Tonga: environmental impact assessment, Fiji-Tonga cable system
The development of many Pacific island countries has long been hampered by small and dispersed populations and vast ocean distances but Landcare Research scientists are helping to minimise what is often to referred to as the ‘digital divide’.
Peter Newsome led a team undertaking the environmental impact asessment of a proposed underwater fibre-optic cable from Fiji to Tonga which, if delivered, could provide the advantages of secure, high-capacity, high-speed and lower cost communications to Tonga, which is vital for improved economic and social development.
But, building and maintaining a cable that would stretch 800km along ecologically sensitive, and seismically, volcanically and tectonically active seabed carries some environmental risks and impacts, and that was where the skills of Landcare Research staff were utilised. Mr Newsome worked alongside James Comley from the University of the South Pacific in Suva, in a collaboration made simpler following the signing of a Memorandum of Understanding between Landcare Research and the university just months earlier.
Their study was based on an extensive literature search in material relating to the locality, the subject domain, and the proposed development. It included extensive consultations with government and private-sector agencies and individuals and the team also visited Fiji and Tonga inspecting the nearshore environment in the vicinity of the proposed landings, including consulting and observing customary users of that environment. Numerous hazards and risks were identified including hazards to the cable from fishing around seamounts, hydrothermally altered water in volcanic vent zones, and future mining in mineralised areas. The simplest – and recommended - mitigation measure in these situations is avoidance.
Meanwhile, significant hazards from the cable (or the cable-laying operation) are to cetaceans, caused by sonar operations by survey and cable-laying vessels. The mitigation measures recommended here are a combination of avoidance (of the whale migrating season) and suspension of activities where conflict is anticipated or observed.
In the Tongan coastal environment there are potential threats to the cable from fishing, shipping and dredging, which requires mitigation in the form of notification and operational awareness. Potential impacts from the cable are in respect to coral reef communities, seagrass beds, aquaculture, and subsistence fishing. Mitigation measures proposed to reduce these effects to low or not-significant levels are a combination of avoidance and minimisation. However, Mr Newsome and Mr Comley’s report concluded that the impact of the proposed cable after all mitigation measures were applied was of low, not-significant, or no environmental or social impact and was a positive economic and social development outcome for the Kingdom of Tonga.
Tonga Cable Ltd funded the EIA which was a necessary step in the investment processes for the Asian Development Bank and the World Bank who are interested in financing this important infrastructure project.