Impacts of coastal land use change in the wet tropics on nearshore coral reefs: Case studies from Papua New Guinea. (July 2021)

• Record Type: Journal Article
• Authors: Turak, Emre; DeVantier, Lyndon; Szava-Kovats, Robert; Brodie, Jon
• Is Part Of: Marine pollution bulletin. Volume 168(2021)
• Publication Date: 2021-07
• Subjects: Nearshore reefs -- Reef-building corals -- Land-based impacts -- Sediment damage -- Oil palm -- Papua New Guinea; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2021.112445
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Logging and plantation agriculture are vital to economies and livelihoods in tropical nations, including Papua New Guinea. To meet global demand, hundreds of thousands of ha of diverse natural habitat have been logged, cleared and replaced with monoculture crops. Resulting hydrological changes have increased sediment, nutrient and pesticide runoff, impacting down-stream habitats. Here, case studies from Kimbe Bay (New Britain) and Mullins Harbour (Milne Bay), examine effects on nearshore coral reefs. In both places, logging and oil palm development had destabilized soils and removed or degraded riparian vegetation. Downstream, nearshore reefs had high silt levels, which, coincident with minor coral bleaching and predation by crown-of-thorns starfish, were correlated with high levels of coral mortality and low coral species richness. Sediment and related impacts can be reduced by effective catchment management, such as avoiding steep slopes, expanding stream and coastal buffer zones, minimizing fertilizer and pesticide use, monitoring and reactive management. Highlights: We examined impacts of coastal development on nearshore reefs in Papua New Guinea, where prior forestry and oil palm plantations had destabilized soils and altered hydrology Downstream sedimentation (silt cover) was significantly associated with high coral mortality and low species richness Comparison with coral cover data from a decade earlier indicated substantial declines on nearshore reefs Appropriate baseline information is crucial for effective monitoring and management Development should avoid steep slopes, and expand stream and coastal buffer zones