During 1992-95, fish were sampled at 70 sites on 38 basin streams using seines and backpack and boat electrofishing methods (Figure Bc01). Sixty-one species were collected. Thirty-nine additional species have been collected during other surveys for a total of 100 species (Table Bc02; MDC 1995c). Grass carp (Ctenopharyngodon idella), creek chubsucker (Erimyszon oblongus), spotted bass (Micropterus punctulatus), warmouth (Lepomis gulosus), and redear sunfish (Lepomis microlophus) (Table Bc01) were collected outside of the range described by Pflieger (1975). Seven other species have distributions that overlap a portion of the basin (Pflieger 1975) but were not collected.
The entire basin lies within the Ozark Faunal Region (Pflieger 1989). During 1992-95, some of the most frequently collected fishes were typical Ozark species, such as smallmouth bass (Micropterus dolomieui), rock bass (Amploplites rupestris), longear sunfish (Lepomis megalotis), northern hogsucker (Hypentelium nigricans), black redhorse (Moxostoma duquesnei), greenside darter (Etheostoma blennioides), rainbow darter (Etheostoma caeruleum), Ozark minnow (Notropis nubilus), and striped shiner (Luxilus chrysocephalus).
Species diversity and number of Ozark species were lowest in lower Big River basin. Number of species was 47, 53, and 36 for upper (Big River RM 93-134 and tributaries), middle (Big River RM 59-93 and tributaries), and lower (Big River RM 0-59 and tributaries) basin streams, respectively. Number of representative Ozark species was 24, 25, and 21 for upper, middle, and lower basin streams, respectively. Negative effects of increasing urbanization surrounding lower basin streams may be responsible for their lower diversity.
Threatened and Endangered Species
Four species of concern are found within the basin. The crystal darter (Ammocrypta asprella) is on the State endangered list and was found in lower Big River (RM 1-8), but only by Pflieger (1975). The Missouri status of the Alabama shad (Alos alabamae) is rare and was infrequently sampled in Big River (RM 1-4). The western sand darter (Ammocrypta clara) is on Missouri's watch list and was found in lower Big River (RM 1-10). Silverjaw minnow (Ericymba buccata) distribution was scattered throughout Big River and lower portions of Calico Creek, Terre Bleue Creek, Flat River, and Salem Creek. It is on the State watch list, but was common where sampled.
Fish Introductions and Stockings
Rainbow trout have been stocked in Mill Creek by a private business in Cadet, MO, but the numbers and stocking frequency are unknown. Grass carp (Ctenopharyngodon idella), redear sunfish (Lepomis microlophus), and hybrid sunfish (species undetermined) are occasionally taken during sampling (unpublished data, K. Meneau, MDC) and are suspected to originate from overflow of private ponds.
Spotted bass were first collected in Big River by Mills et al. (1978), which was the first report of spotted bass in the Meramec River basin. Spotted bass were not collected again until 1987 (unpublished data, K. Meneau, MDC). Since then, spotted bass have greatly increased their numbers below RM 20 (becoming the dominant black bass) and expanded their range above RM 60. (unpublished data, K. Meneau, MDC). Also, genetic tests have revealed that some spotted bass/smallmouth bass hybridization has taken place (unpublished data, K. Meneau, MDC).
Spotted bass may have entered the Meramec River basin as a result of stockings in the Osage River basin before 1940 or in Missouri River tributaries in the 1960s (Pflieger 1975).
Big River offers a variety of game fish, with the most popular being smallmouth bass. Big River is ranked third in Missouri for providing Master Angler smallmouth. In 1992, MDC established a Stream Black Bass Special Management Area (SBBSMA; Figure Bc02) on Big River. During 1994 within the SBBSMA, electrofishing by MDC revealed good numbers of quality-sized fish (Figure Bc03). In MDC's 1995 creel survey, anglers reported catching 4,726 smallmouth bass including seven of Master Angler size, up to 24 inches.
Other popular Big River sportfish are: rock bass, channel and flathead catfish, sunfish, crappie, and suckers. Most rock bass and crappie are caught in spring. MDC sampling has shown good numbers of quality-sized rock bass (Figure Bc04). Though channel and flathead catfish angling effort is difficult to determine, catfishing peaks in summer with many anglers using set lines. Several large (15-25 lbs) flatheads are reported each year. Sunfish (longear and green sunfish and bluegill) angling is best from May to September. Sucker gigging is popular in late fall and early winter, especially above RM 46, where boat access, water clarity, and sucker habitat is best.
Fleener (1988) estimated that 44,008 fish (63% gigged suckers) were caught from Big River and the lower five miles of the Mineral Fork in 1979-80. In April-October, 1995, anglers caught an estimated 11,718 fish within the SBBSMA (unpublished data, K. Meneau, MDC).
Other basin streams with significant sport fisheries that are accessible to wade-anglers include: Mineral Fork, Fourche a Renault, Terre Bleue, Cedar, Clear, and Mill creeks.
Statewide fishing regulations apply to basin streams. The exceptions are black bass regulations within the Big River SBBSMA. The purpose of these regulations (listed below) are to produce more and bigger smallmouth bass, while attempting to reduce the number of slow-growing spotted bass.
Big River SBBSMA Black Bass Regulations
The SBBSMA consists of the Big River from the Hwy. 21 bridge (near Washington State Park) to it's confluence with the Meramec River and Mineral Fork from the Hwy. F bridge (Washington County) to it's confluence with the Big River. Within the SBBSMA the following regulations apply:
•Black Bass Daily Limit: six (6), only one (1) can be a smallmouth bass.
•Black Bass Length Limit: Largemouth bass = 12" minimum
•Spotted bass = no length limit
•Smallmouth bass = 15" minimum
Big River anglers support these regulations. MDC creel results show that 21% of anglers fished the SBBSMA more because of the regulations (unpublished data, K. Meneau, MDC). Four percent fished less and fishing effort was unchanged for 75% (unpublished data, K. Meneau, MDC). Some anglers asked for expansion of the Big River SBBSMA boundaries.
To help further reduce the spotted bass population within the Big River a change in regulations will take effect on March 1, 2002. On March 1, 2002, the daily limit for spotted bass will be twelve (12). The daily limit for largemouth bass will remain six (6) fish, and the daily limit for smallmouth bass will remain one (1) fish. Size limits will remain the same.
Big River has a diverse mussel community. Thirty-four species of mussels (Table Bc02) have been found within basin streams (Buchanan 1980; Ryckman et al. 1973). Three species are of special concern and were sampled only in lower Big River. The pink mucket (Lampsilis abrupta) is Federally-endangered, while the scaleshell (Leptodea leptodon) and spectaclecase (Cumberlandia monodonta) are listed as rare in Missouri. Ryckman et al. (1973) and Buchanan (1980) found that Big River provided favorable mussel habitat throughout its length, except for a 46-mile section (RM 62.7-108.7) which is adversely affected by mine waste. River bed substrate has been covered with fine sediment, eliminating mussel habitat in this reach.
The Big River basin contains eight species of crayfish (Table Bc03; Pflieger), including the belted crayfish (Orconectes harrisoni), which is found only in Missouri and almost exclusively in the St. Francois and Big River basins (one isolated Meramec River sample at the mouth of Big River). With the exceptions of the golden crayfish (Orconectes luteus) and the devil crayfish (Cambarus diogenes), all species are found only in Ozark streams.
The Big River basin benthos communities can be quite diverse (Ryck 1973; Kramer 1976; Duchrow 1976; MDC 1995d). Twelve orders, 55 families and 107 taxa of aquatic insects have been collected since 1976 (Table Bc04). Mayfly and stonefly nymphs were especially prevalent (Ryck 1973; Duchrow 1976), generally indicating good water quality. In places, benthos populations are seriously affected by lead and barite mine waste (Ryck 1973; Duchrow 1976; Kramer 1976). Duchrow (1976) found that invertebrates with exposed gills like dobsonfly (Nigronis serricornis) larvae may become extirpated if mine waste is present.