PROCEEDINGS OF THE OKLAHOMA ACADEMY OF SCIENCE Volume 61—1981

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CRYSTAL LAKE REVISITED

Robert A. Lynch and L. A. Pfiester

Department of Botany-Microbiology, University of Oklahoma, Norman, OK 73019

A comparison of the algal flora of Crystal Lake, Cleveland County, Oklahoma observed by Leake in 1938 is made with that found by the authors forty years later. One hundred-two algal taxa previously unobserved in the state of Oklahoma are reported. Preserved collections are stored in the Department of Botany-Microbiology at the University of Oklahoma.

INTRODUCTION

Prior to the year 1929 almost nothing was known about the algae of Oklahoma. In that year Dr. C. E. Taft began a survey resulting in a number of papers on algae common to the state (1-8). Since then publications on the algae of Oklahoma have been sporadic, correlating understandably with the presence in the State of those interested in "lower" plants (9-30; 41). The first extensive examination of the algae of one body of water in Oklahoma was that by Leake (11) in which she studied the algae of Crystal Lake from 1938 to 1943. The present study, which revisited the algae of Crystal Lake forty years later, compares the algal flora found in 1978 with that observed by Leake in her study and in the process adds 102 new taxa to the state record (Table 1).

Crystal Lake is approximately 800 m long from north to south and 250 m at its widest point. Its deepest basin measures 3 m. The lake lies on the southwest corner of the intersection of Porter and Rock Creek Road in Norman, Oklahoma. The area surrounding the lake is covered by mixed short-grass prairie with a few scattered trees. Flowering plants in the lake were Polygonum lapathifolium L., Myriophyllum spicatum L., many sedges and rushes, and a few cattails.

Ten sampling sites were chosen to correspond to various microhabitats in the lake area. A total of 690 samples were collected at each of these stations on each of 31 sampling dates from Oct. 20, 1977 to Oct. 13, 1978. Plankton tows, rock scrapings, plant squeezings, and log scrapings were taken at each station. In addition collections were made between sampling stations when different specimens were observed.

Algal samples were examined fresh when possible and preserved in Transeau's solution when delayed examination necessitated. All algae exclusive of the diatoms were identified.

Three hundred twenty-three taxa were collected and identified over the one-year period with most of the algal divisions represented. A breakdown of these 331 taxa into divisions is shown in Table 1:

A comparison of algal taxa collected in 1977-1978 with Leake's results reveals a number of similarities and differences (Table 2). Chlorophyta populations tended to be similar while Cyanophyta and Euglenophyta populations differed. Lake identified 155 taxa while 165 were identified in our study. Diversity increased among Chlorococcales and decreased in Zygnematales (Table 2). Diversity in the Euglenophyta populations rose from 8 taxa reported by Leake to 45 taxa found in our study. Most of this increase was in species of Euglena and Trachelomonas, both of which are very abundant today. The most striking change was in the Cyanophyta. We were able to identify 92 taxa while Leake only reported 8 in her study. Although we feel certain that more than 8 taxa were present during Leake's study and that the low number merely represents the most commonly occurring species, we believe the population in this division has increased greatly.

It would be very difficult to pinpoint a cause for the changes in the algal flora that have taken place over the last 40 years. The chemistry of the lake has changed considerably since Leake's time and this

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undoubtedly has been the major cause of change in the composition of the algal flora (31). Also, taxonomic classification of algae, especially at the species level, has been amended a great deal since Leake's time which could create artificial differences between the two studies.

Qualitatively Crystal Lake and the surrounding area have changed in many ways since Leake's study. The drainage basin of the lake, which was heavily grazed during Leake's study, is now covered heavily with grass and ungrazed. This undoubtedly has caused a change in the quality of solid runoff. Crystal Lake was formerly used extensively for boating, skiing and swimming, whereas now recreational use is limited to fishing. The lake has filled in 19-20 feet since Leake's study; this has resulted in reduced resistance to mixing. Myriophyllum spicatum, which has become the dominant plant in the lake, was not present when Leake did her study.

The presence of Myriophyllum has affected populations of algae in several ways. It provided a new habitat for many organisms resulting in greater algal diversity. Because of its presence, shoreline erosion and wave action in shallow areas was reduced, resulting in less sediment disturbance and clearer water. Myriophyllum also has an important effect on lake chemistry. Irwin and Stevenson (32) have shown that aquatic plants secrete substances into the water which combine with suspended particles and expedite their settling, thus reducing turbidity. Rooted submergent macrophytes such as Myriophyllum are important in the nutrient system of the lake as has been demonstrated by Gessner (33), Schwoerbel and Tillmans (34), and Wetzel (35). They function as "nutrient pumps"' by bringing up nutrients from sediments and leaking them into the water through their leaves. Additional amounts of nutrients are released into the water when Myriophyllum dies in the fall. The nutrients added to the water by Myriophyllum are then utilized by algae and bacteria (36). While the Chlorophyta populations have remained relatively constant since Leake's study, the Cyanophyta and Euglenophyta populations have increased in diversity. Crystal Lake, therefore, seems to fit the hypothesis (35, 37) that established populations tend to remain constant. Palmer (38) has found that the green algae are the group most tolerant to changes in the environment, and this appears to be the case in Crystal Lake. The data also agree with the hypothesis (35, 39) that Euglenophytan and Cyanophytan populations tend to diversify with increased eutrophication.

Two factors besides the increase in Euglenophytan and Cyanophytan populations indicate that Crystal Lake is in an advanced state of eutrophication. One is that the surface area/volume ratio has increased greatly since the lake was built. Using the rate of filling in over the last 50 years, one can calculate that the lake will be filled in completely within 20-30 years. Whether or not this will happen is uncertain, but without a doubt, the lake will become shallower and thus will be more prone to eutrophication. The other factor is the heavy growth of Myriophyllum. Several authors (39, 40) indicate that a heavy growth of submerged macrophytes is a definite sign of advanced eutrophication and Crystal Lake certainly fits this description. We believe, therefore, that algal populations in Crystal Lake will continue to

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change but probably faster than over the last 40 years.

LITERATURE CITED

1.   C. E. TAFT, Univ. of Oklahoma Biol. Survey 3: 277-321 (1931).

2.   C. E. TAFT, Trans. Am. Micros. Soc. 53: 95-101 (1934).

3.   C. E. TAFT, Bull. Torrey Bot. Club 62: 281-290 (1935).

4.   C. E. TAFT, Abst. Doctor's Dissertations, Ohio State Univ. 16: 213-222 (1935).

5.   C. E. TAFT, Trans. Am. Micros. Soc. 56: 394-404 (1937).

6.   C. E. TAFT, Bull. Torrey Bot. Club 64: 557 (1937).

7.   C. E. TAFT, Proc. Okla. Acad. Sci. 20: 49-54 (1940).

8.   C. E. TAFT, Trans. Am. Micros. Soc. 68: 208-216 (1949).

9.   E. N. TRANSEAU, L. H. TIFFANY, C. E. TAFT and L. C. LI, Trans. Am. Micros. Soc. 53: 208-230 (1934).

10.   D. V. LEAKE, Proc. Okla. Acad. Sci. 19: 109-110 (1939).

11.   D. V. LEAKE, Am. Midl. Nat. 34: 750-768 (1945).

12.   M. MALONEY, Proc. Okla. Acad. Sci. 24: 43-48 (1944).

13.   I. L. OPHEL, Proc. Okla. Acad. Sci. 33: 179-183, (1954).

14.   D. WILSON and H. S. FOREST, Ecology 38: 309-313 (1957).

15.   M. J. COOPER, Proc. Okla. Acad. Sci. 55: 17-19 (1975).

16.   W. C. VINYARD, Southwest Natur. 11: 196-204 (1966).

17.   J. M. COOPER and J. WILHM, Southwest. Nat. 19: 413-428 (1975).

18.   A. R. KOCH, Proc. Okla. Acad. Sci. 55: 11-13 (1975).

19.   A. R. KOCH and P. G. RISSER, Proc. Okla. Acad. Sci. 54: 14-19 (1974).

20.   L. PFIESTER, J. Phycol. 12: 134 (1976).

21.   L. PFIESTER and W. O. FELKNER, Proc. Okla. Acad. Sci. 56: 66 (1976).

22.   L. PFIESTER, Trans. Am. Micros. Soc. 96: 163 (1977).

23.   R. J. TAYLOR, Proc. Okla. Acad. Sci. 57: 166 (1977).

24.   J. T. WILHM, T. DORRIS, J. R. SEYFER and N. McCLINTOCK, Southwest Nat. 22: 455-467 (1977).

25.   J. R. SEYFER and J. WILHM, Southwest. Nat. 22: 455-468 (1977).

26.   L. PFIESTER and S. TERRY, Southwest Nat. 23: 85-94 (1978).

27.   T. WRIGHT and L. PFIESTER, Southwest. Nat. 23: 431-456 (1978).

28.   D. CONNER, D. J. HUDDLESTON, L. A. PFIESTER, and S. THOMPSON, Proc. Okla. Acad. Sci. 58: 110 (1978).

29.   W. W. TROEGER, Proc. Okla. Acad. Sci. 58: 64-68 (1978).

30.   L. PFIESTER, R. LYNCH, and T. L. WRIGHT, Southwest. Nat. 24: 149-164 (1979).

31.   R. A. LYNCH, The Algae of Crystal Lake 1938-1978. M.S. Thesis, University of Oklahoma, Norman (1978).

32.   W. H. IRWIN and J. H. STEVENSON, Bull. Okla. A. and M. College 48: 1-54 (1951).

33.   F. GESSNER, Hydrobotanik, Die Physiologischcn Grundlagen der Pflanzenverbreitung in Wasser. II. Stoffhaushalt. VEB Deutscher Verlag der Wissenschaften, Berlin, 1959.

34.   J. SCHWOERBEL, and G. C. TILLMANNS, Naturwissenschaften 51: 319-320 (1967).

35.   R. G. WETZEL, Limnology, W. B. Saunders Co., Philadelphia and London, 1975.

36.   R. G. WETZEL, and H. L. ALLEN, In Z. Kajak and A. Hillbrincht-Ilkowska (eds.), Productivity Problems of Freshwaters. PWN Polish Scientific Publishers, Warsaw, 1970, pp. 333-347.

37.   S. EDDY, Trans. Am. Micros. Soc. 44: 138-147 (1925).

38.   C. M. PALMER, J. Phycol. 5: 78-82 (1969).

39.   P. WELCH, Limnology, McGraw-Hill Book Co., New York, N.Y., 1952.

40.   R. G. WETZEL, and R. A. HOUGH, Pol. Arch. Hydrobiol. 20: 9-19 (1973).

41.   G. GABEL, Proc. Okla. Acad. Sci. 6: 82-84 (1927).