in just 10 years, that is, an increase of 185% compared to 1970–2000 (Seto et al. 2012), and 3–4.7 million km2 of roads will be created by 2050, an increase of 25% compared to the current annual rate (Meijer et al. 2018).
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
