2006-205 - Laserfiche WebLink

Home Browse Search

hardbottom, sediment over benthos (where the underlying fauna cannot be identified due to the sediment cover) , and sand . The remainder of the 150-meter video transect shall be reviewed for qualitative changes in benthic community cover/composition in comparison to the pre-construction surveys, previous annual surveys, and the reference sites. If the qualitative review of the video transect suggests sedimentation impacts or cross-shore transport of sediments over the benthic community along the remaining portions of the transect, and the results of the sedimentation monitoring and quadrat assessments indicate burial of hardbottom communities, additional quantitative analysis of the video transects shall be required as directed by the Department to determine the extent of the project-related impacts. Quadrat sampling During each survey , a 0.25 square meter gridded quadrat will be sampled by the diver/biologist at a several point-intercept locations along the 150-meter long transects. The first quadrat will be located at the nearshore hardbottom edge . If the hardbottom edge consists of a vertical ledge, one quadrat will be located along the vertical/sub- vertical face, a second quadrat will be located at the top of the ledge along at the horizontal face of the ledge, and the third quadrat shall be placed at the 5-meter mark along the transect. Additional quadrat sampling shall occur along each transect to capture changes in benthic landscape (physical relief, species dominance/abundance, presence of stony corals/octocorals along or immediate adjacent to the transect) . If the transect crosses a sand gap (i.e. trough) , a quadrat shall be sampled at the seaward edge of the exposed hardbottom , and at the west edge of hardbottom east of the sand gap (i . e. on the horizontal face of the crest of the next ledge). The distance across the sand gap shall be noted and is included within the 150-meter length of the transect. Quadrats shall not be placed in the sand gaps between hardbottom ridges. Each 150- meter transect shall have approximately 9-10 quadrats. A list of the locations of the quadrats along each transect with a description of the quadrat location/benthic community shall be provided to the Department after transect establishment. Parameters for Quadrat Sampling Within each quadrat, visual estimate of percent cover and genus/species identification shall be performed in-situ for the following functional groups: macroalgae (overall percent cover and identification/percent cover of two dominant species within quadrat), microalgae/cyanobacteria, encrusting calcareous algae, sponges (genus level) , with a separate assessment of percent cover of boring sponge (Cliona spp) , tunicates (with identification of dominant genera), zoanthids (genus level), hydroids, wormrock (Phragmatopoma lapidosa) , octocorals (genus level) , and scleractinian corals (species level) . Individual counts shall be conducted for all octocorals, scleractinian corals, sponges (not including Cliona spp. which shall be assessed for percent cover) , solitary tunicates, urchins, and holothuroids within the quadrat. Scleractinian corals and octocorals shall also be assessed for size class distribution : size class 1 : < 5 cm diameter of scleractinian/height of octocoral ; size class 2 : 5 cm to 15 cm diameter of scleractinian/height of octocoral; size class 3: 15 to 25 cm diameter of scleractinian/height of octocoral; and size Gass 4: >25 cm diameter of scleractinian/height of octocoral) . Maximum and average algal height of the two C1Do eft ar WhVsyona wgIL=1 Settlrgl% wrwy kte RmXOIK2M2 sox FPlAI.d 3