Heavy metals in river and coast sediments of the Jakarta Bay region (Indonesia) — Geogenic versus anthropogenic sources Sven Sindern a, ⁎, Martin Tremöhlen a , Larissa Dsikowitzky b , Lars Gronen a , Jan Schwarzbauer b , Tuti Hartati Siregar c , Farida Ariyani c , Hari Eko Irianto d a Institute of Applied Mineralogy and Mineral Deposits, RWTH Aachen University, Germany b Institute of Geology and Geochemistry of Petroleum and Coal (GGPC), RWTH Aachen University, Lochnerstraße 4-20, 52056 Aachen, Germany c Research Center and Development for Marine and Fisheries Product Processing and Biotechnology (BBP4BKP), Ministry of Marine Affairs and Fisheries, Jl. K.S. Tubun, Petamburan VI, Jakarta 10260, Indonesia d Research Center for Fisheries Management and Conservation (P4KSI), Ministry of Marine Affairs and Fisheries, Jl. Pasir Putih II, Ancol Timur, Jakarta 14430, Indonesia abstract article info Article history: Received 28 September 2015 Received in revised form 16 March 2016 Accepted 2 June 2016 Available online xxxx Sediment geochemistry of the Jakarta region, a densely populated tropical coast, is studied — with particular focus on rivers discharging to Jakarta Bay. Weathering volcanics in the river catchment area control the compo- sition of major elements, As, Cr and in part Cu. In contrast, Zn, Ni, Pb and partly Cu are affected by anthropogenic sources, mainly in central Jakarta City. The data reflect a high variability of local emission sources, among which metal processing industries, fertilizers or untreated animal waste may be important. In particular, the role of street dusts is emphasized. Locally, heavy metals reach levels considered to have adverse biological effects. River discharge leads to anthropogenic enrichment of heavy metals in the coastal sediments. Element data also show geogenic effects on the composition of the coastal sediments, such as mixing of detrital silicates with bio- genic carbonates as well as suspended particulate matter from the ocean. © 2016 Elsevier Ltd. All rights reserved. Keywords: River sediment Heavy metals Coastal megacity Tropical coastal ecosystem Jakarta Indonesia 1. Introduction The chemical composition of sediments is on the one hand con- trolled by geogenic components, such as detrital minerals or precipi- tates formed in the water, biogenic minerals or organic matter. On the other hand, the chemical composition of sediments is affected by an- thropogenic emissions. The latter may be present as particulate matter or organic and inorganic contaminants adsorbed to geogenic components. This can well be observed in sediments of densely populated coasts, such as Jakarta Bay, the area which is addressed in this study. Sources of sedimentary components in coastal areas are local river discharges, suspended particulate matter in the oceanic water column, particles de- rived from Aeolian transport or volcanic fallouts as well as biogenic mat- ter or chemical precipitates formed in the coastal water column. The chemical composition of Jakarta Bay sediments and the anthro- pogenic input of heavy metals were in detailed studied by Williams et al. (1997, 2000). According to these studies, the trace metals V, Cr, Co and Ni are mainly controlled by the abundance of geogenic argillaceous terrestrial material whereas Cu, Zn, Pb and Sn derive from anthropogen- ic municipal and industrial sources. This is confirmed by results of Takarina (2010) and Zuraida et al. (2012), who also reported on heavy metal contamination of the Jakarta Bay sediments. On the basis of 210 Pb geochronology, analysis of heavy metals and Pb isotopes, Hosono et al. (2011) showed the onset of the anthropogenic input of heavy metals in the 1920s and a significant increase of Zn and Pb accumulation between the 1970s and the end of the 1990s. Despite of stricter environmental regulations in Indonesia, which are in line with decreasing Pb and Zn concentrations in younger sediments (Hosono et al., 2011), anthropogenic metal discharge to the Jakarta Bay ecosystem still is significant. This is corroborated by other studies, which point to increasing metal contamination in the Jakarta Bay (Takarina, 2010). Enhanced metal contamination in combination with other human-induced stressors is also considered to have caused ad- verse effects on marine communities in the Jakarta Bay (van der Meij et al., 2009, 2010, Cleary et al., 2014, Dsikowitzky et al., in press-a). Dis- charge of untreated municipal wastewaters was shown to be most rel- evant for water quality (Dsikowitzky et al., in press-b). Most rivers debouching into the Jakarta Bay pass densely populated and industrially affected areas, their sediments certainly act as a first Marine Pollution Bulletin xxx (2016) xxx–xxx ⁎ Corresponding author. E-mail addresses: sindern@rwth-aachen.de (S. Sindern), larissa.dsikowitzky@emr.rwth-aachen.de (L. Dsikowitzky), jan.schwarzbauer@emr.rwth-aachen.de (J. Schwarzbauer). MPB-07767; No of Pages 10 http://dx.doi.org/10.1016/j.marpolbul.2016.06.003 0025-326X/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Please cite this article as: Sindern, S., et al., Heavy metals in river and coast sediments of the Jakarta Bay region (Indonesia) — Geogenic versus anthropogenic sources, Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2016.06.003