Impacts of exhaust gas cleaning systems (EGCS) discharge waters on planktonic biological indicators

Abstract

Exhaust Gas Cleaning Systems (EGCS), operating in open-loop mode, continuously release acidic effluents (scrubber waters) to marine waters. Furthermore, scrubber waters contain high concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and alkylated PAHs, potentially affecting the plankton in the receiving waters. Toxicity tests evidenced significant impairments in planktonic indicators after acute, early-life stage, and long-term exposures to scrubber water produced by a vessel operating with high sulphur fuel. Acute effects on bacterial bioluminescence (Aliivibrio fischeri), algal growth (Phaeodactylum tricornutum, Dunaliella tertiolecta), and copepod survival (Acartia tonsa) were evident at 10 % and 20 % scrubber water, while larval development in mussels (Mytilus galloprovincialis) showed a 50 % reduction at ∼5 % scrubber water. Conversely, larval development and reproductive success of A. tonsa were severely affected at scrubber water concentrations ≤1.1 %, indicating the risk of severe impacts on copepod populations which in turn may result in impairment of the whole food web

This paper has been produced as part of the European Union project “EMERGE: Evaluation, control and Mitigation of the EnviRonmental impacts of shippinG Emissions” (referred to as “EMERGE”). The EMERGE project has received funding from the European Union's Horizon - Research and Innovation Framework Programme2020 action under grant agreement No 874990. M. Gros acknowledges her Ramon y Cajal contract (RYC2020-030324-I) funded by the MCIN/AEI 10.13039/501100011033 by “ESF Investing in your future”