Coastal and estuarine environments at the interface of terrestrial and marine areas are among the most productive in the world. However, since the beginning of the industrial era, these ecosystems have been subjected to strong anthropogenic pressures intensified from the second half of the 20th century, when there was a marked acceleration in the warming (climate change) of the continents, particularly at high latitudes. Coastal ecosystems are highly vulnerable to alteration of their physical, chemical and biological characteristics (marine intrusion, acidification of marine environments, changes in ecosystems, evolution and artificialization of the coastline, etc.).In contact with heavily populated areas, these environments are often the receptacle of a lot of chemical and biological pollution sources that significantly diminish their resilience. In this context of accelerated evolution and degradation of these areas important for food security of many populations around the world, it is necessary to better identify the factors of pressure and understand, at different scales of observation, their effects and impacts on the biodiversity and on the socio-eco-systems, in order to determine the degree of vulnerability of these coastal ecosystems and the risks they face. A transdisciplinary and integrated approach is required to prevent risks. Within this framework, operational coastal oceanography occupies an important place but also the implementation of a true socio-eco-system approach in order to set up an environmentally friendly development.

This book documents the effects of natural hazards on coastal ecosystems in detail. The sea is an indispensable component of the Earth system, and human societies obtain many goods and services from the marine environment. Global warming threatens marine ecosystems through seawater temperature rise, acidification, sea-level rise and the increased frequency of severe storms. The repeated effects of tsunamis also have major impacts on coastal ecosystems. Increases in population and industry activities along the coast cause the degradation of coastal ecosystems through direct and indirect uses of the environment such as reclamation, overexploitation of bioresources, and pollution. Given these facts, we need to improve our understanding of the physical, chemical and biological mechanisms characterizing marine ecosystems, in order to better measure the effects of anthropogenic and natural impacts on the sea and its ecosystems. Equipped with a comprehensive understanding of the sea, including the effects of the main pressures on it, we will have a better idea of the future state of the sea based on several scenarios of global warming. The 16th France-Japan Symposium on Marine Science focused on using advances in oceanography to better understand the current status of the sea from physical, chemical, biological and ecological perspectives, including fishery sciences and integrated approaches.