1.1 Monitoring of the relocated seagrass bed (Halophila beccarii) for survival and growth at Pak Nai was required to be conducted quarterly during the construction phase of the Project as specified in Section 6.2.3 of the EM&A Manual.
1.2 Equipment used for monitoring included a 50x50cm quadrat, measuring ruler, digital camera and handheld GPS.
1.3 Monitoring was conducted at the 4 locations (A, B, C and D) on the intertidal flats at Pak Nai as shown in Figure 1.1.
1.4 Sediment plugs on the intertidal flats at Pak Nai were relocated using visual markers that had been placed at each location at the time of transplantation, and using GPS. Care was taken not to disturb each site by avoiding trampling.
1.5 At each location (dimensions of 1.5 x 1.5m), monitoring was conducted by our ecologist to measure presence/absence of seagrasses and seagrass cover. Monitoring also included observations on seed germination, leaf size and general condition of any seagrass present.
1.6 The eighth quarterly survey to monitor the seagrass transplantation sites (A, B, C and D) was conducted on 16 September 2005 following relocation of sediment plugs in September 2003. A photographic record of each transplantation site is presented in Figure 1.2.
1.7 During the monitoring visit, seagrass were found to occur at two transplantation sites - Sites A and C.
Site A
1.8 Seagrasses were found at Site A in previous surveys but were considered to have spread into the transplantation site from the adjacent existing seagrass bed. Coverage within the transplantation area totalled no more than 1%.
Site C
1.9 During the December 2004 survey a small number of about half a dozen seagrass leaves were found at the edge of the transplantation site in one of the corners. It was considered that this seagrass has spread into the transplantation site from seagrasses growing immediately adjacent to the transplantation site and were not derived from germination of seeds in transplanted surface sediment. By the June 2005 surveys, seagrass growth both within and adjacent to the transplantation site was found to be copious and very dense, with coverage within the site estimated at 32%. During the September 2005 surveys, coverage had spread to approximately 70% of the transplantation site.
Sites B and D
1.10 At transplantation sites B and D, close observation of the mud surface did not detect the presence of any seagrasses. At sites B and D, no seagrass plants were present growing on the sediment previously identified as supporting seagrass in the EIA report. Although the transplanted sediment may contain seeds derived from previously existing seagrasses growing on the sediment, monitoring observations revealed no evidence of germination since the previous monitoring survey.
1.11 Monitoring of relocated sediment plugs was conducted at 4 locations on the Pak Nai intertidal flats on September 16 2005. Seagrasses were observed at two locations (Sites A and C). At both locations, it was considered these seagrass shoots have spread to inside the transplantation site from adjacent existing seagrass beds and were not derived from germination of seeds contained in the transplanted sediment plugs. At the two other locations (Sites B and D) monitoring observations indicated that there was no evidence of seed germination despite the possibility that the relocated sediment may contain seeds deposited by seagrasses living on it that had since disappeared.