. The ecological impact of beach nourishment with dredged materials on the intertidal zone at Bogue Banks, North Carolina . 5 cm 5 cm p cm 2 cm 'â 5 cm cm 10 cm cm box cm NUMBER OF CORES, CORE DIAMETER, AND TOTAL AREA SAMPLED BY EACH METHOD Figure 11. Measures of macrofaunal community structure per sampling effort using various sampling devices (5- and 10-centimeter cores and a box). The numbers next to the X-axis represent the number of cores treated as one sample; the number just below is the interior diameter of the coring device; and the bottom number is the tot
. The ecological impact of beach nourishment with dredged materials on the intertidal zone at Bogue Banks, North Carolina . 5 cm 5 cm p cm 2 cm 'â 5 cm cm 10 cm cm box cm NUMBER OF CORES, CORE DIAMETER, AND TOTAL AREA SAMPLED BY EACH METHOD Figure 11. Measures of macrofaunal community structure per sampling effort using various sampling devices (5- and 10-centimeter cores and a box). The numbers next to the X-axis represent the number of cores treated as one sample; the number just below is the interior diameter of the coring device; and the bottom number is the total surface area sampled. All cores were taken to a depth of 15 centimeters. each species. Figure 11 shows no change after three 10-centimeter cores for Simpson's (1949) Index of Dominance, and little change for Shannon-Weaver's (1963) Index of Diversity or Pielou's (1966) Index of Equitability. Since the box method was unwieldy in the swash zone, impossible in the surf zone, and very time consuming, the method of sampling selected was three 10-centimeter cores taken to a depth of 15 centimeters and treated as one sampling unit. Coring was chosen over other sampling methods such as trenching because cores represent discrete sampling units and make statistical analysis more meaning- ful (Cox, 1976). Figure 12 represents a schematic cross section of a typical sandy beach. The X-axis indicates distributional variations perpendicular to the waterline and is usually related to tidal flux. Faunal zonation due to tidal influence has been well documented by Dahl (1953), Cox (1976), and Leber (1977). There- fore, each tidal zone was sampled in order to establish a complete concept of the distribution of the macrofauna and any changes that may occur with time or changing beach configuration. 21
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectecology
