Ecological damage assessment of jiaozhou bay reclamation based on habitat equivalency analysis

Abstract

Assessing the extent of habitat damage resulting from sea reclamation could help policy makers meet the necessary requirements for developing policies on marine ecological damage compensation and ecological restoration. Recently in China, increasing research has been conducted to monetize the ecological damage resulting from reclamation by using revealed and expressed preference techniques, such as travel cost and contingent valuation methods (CVM). The results provide new approaches to quantify ecological impacts, as well as socially and economically based management suggestions to inform policy makers. But the use of CVM, or other revealed preference techniques, for estimating non-use values remains controversial because these techniques tend to overstate actual losses. Habitat Equivalency Analysis (HEA) is a tool for assessing natural resource damage, and has been used in the United States and Europe to identify replacement habitats for a number of coastal habitats injured through oil spills, hazardous substance release, vessel groundings and other anthropogenic actions. Termed "service-to-service", this habitat-based approach seeks to determine the amount of restoration needed to compensate for natural resource losses. HEA is specifically used to find replacement habitats that can provide ecologically equivalent services to those that are lost from the damaged habitat. Jiaozhou Bay, a semi-enclosed bay supporting the coastal city of Qingdao, is undergoing rapid industrialization and urbanization, and facing huge pressure from reclamation to expand its usable space. Data from previous research shows that during 1958-2006, the Jiaozhou Bay's sea area was reduced by 33%, mainly as a result of reclamation. Focusing on the scale of reclamation of Jiaozhou Bay, and its ecological impact during 1988-2005, this paper assesses ecological damage using the HEA method. The results show that approximately 35 km2of Jiaozhou Bay has been reclaimed. The total damage to ecosystem services during 1988-2005 was 41.33%, which represented the combined damage to biological resources, tidal volume, environmental capacity, wetland landscape, and biodiversity. For a restoration project that reclaims farmland into sea, the scale of restoration should be 22.47 km2at the discount rate level of 5% to achieve the reclaimed sea's initial ecological service level. HEA is based on the provision of restoration services that are equivalent to the level of natural resource damage, and this method requires discounting the future cost and benefit. Parameter sensitivities are analyzed showing that the two parameters of restoration time and discount rate will affect the result significantly; the increased discount rate and restoration time will lead to a reduction in the restoration project area. Following damage to a natural area, a restoration project is urgently needed to reduce the resulting ecological damage. We conclude that HEA offers a viable alternative to traditional economic analysis when potential injuries to ecological services resulting from reclamation are being evaluated. Furthermore, our results could be used as a technical reference for local governments when conducting ecological restoration, as well as a tool for ecological compensation management for the highly efficient allocation of marine resources. The HEA method is only beginning to be applied in China, and theoretical discussions have not yet commenced. However, it provides promise for the continuation of in-depth empirical research into the future.