Abstract
The densities of alkali fly larvae and pupae were measured in relation to depth and substrate type at six locations around Mono Lake. Samples representing a mixture of different bottom features were taken to a depth of 10 m (33 ft) using SCUBA. This is at or near the depth limit of fly larvae and pupae. The biomass of larvae and pupae on hard substrate were maximum and approximately equal at depths of 0.5 m and 1 m, substantially lower at intermediate depths of 3 m and 5 m, and over an order of magnitude further reduced at 10 m. Densities of flies on hard or rocky substrates (mainly calcareous tufa deposits), were significantly greater than those found on soft substrates such as mud or sand, at all but the greatest depth surveyed.
Bathymetric maps of the areas of hard and soft substrate occurring at different lake depths were used to estimate the fly population size over the whole lake, based on the density distribution of larvae and pupae with depth on different substrates. The mapped areas of soft and hard substrates were also calculated for different lake levels, and applying the same procedure, a population model comparing the abundance of flies at different lake levels was developed. This habitat-based population model predicts that the abundance of the alkali fly is maximized at 6380 ft (1945 m) lake surface elevation. Most of the tufa substrate submerged at this lake level will become exposed and unavailable as habitat as the lake declines to 6370 ft (1942 m). In late 1991, the lake level was just over 6374 ft (1943 + m).
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Aldrich, J. M., 1912. The biology of some Western species of the dipterous genus Ephydra. J. N.Y. ent. Soc. 20: 77–99.
Bischoff, J. L., D. B. Herbst & R. J. Rosenbauer, 1991. Gaylussite formation at Mono Lake, California. Geohim. Cosmochim. Acta 55: 1743–1747.
Botkin, D. B., W. S. Broecker, L. G. Everett, J. Shapiro & J. A. Wiens, 1988. The Future of Mono Lake. Water Resources Center, University of California, Riverside. Report no. 68.
Brewer, W. H., 1930. Up and Down California in 1860–1864. Berkeley: University of California Press. Repr. 1966.
Elliot, J. M., 1977. Some methods for the statistical analysis of samples of benthic invertebrates. 2nd edition. Freshwater Biol. Assoc. publication no. 25. Ambleside, England. 160 pp.
Gore, J. A., 1978. A technique for predicting in-stream flow requirements of benthic macroinvertebrates. Freshwat. Biol. 8: 141–151.
Gore, J. A. & R. D. Judy, 1981. Predictive models of benthic macroinvertebrate density for use in instream flow studies and regulated flow management. Can. J. Fish. aquat. Sci. 38: 1363–1370.
Herbst, D. B., 1988. Comparative population ecology of Ephydra hians Say (Diptera: Ephydridae) at Mono Lake (California) and Abert Lake (Oregon). Hydrobiologia 158: 145–166.
Herbst, D. B., 1990. Distribution and abundance of the alkali fly (Ephydra hians Say) at Mono Lake, California (USA) in relation to physical habitat. Hydrobiologia 197: 193–205.
Herbst, D. B, 1992. Changing lake level and salinity at Mono Lake: Habitat Conservation Problems for the Benthic Alkali Fly. In: C. Hall (ed.) History of Water in the Eastern Sierra. Volume 4 of the White Moutain Research Station Symposia. University of California, Los Angeles 4: 198–210.
Herbst, D. B., F. P. Conte & V. J. Brookes, 1988. Osmoregulation in an alkaline salt lake insect, Ephydra (Hydropyrus) hians Say (Diptera: Ephydridae) in relation to water chemistry. J. Insect Physiol. 34: 903–909.
Herbst, D. B. & T. J. Bradley, 1989. A Malpighian tubule lime gland in an insect inhabiting alkaline salt lakes. J. exp. Biol. 145: 63–78.
National Academy of Sciences, 1987. The Mono Basin Ecosystem: Effects of Changing Lake Levels. National Academy Press, Washington D.C. 272 pp.
Stine, S., 1988. Geomorphic and geohydrographic aspects of the Mono Lake controversy. Appendix report to The Future of Mono Lake. D. Botkin et al. (eds). Report No. 68, Water Resources Center, University of California.
US Forest Service, 1989. Mono Basin National Forest Scenic Area — comprehensive management plan. Inyo National Forest. 58 pp.
Vorster, P. 1985. A water balance forecast model for Mono Lake, California. US Forest Service Region 5. Monograph No. 10, 350 pp.
Wrona, F. J., P. Calow, I. Ford, D. J. Baird & L. Maltby, 1986. Estimating the abundance of stone-dwelling organisms: a new method. Can. J. Fish. aquat. Sci. 43: 2025–2035.
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Herbst, D.B., Bradley, T.J. A population model for the alkali fly at Mono Lake: depth distribution and changing habitat availability. Hydrobiologia 267, 191–201 (1993). https://doi.org/10.1007/BF00018801
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DOI: https://doi.org/10.1007/BF00018801