Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Release of PAHs and heavy metals in coastal environments linked to leisure boats Jenny Egardt a, ⁎ , Martin Mørk Larsen b , Pia Lassen c , Ingela Dahllöf a a Department of Biological and Environmental Sciences, University of Gothenburg, Carl Skottsbergsgata 22B, 413 19 Göteborg, Sweden b Department of Bioscience – Marine Diversity and Experimental Ecology, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark c Department of Environmental Science – Environmental Chemistry and Toxicology, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark ARTICLE INFO Keywords: PAH Heavy metals Leisure boat WFD EQS ABSTRACT Leisure boats are responsible for elevated levels of heavy metals and PAHs in sediments in- and near marinas and natural harbours. As these compounds are released directly into the water column they also pose a threat to organisms in the pelagic environment. Passive samplers were deployed during peak and post tourist season in the water column of natural harbours, leisure boat waterways and small marinas to measure the dissolved fraction of PAHs and metal ions. Differences between seasons indicative of leisure boat activities were found as PAH composition differed between peak and post season for natural harbours and waterways, where heavier PAHs increased during peak season. During peak season, metal samplers were covered by biofouling, which likely affected the uptake. Post season metal concentrations differ between locations, with concentrations exceeding quality standards at near mainland locations where boats are maintained, compared to the sites in the archipelago. 1. Introduction Coastal areas around the world are used for recreation and private leisure boats are a common feature in these areas. In Sweden, 14% of households own at least one boat and it is estimated that the total number of leisure boats is around 500,000, excluding rowing boats and kayaks (STA, 2015). Leisure boats are associated with emissions of hazardous substances, such as Polycyclic Aromatic Hydrocarbons (PAHs) from exhaust fumes and uncombusted fuel, and heavy metals from antifouling paints that are mainly emitted when boats are moving, but also leach from hulls when boats are moored, albeit at a lower rate (Valkirs et al., 2003). Previous studies have shown a correlation between leisure boats and elevated levels of antifouling paint components and PAHs at heavily boated sites and small marinas (Boyle et al., 2016; Eklund et al., 2009). We have also shown that leisure boats are a likely source of banned antifouling substances like TBT (tributyltin) found in surface sediments of natural harbours (Egardt et al., 2017). The aim of this study was to investigate whether leisure boats also contribute to elevated water concentrations of PAHs, Cu and Zn, and if so, what parts of the coastal areas that are most at risk. Concentration limits for sediment and water have been set within the EU for hazardous substances that are deemed to be a risk to the aquatic environment, defined in the EUs Water Framework Directive (WFD) as Environmental Quality Standards (EQS). Compounds that are of extra concern are known as priority substances, (Directive 2008/ 105/EC, Annex II) which include five individual PAHs, with both an Annual Average (AA-EQS) and a maximum allowable concentration (MAC-EQS) that should not be exceeded (Directive 2000/60/EC; PAH- 5-6-rings EQS dossier, 2011; Directive 2013/39/EU). Legislation exist both on regional level within the WFD, and on national level in the member states. For other hazardous substances such as Cu and Zn, AA- EQS and MAC-EQS are defined on national level, and in Sweden these are set by the Agency for Marine and Water Management (HVMFS 2015:4, HVMFS 2013:19). PAHs are hydrophobic compounds, made up of two or more fused benzene rings (Cerniglia, 1992). They can be pyrogenic or petrogenic in origin, where pyrogenic are formed by incomplete combustion of or- ganic matter and fossil fuels, and petrogenic are natural components of coal and crude oil. Outboard engines release their exhaust fumes below the surface and thereby discharge PAHs directly into the water, but fuel is also release uncombusted. About one third of the boats in Sweden have engines that are of the older two-stroke model (> 25 years old), (STA, 2015) which have the highest release of uncombusted fuel. Even newer two-stroke engines wash out 20% of the fuel uncombusted. The four-stroke engines https://doi.org/10.1016/j.marpolbul.2017.12.060 Received 9 August 2017; Received in revised form 21 December 2017; Accepted 22 December 2017 ⁎ Corresponding author. E-mail address: jenny.egardt@bioenv.gu.se (J. Egardt). Marine Pollution Bulletin 127 (2018) 664–671 0025-326X/ © 2017 Elsevier Ltd. All rights reserved. T