A LONG-TERM ANALYSIS OF FISH SPECIES PROPORTIONS IN SONOITA CREEK, ARIZONA Item Type text; Electronic Thesis Authors Wolsiffer, Sarah Kathleen Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 28/09/2021 04:52:54 Item License http://rightsstatements.org/vocab/InC/1.0/ Link to Item http://hdl.handle.net/10150/630269 A LONG-TERM ANALYSIS OF FISH SPECIES PROPORTIONS IN SONOITA CREEK, ARIZONA By SARAH KATHLEEN WOLSIFFER ____________________ A Thesis Submitted to the Honors College In Partial Fulfillment of the Bachelors Degree With Honors in Natural Resources THE UNIVERSITY OF ARIZONA M A Y 2 0 1 8 Approved by: ______________________________________ Dr. Peter Reinthal Department of Ecology and Evolutionary Biology Abstract Desert streams are unique and fragile ecosystems that are extremely sensitive to system changes. Dams and diversions, introduction of exotic species, global warming, and pollutant runoff from cities and mines are all anthropogenic changes to stream behavior that have resulted in low flow, increased competition, increased temperature, and higher concentration of pollutants. Sonoita Creek, Arizona has experienced all of these stressors and we examined if the native and exotic fish species composition has shifted and the potential roll of these stressors. This paper follows a 36-year (1991-2017) meta-analysis of the proportions of three primary native fish species found in Sonoita Creek; desert sucker, Pantosteus clarki, longfin dace, Agosia chrysogaster,and speckled dace, Rhinichthyes osculus, In the beginning of these surveys in 1991, longfin dace was highly dominant in the creek but decreased over time, likely due to a change in discharge. This analysis shows us that there is a definitive change in species composition. While the trend does provide insight into the stream status, further studies need to be done to determine what surrounding covariates are affecting these changes the most. Introduction Sonoita Creek is a perennial stream located in the Santa Cruz River watershed, Santa Cruz County, Arizona. Its headwaters are fed by groundwater from the Santa Rita Mountains and surface flow is supported by both ground water and treated municipal wastewater discharge. (Minckley 1968). Perennial flow originates just southwest of the city of Patagonia, continues approximately 6.5 miles to Patagonia Lake. It is shallow water and multiple environmental pressures make it a fragile, but important, ecosystem. There are currently four native fish in the creek; desert sucker, Pantosteus clarkia, longfin dace, Agosia chrysogaster, speckled dace, Rhinichthyes osculus, and Gila topminnow, 2 Poeciliopsis occidentalis (endangered). Three additional species, Sonora sucker, Catastomus insignis, Desert pupfish, Cyprinodon macularis, and Yaqui catfish, Ictalurus pricei, have also been recorded in the drainage. There are also seven invasive species present in the system including the yellow bullhead, Ameiurus natalis, largemouth bass, Micropterus salmoides, mosquitofish, Gambusia affinis, and the red shiner, Cyprinella lutrensis (Minckley 1968). Green sunfish, bluegills, and flathead catfish have all been introduced to Patagonia Lake and been known to escape into Sonoita creek from time to time. Little information is available in regard to the other components of the aquatic communities in Sonoita Creek. There are few aquatic plants in the stream as the river bottom is sandy and unstable. There are, however, groups of algae (Cladophora and Hydrodicyton), watercress sedges (Rorippa nasturtium-aquaticum), and spikesedge (Eleocharis radicans) that form along the banks. Invertebrates are equally understudied but an exhaustive sample made in 1968 showed that the most common invertebrates are “snails (Physa), damselfly larvae (Odonata), case- building caddisflies (Odontoceridae), belostomatids, and surface-dwelling bugs such as, gerrids, veliids, and microveliids, springtails (Collembola), and gyrinid beetles” (Minckley 1968). The overstory consists mainly of cottonwoods and willows. Water quality has varied greatly from year to year. In addition to the stressors of invasive species, Sonoita Creek experiences contaminant issues brought on by the Legacy Mines in the Patagonia Mountains (USDA 2016). One of the two mines was abandoned and the other was remediated in 1970 but continues to secrete an “orange sludge” into the surrounding streams (Gray 2017). Although the mining activities are confined to a relatively small area, their impacts are massive. Acid mine drainage and erosion of tailing deposits release dangerous chemicals and 3 metals, in essence toxins and poisons, into the surrounding environment (Swart 2013). The damage is variable from site to site, but aquatic systems are reported to be especially vulnerable (Salomons 1995). Discharge from the mine into nearby streams results in a series of bioaccumulation, where an animal is continually absorbing more contaminants into their system, and biomagnification, where predators receive a more concentrated dose of toxins from consuming their already affected prey. Both of these factors result in minimized reproductive success, increased illness, and eventually death (Chapman 1983). Copper and zinc, even in low concentrations are extremely toxic to fish. There have been cases where heavy metal contamination wiped out entire river ecosystems as seen in Pinal and Mineral Creek. In desert river ecosystems change in the chemical quality of the water is especially detrimental because the rivers are usually intermittent (Lewis & Burraychak 1979). Other Anthropogenic impacts on Sonoita Creek include the construction of Patagonia Lake. A dam was created in 1968 across Sonoita Creek to create what is now known as Patagonia Lake, located about 10 miles south of the town of Patagonia (Kupel 1995). This dam changed the natural course of the river and the stocking of sportfish into the lake introduced nonnatives into the system. According to Patagonia Lake State Park, large mouth bass, flathead catfish, channel catfish, crappie, bluegill, red ear and green ear sunfish are the current stock species of Patagonia Lake. Unfortunately these species can migrate upstream and live in the natural creek. Competition for the limited resources in this desert stream grew with the introduction of nonnatives, who were both competitors with and predators of native fishes. Treated effluent is also added from the Patagonia sewage treatment plant into one portion of Sonoita Creek, which has an impact on water quality. Each of the 46 testing sites along the creek 4 had at least one toxic element that either equaled or exceeded the concentration allowed to adhere to the Drinking Water Standard. Cadmium (Cd) was in 30 of these sites, Copper (Cu) was in 21 of the them, Lead (Pb) in 14, Arsenic (As) in 12, and Flouride (F) in eight (ADWR 2000). Since the founding of Patagonia in 1896, Sonoita Creek has experienced vast changes in physical and organism composition (Kupel 1995). As the population around the stream increases, heavier impacts is made. Impacts such as lower water quality, higher abundance of invasive fish species, changes in river discharge and sinuosity, all affect the native fish populations. The purpose of this paper is to analyze long-term (26 years 1991-2017) trends of fish populations in Sonoita Creek. Comparing long-term data sets will help us see how populations are responding to these impacts on an ecological timescale. This 26-year data analysis will create a timeline of cause and effect and provide a projection for future populations based on upcoming changes. Methods 1991-1999: Fish surveys were taken along Sonoita Creek at 4-8 predetermined sites depending on the year; 1991-1994 had four sites, 1995 had five sites, 1996 had eight sites, and 1997-2000 had seven sites. Each site length varied from 10-60m and was divided up into approximately 10m sections with a specific habitat type (either a run, riffle or pool). Each section was then seined until depletion which was anywhere from 1-13 passes. Because the data was unevenly collected, we cannot make direct comparisons in population estimates with current data. We can, however, compare relative species porportions. 2000-2002: Fish surveys were taken along Sonoita Creek at four predetermined sites. Site 1 is located just 400 m upstream of Patagonia Lake. Site 2 is located at Circle Z Ranch where grazing and 5 other human modifications take place. Site 3 is a road crossing where the Patagonia-Sonoita Creek Preserve, run by the TNC, meets Circle Z Ranch. Site 4 is located on the TNC property perpendicular to their parking lot. In 2000, sites 1-4 were surveyed in June and September. In 2001, sites 1-4 were surveyed in February/March, July, and November/December. In 2002, sites 1-4 were surveyed in August. Each site was separated into two 100m sections. Each section went through a three-pass capture and removal depletion sampling using an electroshocking backpack with similar Catch per Unit effort per pass. Each fish caught was categorized by species and size. Using Zippin’s Total Removal Estimate method we estimated population abundances. Fish surveys were taken along Sonoita Creek at Sites 1 and 4 in 2017 using the same methodology as the previous