8 ECOLOGICAL IMPACT Introduction 8.1 This Chapter Assesses The
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CE 20/96: Outlying Island Sewerage Scheme Stage 1 Phase II Package J – Sok Kwu Wan Sewage Collection, Treatment Drainage Services Department and Disposal Facilities - EIA Report 8 ECOLOGICAL IMPACT Introduction 8.1 This chapter assesses the impacts of the Project upon terrestrial ecology, intertidal ecology and subtidal ecology. 8.2 The Outlying Islands Sewage Scheme Stage 1 Phase II Package J consists of the provision of a sewer system for the Sok Kwu Wan area of Lamma Island as well as sewage treatment and disposal facilities. The sewer system includes pumping stations and gravity sewers/rising mains to collect and transfer the sewage and wastewater arising from the Sok Kwu Wan catchment area to the proposed sewage treatment and disposal facilities. The proposed sewage treatment and disposal facilities include a rising main from the proposed sewage treatment works to a submarine effluent outfall offshore. 8.3 Ecological baseline surveys including a dive survey were conducted from autumn 1998 to summer 1999. A verification survey was conducted in April 2002 to update and verify the ecological data collected. A coral mapping survey was also performed in May 2002. A detailed assessment of ecological impacts of the Project was made based on the baseline conditions. Efforts were made in the planning of the Project to avoid ecological impacts as much as possible. Mitigation measures were developed as necessary to minimize or reduce negative impacts to acceptable levels. Environmental Legislation, Policies, Plans, Standards and Criteria 8.4 The following Hong Kong SAR Government legislation and guidelines are relevant to the assessment of impacts to ecology: · Forests and Countryside Ordinance (Cap. 96); · Forestry Regulations (Cap. 96, subsidiary legislation); · Country Parks Ordinance (Cap. 208) and associated subsidiary legislation; · Marine Parks Ordinance (Cap. 476) and associated subsidiary legislation; · Town Planning Ordinance (Cap. 131); · Wild Animals Protection Ordinance (Cap. 170); · Animals and Plants (Protection of Endangered Species) Ordinance (Cap. 187); · Environmental Impact Assessment Ordinance (Cap. 499) and associated Technical Memorandum on Environmental Impact Assessment Process (the "TM"); and · "Guidelines for Implementing the Policy on Off-site Ecological Mitigation Measures" (PELB Technical Circular 1/97, Works Branch Technical Circular 4/97, dated 17 February 1997) (the "TC"). 8.5 This study also takes note of the following relevant international agreements: · Convention on Wetlands of International Importance Especially as Waterfowl Habitat ("Ramsar Convention"); · Convention on the Conservation of Migratory Species of Wild Animals ("Bonn Convention"); MAUNSELL Page 8/1 P:\A71097\REPORTS\Final EIA\Nov02\Sec_8-rev.doc CE 20/96: Outlying Island Sewerage Scheme Stage 1 Phase II Package J – Sok Kwu Wan Sewage Collection, Treatment Drainage Services Department and Disposal Facilities - EIA Report · Convention on International Trade in Endangered Species of Wild Fauna and Flora ("CITES"); and · Convention on Biological Diversity. Description of the Environment Recognised Sites of Conservation Importance 8.6 The following recognised sites of conservation importance are located at or near the study area and are shown in Figure 8.1: Potential Country Park: the South Lamma Country Park, south of Lo So Shing and excluding villages and residential areas, is one of the fourteen country parks proposed in the Territorial Development Strategy Review (Planning Department 1995). The waters to the west of Ha Mei Wan were identified in the Territorial Development Strategy Review as a ‘Significant Area’ for Marine Conservation (PELB 1998), as were the waters of the northern part of Tung O Bay. Identified as an ‘Unique Area’ for Marine Conservation (PELB 1998), the coastal waters of south Lamma are also a potential Marine Park. The potential South Lamma Marine Park would cover the waters south of Lo So Shing Beach, along the coastline of south Lamma, including Sham Wan, to the north boundary of Shek Pai Wan. Both hard and soft corals are known to occur here (Planning Department 1993). It lies over 2.5 km from the study area at its closest point. SSSI in Sham Wan: an area of 4 hectares including the sandy beach and the adjacent shallow shore in Sham Wan was designated as an SSSI on 3 June 1999. This area has been identified as important for Green Turtle Chelonia mydas nesting (Morton 1998). Restricted Area for green turtles in Sham Wan: The sandy beach of Sham Wan was designated on 30 July 1999 as a Restricted Area under the Wild Animals Protection Ordinance (Cap. 170), and is restricted for entry from 1 June to 31 October each year to protect breeding Green Turtles. South Lamma Island: south Lamma Island was designated as a Site of Special Scientific Interest (SSSI) in 1980. The objective was to protect the nesting habitats of White-bellied Sea Eagle Haliaeetus leucogaster and Bonelli’s Eagle Hieraaetus fasciatus near Mount Stenhouse. 8.7 No other designated, proposed or recognised sites of conservation importance lie within 5 km of the study area. Literature Review 8.8 A literature review was conducted to provide information on existing conditions in the study area and Lamma Island, and to identify habitats and species of potential importance that may be affected by the Project. Literature review included Government and private sector MAUNSELL Page 8/2 P:\A71097\REPORTS\Final EIA\Nov02\Sec_8-rev.doc CE 20/96: Outlying Island Sewerage Scheme Stage 1 Phase II Package J – Sok Kwu Wan Sewage Collection, Treatment Drainage Services Department and Disposal Facilities - EIA Report reports, independent and Government published literature and academic studies. Literature review included the following : · Marine Ecology of Hong Kong: Report on Underwater Dive Surveys (October 1991 - November 1994) (Binnie 1995). Dive surveys at 86 sites in central and eastern Hong Kong waters; · EIA for Outlying Islands Sewerage Stage 1 Phase 1 (Maunsell 1997); · Hong Kong Bird Reports (1992-1998); · Porcupine! Numbers 1 - 27 (Newsletter of Department of Ecology & Biodiversity, University of Hong Kong); · Hong Kong Amphibians and Reptiles (Karsen et al. 1998); · WWF's 1:50000 Hong Kong Vegetation Map (Ashworth et al. 1993); · Aerial photos (CN20772-4 taken in 1998, CN18882-5 taken in 1997) from the Hong Kong Government Map Office; · Avifauna of Hong Kong (Carey et al. 2001); and · Memoirs of Hong Kong Natural History Society. 8.9 Results of the literature review are discussed in Section “Description of the Environment”. Field Survey 8.10 Literature review was supplemented by field surveys. Field surveys were designed to fill data gaps which would prevent an adequate assessment of the project's impacts upon terrestrial, intertidal and subtidal ecology, and the development of appropriate mitigation measures. Four-season ecological surveys, including terrestrial flora survey, terrestrial fauna survey, avifauna survey, intertidal survey and dive survey, conducted between September 1998 to July 1999. A verification survey was conducted in April 2002 to update and verify the ecological data collected, and a coral mapping survey was performed in May 2002. 8.11 Sok Kwu Wan is a deep, rectangular embayment on the eastern coast of Lamma Island, lying southwest to northeast with its opening on the east side. The study area for ecology, based on the sewer alignment and the TM guideline setting the study area boundary 500m from the project boundary, was located south and east of Sok Kwu Wan including the shore line and the subtidal zone. MAUNSELL Page 8/3 P:\A71097\REPORTS\Final EIA\Nov02\Sec_8-rev.doc CE 20/96: Outlying Island Sewerage Scheme Stage 1 Phase II Package J – Sok Kwu Wan Sewage Collection, Treatment Drainage Services Department and Disposal Facilities - EIA Report Terrestrial Ecology Field Survey Methodology Habitats and Vegetation 8.12 Field surveys were performed on 22 September and 7 December 1998, and 19 March and 29 June 1999 to describe habitats and record plant species within the study area. Relative abundance of recorded plant species (common, occasional or rare) was also assessed. Sizes of each habitat type were estimated by manual grid count method. A verification survey was conducted in April 2002 to update habitats and species list. Efforts were made to find species protected under local regulations or known to be uncommon or rare on a regional or territorial basis. In this report, the conservation status of other plant taxa follows Xing et al. 2000. 8.13 A 1:5000 scale habitat map of the study area was produced based on 1997/8 Government aerial photographs, 1993 WWF's vegetation map and ground truthing. 8.14 Colour photographs were taken of all terrestrial habitat types surveyed and other features or species of conservation importance. Stream and Aquatic Fauna 8.15 A main stream to the east of Ling Kok Shan flowed into the south of Sok Kwu Wan, a further incision of the embayment. The outlet portion had been channelled. Several smaller streams joined it in the outlet portion. 8.16 Surveys of aquatic fauna were conducted in the streams by active searching in March and June 1999. Fauna observed were identified to the lowest practicable taxon and recorded. Birds 8.17 The bird communities of the terrestrial and coastal habitats in the study area were surveyed using the transect count method. Birds seen or heard within 25 m from the transect (1.75 km) (Fig. 8.2) were identified to species and counted. Surveys were carried out on 22 September (autumn survey), 7 December 1998 (winter survey), 19 March (spring survey) and 10 June 1999 (summer survey). Bird abundance was estimated as “birds ha-1”. Nomenclature, commonness and distribution of bird species in Hong Kong follows Viney et al. (1996), rarity and protection status of birds follows Zheng and Wang (1998). Results of birds in rocky shore habitats are reported in section “Inter-tidal Ecology” (Section 8.70). Mammals, Reptiles, and Amphibians 8.18 Mammals, reptiles and amphibians in the study area were surveyed by active searching on 22 September (autumn survey), 7 December 1998 (winter survey), 19 March (spring survey) and 10 June 1999 (summer survey).