Abstract
More than a useful text, the creation of this Atlas responds to a necessity. How can we assess or value an ecosystem if we do not know its extent or even its existence? In order to recognise and justify the value of marine angiosperms, it does not matter how overwhelming the list of goods and services they may provide is if it is not accompanied by precise information about their distribution and the total area they occupy. Only in this way can the overall value of the services provided or the future losses or gains resulting from global change or management plans implemented be quantified. Several decades ago, the need to appeal to the instrumental value of ecosystems to fight for their conservation began to emerge (Boyd & Banzhaf, 2007). Their intrinsic value, regardless of what humans may wish to attribute to them, has proven insufficient. From an instrumental point of view, it is quite obvious that, although unevenly, humans depend on marine angiosperm meadows for food supply, raw materials, the maintenance of global biogeochemical cycles, climate regulation, and protection from extreme weather events. More difficult to understand and quantify, but no less relevant and obvious, marine angiosperm meadows provide intangible goods deeply rooted in human societies, ranging from pure aesthetic value to mystical, spiritual, or religious values (Wyllie-Echeverria et al., 2000). Although considerable conceptual progress has been made (e.g. Costanza et al., 1997; Board, 2005; Orth et al., 2006; Vassallo et al., 2013; Table 3), reliable efforts to monetise these values are generally scarce and especially poor in Spain.
