2003-044 - Laserfiche WebLink

Home Browse Search

IIn order to minimize confounding variables, an effort will be made to collect data in the same month of each monitoring year. Project effects will be separated from naturally occurring variation by concurrent sampling along control transects as outlined below . Sampling will be conducted annually, including a pre-construction sample, a sample in the summer immediately following construction, and for two subsequent summers . Invertebrate and algal abundance will be evaluated from digital photography of each quadrat. Species will be identified to the lowest practical taxon and ranked in order of abundance. Superimposing a grid over the digital image and counting bare and colonized grid squares or the use of a random-dot technique will assess overall percent cover (Bohnsack, 1979) . A total of 24 photoquadrats will thus be used to characterize reef I biota in the project area (two photo-quadrats per station, three stations per transect, four } transects) . Twelve photoquadrats will be used to evaluate the area downdrift of the project area (two photoquadrats per station, three stations per transect, two transects) . Species richness, total percent cover, and community structure (rank orders of species abundance) will be compared in the project area pre- and post-construction and between project and control reef areas . Additionally, the standing crop biomass of algae and invertebrates will be assessed at each photoquadrat station on the same schedule as the photoquadrat assessment above. At each station, a 1 Ox l Ocm plot will be identified and all materiel (Invertebrates, algae, and sediment) scraped from the surface. This may be accomplished in the field or by collection of an appropriate sized sample . The resulting materiel will then be sorted to the highest taxonomic level practical and dried to a constant weight. Measuring the relief at each of the photoquadrat stations will assess changes in vertical relief possibly caused by sand movement. Measurements will be taken with a weighted flexible tape from a point one meter shoreward of the quadrat benchmark to the surface of the water and from the top of the reef structure at the benchmark to the surface of the water, with the difference being the relief. The mean of five such measurements will be used to assess changes in relief. Changes in relief at the control reef photoquadrat stations will be assessed by the same method. Concurrent with each photoquadrat sampling, underwater video footage will be collected along the length of each transect. This footage will provide a qualitative overview of conditions in both construction and control areas . . 11