Coral Reefs

, Volume 4, Issue 1, pp 41–44 | Cite as

Estimating length frequency distributions of large reef fish underwater

  • J. D. Bell
  • G. J. S. Craik
  • D. A. Pollard
  • B. C. Russell


We describe the training of divers to recognise and remove bias in estimating lengths of fish underwater. Divers were asked to allocate objects, from a population (N=50) with a known length frequency distribution, to ten 100 mm size classes. Observed and expected distributions were then compared and the divers informed of their errors. Training continued until divers consistently produced length frequency distributions that were not significantly different from the expected distribution (α=0.8) by the one sample Kolmogorov-Smirnov (K-S) test. Divers were trained in five trials, but after six months they had lost all their ability and had to be retrained. Three trained divers observing the “same” population of the large reef fish Plectropomus leopardus (Serranidae) produced length frequency distributions that were not significantly different (P>0.1) on 67% of occasions. Data collected by divers can be used to detect small but real differences in length frequency distributions of populations when analysed using the two sample K-S test. We suggest a means of determining within site variation in length frequency relative to between site variation.


Frequency Distribution Size Classis Sedimentology Reef Fish Site Variation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bell JD (1983) Effects of depth and marine reserve fishing restrictions on the structure of a rocky reef fish assemblage in the north-western Mediterranean Sea. J Appl Ecol 20:357–369Google Scholar
  2. Bell JD, Galzin R (1984) Influence of live coral cover on coral-reef fish communities. Mar Ecol Prog Ser 15:265–274Google Scholar
  3. Brock VE (1954) A preliminary report on a method of estimating reef fish populations. J Wild Manag 18:297–308Google Scholar
  4. Burchmore JJ, Pollard DA, Bell JD, Middleton MJ, Pease BC, Matthews J (1985) Comparison of natural and artificial rocky reef fish communities in Botany Bay, New South Wales, Australia. Bull Mar Sci (in press)Google Scholar
  5. Choat JH (1968) Feeding habits and distribution of Plectropomus maculatus (Serranidae) at Heron Islands. Proc R Soc Queensl 80:13–17Google Scholar
  6. Craik W (1979) Survey identifies trends in reef fish catches. Aust Fish 38:29–32Google Scholar
  7. Craik GJS (1981a) Recreational fishing on the Great Barrier Reef. Proc 4th Int Coral Reef Symp 1:47–52Google Scholar
  8. Craik GJS (1981b) Underwater survey of coral trout Plectropomus leopardus (Serranidae) populations in the Capricorn Section of the Great Barrier Reef Marine Park. Proc 4th Int Coral Reef Symp 1:53–58Google Scholar
  9. GBRMPA (1979) Great Barrier Reef Marine Park Authority Workshop on Reef Fish Assessment and Monitoring. Workshop Series No 2, GBRMP, TownsvilleGoogle Scholar
  10. Goeden GB (1979) Is the Great Barrier Reef being overfished? Aust Fish 38:18–20Google Scholar
  11. Harmelin-Vivien ML, Harmelin JG (1975) Presentation d'une methode d'evaluation “in situ” de la faune ichtyologique. Trav Sci Parc Nat Port-Cros 1:47–52Google Scholar
  12. Keast A, Harker J (1977) Strip counts as a means of determining densities and habitat utilization patterns in lake fishes. Environ Biol Fish 1:181–188Google Scholar
  13. Leum LL, Choat JH (1980) Density and distribution patterns of the temperate marine fish Cheilodactylus spectabilis (Cheilodactylidae) in a reef environment. Mar Biol 57:327–337Google Scholar
  14. Nikolskii GV (1969) Theory of fish population dynamics as the biological background for rational exploitation and management of fishery resources. Oliver & Boyd, LondonGoogle Scholar
  15. Russell BC (1977) Population and standing crop estimates for rocky reef fishes of north-eastern New Zealand. NZ J Mar Freshwater Res 11:23–36Google Scholar
  16. Sale PF (1974) Mechanisms of coexistence in a guild of territorial fishes at Heron Island. Proc 2nd Int Coral Reef Symp 1:193–206Google Scholar
  17. Sale PF, Sharp BJ (1983) Correction for bias in visual transect censuses of coral reef fishes. Coral Reefs 2:37–42Google Scholar
  18. Siegel S (1956) Non-parametric statistics for the behavioural sciences. McGraw Hill, KogakushaTokyoGoogle Scholar
  19. Thompson R, Munro JL (1978) Aspects of the biology and ecology of Caribbean reef fishes: Serranidae (hinds and groupers). J Fish Biol 12:115–146Google Scholar

Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • J. D. Bell
    • 1
    • 2
  • G. J. S. Craik
    • 3
  • D. A. Pollard
    • 1
  • B. C. Russell
    • 4
  1. 1.Division of FisheriesNew South Wales Department of AgricultureHaymarketAustralia
  2. 2.School of Biological SciencesMacquarie UniversityNorth RydeAustralia
  3. 3.Great Barrier Reef Marine Park AuthorityTownsvilleAustralia
  4. 4.Northern Territory MuseumDarwinAustralia

Personalised recommendations