MEPS 284:1-8 (2004)  -  doi:10.3354/meps284001

Estimation of species richness: analysis of the methods developed by Chao and Karakassis

Karl I. Ugland, John S. Gray*

Section of Marine Biodiversity, Department of Biology, University of Oslo, Pb 1066 Blindern, 316 Oslo, Norway
*Corresponding author. Email:

ABSTRACT: The number of studies on marine biological diversity is increasing rapidly. One of the primary goals of such studies is to estimate how many species occur in a given area. Both parametric and non-parametric methods have been developed to make such estimates. Here, we examine 2 categories of methods: one proposed by Chao (1984) Scand J Statist 11:265-270 and one by Karakassis (1995) Mar Ecol Prog Ser 120:299-303. Foggo et al. (2003) Mar Ecol Prog Ser 248:15-26 recently compared these methods. By examining the bases for the methods, we show that both give large underestimates of the likely number of species in a given area, and an alternative solution is suggested.


KEY WORDS: Species richness · Extrapolation · Accumulation · Large samples · Sampling effort


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