Abstract
The effects of fish length on visual estimates of fish abundance and biomass are assessed based on analyses of size frequency distributions. A 2 cm change in the specified minimum size of fish surveyed produced a calculated change of 14.5 to 126% in numerical estimates. A change of 28.4 to 411% was calculated for a 4 cm change. The extent of the change in the numerical estimate varies with the family considered but, in all cases, was most marked if the specified minimum size was decreased. The effects upon biomass estimates are less marked. In the Scaridae, for example, there is a calculated change of 4.1 to 7.4% for a 2 cm change in the minimum specified size. The changes in the estimates are discussed in relation to the use of visual survey techniques for assessing reef fish standing stocks.
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Bell JD, Craik GJS, Pollard DA, Russell BC (1985) Estimating length frequency distributions of large reef fish underwater. Coral Reefs 4:41–44
Bellwood DR (1986) The functional morphology, systematics and ecology of parrotfishes (family Scaridae). Unpublished PhD thesis, James Cook University of North Queensland, Australia
Bouchon-Navaro Y, Harmelin-Vivien ML (1981) Quantitative distribution of herbivorous reef fishes in the Gulf of Aquaba (Red Sea). Mar Biol 63:79–86
Brock RE (1982) A critique of the visual census method for assessing coral reef fish populations. Bull Mar Sci 32:269–276
Choast JH, Bellwood DR (1985) Interactions amongst herbivorous fishes on a coral reef: influence of spatial variation. Mar Biol 89:221–234
Craik GJS (1981) Underwater survey of coral trout Plectropomus leopardus (Serranidae) populations in the Capricornia Section of the Great Barrier Reef Park. Proc 4th Int Coral Reef Symp 1:53–58
Fowler AJ (1987) The development of sampling strategies for population studies of coral reef fishes. A case study. Coral Reefs 6:49–58
Goldman B, Talbot FH (1976) Aspects of the ecology of coral reef fishes. In: Jones OA, Endean R (eds) Biology and geology of coral reefs, vol III: Biology 2. Academic Press, New York, pp 125–154
Harmelin-Vivien ML, Bouchon-Navaro Y (1981) Trophic relationships among chaetodontid fishes in the Gulf of Aquaba (Red Sea). Proc 4th Int Coral Reef Symp 2:537–544
Randall JE (1963) An analysis of the fish populations of artificial and natural reefs in the Virgin Islands. Caribb J Sci 3:1–16
Russ G (1984a) Distribution and abundance of herbivorous grazing fishes in the central Great Barrier Reef. I. Levels of variability across the entire continental shelf. Mar Ecol Prog Ser 20:23–34
Russ G (1984b) Distribution and abundance of herbivorous grazing fishes in the central Great Barrier Reef. II. Patterns of zonation of midshelf and outershelf reefs. Mar Ecol Prog Ser 20:35–44
Russ G (1985) Effects of protective management of coral reef fishes in the central Philippines. Proc 5th Int Coral Reef Symp 4:219–224
Sale PF, Sharp BJ (1983) Correction for bias in visual transect censuses of coral reef fishes. Coral Reefs 2:37–42
Savina GC, White AT, Torrequemada E, Adanza A (1986) Description and analysis of the fish yield from the coral reef and deep water areas surrounding Pamilacan Is., Bohol, Philippines. First Asian Fisheries Forum, Manila, Philippines, May 1986. Scientific Sessions Abstracts, p 239
Thresher RE, Gunn JS (1986) Comparative analysis of visual census techniques for highly mobile, reef-associated piscivores (Carangidae). Environ Biol Fish 17:93–116
Williams DMcB (1982) Patterns in the distribution of fish communities across the central Great Barrier Reef. Coral Reefs 1:35–43
Williams DMcB (1983) Longitudinal and latitudinal variations in the structure of reef fish communities. In: Baker JT, Carter RE, Sammarco PW, Stark K (eds) Proceedings of the Inaugural Great Barrier Reef Conference, Townsville, Australia. James Cook University Press, Townsville, pp 265–270
Williams DMcB, Hatcher AI (1983) Structure of fish communities on the outer slopes of inshore, midshelf and outershelf reefs of the Great Barrier Reef. Mar Ecol Prog Ser 10:239–250
Zar JH (1974) Biostatistical Analysis. Prentice-Hall, Englewood Cliffs, NJ
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Bellwood, D.R., Alcala, A.C. The effect of a minimum length specification on visual estimates of density and biomass of coral reef fishes. Coral Reefs 7, 23–27 (1988). https://doi.org/10.1007/BF00301978
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DOI: https://doi.org/10.1007/BF00301978