Freshwater biodiversity conservation through source water protection: Quantifying the potential and addressing the challenges

Abstract

Water insecurity is a defining feature of the Anthropocene, with degraded water quality and unreliable flows putting the well‐being of upstream and downstream communities, both human and aquatic, at risk. Within this context, the protection of drinking water at its source – ‘source water protection’ – is growing as a complementary water security solution to conventional built infrastructure, particularly but not only to address non‐point source pollution. An assessment of the likely source catchments of 4000 cities, supplying water to as many as 1.7 billion city dwellers, found that 85% of the total area of the catchments overlaps with freshwater ecoregions of high biodiversity value. Source water protection could contribute to conserving important freshwater biodiversity elements in these catchments, through activities such as land protection, restoration, and agricultural and ranching best‐management practices. Empirical evidence supporting the benefits of these types of activities to freshwater species and ecosystems is sparse, especially when considered at the scales required to achieve meaningful conservation objectives. This article explores the potential of source water protection to deliver freshwater conservation benefits, and solutions are proposed to address the challenges related to evidence gaps, trade‐offs, and financing. The broader opportunity for leveraging water security investments for biodiversity conservation, and the overall efficiencies that may accrue from optimizing for multiple benefits simultaneously, are discussed in the context of global frameworks such as the Sustainable Development Goals.

Fish life history trends indicate increasing flow stochasticity in an unregulated river

“…Our results cannot be attributed solely to water quality improvements. Observed decreases in sediment and nutrient loads (Chanat et al 2016) are expected to improve fish habitat by increasing spawning substrate quality and decreasing eutrophication and algal production (Abell et al 2019), but our results show inconsistent patterns in this regard. On one hand, central stoneroller increased in abundance (Table 5) suggesting degrading habitat conditions as seen elsewhere in response to agricultural development (Hitt and Roberts 2012) and loss of riparian forest cover (Fischer et al 2010).…”

Principal threats to the conservation of freshwater habitats in the continental biogeographical region of Central Europe

“…This trend was observed even in regions with decreasing populations outside of Poland, notably in Italy and eastern Germany (Ustaoglu and Williams 2017). In the case of numerous standing water habitats, another problem is highlighted: whether the ecosystem change is a result of natural succession or human activity (Abell et al 2019).…”

“…The freshwater habitats within the CBR of Europe are represented by degraded river and lake basins, the ability of which to sustain biodiversity is typically reduced (Abell et al 2019), and their resilience has been reduced as a consequence of human actions (Folke et al 2004). Loss of resilience through the combined and often synergistic effects of a variety pressures can make ecosystems more vulnerable to changes that previously could be absorbed.…”

Theory and practice to conserve freshwater biodiversity in the Anthropocene

“…natural ecosystems that are in a reasonably intact and functional condition) for the provision of water to downstream users. Here, Abell et al () take these concepts and highlight how ‘source water protection’ – the protection of water at its source to secure the quality and quantity for downstream human needs – can bring diverse co‐benefits for protecting freshwater ecosystems. This approach of integrating human needs of freshwater systems with the requirement to conserve and protect the ecosystems that supply freshwater ecosystem services is essential for freshwater biodiversity conservation in the Anthropocene.…”

“…Here, Abell et al (2019) contribute to the call to evaluate the effectiveness of programmes aimed at accomplishing the shared objectives of water protection and freshwater biodiversity conservation. These authors note that, even with this information, it is necessary to ensure the effective design and implementation of projects, and to be ready One of the great challenges to freshwater ecosystem conservation is that fresh waters are embedded within the terrestrial matrix.…”