ABSTRACT

Freshwaters contain a disproportionately high level of biodiversity, yet have experienced very high levels of loss over the last few decades: protected areas (PAs) play a critical role in reducing and reversing this decline. External influences can originate nearby or far away across national boundaries. Long-range transport of sulphur and nitrogen oxides, falling as acidic deposition or "acid rain" altered river and stream chemistry in large areas of southern Scandinavia during the 1980s, including lakes in national parks. External influences can originate nearby or far away across national boundaries. Managers of freshwater PAs have limited options for addressing offsite problems except through lobbying for policy changes. PAs help to conserve biodiversity and water resources as a common good, but if planned or managed badly can undermine local livelihoods by restricting access to freshwater resources. An increasing number of PAs have some kind of shared governance: either formally or informally; others are entirely controlled by local owners.