Non-proportional bioaccumulation of trace metals and metalloids in the planktonic food web of two Singapore coastal marine inlets with contrasting water residence times

11 pages, 5 figures, 5 tables, 1 appendix supplementary data https://dx.doi.org/10.1016/j.scitotenv.2016.03.234.-- This work is a contribution to the consolidated research group 2014 SGR 498 of the Generalitat de Catalunya

We analyzed the concentrations of trace metals/metalloids (TMs) in the water, sediment and plankton of two semi-enclosed marine coastal inlets located north of Jurong Island and separated by a causeway (SW Singapore; May 2012-April 2013). The west side of the causeway (west station) has residence times of approximately one year, and the east side of the causeway (east station) has residence times of one month. The concentrations of most of the TMs in water and sediment were higher in the west than in the east station. In the water column, most of the TMs were homogeneously distributed or had higher concentrations at the surface. Preliminary evidence suggests that the TMs are primarily derived from aerosol depositions from oil combustion and industry. Analyses of TMs in seston (>. 0.7 μm; mostly phytoplankton) and zooplankton (>. 100 μm) revealed that the seston from the west station had higher concentrations of most TMs; however, the concentrations of TMs in zooplankton were similar at the two stations. Despite the high levels of TMs in water, sediment and seston, the bioaccumulation detected in zooplankton was moderate, suggesting either the presence of effective detoxification mechanisms or/and the inefficient transfer of TMs from primary producers to higher trophic levels as a result of the complexity of marine planktonic food webs. In summary, the TM concentrations in water and seston are not reliable indicators of the bioaccumulation at higher trophic levels of the food web

This work was funded through grant MadeInPlankton from Singapore National Parks Board - Singapore (NParks) and DHI-NTU Research Centre and Education Hub, Ung EliteForsk grants 10-093759 and 10-094773 from the Danish Ministry for Independent Research to GD, and Projects PROTOS (CTM2009-08783), TOPCOP (CTM2011-23480) and FERMI (CGL2014-59227-R) from the Spanish Ministry of Economy and Competitiveness to AC

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