Freshwater protected areas and defining a conservation blueprint for desert fishes
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This document summarizes a study that aimed to identify priority areas for conserving freshwater fish diversity in the Lower Colorado River Basin. The study developed species distribution models for 40 native and non-native fish species. Using these models and metrics of taxonomic, functional, and phylogenetic diversity, a conservation prioritization algorithm identified the top conservation priorities. The study found opportunities for conservation but also trade-offs between different diversity targets and challenges from contemporary and future threats.
Freshwater protected areas and defining a conservation blueprint for desert fishes
- 1. Freshwater Protected Areas and Defining a Conservation Blueprint for Desert Fishes Julian D. Olden and Angela L. Strecker University of Washington
- 2. The Blue Planet Crisis • Freshwater organisms are among the most imperiled worldwide. • Actual and estimated future extinction rates exceed most terrestrial and marine systems (Ricciardi & Rasmussen 1999). • Recent global estimates indicate that 25-30% of evaluated freshwater fishes are considered threatened with extinction (Vié et al. 2009).
- 4. Threats to Freshwater Ecosystems Habitat loss Invasive species Pollution Fragmentation Disease Climate change
- 5. • Despite the severity of the threats they face, amphibians and fish were the least-studied groups over the past 20 years
- 6. Challenge Synopsis • Comparatively little effort has been devoted to the design and implementation of freshwater conservation planning. • Instead, uninformed opportunism has reigned, whereby conservation goals of freshwater ecosystems are often secondary to those developed for terrestrial ecosystems. • Traditional notions of conservation planning translate imperfectly to the freshwater realm, therefore freshwaters have been largely ignored in conservation accounting schemes.
- 7. • Freshwater ecosystems have distinctive properties that challenge many key tenets of conservation planning Longitudinal, lateral and groundwater connectivity Threats originate within and outside watershed boundaries EPA Limited dispersal that is confined to defined habitat corridors
- 8. Today’s Presentation Conservation Opportunities for Today … • Can lands set-aside for terrestrial conservation serve as a foundation for a comprehensive network of freshwater protected areas? … and the Future • Where should we seek new conservation opportunities to protect freshwater biodiversity in a cost-efficient manner?
- 9. Freshwater Protected Areas • Scientists have recently begun to explore the potential of establishing freshwater protected areas (FPAs) as one approach to curtail the loss of biodiversity in freshwater ecosystems. • Originally developed for terrestrial conservation, and applied over the past two decades to marine systems, protected areas have emerged as a leading tool for conservation. 2007 2009 2002
- 10. • One of the first steps in designing a representative network of FPAs is taking stock of what is contained within current protected area systems. • Protected areas that combine protection for terrestrial and freshwater resources could be prioritized to promote efficient spending of limited conservation dollars (Abell et al. 2010). • Somewhat surprising is the almost complete lack of broad- scale empirical information on freshwater resources within terrestrial protected areas.
- 11. Objective • To provide the first national assessment of the biological representation for native freshwater fishes provided by the National Park Service (NPS) • We assess the ecological threats to park watersheds and management challenges to utilizing NPS units as FPAs • Our priority was to identify parks that could serve as the core members of a FPA network to “protect” freshwater fish diversity • Dave Lawrence, Eric Larson, Cathy Reidy Liermann , Meryl Mims, Thomas Pool, and Julian D. Olden (Conservation Letters, in revision)
- 12. Methods National Parks Representation • Selected 147 parks whose • Compiled a list of all US fishes primary mission was the (and those considered preservation of natural threatened) resources • Derived species lists for major • Collated species lists using the watershed and ecoregions National Park Service Biodiversity Database Ecological threats • Validated (and supplemented!) • Developed a cumulative threat species lists based on a index to rank each park’s current literature review and (and projected) future integrity conversations with park managers – Human land use – River regulation by dams – Species invasiveness
- 13. Findings • National parks provide representation for 62% (478 species) of the native US fishes • NPS units provide relatively poor representation for species of conservation concern: 27 of the 153 highly imperiled fish species (18%) • One-third (30%) of all the native fish species contained in the NPS occurred in only one park across all parks considered in this study
- 15. Management Challenges • A major constraint to utilizing NPS units as protected areas is that their ecological integrity is subject to anthropogenic disturbances that occur outside of park boundaries.
- 16. Conclusion • NPS units contain almost two-thirds of the freshwater fish species within the United States • Additional representation may be achieved by: • Adding units for ecoregions with poor representation • Expanding the mission of some historic and recreational NP units to increase protection for fish biodiversity • Our results assist the NPS to understand each parks’ contribution to the broader national biodiversity puzzle, and help in the development of new policy that supports a comprehensive, network-based conservation strategy
- 17. Conclusion • The vast majority of parks had contributing watersheds that extended well outside of their boundaries, but the contributing catchment of many NPS units is held in some form of conservation status • Vast opportunities for integrated watershed protection
- 18. Conservation challenges are likely the greatest in dryland regions • Over two billion people are currently inhabiting arid regions globally • Nexus of population growth, complex water policy, and endemic native species • Represent one of the most threatened habitat types (Olson and Dinerstein 1998)
- 19. Lower Colorado River Basin • The Lower Colorado River Basin is emblematic of the conservation challenges facing dryland systems. • Wild, volatile, and unpredictable, the natural river varied dramatically from its headwaters to the delta, from year to year, and from season to season.
- 20. Settlement and Change • Discovery of gold in California (1849) triggered a western migration and brought with it Amon Carter Museum ranching, mining and steamboats • Rapid urbanization and population growth after WWII
- 21. The Lifeline of the American Southwest • The Colorado River was critical in the settlement, growth and economic development of the American Southwest The river provides: – Irrigation water for >3 million acres of farmland – Domestic water to 30 million people in the U.S. and Mexico – 12 billion kilowatt-hours of hydroelectric power a year
- 24. Over-allocated most years Woodhouse et al. (2006) Increased aridity in the future Seager et al. (2007)
- 25. A desert river and its lost native fishes • Harsh hydrologic, thermal Mueller and Marsh (2002) and sediment conditions have resulted in a globally- endemic fish fauna • Only one predatory species • Strong naivety to predation • Extreme longevity • High species endangerment: 49 species (42 are endemic, over half listed under ESA) USGS
- 27. Devil’s Hole, Nevada
- 28. Rapidly spreading invasive species • LCRB has the dubious distinction of being a global invasion hotspot, where the number of non-native fish species more than double the number of native species. • Ecological impacts of invasive fishes are widespread. Data from Olden & Poff (2005)
- 29. Conservation Needs • Practitioners in the LCRB are seeking guidance on how best to allocate limited resources toward freshwater protection • Most management efforts target individual sites or rivers without being informed by broader-scale conservation needs or priorities Abell etet al. 2007 Abell al. (2007)
- 30. Objectives • Provide the first systematic prioritization for freshwaters that incorporates multiple (and complementary) conservation values describing fish taxonomic, functional and phylogenetic diversity. • Test the concordance of different conservation strategies under scenarios of contemporary threats to biodiversity, as well as under projections of future climate change and human population growth. • Highlight the use of systematic conservation planning for the optimal allocation of limited resources for freshwater conservation.
- 31. Approach • Conservation prioritization algorithm using Zonation best 5-10% software best 2-5% – hierarchical ranking of priority best 2% areas/cells – emphasis complementarity Moilanen et al. 2005 • Strengths: – can incorporate interactions among species – can incorporate freshwater connectivity, i.e., river catchments are linked planning units no connectivity habitat connectivity Hermoso et al. 2010
- 32. Methods: Data acquisition • Assembled species records for entire basin – combination of government, university, and museum records – > 1.8 million records dating from 1840s – only include recent species records (1980 onwards) • Unequal sampling effort – large focus on Grand Canyon & Little Colorado regions – poor representation of some taxa
- 33. Methods: Species distribution models • We used multivariate adaptive regression splines (MARS: Friedman 1991) to model species distributions – non-linear responses – multi-response model informed by data from well- represented species Bill Williams River, Arizona • Illustrated success for modeling species distributions in freshwater ecosystems (Leathwick et al. 2005) • Model performance was evaluated using area under the Receiver Operating Characteristic curve based on 10-fold cross validation
- 34. Methods: Species distribution models Temperature • Modeled distribution of 40 native and non-native species as a function of: Precipitation – landscape variables (e.g., elevation, gradient) – local variables (e.g., canals, dams, agriculture) – climatic variables (e.g., CV spring precipitation, average temperature) – historical biogeography Dams Urban
- 35. Desert sucker • Native species • AUC = 0.88 Probability of occurrence 0.2 0.4 0.6 0.8 CV winter precipitation
- 36. Red shiner • Non-native species • AUC = 0.87 Probability of occurrence 0.2 0.4 0.6 0.8 CV winter precipitation
- 37. Metrics of Biodiversity Taxonomic diversity – Used actual and modeled species distributions to describe species composition of each watershed Functional diversity – Used data on 9 life-history traits (Olden et al. 2006) to quantify trait composition of each watershed Phylogenetic diversity – Used a qualitative phylogeny (Olden et al. 2008) to describe phylogenetic (node) composition of each watershed Species Node Trait State Node Trait State Watershed Watershed Species X =
- 38. Zonation Methods Fragmentation and home range Defined 3 parameters: 1. Fragmentation curves for 3. Species’ weightings species’ connectivity – equal requirements – based on Desert Fishes Council – based on historic vs. recommendations (e.g., desert contemporary sensitivity to sucker = 1.67; Virgin River fragmentation spinedace = 2.33) (Fagan et al. 2002, 2005) 2. Species’ landscape requirements based on predicted home range size from maximum body size (Minns 1995)
- 39. Zonation Methods Threats and non-native species • Multi-parameter threat index • Non-native species interaction describing land use, waterway layer (non-native richness) and human development low threat 0 0-1 1-3 3-5 5-7 Las Vegas high threat Las Vegas 7-12 Phoenix Phoenix Paukert et al. (2011)
- 40. Findings Efforts to conserve endangered fishes of the LCRB will be met with a number of opportunities, trade- offs and challenges.
- 41. Conservation Opportunities Identifying critical locations Taxonomic Diversity major cities Conservation priority (%) NV NV large dams 0 - 10 50 - 60 UT UT 10 - 20 60 - 70 large rivers 20 - 30 70 - 80 state lines 30 - 40 80 - 90 40 - 50 90 – 100 Las Vegas Hoover Dam AZ AZ NM NM Grand Canyon Flagstaff CA Phoenix Salt R. CA Gila R. Mexico Mexico Tucson 0 3060 120 180 240 Kilometers
- 42. Conservation Opportunities Identifying a comprehensive network • High level of concordance functional – taxonomic between areas of conservation functional – phylogenetic taxonomic – phylogenetic priority (top 10%) for different all scenarios dimensions of biodiversity 100 Congruence (%) • 75-88% congruence for the 80 conservation priorities for 60 each diversity measure 40 (p<0.001) 20 0 • ~5500 km2 represents at least 0 20 40 60 80 100 10% of all species occurrences Best % of landscape
- 43. Conservation Opportunities Identifying immediate targets GAP classifications of protected areas 1 • 34-39% of the top 2 3 conservation priorities are 4 currently within lands classified as having permanent “protection” from land conversion – 14-15% with a natural disturbance regime – 20-24% with a managed disturbance regime
- 44. Conservation Trade-offs Identifying a comprehensive network Difference in • Notable regions of spatial conservation priority mismatch between -1.00 – -0.75 -0.75 – -0.45 phyl > conservation priorities for -0.45 – -0.15 tax -0.15 – 0.15 0.15 – 0.45 biodiversity targets tax > 0.45 – 0.75 0.75 – 1.00 phyl • Mismatches may indicate unique ecological or evolutionary processes that are critical for conservation Apache Trout
- 45. Conservation Trade-offs Identifying a comprehensive network 1.0 Proportion of distribution 0.8 remaining 0.6 0.4 taxonomic diversity functional diversity 0.2 phylogenetic diversity 0.0 0.0 0.2 0.4 0.6 0.8 1.0 Proportion of landscape removed
- 46. Conservation Challenges Contemporary threats • > 25% of the conservation taxonomic diversity functional diversity priorities are located in areas phylogenetic diversity with high non-native species 40 richness and high contemporary threats Congruence (%) 30 • Inclusion of species 20 interactions in algorithm resulted in a 16% increase in 10 area required to meet conservation priorities 0 Non-native Environmental Richness Threats • The continuous nature of (top 20%) (top 20%) riverine ecosystems challenges conservation efforts
- 47. Conservation Challenges Future threats • Projections of future (2100) air temperature, precipitation and impervious land cover for A2 emissions scenario. Δ Annual temperature (%) Impervious surface - 2100 (%) 0-1 9 – 11 Δ Annual precipitation (%) 2 - 10 11 – 13 11 - 20 -13 – -9 13 – 15 21 - 30 -9 – -6 31 - 40 15 – 17 -6 – -3 41 - 50 17 – 19 -3 – 0 51 - 60 0–3 61 - 70 3–6 6–9 9 – 12 Ensemble of 16 GCMs ICLUS (EPA, 2010) (ClimateWizard, 2010)
- 48. Conservation Challenges Future threats • Conservation efforts must taxonomic diversity contend with projected functional diversity phylogenetic diversity warming (3-4°C by 2100) and harsher droughts and extreme 40 floods Congruence (%) 30 • Percent congruence with 20 conservation priorities: 10 – Temperature: 14-15% – Precipitation: 26-32% 0 – Impervious: 3-6% Temp Prec Impervious (top 20%) (top 10% & surface bottom 10%) (top 20%)
- 49. Conclusions • Systematic conservation planning requires: – a focus on multiple and complementary aspects of biological diversity – information on both contemporary and future threats to maximize long-term species persistence • Efforts to conserve endangered fishes of the LCRB will be met with a number of opportunities, trade-offs and challenges • Prioritizing watersheds that are the most important for their contribution to basin-wide representation of biodiversity can inform land transactions and local-scale conservation efforts
- 51. Prospectus • Meeting the conservation needs of freshwater ecosystems will require the use of systematic planning that accounts for multiple dimensions of biodiversity and ecological threats
- 52. Acknowledgements Angela Strecker Dave Lawrence Craig Paukert (University of Missouri) Jodi Whittier (University of Missouri) Mark Kennard (Griffith University) Desert Fish Habitat Partnership Funding: USGS Status and Trends Program USGS National Gap Analysis Program