Fish Populations, Following a Drought, in the Neosho and Marais des Cygnes Rivers of Kansas Part 10

The mimic shiner, spotted ba.s.s, smallmouth, and fan-tailed darter are characteristic of upstream habitats with clear water (tributaries, rather than the mainstream), and were taken in the Neosho River only in 1957 or became less abundant from 1957 to 1959.

The silver chub, slender madtom and tadpole madtom were taken in the Marais des Cygnes River only in 1957 and were not taken in the Neosho River.

The following species, common to both rivers, were more abundant in the Neosho: long-nosed gar, short-nosed gar, river carpsucker, creek chub, sucker-mouthed minnow, red-finned shiner, red shiner, ghost shiner, blunt-nosed minnow, fat-headed minnow, stoneroller, yellow bullhead, channel catfish, flathead, stonecat, largemouth, long-eared sunfish, slender-headed darter, and freshwater drum. These species, collectively, reflect the more diversified habitats (more gravel-bottom, more riffle-areas, more gradient, greater range of stream-size sampled) in the Neosho River.

The following species, common to both rivers, were more abundant in the Marais des Cygnes: gizzard shad, carp, sand shiner, black bullhead and white c.r.a.ppie. These species (with the exception of sand shiner) emphasize the fact that the Marais des Cygnes is a sluggish stream with large areas of mud bottom. Differences in the abundance of the sand shiner in the two rivers are part of taxonomic and distributional studies being conducted by Mr. Bernard C. Nelson.

The following species were not consistently more abundant in one river than the other: big-mouthed buffalo, black buffalo, small-mouthed buffalo, short-headed redhorse, green sunfish, orange-spotted sunfish and orange-throated darter. These species, excepting the orange-throated darter and short-headed redhorse, occurred in a wide variety of habitats.

FAUNAL CHANGES, 1957 THROUGH 1959

The following species increased in abundance from 1957 to 1959 (Tables 10 and 11): long-nosed gar, short-nosed gar, river carpsucker, creek chub, gravel chub, sucker-mouthed minnow, mountain minnow, blunt-nosed minnow, parrot minnow, stoneroller, stonecat, Neosho madtom, green sunfish, slender-headed darter, and orange-throated darter.

These species can be separated into three groups, characteristic of different habitats but having in common a preference for permanent flow.

One group, composed of long-nosed gar, short-nosed gar, river carpsucker, gravel chub, mountain minnow, parrot minnow, and Neosho madtom, prefers streams of moderate to large size.

A second group composed of creek chub, sucker-mouthed minnow, stoneroller, and orange-throated darter occurs most abundantly in small, permanent streams. The green sunfish may be included here on the basis of its abundance at the upper Neosho station; however, this is a pioneer species and does not require permanent flow.

The third group is characteristic of continuously flowing water, but in both upstream and downstream situations. The species in this group (blunt-nosed minnow, stonecat, and slender-headed darter), increased in response to a resumption of permanent flow, but did not respond as quickly as did channel catfish, flatheads and freshwater drum, which are discussed subsequently.

The fact that riffle-insects were abundant throughout my study convinces me that food was not a limiting factor in the re-establishment of the fish-fauna on riffles of the Neosho River.

The following species decreased in abundance during my study (Tables 10 and 11): gizzard shad, carp, rosy-faced shiner, blunt-faced shiner, red shiner, mimic shiner, black bullhead, yellow bullhead, channel catfish, flathead, slender madtom, tadpole madtom, freckled madtom, spotted ba.s.s, largemouth, black c.r.a.ppie, fan-tailed darter, and freshwater drum.

Among the species that decreased, three groups, characteristic of different habitats, can be distinguished. The first group occurs most commonly in ponded conditions or in slowly flowing streams. Species in this group are: shad, carp, black bullhead, tadpole madtom, largemouth, black c.r.a.ppie, and white c.r.a.ppie. Bullhead, ba.s.s and c.r.a.ppie commonly occur in farm ponds and lakes in Kansas and seem less well adapted to streams. It is therefore not surprising to find that these species decreased in abundance when flow was resumed.

A second group, composed of rosy-faced shiner, blunt-faced shiner, mimic shiner, slender madtom, freckled madtom, spotted ba.s.s, and fan-tailed darter, normally is characteristic of clear tributaries rather than the mainstream of rivers. These species probably used the mainstream as a refugium during drought; with the resumption of flow, conditions became unsuitable for these populations in the mainstream. At the same time, conditions probably became favorable to the re-establishment of these species in tributaries. Metcalf (1959:396) listed the rosy-faced shiner, blunt-faced shiner and mimic shiner as species that were characteristic of upland tributaries in the Flint Hills and Chautauqua Hills of Chautauqua, Cowley and Elk counties in Kansas. The slender madtom and fan-tailed darter are more common in clear streams of southeast Kansas than in other areas of the state (Cross, personal communication and data of the State Biological Survey of Kansas). Both species are recorded by Hall (1952:57-58) only in upland tributaries on the east side of Grand (Neosho) River in the Fort Gibson Reservoir area of Oklahoma. Neither species was taken in faunal studies of the Verdigris River in Oklahoma (Wallen, 1958), in the Verdigris and Fall rivers in Kansas (Schelske, 1957), or by Metcalf (1959).

The spotted ba.s.s is not so restricted in its distribution and its habitat-requirements as are other species in this group; but, in Kansas, spotted ba.s.s are most abundant in clear creeks in the southeast part of the state.

The freckled madtom was taken in most of the studies cited above and is most common in the smaller streams of the southeast one-fourth of Kansas and the northeast one-fourth of Oklahoma. Schelske (1957:47) reports that the freckled madtom was taken only in March, April, October and November in the Verdigris River, Kansas. My only record of this species was obtained in the Neosho River in April, 1958.

The third group is composed of channel catfish, flathead, and freshwater drum. This group represents that element of the population that responded most quickly to the resumption of continuous flow. The fact that adult channel catfish and flatheads live in pools and do not require flowing water to sp.a.w.n gives these species a survival advantage as well as a reproductive advantage over obligatory riffle fishes (such as most darters) in the highly variable conditions found in Kansas streams. These factors resulted in unusually high reproductive success in 1957. Subsequent survival of fry was excellent; however, some mortality in the highly-dominant 1957 year-cla.s.s became apparent in the 1958 and 1959 collections, accounting for a numerical decline in these species. The ability to respond immediately to increased flow is an adaptive feature that allows these species to maintain high levels of abundance in the highly fluctuating streams of Kansas.

The continuous flow that occurred in 1957 in the Neosho and Marais des Cygnes rivers, for the first time in four years, provided the necessary habitat for survival of young catfish hatched in that year. The nearly complete absence of other species on the riffles, and the abundant populations of riffle-insects that I observed in the summer of 1957, were undoubtedly factors contributing to the survival of young.

The decrease in abundance of the red shiner may be partially due to an increase in the numbers of other species that are well adapted to conditions of permanent flow. At the completion of my study, the red shiner was still the most abundant minnow in both rivers. In 1957 this species was common in many habitats, including swift riffles, that were later occupied by madtoms, darters, the gravel chub, mountain minnow and sucker-mouthed minnow.

The basic pattern of change was clearly an increase in the species that are characteristic of permanently flowing waters, and a decrease in the species that are characteristic of ponds or small, clear streams.

PLATE 26

[Ill.u.s.tration: FIG. 1. Neosho River, Middle Station, Sec. 3 and 4, T. 24 S., R. 17 E., looking upstream, July, 1958.]

[Ill.u.s.tration: FIG. 2. Neosho River, Lower Station, Sec. 16, T. 29 S., R. 20 E., along gravel bar, July, 1959.]

PLATE 27

[Ill.u.s.tration: FIG. 1. Marais des Cygnes River, Upper Station, Sec. 12, T. 17 S., R. 17 E., looking downstream, June, 1960.]

[Ill.u.s.tration: FIG. 2. Marais des Cygnes River, Middle Station, Sec. 6, T. 17 S., R. 20 E., looking downstream, June, 1960.]

PLATE 28

[Ill.u.s.tration: FIG. 1. Electrical fishing gear used at night.]

[Ill.u.s.tration: FIG. 2. Pool at the upper Neosho station in which rotenone was used, Sec. 33, T. 15 S., R. 8 E., looking downstream, June, 1960.]

PLATE 29

[Ill.u.s.tration: FIG. 1. Area 1, upper Neosho station, Sec. 33, T. 15 S., R. 8 E., looking upstream, June, 1960.]

[Ill.u.s.tration: FIG. 2. Area 3, upper Neosho station, Sec. 10, T. 16 S., R. 8 E., looking downstream, June, 1960.]

PLATE 30

[Ill.u.s.tration: FIG. 1. Area 5, upper Neosho station, Sec. 3, T. 16 S., R. 8 E., looking upstream, June, 1960.]

[Ill.u.s.tration: FIG. 2. Area 6, upper Neosho station, Sec. 3, T. 16 S., R. 8 E., looking upstream, June, 1960.]

CONCLUSIONS

The fauna of the Neosho and Marais des Cygnes rivers is capable of a wide range of adjustment in response to marked environmental changes. As these rivers become low and clear they take on many of the faunal characteristics of smaller tributaries and ponds. Species such as black bullhead, spotted ba.s.s, largemouth, white c.r.a.ppie, red shiner, rosy-faced shiner, blunt-faced minnow, mimic shiner, and slender madtom a.s.sume a more prominent position in the total population. Other species such as channel catfish, flathead, freshwater drum, blue sucker, and such riffle-dwelling species as the gravel chub, Neosho madtom, and slender-headed darter hold a less prominent position in the total population.

When permanent flow is re-established the more mobile and the more generalized species (with respect to habitat) are able to utilize the available s.p.a.ce immediately. As a result, these species increase rapidly in numbers. This increase occurs both by movement from more permanent waters and by reproduction. Channel catfish, flathead, freshwater drum, and river carpsucker are mobile species (Funk, 1957; Trautman, 1957) and long-nosed gar probably are mobile. Individuals that move supplement those that survive in residual pools, and provide brood stock adequate to produce a large year-cla.s.s in the first year of permanent flow.

The five species last mentioned are found in diverse kinds of streams, indicating that they are adaptable to varying habitats. A sixth species, the red shiner, although probably less mobile, is able to utilize opportunistically nearly any kind of habitat in Plains streams.

Although this species seldom is abundant in riffles, it was, in 1957, abundant in both pool and riffle situations at all my stations. These riffles were almost unoccupied by other species in 1957 until mid-summer, when hatches of channel catfish and flatheads occurred.

Although adult channel catfish and flatheads live well in pools, the young occupy mainly riffles. This age- and size-segregation, in different habitats, was an advantage to the rapid re-establishment of these species in the Neosho and Marais des Cygnes rivers in 1957.

Species that occupy restricted habitats, especially riffle-dwellers such as the Neosho madtom, gravel chub, and slender-headed darter, were slowest to increase following drought. These species seem less capable of adapting to the variable conditions prevalent in the Neosho and Marais des Cygnes rivers than species that have more generalized habitat-requirements.

In the Neosho and Marais des Cygnes rivers nearly all species that were found in years just prior to the drought of 1952-1956 were again found in the last year of my survey; however, some species that live in a restricted habitat may eventually be extirpated in these two rivers. The high-finned carpsucker _Carpiodes velifer_, common shiner _Notropis cornutus_, h.o.r.n.y-headed chub _Hybopsis biguttata_, and johnny darter _Etheostoma nigrum_ all have specific habitat requirements and have disappeared or become restricted to one tributary in the Wakarusa River System (Deacon and Metcalf, 1961). The disappearance or reduction of these species implies long-term changes in the environment.

Suckers, minnows and catfishes const.i.tute the main fauna of the Neosho and Marais des Cygnes rivers, because these families contain many species that have generalized habitat-requirements. Many of these fish are able to live successfully in either ponds or flowing waters and others are capable of long migrations. Because these fish predominate in the streams of Kansas, attempts should be made to utilize them more effectively.