Fish community data were collected by Missouri Department of Conservation (MDC) staff from 42 sites throughout the basin during 1988-1989 (Table Bc01). Fish were collected using a seine 15 or 25 feet long with 1/8" mesh . Kick seine methods were used to sample riffles. A boat-mounted electrofishing unit was used where possible to sample deep pools. Large fish were identified on site and returned to the water. Small fish were preserved and later identified in the lab. Data collected prior to 1988 were obtained from the MDC database (Pflieger, unpublished).
A total of 63 fish species from 13 families has been collected in the Fabius River basin (Table Bc02). Fifty-eight species and several Lepomis hybrids were found in recent surveys. From a basin-wide perspective, the community includes fishes representative of the Prairie, Lowland, Ozark, and Big River faunal regions. According to Pflieger (1971), one-third are wide-ranging, 17% are Big River species, 27% are Prairie species, 27% are Ozark species, and 9% are representative of the Lowlands. Several species are associated with more than one faunal region, so the sum of these percentages exceeds 100%. Six species associated with both Prairie and Ozark streams accounted for 6.5% of the total number of fish collected in 1988-1989.
The dominant fish families were the minnows (Cyprinidae, 20 species), perches (Percidae, 9 species), sunfishes (Centrarchidae, 7 species), suckers (Catostomidae, 7 species), and catfishes (Ictaluridae, 7 species). The most common and abundant species collected in recent surveys was the red shiner (Cyprinella lutrensis), which comprised 31 to 38% of the total sample in each sub-basin and occurred at 95% of all sites. The bluntnose minnow (Pimephales notatus) was the second most abundant species, comprising 11 to 20% of the total sample in each sub-basin and occurring at 86% of all sites.
Other commonly occurring species (found in at least 60% of all sites) included quillback (Carpiodes cyprinus), creek chub (Semotilus atromaculatus), bigmouth shiner (Notropis dorsalis), sand shiner (Notropis stramineus), central stoneroller (Campostoma anomalum), johnny darter (Etheostoma nigrum), green sunfish (Lepomis cyanellus), and orangespotted sunfish (Lepomis humilis).
Sport fish (16 species that provide angling opportunity) comprised 10% of all fish collected in basin streams. Due to their large size, these fishes were under-represented numerically because they were not fully vulnerable to our sampling gear. Green sunfish were the most abundant species in this group and were found at nearly all sample sites. Channel catfish (Ictalurus punctatus), the most popular game species in the basin, were found at 38% of the sites, but accounted for fewer than 1% of the total fish collected. Smallmouth bass (Micropterus dolomieu) were also collected at 38% of the sample sites and were more than twice as abundant as largemouth bass (M. salmoides). Bullheads (Ameiurus spp.), bluegill (Lepomis macrochirus), carp (Cyprinus carpio), and white crappie (Pomoxis annularis) were abundant in parts of the basin as well. Limited age and growth data for bluegill, white crappie, smallmouth bass, largemouth bass, channel catfish, and flathead catfish (Pylodictis olivaris) are available from the Missouri Department of Conservation, Hannibal, Missouri.
Five species found in the basin prior to 1988 and not found in recent surveys include the striped shiner (Luxilus chrysocephalus), last collected in 1941; Mississippi silvery minnow (Hybognathus nuchalis), last collected in 1941; American eel (Anguilla rostrata), last collected in 1975; blackstripe topminnow (Fundulus notatus), last collected in 1941; and logperch (Percina caprodes), last collected in 1979. Striped shiners and Mississippi silvery minnows have been extirpated from the basin. Similar declines of these two species have occurred in other northeastern Missouri streams, including the Mississippi River (Pflieger 1975, Hrabik 1992). Reasons for the declines are not well understood; however, these species prefer clear water and seem intolerant of high turbidity (Pflieger 1997). Logperch also avoid continuously turbid or silty streams.
Species collected in 1988-1989 that were not found by previous investigators include the goldeye (Hiodon alsoides), speckled chub (Extrarius aestivalis), channel shiner (Notropis wickliffi), spotfin shiner (Cyprinella spiloptera), mosquitofish (Gambusia affinis), and the western sand darter (Ammocrypta clara). With the exception of the western sand darter, these species are tolerant of high turbidity. One western sand darter was collected from a site in the Middle Fabius River.
The South Fabius sub-basin yielded the most species (49), followed by the Middle Fabius (43), and North Fabius (40). Thirty-five species were collected from a single site on the Fabius River. The proportions of species associated with each faunal region were similar for the three main sub-basins. The most apparent difference between the sub-basins was that Ozark species were generally more abundant and widely-distributed in the Middle and South Fabius drainages than in the North Fabius sub-basin. Less of the North Fabius sub-basin lies in the region of thin till and exposed rock than the other two sub-basins, and it has been more severely degraded.
Fish Contamination Levels and Health Advisories
Fish from the basin have not been tested for contaminants and no health advisories have been issued specifically for the basin. However, the Fabius River basin is included in the limited consumption advisory (one pound per week) for fatty fish (e.g. catfish, carp, buffalo, drum, suckers, paddlefish) for all of Missouri outside of the Ozark region
Aquatic Invertebrate Communities
Limited mussel surveys have been conducted in the basin. Buchanan (1992) surveyed the North, Middle, and South Fabius rivers in 1991 while determining the status of the endangered winged mapleleaf (Quadrula hagosa). He reported 24 mussel species from the basin (Table Bc03). In limited crayfish surveys, only two species have been recorded (golden crayfish, Orconectes luteus and northern crayfish, Orconectes virilis; Missouri Department of Conservation records, S. Bruenderman, personal communication). Other species are likely to occur in basin streams.
The Missouri Department of Natural Resources initiated a quantitative study of aquatic insects in reference streams throughout the state in 1992. The Middle Fabius River was surveyed in 1993 (C. Rabeni, Missouri Cooperative Fish and Wildlife Research Unit, personal communication). Seventy genera representing seven orders were collected (Table Bc04).