Marine Benthic Diversity: A Comparative Study

TLDR

The study presents a rarefaction‑based methodology for measuring marine benthic diversity from actual samples. Using rarefaction, the authors performed within‑habitat analyses of bivalve and polychaete communities across gradients of latitude, depth, temperature, and salinity, and compared the method to other diversity indices on identical data. Diversity values correlated strongly with physical stability and historical conditions, supporting a stability‑time hypothesis that predicts diversity in unstudied environments; species‑number metrics proved more reliable than percentage‑composition metrics, and rarefaction agreed well with the Shannon‑Wiener index while other indices were sensitive to sample size.

Abstract

In this paper a methodology is presented for measuring diversity based on rarefaction of actual samples. By the use of this technique, a within-habitat analysis was made of the bivalve and polychaete components of soft-bottom marine faunas which differed in latitude, depth, temperature, and salinity. The resulting diversity values were highly correlated with the physical stability and past history of these environments. A stability-time hypothesis was invoked to fit these findings, and, with this hypothesis, predictions were made about the diversities present in certain other environments as yet unstudied. The two types of diversity, based on numerical percentage composition and on number of species, were compared and shown to be poorly correlated with each other. Our data indicated that species number is the more valid diversity measurement. The rarefaction methodology was compared with a number of diversity indexes using identical data. Many of these indexes were markedly influenced by sample size. Good agreement was found between the rarefaction methodology and the Shannon-Wiener information function.