Synopsis
A number of factors can influence the accuracy and precision of underwater visual transect techniques. Among these are observer swimming speed and, during multispecies surveys, the effect of counting all fishes on estimates of particular species. This paper examines the effect of these factors on population estimates of inconspicuous fishes (defined as Type 1) in a temperate reef fish assemblage near Sydney, Australia. Counting Type 1 fishes with all others yielded significantly lower estimates of species richness and abundance than when counted alone. This suggests that multispecies surveys should be split into 2 or more counts, using a census procedure that is appropriate to the group of species cencused. Further, the effect of counting all other fishes on estimates of Type 1 fishes varied according to the relative abundance of the former: their effect was lowest when abundance of other fishes was lowest. There was a negative relationship between observer speed and estimated abundance for Type 1 fishes. Survey precision of Type 1 fishes was generally improved by surveying at slower observer speeds.
Similar content being viewed by others
References cited
Clarke, R.D. 1980. Habitat distribution and species diversity of chaetodontid and pomacentrid fishes near Bimini, Bahamas. Mar. Biol. 40: 277–289.
De Martini, E.E. & D. Roberts. 1982. An empirical test of biases in the rapid visual technique for species-time censuses of reef fish assemblages. Mar. Biol. 70: 129–134.
Ebeling, A.W. & R.N. Bray. 1976. Day versus night activity of reef fishes in a kelp forest off Santa Barbara, California. U.S. Fish. Bull. 74: 703–717.
Jarman, P.J. 1979. The types of information available from aerial surveys, and their applicability to management in aerial surveys of fauna populations. Australian National Parks and Wildlife Service, ANPWS, Canberra, ACT, Australia, Special Publication 1: 107–113.
Jones, R.S. & M.J. Thompson. 1978. Comparison of Florida reef assemblages using a rapid visual technique. Bull. Mar. Sci. 28: 159–172.
Keast, A. & J. Harker. 1978. Strip counts as a means of determining densities and habitat utilization in lake fishes. Env. Biol. Fish. 1: 181–188.
Kimmel, J.J. 1985. A new species-time method for visual assessment of fishes and its comparison with established methods. Env. Biol. Fish. 12: 23–32.
Lincoln Smith, M.P. 1985. The development and application of visual survey procedures for fish communities on shallow rockey reefs. MSc. Thesis, University of Sydney, Sydney. 187 pp.
Lincoln Smith, M.P. 1988. Effects of observer speed on sample counts of temperate rocky fish assemblages. Mar. Ecol. Prog. Ser. 43: 223–231.
Luckhurst, B.E. & K. Luckhurst. 1978. Analysis of the influence of substrate variables on coral reef fish communities. Mar. Biol. 49: 317–323.
Molles, M.C., Jr. 1978. Fish species diversity on model and natural reef patches: experimental insular biogeography. Ecol. Monogr. 48: 289–305.
Nolan, R.S., R.R. McConnaughey & C.R. Stearns. 1975. Fishes inhabiting two small nuclear test craters at Enewetak Atoll, Marshall Islands. Micronesica 11: 205–217.
Russell, B.C. 1977. Population and standing crop estimates for rocky reef fishes of north eastern New Zealand. N. Z. J. Mar. and Freshw. Res. 11: 23–26.
Russell, B.C., F.H. Talbot, G.R.V. Anderson & B. Goldman. 1978. Collection and sampling of reef fishes. pp. 329–345. In: D.R. Stoddart & R.E. Johannes, Coral Reefs: Research Methods UNESCO, Paris.
Sale, P.F. 1980. The ecology of fishes on coral reefs. Oceanogr. Mar. Biol. Ann. Rev. 18: 367–421.
Sale, P.F. & W.A. Douglas. 1981. Precision and accuracy of visual census techniques for this assemblages on coral patch reefs. Env. Biol. Fish. 6: 333–339.
Sale, P.F. & B.J. Sharp. 1983. Correction of bias in visual transect censuses of coral reef fishes. Coral Reefs 2: 37–42.
Sale, P.F., P.J. Doherty, G.J. Eckert, W.A. Douglas & D.J. Ferrell. 1984. Large scale spatial and temporal variation in recruitment to fish populations on coral reefs. Oecologia (Berlin) 64: 191–198.
Seigel, S. 1956. Non parametric statistics. McGraw Hill, Kogakusha. 312 pp.
Thompson, M.J. & T.W. Schmidt. 1977. Validation of the species/time random count technique sampling fish assemblages at the Dry Tortugas. Proc. 3rd. Int. Coral Reef Symp. 283–288.
Willan, R.C., J.M. Dollimore & J. Nicholson. 1979. A survey of fish populations at Karikari Penninsular, Northland, by SCUBA diving. N. Z. J. Mar. and Freshw. Res. 13: 447–448.
Williams, D.McB. 1986. Temporal variation in the structure of reef slope fish communities (central Great Barrier Reef): short-term effects of Acanthaster planci infestation. Mar. Ecol. Prog. Ser. 28: 157–164.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lincoln Smith, M.P. Improving multispecies rocky reef fish censuses by counting different groups of species using different procedures. Environ Biol Fish 26, 29–37 (1989). https://doi.org/10.1007/BF00002473
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00002473