A Fish Distribution Study of the Blue and San Francisco Rivers, Arizona By, Tim Hurst & Dr

A Fish Distribution Study of the Blue and San Francisco Rivers, Arizona by, Tim Hurst & Dr. W. L. Minckley Abstract Eastern fish, which thrive on competition, are widely introduced into altered western streams. The extirpation, and in some cases, the extinction of many native Arizona fish has occurred. Therefore, the continued conservation of western native freshwater fish is extremely important. An examination of fish distributions on the Blue and San Francisco Rivers in southeastern Arizona, from collections made from June of 1994 to July of 1995, was made. This study consists of several steps, a description of fish found in abundance in the region, graphs showing the potential interactions that may be occurring between the different species, a visual perspective as to where the different species of fish are using a mapping program called GIS (Geographical Information System), and finally, an examination of the data in context to draw conclusions as to what kinds of interactions may be occurring. Introduction & Methods Western North American freshwater fish are different then those in the east. Habitats in the east are much more connected, therefore more biodiversity exists. There are as many as 600 species of fish in the east. In sharp contrast to only 200 or so species in the west. The low diversity in the west makes fishes a high priority for conservation. For example, according to Dr. W. L. /vfmckley's and James E. Deacon's book Battle Against Extinction (1991), almost half of all fish species (-122) listed by the U.S. Fish and Wildlife Service as threatened or endangered, or being considered for listing, are west of the continental divide. Why such a difference? Eastern fishes are "specialists" that thrive despite competition for space and food. Western fishes, in contrast, are "generalists" that usually live in well defined niches and are poor competitors. Western fish are more adapted to high variance systems (high altematly with low runoff in streams). Introduced eastern fishes cannot tolerate high flow periods and are often flushed downstream. This downstream flushing no longer occurs in many western streams since man's building of dams and other structure that stabilize flow. What has been created is a more connected habitat, ideal for eastern fishes, such as rainbow trout (Oncorhynchus mykiss), channel catfish (Ictalurus punctatus), and others in western streams. Unaltered streams such as the Blue River in eastern Arizona, are, however, largely unaffected by non-native introductions because frequent flooding events prevent there persistence in the system. In contrast, streams such as the Lower Colorado River, dubbed by many to be one of the most altered streams in North America, supports substantial populations of non-native fish. In other words, it is not only that non-native fishes have been introduced into western streams, we have created more habitat for their continued existence at the expense of natives. Non-native fish are now out-competing natives for both food and space, in many streams, a major reason why many native western fish are on the brink of extinction. This study focuses on the types of native and non-native fishes in one particular area of Arizona, the Blue and San Francisco rivers. These rivers are located in Greenlee county, near the mining towns of Clifton and Morenci. The Blue River's headwaters start in New Mexico and flow into Arizona into and through its mouth at the San Francisco River. This unaltered, remote stream flows through canyons and recieves many tributaries. Five species of native fish can be found in abundance. They include longfin dace (Agosia chrysogaster), speckled dace (Rhinichthys osculus), Sonoran sucker (Catostomus insignis), desert sucker (Pcmtosteus cicrrki), and loach minnow (Tiaroga cobitus). Both Gila trout (Oncorhynchus gilae) and Apache trout (Oncorhynchus apache) were found there historically. While non-native fish such as rainbow trout (Oncorhynchus mykiss) and red shiner (Cyprinella lutrensis) were collected in recent years, they were not abundant. Abundance of non-natives in the San Francisco River, however, is a different matter. The San Francisco River has its headwaters flowing from Arizona into New Mexico and back into Arizona in Greenlee county. With its deeper pools, it supports a fairly large population of non- native fishes. For example common carp (Cyprinus carpio) and flathead catfish (Pylodictis olivaris) were collected or seen in abundance, especially in the deeper pools. This river is less remote than the Blue and more altered by humans. This study places collections of fish made on the Blue and San Francisco Rivers in perspective by looking at several parameters. Collections were made from June 1994 to July 1995, starting from Raspberry Creek on the Blue River to its confluence with the San Francisco River and onto the western Forest Service border. Collectors included Paul Marsh, Brian Bagley, Tim Hurst, Terry Inman, Glen Knowles, and others from the Apache Sitgraves United States Forest Service office. This was done using a Smith-Root model 15-A gasoline powered backpack electrofisher and, on rare occasions, a 6 by 4 feet 1/8 inch mesh nylon seine. The number of each species of fish were tabulated and habitat data recorded for each locality sampled. I took these data and examined it relative to several parameters. First, described are the types of fish found in abundance. Second, I prepared three tables and graphs that depict some of potential interactions that many occur between different species. From these data, I computed drawn correlation coefficients. Third, localities were mapped on a Geographical Information System (GIS) using Arc Info and Arc View. This allows us an accurate visual perspective onto where certain species of fish were found. Finally, I described why the apparent interactions may be occurring. I must, however, stress the limitations of the data that is being presented. Different localities received different amounts of electrofish shocking time (minutes of electroshocking). Therefore, fish abundances at certain localities many be greater then was accounted for. Also, many statisticians may not think that the correlation coefficients found in this region are substantial, but we must realize that we are dealing with a western stream that already does not have a whole lot of competition. For this reason, I am taking correlation coefficients a lot lower then if! were dealing with a more congenial habitat. Description of Fish Found in the Blue River, the San Francisco River, and Selected Tributaries Native Fish Longfin Dace (Agosia chrysogaster) Longfin dace are small fish that rarely exceed 100 mm in length and generally live at elevations below 1,500 meters. They live in sandy bottomed desert streams to clear cooler streams in conifer zones (Minckley, 1973). The adaptability of this fish allows it to live in a wide range of temperature extremes. For example, they have been found living with desert pupfish, who are already quite tolerant to high temperatures. These night feeding opportunistic omnivores eat algae, detritus, and aquatic insects (Kepner, 1982). Potential interactions may occur with speckled dace (Rhinichthys osculus) and loach minnows (Tiaroga cobitis) (Rinne, 1992). The red shiner (Cyprinella lutrensis), an introduce non-native bait fish, is believed to directly effect the number of longfin dace, due to competition (Jalde et al, 1991). Spawning generally occurs from December to July and is often correlated with flooding events and the biannual rain pattern (Kepner, 1982). It is currently listed as a Candidate 2 species by the U.S. Fish and Wildlife. Speckled dace (Rhinichthys osculus) Speckled dace are a small fish that usually reach 45 to 63 mm in length and live from 3 to 4 years (Addley, 1994 and John, 1964). It is generally found in headwater streams at elevations ranging from 2,000 to 3,000 meters. Speckled dace live in swift flowing pool and riffle creeks in water that is usually less then 0.5 meters deep. This fish is unique because it is the only native fish to be found in all seven freshwater drainages in the western United States. Like the longfin dace, they are opportunistic omnivores feeding generally on algae, detritus, and smaller aquatic invertebrates (Minckley, 1973). These feeding habitats are believed to strongly overlap with that of desert suckers (Pcmtosteus clarki) (Fisher et al, 1981). In addition, many non-native fish, such as red shiners (Cyprinella lutrensis) and rainbow trout (Oncorhynchus mykiss), are believed to compete directly with speckled dace for food (Joseph et al, 1977). Spawning generally occurs during the spring and late summer. Spawning appears to be induced by and increase in water temperature, day length, and spring runoff (John, 1964). Sonoran Sucker (Catostomus insignis) This large native sucker fish can reach lengths of 800mm and is found at elevations ranging from 300 to over 2,000 meters (IVfmcIdey, 1973). They generally inhabit shallow swift waters as juveniles and migrate to deeper calm waters as adults (Clarkson, 1982). They usually eat algae, aquatic invertebrates, and sometimes even seeds. Spawning generally occurs in late winter to early spring (Minckley, 1973). They are often found in close interaction with desert suckers (Pantosteus clarki) and will occasionally hybridize with them (Clarkson & Minckley, 1988). Desert Sucker (Pantosteus dark) Desert suckers are a medium sized sucker fish that reach from 100 to 280 nun in length at maturely (vfmcIdey, 1973). They can be found in riffles and often migrate to protected areas near boulders and "large adults frequent strongly flowing, deeper waters near undercut banks." Thus, desert suckers live in similar habitats to Sonoran suckers (Catostomus insignis) (Schreiber & Minckley, 1981). However, they eat more vegetative material than Sonoran suckers, feeding primarily on algae and other aquatic plants (Amine, 1969). Their range can overlap with longfm dace (Agosia chrysogaster), loach minnows (Tiaroga cobitus), and speckled dace (Rhinichthys osculus), but they are rarely preyed upon by other fish (Fisher et al, 1981 & Rinne, 1992).

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