Coral reefs facing to global and regional environmental changes Hiroya Yamano (National Institute for Environmental Studies) Importance of coral reefs Photo: H. Kan Photo: H. Kayanne Biodiversity Fisheries Tourism Natural breakwater Island and beach maintenance Estimated value for the ecosystem service $375,000,000,000/year =$6,075/ha/year (Wilkinson, 2002) Geomorphic type of coral reefs Coral reefs of Japan Fringing reef Barrier reef Atoll ReefBase (http://www.reefbase.org) 1
Recent decline of coral reefs 50% Sea surface temperature rise Ocean acidification Terrestrial input (sediment/nutrient discharge) Overuse Combined effect of global and regional stresses 0 Coral cover in the Caribbean region Gardner et al. (2005) 1980 1990 2000 year Nutrients Phase shift of coral reefs Fishing pressure Red: High risk Yellow: Medium risk Blue: Low risk Healthy Reefs at Risk (http://www.reefbase.org) High risk is suggested for fringing reefs close to land Declined Bellwood et al. (2004) Sea surface temperature rise and coral bleaching Red-soil runoff 1998 summer S Harii http://www.kahaku.go.jp/ 2
Overfishing/ destructive fishing t/year 2000 Fishing in Okinawa Possible combined effect (SST rise and terrestrial influence) on bleaching 0 1973 1978 1983 1988 1993 1998 year Overfishing of herviborous fish Blast fishing Coral reef decline Ishigaki Island (with rivers) Miyako Island (without rivers) Significant difference in the number of points with coral bleaching http://www.coremoc.go.jp Classification of coral reefs from conservation and management perspectives Coral reef conservation for the GBR Type coral reefs Asia Type Close to densely populated land High human impact Red: High risk Yellow: Medium risk Blue: Low risk Great Barrier Reef Type Remote from land low human impact Conservation and management for the Asia Type is needed Zoning plan (http://www.gbrmpa.gov.au) Protected area Regulation may work Fisheries area 3
Coral reef conservation for the Asia Type coral reefs Coastal fisheries Conservation and restoration is possible Local society River discharge Landfill Breakwater Dredging Facing to global and regional environmental changes Sustainable coexistence between human and coral reefs is required Climate change Healthy coral community on artificial breakwater at Naha Port Okinawa Declaration on Conservation and Restoration of Endangered Coral Reefs of the World (2004) 1) achieve sustainable fishery on coral reefs 2) increase effective marine protected areas on coral reefs 3) ameliorate land-use change impacts 4) develop technology for coral reef restoration. Sectors working for coral reef conservation Administration Research Society 4
Ministry of the Environment -Action plan for coral reef conservation -MPA (Marine Protected Area) networking (2007~) Administration Okinawa Prefecture -Regulation to reduce redsoil inflow (1995~) Reef connectivity SST rise Sea-level rise 20 km Maintenance mechanism for coral reef communities Evaluation of combined effect of global and local stresses Material cycle Research Society Coexistence Biodiversity Terrestrial input Japanese Coral Reef Society (1997~) MEXT Research Project: Coral Reef Science (2008~) Community-based management International Year of the Reef (2008) Identification of causes and thresholds Cultivation Restoration techniques Effective Marine Protected Areas Transplantation Reef connectivity 20 km Resource management, Resilience enhancement 5
Community-based management Kerama Islands, Japan Effective MPA 20 km Sustainable use Integrated Coastal Zone Management Networking Researcher Stakeholders Local people Government Amelioration of terrestrial influence Restoration Kakibana (2008) Some are based on traditional knowledge of resource management Mapping and monitoring Community-based monitoring programs Remote sensing ReefCheck http://www.reefcheck.org/ Reports 80 In-situ monitoring 60 40 20 0 1997 1998 1999 2000 Conservation and management planning Evaluation of the effectiveness of the conservation action http://www.sangomap.jp CoralWatch http://www.coralwatch.org/ 6
Regulation Administration Interactions Networking (Interpreter) Research Society Identification of causes and thresholds (stress reduction, MPA areas, etc.) Adaptive management (case examples) International Year of the Reef ICRI NGO http://www.iyor.jp/ http://www.coralreefscience.jp/english/ 7
2007 WGWG ML ML Coral Watch http://www.coralwatch.org/j a http://interpreter.ne.jp/umibe/ C http://coralnetwork.jp/reefche ck http://www.sangomap.jp WG WG WG WG ML 2007 http://www.coremoc.go.jp 1 2007 http://www.coremoc.go.jp/ 2008 hyamano@nies.go.jp Coral: animal with symbiotic algae Life cycle of corals Dispersal Fertilization Planulae http://www.kahaku.go.jp/ Spawning S Harii 8
Just before spawning Spawning Acropora millepora Acropora millepora S Harii S Harii Slicks with eggs Planulae 200µm Settlement Polyp Heron Island GBR S Harii S Harii 9
Polyp (3 weeks after settlement) Corals accumulate to form coral reefs 1994 Acropora millepora S Harii Countries formed by coral reefs Maldives Landsat ETM+ image Fongafale Islet, Tuvalu (photo: H. Kayanne) 10