Borders, Boundaries, and Time ScalesFronteras, Limites, y Escalas de Tiempo

Proceedings of the Sixth Conference on Research andResource Management in the Southwestern Deserts

Extended Abstracts: December 2006

Bill Halvorson, EditorUSGS Southwest Biological Science CenterSonoran Desert Research Station

MAR - 1 2007

Native Fish Conservation and Climate Variability inSoutheastern Arizona.

Doug Dunam' and Cregg Garfirl. 'U.S. Fisll 6- WildlifeXn';ct; ~CLJMj£,S- University 0/Arizona

The conservalion of nati,'c fish in southeastern Arizonahas always been reliant on finding waler that isn't "used," orthat is not constr.'lined by conflicts thai make sitesunavailable. Examples of conflicts that may render a siteunsuitable 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 multipleimpacts flowing from other human activities insoutheastern Arizona also impacl ,,'aters. Another issueimpacting waters for native fish conservation is that otherrare aquatic species in southeastern Arizona also needmany of these \valers. Some fish species arc not compatiblewith other aquatic species in some sites. Climate variability,including drought, and climate change both have thepotential to al!<'T sitrs for conservation of native fishes insoutheastern AriZOna.

Here we consider southeastern Arizona that area east oflhe Tohono O'odham Nation and the lower-most (north)Santa Cruz River, and south of the Gila River. This areaincludes 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 areextirpated, and one is extinct. There are 13 species listedunder the Endangered Species Act; nine arc listed asendangered, four as lhreatened, and an additional specieshas been petitioned for listing.

There are a multitude of issues facing native fish in thestudy area. Threats that have been factors in the listing offish and continue today include the standard litany:nonindigenous species. species' habitat loss, and reductionin habitat quality. Habitat destruction and the introductionof nonindigenous species are responsible for the decline of98 percem of North American fishes listed as endangered,threatened, or of special concern (Williams et al. 1985).Impacts to habitat and impacts from non indigenousspedes do not occur independently. Degradation of aquaticS)'Stems is a major faclor in the invasion, establishment.and irruption of nonindigenous species (Aquatic NuisanceSpecicsTask Force 1994).

Though the discussion here centers on native fish, it islikely that negative impacts could also occur to olher nativeaquatic vertebrates. There are three native ranid frogs(Rana spp.) and a native salamander (Ambysroma tigr;l1l1msrrbbet,sj) in southeastern Arizona. There are also severalgarter snakes (11lamnoplJis spp.). All arc of conservationconcern. The single greatest difference in how impacts to

aquatic systems will impact nati\'e fish or herpetofauna, isthat the herpetofauna are far more mobile than fish and atleast ha\'c the potential to move between aquatic s}'Stems.

That southeastern Arizona and much of the AmericanSouthwest are in drought is well known. What is knownwith far less certainty is how long this drought mightlasl.Currently, only seasonal drought predictions are availablefor three-month seasons (e.g.• February·Apri1), at a leadtime of two weeks in advance (e.g., issued January 15).These predictions. based on a subjecti\'e combination ofresults of statistical and dynamical climale models andinsights from past climate history, are a\'3ilable through theNOAA Climate Prediction Center. State-of-the-art climatescience does not yet support multi-year or decade-scaledrought predictions. However, instrumental andpaleoclimate records from the South\\'est indicate that theregion has a history of multi-year and multi-dCCldedrought (Hereford el al. 2002; Jacobs et a!. 2005; Sheppardet oIl. 2002). Multi-decade drought in the South\\'est iscontrolled primarily by persistent Pacific Ocean­atmosphere interactions. which have a strong effect onwinter precipitation (Brown and Comrie 2004; Schneiderand Cornudle 2005); persistent Atlantic Ocean circulationis theorized to ha\'e a role in multi-decadal drought in theSouthwest, particularly with respect to summerprecipitation (Gray et al. 20CB; McCabe et al. 2(04). Giventhese multi-decade "regimes" of ocean circulation. and theseverity and persistence of the present multi-rear drought,there is a fair likelihood that this droughl will persisl formany more years. albeit with periods of high rear-to·yearprecipitation variability characteristic of Southwest climate.

The information on how climate change might impactsoutheastern Arizona is less certain than currenl droughtpredictions. Howevcc, virtually all climate change scenariospredict that the American Southwest will get \\'3rmerduring the 21st century (lPeC 2001). Precipitationpredictions show a greater range of possibilities, dependingon the model and emissions scenario (USGCRP 2001). Tomaintain the present water balance with warmerlemperatures and all other biotic and abiotic factorsconstant, precipitation will need to increase to keep pacewith the increased evaporation and transpiration caused by\\'3rmer temperatures. Key projections 10 keep in mindinclude:

• decreased snowpack - an increasing fraction ofwinter precipitation could fall as rain instead of snow,periods of sl10wpack accumulation could be shorter,and snowpacks could be smaller; ironically, due tochanges in snow-precipitation characteristics. runoffmay decrease e\"Cn if total precipitation increases(Gamn, 2005);

Borders, Boundaries, and TIme Scales 2006 41 CONSERVATION

• earlier snowmelt - increased minimum winter andspring temperatures could melt snowpacks sooner,causing peak water flows to occur that much soonerthan the historical spring and summer peak flows(Stewart et aI., 2(04);

• enhanced hydrologic cycle - in a warmer \,rorld anenhanced hydrologic cycle is expected; flood extremescould be more common causing more large floods;droughts may be more intense. frequent, and longer­lasting.

Continuing drought and climate change, when addedto the historical and continuing threats, will make nativefish conservation in southeastern Arizona even moredifficult. The impact to fish of site desiccation is obvious.There are many less obvious effects that could occur withdrought and a wanner climate. A site with reducedstr~mf1ow, or a pond or pool with low water levels couldbecome fishless due to reduced dissoh-ed oxygen. We hawset"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 impactwatersheds and subsequently the water bodies in thosewatersheds. Drought, and especially long-term climalechange will impact how ecosystems and watershedsfunction. These changes will cause a cascade ofecosystemchanges, which may be hard to predict and are likely tooccur non-linearly.

As an example. drought and climate change will causechanges in fire regimes in all southeastem Arizonavegetation communities. The timing, frequency. extent, anddestructiveness of wildfires is likely to increase and mayalso facilitate the invasion and increase of nonindigenousplants. These changed fire regimes will change vegetationcommunities, the hydrological cycle, and nutrient cyclingin affected watersheds (Brown ct OIL 2004). Some regionalanalyses conservatively predict that acreage burnedannually will double with climate change (MacKenzie el a1.2004). Such watershed impacts could cause enhancedscouring and sediment deposition, more extreme flooding(quicker and higher peak flows), and changes to waterquality. ) Severe watershed impacts such as these, \\'henadded to reductions in e~1ant aquatic habitats. will severelyrestrict sites ll\'ailable for the consenration of nati"e fishand other aquatic vertebrates and make management ofextant sites more difficult.

Many of the predictions about the impacts of climatechange arc based on modcling. but man}' predictions havealready occurred. The tree die-offs and fires that haveoccurred in the Southwest early in this century shO\\' theimpacts of the curren! drought.

The potenlial impacts from climate change and droughtneed to be addressed, while considering the potentialduration of and uncertainly of their effects. The

precautionary principle should be adhered to whenplanning for native fish conservation. While there may notnecessarily be solutions to the problems presented bydrought and climate change, there are things that can bedone to minimi7-c the impacts to native fishes and increasethe resilience of fish habitat in southeastern Arizona.

After the fires of 2005, the Ari7.0na Game and FishDepartment and U.S. Fish and Wildlife Service begandrafting a salvage protocol for native fish. This protocolshould be expanded to include any impacts to nati\>e fish,such as drought and climate change, invasion ofnonindigenous species, and release of em'ironmentalcontaminants.

We recommend the following actions:

• Natural resource managers should be informed aboutclimate change:

• Constructive dialog regarding native fish consen-ationneeds and drought and climate change should occurnow;

• Consen'ation planning should address climate changethrough adaptive management provisions;

• Important fish populations should be replicated acrossthe landscape when possible:

• Important fish populations should be replicated inrefuge populations;

• Genetic information will be crucial to determineimportant populations;

• Natural resource and land management agenciesshould begin work on identifying and creatingpotential refuge sites.

Regular and systematic monitoring of importantaquatic sites and fish populations, and expandedmonitoring programs are essential to enhancing droughtprerarcdness for fish conservation. Also, research focusedon specific impacts of climate change in southeasternArizona would be incredibly useful 10 managers. Lastly, th"uncertainty surrounding the timing and impacts of climatechange requires flexibility and the need for adaptivemanagement Agencies do not have a good track record ofeffectively implementing adaptive management, but theconservation of native fish and other aquatic wrtebratesrequires it.

References CitedAquatic l'uisance Species lask Force. 1994. Report to

Congress: Findings, conclusions, andrecommendations of the intentional introductionspolicy rC\'iew. Http;llnas.nfrcg.gov/iirpt.htm.53pp.

Brown, T. J., B. L. Hall. and A. L Westerling. 2004. Theimpact of twenty-first century climate change onwildlife fire danger in the western United States: Anspplications perspccth>e. Climatic Change 62:365-388.

CONSERVATION 42 Sixth Conference on Research and Resource Management in the Southwest Deserts

Brown, D. P., and A. C. Comrie. 2004. A winterprecipitation 'dipole' in the western United Statesassociated with multidecadal ENSO variability.Geophysical Research Letters 31.

Garlln. G. 2005. Climate change in the Colorado RiverBasin. 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.pdfGray, S.T., J. L.Betancourt, C. L.Fastie. and S. T. Jackson.

2003. Patterns and sources of multid('(3dal oscillationsin drought-sensitive tree-ring records from the centraland southern Rocky Mountains. Geophysical ResearchLeners 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 200 1: The scientific basis.Contribution of Working Group 1to the thirdassessment report of the intergo\'ernmental Panel onClimate 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 Arizonaexperience. Journal of the American Water ResourcesAssociation 41:437-445.

McCabe. G. j .• M. A. Palecki. and J. L. Betancourt. 2004.Pacific and Atlantic Ocean influences on multidecadaldrought frequency in the United States. Proceedings ofthe 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 ofthe Pacific Decadal Oscillation. Journal of Climate18:4355-4373.

Sheppard, P. R., A. C. Comrie, G. D. Packin. K.Angersbach. and M. K. Hughes. 2002. The climate ofthe Southwest. Climate Research 21:219~238.

Stewart. I. T., D. R. Caran. M. D. Dettinger. 2004.Changes in snowmelt runoff timing in western NorthAmerican under a 'business as usual' climate changescenario. Climatic Change 62: 217-32.

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Resumen:

La conservaci6n de peces nativos en el surestI.' deArizona ha sido sicmpre un asunto rclacionado conencontrar agua que no estc slendo "us.1da~ 0 tengaconfliclos que haccn cl sitio indisponible. Ejemplos quecausan a un sitio inapropiado 0 inusable para peces nativosson: pesca deportiva, aguas corrientes de baja calidad, pecesno nativos y uso por ganado. La variabilidad c1imatica, esdccir.los cambios c1imaticos y la sequia tiencn eI potencialde aherar negativ3 )' dr.i5ticamente las actividadcs deconserv3ci6n para peces nath'Os. Adcffias de los impactosenlistados arriba, los impaetos multiples que fluyen deactividades humanas en eI sureste de Arizona tambienimpactan las aguas. EI ultimo asunto que impacta las aguaspara consen'3ci6n de peces nativos 10 conforman otrasespecies acuaticas raras en el sureste de Arizona (ranasr3nidas y una salamandra) tambien necesitan muchas deestas aguas. A!gunas especies de peces pueden no sercompatibles con otras especies acu31icas raras en algunossitios. Los impactos potenciales del cambio c1imatico y lasequla nccesitan ser alcndidos par cl factor tiempo y laincertidumbre de los cfcclOS. Debe anadirse el principiopreventivo a los planes de conservaci6n para peces nativos.Aunque puede no haber necesariamente soluciones a losproblemas prcsentados por la sequla y los cambiosc1imaticos. existen cosas que pucdcn hacerse paraminimizar los impactos en peces nati\'os del $Urestc deArizona.

Borders, Boundaries, and Time Scales 2006 43 CONSERVATION