PARENT SESSION
Poster Session #24: Plankton.
Wednesday, August 8, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall

Accounting for spatial variability in the design of sampling programs for migrating Chaoborus larvae.

PERSAUD, ANURANI¹, YAN, NORMAN^{1, 2}, ^{1 2}

ABSTRACT- We developed a model to estimate the number of net hauls (n) needed to quantify the mean abundance (m) of vertically migrating species of Chaoborus larvae - C. flavicans, C. punctipennis and C. trivittatus - in the entire pelagic zone of temperate lakes at a specified level of precision (P=SE/m, where SE = Standard Error). The model was n=1.94*m^-0.30*P^-2. It was derived by combining Taylor's Power law with a model that estimates sample size at a specified level of precision. The model indicates that for a typical temperate-lake with a Chaoborus population of 50 larvae/m3, 15 net hauls are required to obtain a precision of 0.2. As the precision of a single pelagic, vertical haul is only 50%, the role of Chaoborus in food webs should only be quantified with multi-station sampling programs.

KEY WORDS: Chaoborus, spatial variability, migrating, multi-station sampling