A freshwater conservation blueprint for California: prioritizing watersheds for freshwater biodiversity

Abstract

Conservation scientists have adapted conservation planning principles designed for protection of habitats ranging from terrestrial to freshwater ecosystems. We applied current approaches in conservation planning to prioritize California watersheds for management of biodiversity. For all watersheds, we compiled data on the presence/absence of herpetofauna and fishes; observations of freshwater-dependent mammals, selected invertebrates, and plants; maps of freshwater habitat types; measures of habitat condition and vulnerability; and current management status. We analyzed species-distribution data to identify areas of high freshwater conservation value that optimized representation of target taxa on the landscape and leveraged existing protected areas. The resulting priority network encompasses 34% of the area of California and includes ≥10% of the geographic range for all target taxa. High-value watersheds supported nontarget freshwater taxa and habitats, and focusing on target taxa may provide broad conservation value. Most of the priority conservation network occurs on public lands (69% by area), and 46% overlaps with protected areas already managed for biodiversity. A significant proportion of the network area is on private land and underscores the value of programs that incentivize landowners to manage freshwater species and habitats. The priority conservation areas encompass more freshwater habitats/ha than existing protected areas. Land use (agriculture and urbanization), altered fire regimes, nonnative fish communities, and flow impairment are the most important threats to freshwater habitat in the priority network, whereas factors associated with changing climate are the key drivers of habitat vulnerability. Our study is a guide to a comprehensive approach to freshwater conservation currently lacking in California. Conservation resources are often limited, so prioritization tools are valuable assets to land and water managers.

Approaches to the selection of a network of freshwater ecosystems within New Zealand for conservation

“…Overall, the approach used here is congruent with similar, evidence‐based planning in other jurisdictions, including those in Australia (Linke, Pressey, Bailey, & Norris, ), South Africa (Nel et al, ), and North America (Howard et al, ). The use of existing extents of protection and connectivity also enabled the identification of sites that provide the integrated protection (Abell, Lehner, Thieme, & Linke, ) required for effective catchment restoration and protection.…”

“…The approach taken here incorporates the benefits of including data describing species locations (Esselman & Allan, ), the consideration of connectivity between freshwater ecosystems (Nel, Reyers, Roux, & Cowling, ; Nel, Reyers, Roux, Impson, & Cowling, ), the benefits of existing restoration projects (Linke, Turak, & Nel, ), and the generation of prioritizations suitable for use in engaging with local communities (Boon, ). Comparable catchment evaluations and prioritizations are increasingly being used to inform freshwater conservation in a number of other countries (Boon, Holmes, Maitland, & Fozzard, ; Howard et al, ; Nel et al, ), and the prioritizations here follow the comprehensive, adequate, representative, and efficient (CARE) principles, which are judged to be the most effective planning approach for freshwater conservation (Linke et al, ).…”

Missing the Boat on Freshwater Fish Conservation in California

“…Such efforts are underway by a multi‐institution team of river scientists and managers (Howard et al . ). Given the threat of climate change and other anthropogenic stressors, effective freshwater conservation will require a portfolio approach that is tailored to regional conditions and opportunities.…”

Protected areas and freshwater biodiversity: a novel systematic review distils eight lessons for effective conservation

“…Lack of multi-direction connectivity, including longitudinal, lateral (river to riparian and floodplain habitats), vertical (surface-groundwater), and temporal connectivity, may compromise biodiversity protection (Linke, Turak, & Nel, 2011). We recommend application of systematic conservation planning principles and modelling techniques (e.g., Grantham et al, 2016;Howard et al, 2018) during the placement, design, and gazettal of freshwater protected areas.…”