Aquatic Conservation: Marine and Freshwater Ecosystems

Millennial perspectives, like the one prompted by this Special Issue of Aquatic Conser6ation, are challenging. If we look back, we realize the degree of change in culture, technology, science and environmental quality that can occur over such time scales. Consider, for example, that by the turn of the last millennium, our global population was somewhere between 200 and 500 million (Ehrlich et al., 1977; Goode, 1993). Homo sapiens had only just colonized Madagascar (ca 500 AD) and New Zealand (ca 700–800 AD). Forest clearance was already under way in some areas, including Britain (Birks, 1988), but large areas of the rest of the world were still largely under semi-natural vegetation (Goode, 1993). Emerging from the dark ages, major new technologies were the compass (ca 1100 AD)—among the first of all hand-held instruments—but also features that from here on would hasten the worldwide modification of wetlands and their catchments: the horse collar, the stirrup, the heavy plough, the windmill, and the water wheel. Now, 1000 years later, technology pervades most of our activities. We approach our 6th billion (population), and large areas of the world are dominated by human activity or management: 65% of Europe, 29% of Asia, 25% of North America, and 36% of the exploitable global surface in total (Hannah et al., 1994). Global extinctions have accelerated from a background rate of just 2–3 species per year to 100–1000 times this value, with the prospect of increase in the coming decades by a further order of magnitude (Lawton, 1996). All this has occurred in the equivalent of about 13 human lifetimes. Looking forward, therefore, there are bound to be difficulties in making straightforward predictions about the shape of things to come. Yet, there is one certainty of both our past and future: we are fundamentally dependent on the need to exploit water resources, and to protect their quality for the services, resources and intrinsic ecosystem value they contain. It was no coincidence that human civilizations grew along the fertile and richly irrigated floodplains of the Nile, the Indus, the Euphrates and the Tigris. Already by 2500 BC human settlements were characterized by wells, reservoirs, aqueducts, canals, piped distribution systems and sanitary drainage. Intimately bound with water as we have been, archaeological artefacts provide evidence that exploitation of aquatic resources is ancient: pots, boats, fish-traps, the use of Papyrus or Salix spp. Now, however, there are indications that this fundamental bond with water is under strain. Current global trends in population mean that demands on surface water and groundwater resources must