Duncan & Garfin 2006

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climate change & native fish conservation in SE AZ

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Duncan & Garfin 2006

  1. 1. Borders, Boundaries, and Time Scales Fronteras, Limites, y Escalas de Tiempo Proceedings of the Sixth Conference on Research and Resource Management in the Southwestern Deserts ExtendedAbstracts: December 2006 Bill Halvorson, Editor USGS Southwest Biological Science Center Sonoran Desert Research Station MAR - 1 2007
  2. 2. Native Fish Conservation and Climate Variability in Southeastern Arizona. Doug Dunam' and Cregg Garfirl. 'U.S. Fisll 6- Wildlife Xn';ct; ~CLJMj£,S- University 0/Arizona The conservalion of nati,'c fish in southeastern Arizona has always been reliant on finding waler that isn't "used," or that is not constr.'lined by conflicts thai make sites unavailable. Examples of conflicts that may render a site unsuitable or unusable for native fish are: sport fisheries: low-quality effluent; nonindigcnolls fish; and lando'ller. lessee, or permittee resistance. In addition 10 conflicts listed abo'e, the multiple impacts flowing from other human activities in southeastern Arizona also impacl ,,'aters. Another issue impacting waters for native fish conservation is that other rare aquatic species in southeastern Arizona also need many of these valers. Some fish species arc not compatible with other aquatic species in some sites. Climate variability, including drought, and climate change both have the potential to al!<'T sitrs for conservation of native fishes in southeastern AriZOna. Here we consider southeastern Arizona that area east of lhe Tohono O'odham Nation and the lower-most (north) Santa Cruz River, and south of the Gila River. This area includes parts of the Rio Concepcion, Santa Cruz River, San Pedro River, Rio Yaqui, and Gila River Basins. Depending on how they arc included, split, or lumped, there are 21 species of native fish in southeastern Arizona. Of those 21 species, 16 still occur in the area. four are extirpated, and one is extinct. There are 13 species listed under the Endangered Species Act; nine arc listed as endangered, four as lhreatened, and an additional species has been petitioned for listing. There are a multitude of issues facing native fish in the study area. Threats that have been factors in the listing of fish and continue today include the standard litany: nonindigenous species. species' habitat loss, and reduction in habitat quality. Habitat destruction and the introduction of nonindigenous species are responsible for the decline of 98 percem of North American fishes listed as endangered, threatened, or of special concern (Williams et al. 1985). Impacts to habitat and impacts from nonindigenous spedes do not occur independently. Degradation ofaquatic S)'Stems is a major faclor in the invasion, establishment. and irruption of nonindigenous species (Aquatic Nuisance SpecicsTask Force 1994). Though the discussion here centers on native fish, it is likely that negative impacts could also occur to olher native aquatic vertebrates. There are three native ranid frogs (Rana spp.) and a native salamander (Ambysroma tigr;l1l1m srrbbet,sj) in southeastern Arizona. There are also several garter snakes (11lamnoplJis spp.). All arc ofconservation concern. The single greatest difference in how impacts to aquatic systems will impact nati'e fish or herpetofauna, is that the herpetofauna are far more mobile than fish and at least ha'c the potential to move between aquatic s}'Stems. That southeastern Arizona and much of the American Southwest are in drought is well known. What is known with far less certainty is how long this drought mightlasl. Currently, only seasonal drought predictions are available for three-month seasons (e.g.• February·Apri1), at a lead time of two weeks in advance (e.g., issued January 15). These predictions. based on a subjecti'e combination of results of statistical and dynamical climale models and insights from past climate history, are a'3ilable through the NOAA Climate Prediction Center. State-of-the-art climate science does not yet support multi-year or decade-scale drought predictions. However, instrumental and paleoclimate records from the South'est indicate that the region has a history of multi-year and multi-dCClde drought (Hereford el al. 2002; Jacobs et a!. 2005; Sheppard et oIl. 2002). Multi-decade drought in the South'est is controlled primarily by persistent Pacific Ocean- atmosphere interactions. which have a strong effect on winter precipitation (Brown and Comrie 2004; Schneider and Cornudle 2005); persistent Atlantic Ocean circulation is theorized to ha'e a role in multi-decadal drought in the Southwest, particularly with respect to summer precipitation (Gray et al. 20CB; McCabe et al. 2(04). Given these multi-decade "regimes" of ocean circulation. and the severity and persistence of the present multi-rear drought, there is a fair likelihood that this droughl will persisl for many more years. albeit with periods of high rear-to·year precipitation variability characteristic of Southwest climate. The information on how climate change might impact southeastern Arizona is less certain than currenl drought predictions. Howevcc, virtually all climate change scenarios predict that the American Southwest will get '3rmer during the 21st century (lPeC 2001). Precipitation predictions show a greater range of possibilities, depending on the model and emissions scenario (USGCRP 2001). To maintain the present water balance with warmer lemperatures and all other biotic and abiotic factors constant, precipitation will need to increase to keep pace with the increased evaporation and transpiration caused by '3rmer temperatures. Key projections 10 keep in mind include: • decreased snowpack - an increasing fraction of winter precipitation could fall as rain instead of snow, periods of sl10wpack accumulation could be shorter, and snowpacks could be smaller; ironically, due to changes in snow-precipitation characteristics. runoff may decrease e"Cn if total precipitation increases (Gamn, 2005); Borders, Boundaries, and TIme Scales 2006 41 CONSERVATION
  3. 3. • earlier snowmelt - increased minimum winter and spring temperatures could melt snowpacks sooner, causing peak water flows to occur that much sooner than the historical spring and summer peak flows (Stewart et aI., 2(04); • enhanced hydrologic cycle - in a warmer ,rorld an enhanced hydrologic cycle is expected; flood extremes could be more common causing more large floods; droughts may be more intense. frequent, and longer- lasting. Continuing drought and climate change, when added to the historical and continuing threats, will make native fish conservation in southeastern Arizona even more difficult. The impact to fish of site desiccation is obvious. There are many less obvious effects that could occur with drought and a wanner climate. A site with reduced str~mf1ow, or a pond or pool with low water levels could become fishless due to reduced dissoh-ed oxygen. We haw set"n this occur at three important natural Gila topminnow (P. ocddenrafjs) sites (i.e. Sharp Spring, Redrock Canyon, Cienega Creek). Drought and climate change will also impact watersheds and subsequently the water bodies in those watersheds. Drought, and especially long-term climale change will impact how ecosystems and watersheds function. These changes will cause a cascade ofecosystem changes, which may be hard to predict and are likely to occur non-linearly. As an example. drought and climate change will cause changes in fire regimes in all southeastem Arizona vegetation communities. The timing, frequency. extent, and destructiveness of wildfires is likely to increase and may also facilitate the invasion and increase of nonindigenous plants. These changed fire regimes will change vegetation communities, the hydrological cycle, and nutrient cycling in affected watersheds (Brown ct OIL 2004). Some regional analyses conservatively predict that acreage burned annually will double with climate change (MacKenzie el a1. 2004). Such watershed impacts could cause enhanced scouring and sediment deposition, more extreme flooding (quicker and higher peak flows), and changes to water quality. ) Severe watershed impacts such as these, 'hen added to reductions in e~1ant aquatic habitats. will severely restrict sites ll'ailable for the consenration of nati"e fish and other aquatic vertebrates and make management of extant sites more difficult. Many of the predictions about the impacts of climate change arc based on modcling. but man}' predictions have already occurred. The tree die-offs and fires that have occurred in the Southwest early in this century shO' the impacts of the curren! drought. The potenlial impacts from climate change and drought need to be addressed, while considering the potential duration of and uncertainly of their effects. The precautionary principle should be adhered to when planning for native fish conservation. While there may not necessarily be solutions to the problems presented by drought and climate change, there are things that can be done to minimi7-c the impacts to native fishes and increase the resilience of fish habitat in southeastern Arizona. After the fires of 2005, the Ari7.0na Game and Fish Department and U.S. Fish and Wildlife Service began drafting a salvage protocol for native fish. This protocol should be expanded to include any impacts to nati>e fish, such as drought and climate change, invasion of nonindigenous species, and release of em'ironmental contaminants. We recommend the following actions: • Natural resource managers should be informed about climate change: • Constructive dialog regarding native fish consen-ation needs and drought and climate change should occur now; • Consen'ation planning should address climate change through adaptive management provisions; • Important fish populations should be replicated across the landscape when possible: • Important fish populations should be replicated in refuge populations; • Genetic information will be crucial to determine important populations; • Natural resource and land management agencies should begin work on identifying and creating potential refuge sites. Regular and systematic monitoring of important aquatic sites and fish populations, and expanded monitoring programs are essential to enhancing drought prerarcdness for fish conservation. Also, research focused on specific impacts of climate change in southeastern Arizona would be incredibly useful 10 managers. Lastly, th" uncertainty surrounding the timing and impacts of climate change requires flexibility and the need for adaptive management Agencies do not have a good track record of effectively implementing adaptive management, but the conservation of native fish and other aquatic wrtebrates requires it. References Cited Aquatic l'uisance Species lask Force. 1994. Report to Congress: Findings, conclusions, and recommendations of the intentional introductions policy rC'iew. Http;llnas.nfrcg.gov/iirpt.htm.53pp. Brown, T. J., B. L. Hall. and A. L Westerling. 2004. The impact of twenty-first century climate change on wildlife fire danger in the western United States: An spplications perspccth>e. Climatic Change 62:365-388. CONSERVATION 42 Sixth Conference on Research and Resource Management in the Southwest Deserts
  4. 4. Brown, D. P., and A. C. Comrie. 2004. Awinter precipitation 'dipole' in the western United States associated with multidecadal ENSO variability. Geophysical Research Letters 31. Garlln. G. 2005. Climate change in the Colorado River Basin. P. 36-44 in Colorado River Basin Climate: Paleo. Present. Future. at http://wwa.colorado.edu/ resourcesJcolorado_ri'er/Colorado_Ri'er_Basin~C1im ate.pdf Gray, S.T., J. L.Betancourt, C. L.Fastie. and S. T. Jackson. 2003. Patterns and sources of multid('(3dal oscillations in drought-sensitive tree-ring records from the central and southern Rocky Mountains. Geophysical Research Leners 30: I0.1 029/2002GLO 16154. Hereford, R.• It H. 'ebb, and S. Graham. 2002. Precipitation history of the Colorado Plateau Region. 1900-2000. USGS Fact Sheet 119-02 (http:"geopubs.,,'r.usgs.gov/fact-sheet/fs119-02/). IPCC (Intergovernmental Panel on Climate Change). 2001. Climate Change 2001: The scientific basis. Contribution of Working Group 1to the third assessment report of the intergo'ernmental Panel on Climate Change. Houghton. J. T.,Y. Ding. D. J. Griggs, M. Noguer, P. J. "'an der Linden, X. Dai, K. Maskell, and C. A. Johnson. «Is. Cambridge Univ. Press. Cambridge. United Kingdom and Ne..... York, NY. Jacobs, K. L.. G. M. Gartin, B.I. Morehouse. 2005. Climate science and drought planning: The Arizona experience. Journal of the American Water Resources Association 41:437-445. McCabe. G. j .• M. A. Palecki. and J. L. Betancourt. 2004. Pacific and Atlantic Ocean influences on multidecadal drought frequency in the United States. Proceedings of the National Academy of Sciences 101 (12):4136-4141. MacKenzie. D.• Z. Gedalof. D. L. Peterson. and P. Mote. 2004. Climatic change, wildlife. and conservation. Conservation Biology 18(4):890-902. Schneider, N., and B. D. Cornucllc. 2005. The forcing of the Pacific Decadal Oscillation. Journal of Climate 18:4355-4373. Sheppard, P. R., A. C. Comrie, G. D. Packin. K. Angersbach. and M. K. Hughes. 2002. The climate of the Southwest. Climate Research 21:219~238. Stewart. I. T., D. R. Caran. M. D. Dettinger. 2004. Changes in snowmelt runoff timing in western North American under a 'business as usual' climate change scenario. Climatic Change 62: 217-32. USGCRP (U.S. Global Change Research Program). 2001. Preparing for a changing climate: the potential consequences of climate variability and change- South,,·cst. A Report of the Southwest Regional Assessment Group for the U.S. Global Change Research Program. Institute for the Study of Planet Earth. Uni"ersity ofArizona. Tucson, 6Opp. Williams, J. E.• D. B. Bo,,'man. J. E. Brooks. A. A. Echelle. R. J. Ed..ards. D. A. Hendrickson, and J. J. Landye. 1985. Endangered aquatic ecosystems in North American deserts with a list of vanishing fishes of the region. Journal of the Arizona-Nevada Academy of Science 20: 1-62. Resumen: La conservaci6n de peces nativos en el surestI.' de Arizona ha sido sicmpre un asunto rclacionado con encontrar agua que no estc slendo "us.1da~ 0 tenga confliclos que haccn cl sitio indisponible. Ejemplos que causan a un sitio inapropiado 0 inusable para peces nativos son: pesca deportiva, aguas corrientes de baja calidad, peces no nativos y uso por ganado. La variabilidad c1imatica, es dccir.los cambios c1imaticos y la sequia tiencn eI potencial de aherar negativ3 )' dr.i5ticamente las actividadcs de conserv3ci6n para peces nath'Os. Adcffias de los impactos enlistados arriba, los impaetos multiples que fluyen de actividades humanas en eI sureste de Arizona tambien impactan las aguas. EI ultimo asunto que impacta las aguas para consen'3ci6n de peces nativos 10 conforman otras especies acuaticas raras en el sureste de Arizona (ranas r3nidas y una salamandra) tambien necesitan muchas de estas aguas. A!gunas especies de peces pueden no ser compatibles con otras especies acu31icas raras en algunos sitios. Los impactos potenciales del cambio c1imatico y la sequla nccesitan ser alcndidos par cl factor tiempo y la incertidumbre de los cfcclOS. Debe anadirse el principio preventivo a los planes de conservaci6n para peces nativos. Aunque puede no haber necesariamente soluciones a los problemas prcsentados por la sequla y los cambios c1imaticos. existen cosas que pucdcn hacerse para minimizar los impactos en peces nati'os del $Urestc de Arizona. Borders, Boundaries, and Time Scales 2006 43 CONSERVATION

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