Fish Populations, Following a Drought, in the Neosho and Marais des Cygnes Rivers of Kansas Part 9

Fat-headed minnows also declined markedly in successive collections from Area 6, the only area in which the species was common. No marked fat-headed minnows were taken outside the area of release, indicating low mobility of the species. I cannot certainly account for their decline; possibly there was latent mortality due to shocking.

The numbers of red s.h.i.+ners, blunt-nosed minnows, and juvenile channel catfish varied erratically in successive collections, probably as a result of movement. This problem is discussed for all species in a later section.

Population-Estimation

The direct-proportion method was used to estimate fish populations in Areas 1, 3 and 6. Reliable results could not be obtained for all species because of scarcity, mortality in handling, mobility, or other factors.

A high rate of mortality due to handling was observed in Area 1 for the red s.h.i.+ner and in Area 6 for river carpsucker (young-of-the-year), sucker-mouthed minnows, red-finned s.h.i.+ner, red s.h.i.+ner, blunt-nosed minnow, and stoneroller. In Area 3, in contrast, there was little mortality in the same species during the twelve-hour interval that fish were held in traps prior to release as marked individuals.

The following species were common in at least one area, but probably are sufficiently mobile (see page 416) to invalidate estimates of static populations in small areas: red s.h.i.+ner, red-finned s.h.i.+ner, and channel catfish (yearlings and older). Other species were rare and are indicated as "T" in Table 13.

Those species for which population-estimates seem warranted include: golden redhorse, sucker-mouthed minnow, red s.h.i.+ner, sand s.h.i.+ner, fat-headed minnow, stoneroller, stonecat, channel catfish (young-of-the-year), green sunfish, long-eared sunfish, slender-headed darter, and orange-throated darter. I consider the estimate valid if a high percentage of the marked fish is recaptured. Results are presented in Table 15, and ordinarily will not be referred to in the following discussion of the population in each of the three areas.

_Area 1_

The order of abundance at Area 1, in terms of the estimated population per 500 square feet, was as follows: stoneroller (47.6), stonecat (29.4), channel catfish (young-of-the-year) (20.6), green sunfish (19.4), red s.h.i.+ner (18.2), long-eared sunfish (9.4), channel catfish (yearlings and older) (6.5), golden redhorse (1.2). Insufficient data make inclusion of other species unreliable.

A comparison of the order of abundance between the estimated total population and the percentage composition in the first collection from each area shows significant correlations. The percentage-composition of the fish fauna at Area 1 was calculated as follows: stoneroller (27.7%), red s.h.i.+ner (18.2%), green sunfish (11.2%), stonecat (10.3%), channel catfish (young-of-the-year) (9.5%), channel catfish (yearlings and older) (5.8%), long-eared sunfish (5.4%), golden redhorse (0.8%). It can be seen that the stoneroller, green sunfish, long-eared sunfish and golden redhorse follow each other in the same order in both calculations. The stonecat is shown to be more common than channel catfish (young-of-the-year) in both calculations, but both species appear to be more abundant than green sunfish and red s.h.i.+ner in calculations of the total population and less abundant in the percentage-composition in the first collection. I think that the order of abundance as shown by percentage-composition is the more accurate figure for Area 1. The abundance of the red s.h.i.+ner is known to have been affected by mortality in collecting. Furthermore, as will be shown later, the species is so mobile that its abundance often changes markedly in a short time. Therefore, it is not surprising to find the red s.h.i.+ner in widely varying positions of relative and absolute abundance. However, the green sunfish maintains stable populations and should remain in about the same position of abundance in relation to other species (such as the stonecat and channel catfish young-of-the-year) that also maintain stable populations. The differences in order of abundance obtained by the two methods for green sunfish and channel catfish young-of-the-year are not great. However, in the estimation of total population the abundance of the stonecat seems significantly greater, in relation to other species, than in the calculation of percentage-composition. I believe that this difference can be attributed to the relatively low number of marked fish recaptured, which is probably due to a slow rate of dispersal from the point of release. Stonecats were released in relatively quiet water, and if they remained there they might be missed in subsequent collections, because they lack air-bladders and tend to remain on the bottom when shocked. Therefore, the calculated total population of the stonecat in Area 1 may be too high.

TABLE 15. DATA USED IN ESTIMATING TOTAL POPULATIONS, BY DIRECT PROPORTIONS, IN AREAS 1, 3, AND 6 AT THE UPPER NEOSHO STATIONS.

====================================================================== Number Number Number captured first marked and captured second SPECIES collection released collection +----+-----+-----+----+----+----+----+-----+---- 1 3 6 1 3 6 1 3 6 ----------------------+----+-----+-----+----+----+----+----+-----+---- Golden Redhorse 2 5 0 2 5 0 2 5 0 Sucker-mouthed Minnow 0 54 31 0 51 15 0 42 12 Red s.h.i.+ner 44 116 186 22 106 86 7 165 202 Sand s.h.i.+ner 0 25 10 0 25 7 0 35 10 Blunt-nosed Minnow 0 4 108 0 3 28 0 10 91 Fat-headed Minnow 1 1 112 1 1 101 0 2 156 Stoneroller 67 84 54 58 79 33 39 107 67 Channel Catfish(j)[I] 14 37 3 9 32 3 7 16 1 Channel Catfish(yy)[J] 3 34 40 22 33 39 16 34 23 Stonecat 25 7 0 25 7 0 8 7 0 Green Sunfish 27 [K]-- 62 27 -- 62 17 -- 62 Long-eared Sunfish 13 6 10 13 6 10 12 3 22 ----------------------+----+-----+-----+----+----+----+----+-----+---- ====================================================================== Number of Estimated Percent of Number marked fish total marked fish per 500 recaptured population recovered square feet ----+----+----+----+-----+------+-----+-----+----+------+------+------ 1 3 6 1 3 6 1 3 6 1 3 6 ----+----+----+----+-----+------+-----+-----+----+------+------+------ 2 5 0 2 5 0 100 100 -- 1.2 .4 0 0 17 0 0 126 -- -- 33 0 0 10.0 -- 5 18 14 31 972 1284 23 17 11 18.2 77.1 64 -- 12 1 0 73 -- -- 48 -- 0 5.8 -- 0 1 8 0 -- 319 -- 33 28 0 -- 16 0 0 19 -- -- 830 0 0 19 -- -- 41.5 28 35 8 81 242 276 48 44 24 47.6 19.2 13.8 6 13 0 11 39 -- 67 41 0 6.5 3.1 -- 10 11 1 35 102 -- 45 33 3 20.6 8.1 -- 4 1 -- 50 -- 0 16 14 -- 29.4 -- 0 14 -- 22 33 -- 175 52 -- 35 19.4 -- 8.8 10 3 6 16 6 37 76 50 60 9.4 .5 1.9 ----+----+----+----+-----+------+-----+-----+----+------+------+------

[I] (j) Denotes juveniles only.

[J] (yy) Denotes young-of-year only.

[K] A dash denotes incomplete or insufficient data.

_Area 3_

The order of abundance of the species at Area 3, in terms of the estimated population per 500 square feet, was as follows: red s.h.i.+ner (77.1), stoneroller (19.2), sucker-mouthed minnow (10.0), channel catfish (young-of-the-year) (8.1), sand s.h.i.+ner (5.8), channel catfish (yearlings and older) (3.1), long-eared sunfish (0.5), golden redhorse (0.4). Insufficient data make inclusion of other species unreliable.

For comparison with the estimates of total population, the percentage-composition in the first collection gives the following results: red s.h.i.+ner (24.0%), stoneroller (17.4%), sucker-mouthed minnow (11.2%), channel catfish (yearlings and older) (7.6%), channel catfish (young-of-the-year) (7.0%), long-eared sunfish (6.0%), sand s.h.i.+ner (5.2%), and golden redhorse (1.0%).

For the most part, the species have the same order of abundance in both methods of a.n.a.lysis. Those that are apparently out of order are channel catfish (yearlings and older) and long-eared sunfish. The first species is mobile (excepting young-of-the-year) and commonly fluctuates widely in numbers in the same area; the second species was treated differently in that only adults were considered in the population-estimation whereas both young and adults were considered in calculating percentage-composition. (I found that I could not confidently distinguish between young-of-the-year of green sunfish, long-eared sunfish and orange-spotted sunfish after staining.)

_Area 6_

The order of abundance of the species at Area 6, in terms of the estimated population per 500 square feet, was as follows: red s.h.i.+ner (64.0), fat-headed minnow (41.5), blunt-nosed minnow (16.0), stoneroller (13.8), green sunfish (8.8), long-eared sunfish (1.9). Insufficient data make inclusion of other species unreliable.

Calculations of percentage-composition give the following results: red s.h.i.+ner (20.1%), long-eared sunfish (14.6%), green sunfish (12.2%), fat-headed minnow (12.1%), blunt-nosed minnow (11.7%), stoneroller (5.8%). The two species of sunfish form a more significant part of the population in the latter a.n.a.lysis because young are included. Only adults were considered in the estimation of total population.

The fact that estimates of the total population and the percentage-composition agree in most respects lends support to the validity of both methods of a.n.a.lysis. It should be re-emphasized that differences in the order of abundance in the various areas reflect the ability of each species to utilize each particular kind of habitat.

Movement of Marked Fish

TABLE 16. DATA ON MOVEMENT OF MARKED FISH AT THE UPPER NEOSHO STATION, SEPTEMBER, 1959.

====================================================================== Number Number Number Number SPECIES marked recaptured moved moved upstream downstream ------------------------+--------+------------+----------+-------------- Golden Redhorse 24 16 0 2 Sucker-mouthed Minnow 68 27 7 0 Red-finned s.h.i.+ner 74 0 0 0 Red s.h.i.+ner 1326 152 48 25 Blunt-nosed Minnow 136 32 1 10 Fat-headed Minnow 151 40 0 0 Stoneroller 177 90 1 0 Black Bullhead 25 6 2 0 Channel Catfish (j)[L] 294 36 4 7 Channel Catfish (yy)[M] 145 34 2 0 Stonecat 33 6 0 0 Green Sunfish 124 68 1 0 Long-eared Sunfish 33 21 0 0 Slender-headed Darter 70 1 0 0 Orange-throated Darter 13 0 0 0 ------------------------+--------+------------+----------+------------

[L] (j) denotes juveniles only.

[M] (yy) denotes young-of-year only.

Some measure was gained of the amount of movement exhibited by several species of fish. Results are biased in favor of a conclusion that a species is sedentary because a large percentage of the recaptures were made in collections taken in the same immediate area three hours after release of marked fish, the total area checked was not large (one mile), and collecting was limited to an eleven-day period. Nevertheless, some species were shown to be definitely mobile and others exhibited p.r.o.nounced sedentary tendencies. The results of experiments on movement are presented in Table 16. Marked fish (dyed and fin-clipped) were taken as long as seven days after being marked. Only those species in which more than ten individuals were marked are included.

Blunt-nosed minnow, red s.h.i.+ner, and channel catfish (yearlings and older) are more mobile than other species.

The mobility of channel catfish has been discussed by Muncy (1958) and Funk (1957). My records show that of 36 marked channel catfish that were recaptured, 11 were taken in areas other than the one into which they had been returned. A p.r.o.nounced mobile tendency on the part of the red s.h.i.+ner and blunt-nosed minnow is shown by the fact that of 152 marked red s.h.i.+ners recaptured, 73 had moved from the area of release; and of 32 marked blunt-nosed minnows recaptured, 11 had moved from the area of release. The fact that the habitat occupied by these species is not precise (ranging from swift riffles to quiet pools) supports a conclusion that the species are mobile.

The fat-headed minnow, stoneroller, channel catfish (young-of-the-year), green sunfish and long-eared sunfish form a sedentary element of the population. With the exception of the fat-headed minnow, the sedentary group also maintained relatively stable numbers in Areas 1, 3 and 6 throughout the study (Table 14). It is interesting to note that, in contrast to the mobile group, the species forming the sedentary group have rather well-defined habitat preferences.

A third group of species, represented by the red-finned s.h.i.+ner, stonecat, slender-headed darter and orange-throated darter, was characterized by having a low rate of recapture. I suspect that mortality is a factor contributing to the failure to recapture red-finned s.h.i.+ners, because in one collection only four of 31 red-finned s.h.i.+ners captured were successfully marked and released, in another case 70 of 818. The red-finned s.h.i.+ner occurs most often in pools but is also taken in other areas, is pelagic, and probably is a mobile species.

The stonecat, slender-headed darter and orange-throated darter are generally restricted to riffle-habitats, and are probably sedentary. The low number of recaptures for these three species probably is due either to a slow rate of dispersal from the point of release or to latent mortality resulting from shock. Table 14 shows that these three species maintain comparatively stable populations, but there seems to be a tendency for a reduction in numbers with continued collecting, even though all fish captured were returned to the stream.

Golden redhorse showed a high rate of recapture. All individuals marked were recaptured three hours after release in Areas 1 (two fish) and 3 (five fish). Nine individuals were taken from Area 4 on 11 September; seven of these were marked and released in the next pool downstream (Area 3). On 15 September, two fish were retaken in Area 3 and two were retaken in Area 2, the next pool downstream. The species was common in Area 5 also where five of eight marked individuals were recaptured two days after release. It seems that the golden redhorse is somewhat restricted in movement, at least for short periods.

The sucker-mouthed minnow and black bullhead showed some movement--less than such mobile species as red s.h.i.+ners and channel catfish, but more than the sedentary group. Seven of 27 marked sucker-mouthed minnows were taken in areas adjacent to the one to which they had been returned. Two of six black bullheads that were recaptured had moved. The black bullhead moved the greater distance. The extent of short-term movement by several of the species in the Upper Neosho correlates well with redistribution subsequent to drought in the Wakarusa River, discussed by Deacon and Metcalf (1961).

Similarity of the Fauna at the Upper Neosho Station to the Faunas of Nearby Streams

The fauna that I found to be characteristic at the upper Neosho station has affinity with the upland tributary-fauna described by Metcalf (1959) for Chautauqua, Cowley and Elk Counties, Kansas. The primary difference is a nearly complete absence at my station of the Ozarkian element of the population. Some species (red-finned s.h.i.+ner, long-eared sunfish, and spotted ba.s.s) listed by Metcalf as characteristic of the mainstream of smaller rivers occur at the upper Neosho station in greater abundance then elsewhere in the Neosho. This difference is probably due to the fact that the upper Neosho station is somewhat larger and slightly more turbid than Metcalf's "upland tributaries."

Hall (1952) reported on the distribution of fishes in the vicinity of Fort Gibson Reservoir, an impoundment on the Grand (Neosho) River in Oklahoma. He separated the fishes into three groups according to habitat-preference: species restricted to upland tributaries on the east side of Grand (Neosho) River, species restricted to lowland tributaries on the west side of Grand (Neosho) River, and species occurring in the Grand River proper and/or tributaries on one or both sides.

Several species found in the upper Neosho River also occur in the area studied by Hall. Of these, only the creek chub was restricted to upland tributaries on the east side of Grand (Neosho) River. The sucker-mouthed minnow and red-finned s.h.i.+ner were restricted to the lowland tributaries on the west side of Grand (Neosho) River in the Fort Gibson Reservoir Area. Golden redhorse, stoneroller, yellow bullhead, spotted ba.s.s, green sunfish, long-eared sunfish, and orange-throated darter were present in collections from the Grand River proper and/or tributaries on both sides of the river, most commonly in tributaries.

Hall's data show that black bullhead, large-mouthed ba.s.s, white c.r.a.ppie, and logperch occurred most frequently in or near the quiet water of the reservoir. In my study these fish were most common in the larger, quiet pools at the upper Neosho station.

COMPARISON OF THE FISH FAUNAS OF THE NEOSHO AND MARAIS DES CYGNES RIVERS

The Marais des Cygnes River has less gradient (especially in the upstream portions), fewer and shorter riffles, and more mud bottom than does the Neosho River. Stream-flow during drought was reduced to a proportionately greater degree in the Neosho River than it was in the Marais des Cygnes River. Average flow of the Neosho River near Parsons (drainage area: 4905 square miles), Kansas, was less than average flow of the Marais des Cygnes River at Trading Post (drainage area: 2880 square miles), Kansas, in 1953, 1955 and 1956. In normal times the Neosho River carries a larger volume of water than the Marais des Cygnes. The Neosho River has a greater variety of habitat-conditions and a more diversified fish-fauna than the Marais des Cygnes.

The following species were taken in the Neosho River but not in the Marais des Cygnes River: blue sucker, high-finned carpsucker, golden redhorse, gravel chub, mimic s.h.i.+ner, mountain minnow, parrot minnow, Neosho madtom (the only endemic in either river), mosquitofish, spotted ba.s.s, smallmouth, black c.r.a.ppie, logperch and fan-tailed darter. Most of the above species are usually found in a.s.sociation with gravel-bottom, which is prevalent in Neosho River. The blue sucker, high-finned carpsucker, gravel chub, mountain minnow, and parrot minnow normally occur in the larger streams in Kansas. The last three species became more abundant in the Neosho River following resumption of flow. The golden redhorse also increased in abundance from 1957 to 1959, but was most numerous at the upper Neosho station, whereas the other species occurred mainly at the lower stations.