Can We Estimate Molluscan Abundance and Biomass On the Continental Shelf?
Coastal Sciences, Gulf Coast Research Laboratory
Few empirical studies have focused on the effect of sample density on the estimate of abundance of the dominant carbonate-producing fauna of the continental shelf. Here, we present such a study and consider the implications of suboptimal sampling design on estimates of abundance and size-frequency distribution. We focus on a principal carbonate producer of the U.S. Atlantic continental shelf, the Atlantic surfclam, Spisula solidissima. To evaluate the degree to which the results are typical, we analyze a dataset for the principal carbonate producer of Mid-Atlantic estuaries, the Eastern oyster Crassostrea virginica, obtained from Delaware Bay. These two species occupy different habitats and display different lifestyles, yet demonstrate similar challenges to survey design and similar trends with sampling density. The median of a series of simulated survey mean abundances, the central tendency obtained over a large number of surveys of the same area, always underestimated true abundance at low sample densities. More dramatic were the trends in the probability of a biased outcome. As sample density declined, the probability of a survey availability event, defined as a survey yielding indices >125% or
Estuarine, Coastal and Shelf Science
Powell, E. N.,
Mann, R. L.,
Kuykendall, K. M.,
Long, M. C.
(2017). Can We Estimate Molluscan Abundance and Biomass On the Continental Shelf?. Estuarine, Coastal and Shelf Science, 198(A), 213-224.
Available at: https://aquila.usm.edu/fac_pubs/14930