Local and Regional Impacts of Pollution on Coral Reefs along the Thousand Islands North of the Megacity Jakarta, Indonesia

Abstract

Worldwide, coral reefs are challenged by multiple stressors due to growing urbanization, industrialization and coastal development. Coral reefs along the Thousand Islands off Jakarta, one of the largest megacities worldwide, have degraded dramatically over recent decades. The shift and decline in coral cover and composition has been extensively studied with a focus on large-scale gradients (i.e. regional drivers), however special focus on local drivers in shaping spatial community composition is still lacking. Here, the spatial impact of anthropogenic stressors on local and regional scales on coral reefs north of Jakarta was investigated. Results indicate that the direct impact of Jakarta is mainly restricted to inshore reefs, separating reefs in Jakarta Bay from reefs along the Thousand Islands further north. A spatial patchwork of differentially degraded reefs is present along the islands as a result of localized anthropogenic effects rather than regional gradients. Pollution is the main anthropogenic stressor, with over 80% of variation in benthic community composition driven by sedimentation rate, NO2, PO4 and Chlorophyll a. Thus, the spatial structure of reefs is directly related to intense anthropogenic pressure from local as well as regional sources. Therefore, improved spatial management that accounts for both local and regional stressors is needed for effective marine conservation.

Spatio-Temporal Patterns in Coral Reef Communities of the Spermonde Archipelago, 2012–2014, I: Comprehensive Reef Monitoring of Water and Benthic Indicators Reflect Changes in Reef Health

“…The increase in live coral and CCA cover further offshore demonstrates the influence of increasing water quality on community structure with distance from the coast. This pattern along a cross-shelf gradient is evident in other reef systems within Indonesia (Baum et al, 2015;Breckwoldt et al, 2016;Cleary et al, 2016) and around the world (Grigg, 1995;Mallela et al, 2004;Fabricius et al, 2005;Lirman and Fong, 2007) that are directly influenced by heavily populated cities on the coastline. Coastal areas along the Great Barrier Reef, Australia similarly showed community shifts from phototrophic invertebrates to macroalgae and heterotrophic invertebrates under high nutrient and sediment loads (Fabricius et al, 2012).…”

“…This in turn could negatively impact the fish species that rely on live coral cover (Alvarez-Filip et al, 2011), while other species could benefit from the new habitat composition (Öhman et al, 1997). However, the relationship between water quality and benthic composition can be even more complex due to seasonal and inter-annual variation in weather conditions that alters the composition of land-based effluents and their resultant water quality gradients (Alvarez-Filip et al, 2011;Baum et al, 2015). Mitigating the impacts that affect coral reefs can only be accomplished once the source of the impact has been identified.…”

Influence of predation risk on the sheltering behaviour of the coral-dwelling damselfish, Pomacentrus moluccensis

“…1). Most of these islands are flat, small-sized (<10 ha), and relatively close to each other (Madduppa et al 2013;Baum et al 2015). Four patch reef sites were selected, aiming to include a range of low-to-high predator abundance.…”

Analysis of Water Quality to Industrial and Residential Development Area in Bogor, West Java, Indonesia (A Case Study)

“…Because the industrial environment is growing so fast, research should be done regularly to check the industry's impact on water quality [3][4][5][6]. Bogor areas is close to Jakarta, which has many pollution studies [7][8][9][10][11][12][13][14][15], Bogor itself has been studied for the open space and pollution [9,16,17]. The open space research was supported by the study of social welfare and young generation under the Ministry of Young and Sport Of Republic Indonesia [18][19][20].…”