Abstract
A study of diurnal variation over a 48 hour period was undertaken in July 1973 to ascertain the extent and timing of some major chemical, physical and biological variables in Loch Lomond. The phytoplankton population was dominated by the diatom Tabellaria fenestrata, with a maximum abundance between 04.00 and 06.00 h in surface waters on both days. A distinct diurnal variation in cell numbers was also recorded. Chlorophyll a values also showed a regular pattern of variation with a single peak between 10.00 and 14.00 h each day. Some chemical changes appeared to be a direct consequence of phytoplankton multiplication. Nitrate-nitrogen showed a decrease in concentration coinciding with the period of cell multiplication, whereas dissolved silica concentrations only fell on the completion of this process. Other common diatoms displayed less distinct patterns of variation although Fragilaria crotonensis attained its maximum abundance in surface waters. Considerable variation was recorded in the number of organisms and chlorophyll a levels at 25 cm intervals in the upper metre of the water column, with large variations in standing-crop and chemical parameters in the space of one hour. Diurnal oscillations in the position of the thermocline were recorded, with the thermal discontinuity being at its greatest depth in the early hours of the morning. The hypolimnion and thermocline regions clearly acted as a source of nutrient supply to the epilimnion. From this investigation it is apparent that for the proper understanding of diurnal variation a 24 hour study alone is insufficient and may give rise to misleading results.
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Allen, S. E., Carlisle, A., White, E. J. & Evans, C. C. 1968. Plant nutrient content of rain water. J. Ecol. 56: 497–504.
Baker, A. L., Brook, A. J. & Kleiner, A. R. 1969. Some photosynthetic characteristics of a naturally occurring population of Oscillatoria agardhii Gomont. Limnol. Oceanogr. 14: 327–333.
Benschneider, K. & Robinson, R. J. 1952. A new spectrophotometric method for the determination of nitrite in sea water. J. Mar. Res. 11: 87–96.
Brown, D. H., Gibby, C. E. & Hickman, M. 1972. Photosynthetic rhythms in epipelic populations. Brit. phycol. J. 7: 37–44.
De Noyelles, F. 1968. A stained organism filter technique for concentrating phytoplankton. Limno. Oceanogr. 13: 562–565.
Doty, M. 1959. Phytoplankton photosynthetic periodicity as a function of latitude. J. mar. biol. Ass. India 1: 66–68.
Doty, M. & Oguri, M. 1957. Evidence for a photosynthetic daily periodicity. Limnol. Oceanogr. 2: 37–40.
Edmonson, W. T. 1971. In: Manual on methods for measuring primary production in aquatic environments (R. A. Vollenweider, Ed.), pp. 14–15.
Enright, J. T. 1970. Ecological aspects of endogenous rhythmicity. Ann. Rev. Ecology & Systematics 1: 221–238.
Eppley, R. W., Holm-Hansen, O. & Stirckland, J. D. 1968. Some observations on the vertical migration of Dinoflagellates. J. Phycol. 4: 333–340.
Fogg, G. E. 1965. Algal Cultures and Phytoplankton Ecology. Athlone Press, London, 126 pp.
Forsbergh, E. D. 1969. On the climatology, oceanography and fisheries of the Panama Bight. Inter-American Tropical Tuna Commission Bull. 14: 43–385.
Glooschenko, W. A., Curl, H. & Small, L. F. 1972. Diel periodicity of chlorophyll a concentration in Oregon coastal waters. J. Fish. Res. Bd. Canada 29: 1253–1259.
Goering, J. J., Nelson, D. M. & Carter, J. A. 1973. Silicic acid uptake by natural populations of marine phytoplankton. Deep-Sea Res. 20: 777–789.
Hasle, G. R. 1954. More on phototactic diurnal migration in marine dinoflagellates. Nytt. Mag. f. Bob. 2: 139–147.
Hopkins, J. T. 1966. Some light-induced changes in behaviour and cytology of an estuarine mud-flat diatom. In: ‘Light as an Ecological Factor’ (R. Bainbridge, G. C. Evans and O. Rackham, eds.). pp. 335–385 Symposium of British Ecological Society, Oxford.
Horne, A. J. 1975. Algal nitrogen fixation in California streams: diel cycles and nocturnal fixation. Fresh. Biol. 5: 471–477.
Hutchinson, G. E. 1967. A Treatise on Limnology Vol. II. John Wiley, New York, 1115 pp.
Ichimura, S-e. 1960. Diurnal fluctuation of chlorophyll content in lake water. Bot. Mag. 71: 110–116.
Kramer, J. R., Allen, H. E., Balue, G. W. & Burns, N. M. 1970. Lake Erie Time Study. Canada Centre for Inland Waters 4.
Lewin, J. & Hruby, T. 1975. Blooms of surf zone diatoms along the coast of the Olympic Peninsula, Washington. II A diel periodicity in buoyancy shown by the surf-zone diatom species, Chaetoceros armatum T. West. Estuarine & Coastal Marine Science, 1: 101–105.
Lorenzen, C. J. 1963. Diurnal variation in the photosynthetic activity of natural phytoplankton populations. Limnol. Oceanogr., 8: 56–62.
Lund, J. W. G. 1965. The ecology of freshwater phytoplankton. Biol. Rev. 40: 231–293.
Lund, J. W. G. & Talling, J. F. 1957. Botanical limnological methods with special reference to algae. Bot. Rev. 23: 489–583.
McNabb, C. D. 1960. Enumeration of freshwater phytoplankton concentrated on a membrane filter. Limnol. Oceanogr. 5: 57–61.
Mackereth, F. J. H. 1963. Some methods of water analysis for limnologists. Freshwater Biological Association. Scientific Publication No. 21, 70 pp.
Malone, T. C. 1971. Diurnal rhythms in net plankton and nanoplankton assimilation rates. Mar. Biol. 10: 285–289.
Mullen, J. D. & Riley, J. P. 1955. The colorimetric determination of silicate with special reference to sea and natural waters. Analyt. Chem. Acta 12: 162–176.
Murphy, J. & Riley, J. P. 1962. A modified single solution method for the determination of soluble phosphate in natural waters. Analyt. Chem. Acta. 12: 162–176.
Odum, E. 1971. Fundamentals of Ecology (3rd Edit.). W. B. Saunders & Co., Philadelphia.
Richards, F. A. & Thompson, T. G. 1952. The estimation and characterization of plankton populations by pigment analysis. J. Mar. Res. 11: 156–172.
Raymont, J. E. G. 1963. Plankton and Productivity in the Oceans. Pergamon Press, Oxford.
Rodina, A. G. 1975. Methods in Aquatic Microbiology (R. R. Colwell and M. S. Zambruski), Baltimore, University Park Press. 461 pp.
Round, F. E. & Palmer, J. D. 1966. Persistent vertical migration rhythms in benthic microflora — III. Field and laboratory studies on diatoms from the banks of the River Avon. J. mar. Biol. Ass. U.K. 46, 191–214.
Sagi, T. 1970. On the distribution of nitrate nitrogen in the Western North Pacific Ocean. Oceanogr. Mag. 22: 63–74.
Saksena, S. B. & Adoni, A. D. 1973. Diurnal variation in Sagar Lake. Hydrobiologia 43: 535–543.
Sournia, A. 1974. Circadian periodicities in natural populations of marine phytoplankton. Adv. mar. Biol. 12, 325–389.
Sournia, A. 1968. Variations saisonmés et rycthémŕales du phytoplancton marin et de la production primaire dans une baie tropicale,, à Nosy-Bé, Madagascar. Internat. Revue der gesamten Hydrobiologie 53, 1–76.
Staley, J. T. 1971. Growth rates of algae determined in situ using an immersed microscope. J. Phycol. 7, 13–18.
Stephens, K. 1963. Determination of low phosphate concentration in lake and marine waters. Limnol. Oceanogr. 8: 361–362.
Strickland, J. D. H. & Parsons, T. R. 1968. A practical handbook of seawater analysis. Fish. Res. Bd. Canada, Bulletin 167, 311 pp.
Stross, R. G., Chisholm, S. W. & Downing, T. A. 1973. Causes of the daily rhythms in photosynthetic rates of phytoplankton. Biol. Bull. 145, 200–209.
Talling, J. F. 1966. Photosynthetic behaviour in stratified and unstratified lake populations of the planktonic diatom. J. Ecol., 54: 99–127.
Vijayarachavan, S. 1971. Studies on the diurnal variation in physicochemical and biological factors in Teppakulm Tank. Proc. Indian Acad. Sci. 74: Section B., 63–73.
Wood, E. J. F. & Corcoran, E. F. 1966. Diurnal variation in phytoplankton. Bull. Mar. Sci. 16: 383–403.
Wood, E. D., Armstrong, F. A. J. & Richards, F. A. 1967. Determination of nitrate in sea water by Cadmium-Copper reduction to nitrite. J. mar. biol. Ass. U.K., 47: 23–31.
Yentsh, C. S. & Ryther, J. H. 1957. Short-term variations in phytoplankton chlorophyll and their significance. Limnol. Oceanogr. 2, 140–142.
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Department of Botany, University of Glasgow
Department of Botany, University of Glasgow
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Maulood, B.K., Hinton, G.C.F. & Boney, A.D. Diurnal variation of phytoplankton in Loch Lomond. Hydrobiologia 58, 99–117 (1978). https://doi.org/10.1007/BF00007992
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DOI: https://doi.org/10.1007/BF00007992