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A More Cost-Effective EMAP-Estuaries Benthic Macrofaunal Sampling Protocol
Steven P. Ferraro 1, Faith A. Cole 1 and Anthony R. Olsen 2
1 U.S. Environmental Protection Agency (USEPA), ORD, Newport, Oregon
2 U.S. Environmental Protection Agency (USEPA), ORD, Corvallis, Oregon
The standard benthic macrofaunal sampling protocol in the U.S. Environmental Protection Agency's Pacific Coast Environmental Monitoring and Assessment Program (EMAP) is to collect a minimum of 30 random benthic samples per reporting unit (e.g., estuary) using a 0.1 m2 grab and to sort out macrofauna using a 1.0 mm mesh screen. Benthic macrofaunal community conditions are then characterized by cumulative distribution functions on endpoints of interest, for example, number of species (S), abundance (A), and Shannon-Wiener diversity (H'). We conducted an EMAP-Estuaries study in Tillamook Bay, Oregon, in which benthic macrofaunal samples were collected using both the standard (0.1 m2 × 7 cm deep) and a much smaller (0.01 m2 × 5 cm deep) sample unit. After performing a linear scale transformation on the smaller sample unit data to adjust for mean shift and scale change, there was no significant difference between S, A, and H' cumulative distribution functions for the standard and the smaller sample unit data. Benthic macrofaunal samples collected using the smaller sample unit were, on average, about ten times easier, faster, and less costly to process yet just as effective for characterizing benthic macrofaunal conditions in Tillamook Bay as those collected using the standard sample unit. If the smaller sample unit used in this study is confirmed to be generally as effective in characterizing benthic conditions as the current standard EMAP sample unit, its adoption as a new standard would greatly increase the cost effectiveness of future EMAP-Estuaries studies.
Keywords: benthic macrofauna, cost-effective, sample unit, monitoring, estuaries, and EMAP.