Since 1941, the fish communities at 48 localities in the Cuivre River Basin have been studied. Ten sites were surveyed in 1941, 13 from 1962 to 1967, 15 from 1978 to 1979 and 25 from 1986 to 1991 (Table Bc01, Figure Bc01). A total of 71 samples were collected. Collection data were summarized by time period. Time period I included the oldest collections, those made prior to 1946; time period II include samples taken from 1946 to 1970; and time period III or recent collections are those made after 1970. Fourteen sits were sampled in two or more time periods. In addition, creel survey data were collected by telephone from 1983 to 1988 (A. S. Weithman, MDC, unpublished).
In 69 of the 71 fish community samples, fish were captured with seines. Electrofishing equipment was used at three sites: site 4 in 1962 and sites 44 and 47 in 1990, in conjunction with seining. Only electrofishing equipment was used at site 48, on the Cuivre River in 1991. A fish toxicant was used once in conjunction with seining, at site 37 in 1967. Fisheries Management District 4 staff used seines with the following dimensions when making collections from 1989 to 1990; 6-by-4 feet with 1/8-inch mesh, 15-by-6 feet with 1/4-inch mesh and 25-by-8 feet with 1/4-inch mesh. A summary of seine sizes and other gear used at each site during this period (1989-1990) is given in Appendix B, Table 1. Seines were generally pulled through habitat types in an upstream direction or held around cover that was then disturbed to scare fish into the net. When the 1/8-inch mesh seine was used in riffles, it was held stationary and the substrate upstream from it was disturbed. At least two riffle/pool sequences were sampled at each site. The number of seine hauls at each site varied. Seining continued until a gallon jar of specimens was collected or no new species were observed. Large fish were identified and enumerated in the laboratory.
Seventy-one different fish species have been observed in the basin since the 1940s (Table Bc02). Investigators surveying the fish population collected 47 species in period I, 54 species in period II and 62 species in period III; altogether, 66 different species were observed. In addition, five other species were reported caught by anglers (A. S. Weithman, MDC, unpublished data), collected by Cuivre River State Park personnel (and verified) or were among dead fish observed in the Cuivre River after a major fish kill during 1992 (Duchrow 1992b). Fish distribution maps for each species collected by Fisheries Management staff, state park personnel (only one species) and earlier investigators are included in Appendix B. Distribution data obtained from the creel surveys and 1992 fish kill were not included because the original location of the fish could not be determined.
Fish fauna of the Cuivre River Basin is transitional in nature, having high proportions of Ozark and Prairie species. On the mainstem of the Cuivre River, 29 fish species were collected in period III. According to the faunal region classification of species as developed by Pflieger (1971), they could be described as 22% Prairie, 29% Wide-ranging, 20% Ozark, 10% Big River, 10% Ozark-Prairie, 6% Lowland and 2% Ozark-Lowland (Figure Bco2). In terms of numbers of fish represented in samples, Prairie fish accounted for 73% of all fish collected in the Cuivre River mainstem. The samples, however, were dominated by one extremely abundant Prairie species, the red shiner. It accounted for 66% of all fish caught in the mainstem. The red shiner is particularly tolerant of high turbidity and silty conditions which are typical of this section of the river.
The fish fauna of the Big Creek and Sugar Creek drainages, tributaries entering the Cuivre River downstream of the confluence of the West Fork and North Fork Cuivre rivers, differs from the mainstem by favoring Ozark species (Figure Bco2). In these tributaries, no one species totally dominates in abundance. Habitat conditions consisting of rocky substrates, clear water and cooler water temperatures support fish like the bigeye shiner, orangethroat darter, steelcolor shiner and striped shiner.
On the West Fork and North Fork Cuivre River drainages, numbers of Ozark and Prairie species are similarly represented; 29% and 31% were Ozark and 20% and 23% were Prairie, respectively in these streams. These subbasin differed in the relative abundance of fish present. The West Fork had numerous Wide-ranging fish and fewer Prairie fish while the North Fork had high numbers of Prairie fish and few Wide-ranging fish (Figure Bco3). In the West Fork no one species was strongly dominant, but in the North Fork the red shiner was extremely abundant. It accounted for 42% of the fish in the North Fork collections while contributing only 15% to the West Fork collections.
Basin-wide, the green sunfish was the most widely distributed fish in period III samples. It was observed at 98% of the 40 sites surveyed. The next most widespread fish were the orangethroat darter (88%), bluntnose minnow (88%), red shiner (85%) and redfin shiner (85%). Pflieger (1971) indicated that the green sunfish and bluntnose minnow were among ubiquitous fish in the state. The most abundant fish, the red shiner, accounted for 25% of the 37,177 fish collected in recent samples. It was followed in abundance by the redfin shiner (12%), bluntnose minnow (11%), bigeye shiner (9%) and orangethroat darter (6%).
Ten new species were found in the basin after 1970 (Appendix B, contact authors for Appendix B information). Seven of these species-- brook silverside, skipjack herring, silver chub, mimic shiner, bigmouth buffalo, stonecat and freckled madtom--were collected by field investigators from the larger reaches (fourth-order-and-larger) of the Cuivre River or its major tributaries. Two species--northern pike and bighead carp--were observed in 1992 among dead fish after a major fish kill on the Cuivre River. One species, pirate perch, was collected by State Park personnel while sampling Little Sugar Creek in 1983. The bighead carp is an exotic species from China that has recently been found in Missouri. Observations of the brook silverside and mimic shiner represent extensions in range from that reported by Pflieger (1975).
Although less dramatic, the steelcolor shiner, bluegill, mosquitofish, quillback, northern studfish and bullhead minnow appear to be more widespread than in the past (Appendix B, contact authors for Appendix B information). The increased prevalence of the bluegill and mosquitofish, quillback, northern studfish and bullhead minnow appear to be more widespread than in the past (Appendix B). The increased prevalence of the bluegill and mosquitofish is probably partly due to their introduction into ponds and sewage lagoons. The golden redhorse, blackside darter and white sucker appear to be less widespread than in the past (Appendix B).
Twenty-six intolerant species, species ver sensitive to changes in environmental condition, have been observed in the Cuivre River Basin (Table Bc02; W. L. Pflieger, MDC, unpublished data). Streams supporting the highest proportion of intolerant species during period III were the West Fork Cuivre River (38%), Sandy Creek (37%), North Fork Cuivre River (32%), Cuivre River (31%) and Bear Creek (30%) (Table 15, Appendix B; contact authors for Table 15 information). Streams showing the greatest number of intolerant species missing in period III (but found in period I or II) were Lead Creek and tributaries (6), Big Creek and tributaries (3), Mill Creek (3) and Elkhorn Creek (3) (Table 15). The disappearance of intolerant species from streams suggests a deterioration of their habitat quality. In addition, the Big Creek drainage also has two intolerant species of unknown status; the southern redbelly dace and banded sculpin were last found in period II but the areas where these fish were collected were not resampled in period III.
The ghost shiner, a species on the state watch list (a watch list designation is defined as not currently rare or endangered, but has a restricted distribution or has experienced sufficient decline to indicate it may soon become rare or endangered [MDC 1991a]), was found at nine sites along the mainstem portions of the Cuivre, the North Cuivre River and the West Fork Cuivre rivers, at or near localities where they were previously collected (Appendix B). During period III, the bluntnose darter and highfin carpsucker maybe have become extirpated in the basin (Table 15). They were not recollected in areas where they were previously observed (Appendix B). Pflieger (1975) indicated that these species have been declining in abundance for years.
Anglers can pursue eight species of game fish and a variety of other sport fish in the Cuivre River Basin. Game fish include smallmouth bass, largemouth bass, channel catfish, flathead catfish, black crappie, white crappie, walleye and white bass. Bluegill, common carp, freshwater drum and green sunfish are the most commonly sought after non-game fish. Black bass (largemouth and smallmouth bass) were widely distributed, occurring in nearly all major streams sampled (Appendix B). Channel catfish and crappie were less commonly found. However, they probably do occur in most streams with permanent pools of water. Flathead catfish and white bass were only collected from Cuivre River (Appendix B). No single game fish exceeded 1% of the total number of fish collected. This low estimate of abundance is not unusual for large fish such as they because they are not fully vulnerable to capture in a seine as adults. Walleye were not collected by field investigators in Cuivre River but were caught by fishermen during creel surveys. Walleye are found in the upper Mississippi River and probably travel up into the Cuivre River.
From 1983 to 1988, the Cuivre River annually supported an estimated 9,276 to 25,128 fishing trips. During this period, catfish were the most sought-after species by anglers. Catfish anglers accounted for 43% of all hours fished. On average 10,493 catfish, 8,905 sunfish, 3,561 crappie, 1,773 bass, 1,766 common carp, 1619 freshwater drum, 328 white bass and 79 walleye were harvested each year. The overall quality of the fishery was rated as fair by anglers (A. S. Weithman, MDC, unpublished data).
Grass carp, bluegill, largemouth bass, crappie, redear sunfish, channel catfish and mosquitofish often are stocked in lakes, sewage lagoons and ponds within the basin and probably enter streams during periods of high precipitation. Bait bucket releases also occur into streams.
Statewide fishing regulations apply to all streams in the basin. Special regulations (3CSR10-4.115) apply to fishing in public lakes managed by the MDC (see current Wildlife Code for more detail).
Sixteen mussel species are found in the Cuivre River Basin (Table Bc03; Oesch 1984; A. C. Buchanan, MDC, personal communication). Most species are commonly found; however, one species, the hickorynut, is on the state watch list. Although the streams in the basin are not open for commercial harvest operations, they do contain seven species--the mapleleaf, pimpleback, threeridge, Wagbash pigtoe, mucket, yellow sandshell and pocketbook--which are commercially important. Their shells may be used in the bottom, pearl or polished chip industry.
Native mussel populations may become threatened in the future if the zebra mussel, Dreissena polymorpha, a harmful European mussel recently detected in the Missouri portion of the Mississippi River, becomes overly abundant. This mussel is prolific and has the ability to adhere to almost any firm substrate and clog or smother objects. It could damage native mussel populations, water intakes, boat motors, aquatic habitats and the aquatic food chain (it removes significant amounts of phytoplankton from the water).
Five species of crayfish--northern crayfish (Orconectes virilis), golden crayfish (Orconectes luteus), papershell crayfish (Orconectes immunis), prairie crayfish, (Procambarus gracilis) and devil crayfish (Cambarus diogenes)--are found in the Cuivre River Basin (Pflieger 1987). The northern, golden and papershell crayfishes are primarily aquatic, while the
prairie and devil crayfishes live on land in burrows. Northern and golden crayfish were incidentally captured in our seine in our seine collections of stream fish. Crayfish distribution information from fisheries management personnel (Fisheries District 4, MDC, unpublished data) and Pflieger's collection (W. L. Pflieger, MDC, unpublished data) is summarized in Appendix C (contact authors for information from Appendix C).
Benthic invertebrates of the Cuivre drainage were studied by Duchrow (1974) to evaluate the effects of pollution and water quality. He collected invertebrate samples in 1969 and 1970 at 17 locations in the basin including the Cuivre River, Big Creek, North Fork Cuivre River, Sulphur Creek, Indian Creek, West Fork Cuivre River, Lead Creek, Elkhorn Creek, White Oak Creek and Hickory Creek. Duchrow used a species diversity index, "d", described by Wilhm (1967) and found that benthic invertebrate species diversity was low ("d" usually less than 3.0) and silt-intolerant species often were absent. He concluded that these conditions implied pollution. Siltation, organic pollution from agricultural operations and municipal sewage discharges were indicated as major problems in the basin.
Threatened and Endangered Species:
Sixteen sensitive plant and animal species are found in the Cuivre River Basin (Bogler and Nigh) 1986; MDC 1991a; MDC 1991b; Fisheries District 4, MDC, unpublished data; Reese 1986; J. Meyer, MDC, personal communication; A.C. Buchanan, MDC, personal communication; Table 11, contact authors for information from Table 11). The auriculate false foxglove (Tomanthera auriculata) is rare within the state and is candidate for federal listing. Of the remaining species, the black huckleberry and thread-like naiad are considered endangered within the state. Other Missouri rare species include the greater prairie chicken, four-toed salamander, star duckweed, wild sarsaparilla and prairie dandelion. Six species--the river otter, ringed salamander, ghost shiner, hickorynut mussel, heart-leaf plantain and adder's tongue fern--are on the Missouri watch list. Two plants, American pillwort fern and lance-like spike rush have undetermined status due to insufficient information. Five of the ten sensitive plants-- American pillwort fern, heart-leaf plantain, lance-like spike rush, star duckweed and thread-like naiad--require high moisture environments for their survival. They live in very damp areas or in water. The ghost shiner (watch list) is found in large rivers. It was recently observed in the mainstem of the Cuivre River, North Fork Cuivre and West Fork Cuivre rivers, (Appendix B, contact authors for information from Appendix B). The hickory mussel was observed by Buchanan (1992) in Cuivre River.
The river otter was reintroduced into the Cuivre River Basin as part of a statewide otter restoration project begun in 1982 (J. Meyer, MDC, personal communication). During 1986, 22 otters were released in the West Fork Cuivre River just north of Truxton and 23 otters were released in Argent Slough near the mouth of Cuivre River. The release program has been considered successful in Missouri. The status of the river otter has been declassified from rare in the early 1980s to watch list in 1991.