A.W. Kim

Organic and metal contamination in surface mangrove sediments of South China

Mangrove forests, the intertidal wetlands of the tropics and subtropics, are key ecological habitats that link terrestrial and marine environments. Mangrove forests and adjacent mudflats are increasingly impacted by urban/industrial development in the tropical coastal zone, suffering pollution from multiple sources including but not limited to municipal waste, aquaculture, mariculture and shipping as well as onshore industries and run-off from urban centres (Cuong et al. 2005; Huang et al. 2003; Zheng et al. 2000). Sediments that accumulate in mangroves are potential repositories of anthropogenic pollution because of high total organic carbon content, anaerobic properties and rapid turnover and burial (Marchand et al. 2005; Tam and Yao, 2002). The world wide denigration and loss of mangrove habitats is of global concern given they account for an estimated 11 % of the input of terrestrially-derived carbon into the ocean and about 10 % dissolved organic carbon (DOC) sourced from land; the long term effect of altering the carbon cycle is uncertain (Dittmar et al. 2006; Jennerjahn and Ittekkot, 2002). It has been widely postulated that mangroves afford physical protection against catastrophic storm events such as hurricanes and tsunamis (Alongi, 2007). Recent post-impact surveys along the Tamil Nadu coast follwing the 2004 Indian Ocean tsunami confirmed this notion and demonstrated that man-made structures built behind mangroves were significantly less damaged than their unprotected counterparts (Alongi, 2007).

Status of organic pollutants in surface sediments of Barnegat Bay-Little Egg Harbor Estuary, New Jersey, USA

Numerous surveys have demonstrated that diffuse pollution from urban-residential run-off and industrial discharges can adversely impact salt marsh and tidal creek sediment quality (Barrett & McBrien, 2006; Fox et al., 2001; Iannuzzi et al., 1995; Long et al., 1995; Sanger et al., 2004; White et al., 2005). The impact of shipping activities, including major discharge of fuel oil onto salt marshes, has also been reported (White et al., 2005). However, few studies have assessed organic pollution accumulating in salt marshes with watersheds that are mainly comprised of forests and wetlands but which have major residential areas located off-shore of the mainland. The salt marshes of Barnegat Bay-Little Egg Harbor Estuary, southeast New Jersey represent one such geographical setting (Fig .1). The shallow (17 m), narrow (3-9 mile) bay is separated from the Atlantic Ocean by a back barrier island complex (Long Beach Island) which is heavily developed and a major area of tourism (Fig. 1). The salt marshes are protected and managed as part of the Edwin B. Forsythe National Wildlife Refuge, this comprises 186 km of wetlands and 145 km of salt marshes and has a mixed pattern of watershed land use such as forestry (45.9 %), wetlands (25.2 %), urban/residential (19.5 %) and agricultural (6.6 %).

Sedimentary transport and fate of polycyclic aromatic hydrocarbons (PAH) from managed burning of moorland vegetation on a blanket peat, South Yorkshire, UK.

This study reports the concentrations of 18 polycyclic aromatic hydrocarbons (PAH) from managed burning of moorland vegetation and compares them to PAH in catchment vegetation, underlying peats, head water suspended sediment (HSS), stream water and reservoir sediment cores. Total PAH ranged from 203 to 11,112 μg/kg in the blanket peats, 101-290 μg/kg in the fresh moorland vegetation, 4186 μg/kg at the burnt site, 17,439 μg/kg in the HSS, 56 ng/L in the stream water and 987 to 7346 μg/kg in the reservoir sediments. No total or individual PAH concentrations exceeded the published sediment quality guidelines. The perylene content of selected moorland vegetation (sphagnum, heather and bilberry) ranged from 10 to 18% as compared to only 2% for the sediment hosted PAH. A comparison of whole and <250 μm fractions from the burnt surface layer revealed a near threefold increase in PAH concentration in the fine fraction and a change in the PAH distribution such that naphthalene>>phenanthrene>2-methylnaphthalene. Elevated total PAH contents were observed close to the blanket peat sediment surface (0-10 cm) and then declined at greater depths. The high PAH content of the HSS was attributed to the high sorption capacity of the organic-rich particles (TOC 25.8% (wt/wt)). The distribution of individual PAH in reservoir cores and HSS was consistent and the results of the principal component analysis and isomeric ratios suggest mainly pyrolytic inputs, from either vegetation burning and coal combustion. A comparison of the reservoir core PAH profiles shows that the source(s) have remained largely unchanged since the reservoir construction in 1929A.D. reflecting consistent moorland management practices.

Bioaccumulation surveillance in Milford Haven Waterway

Biomonitoring of contaminants (metals, organotins, polyaromatic hydrocarbons (PAHs), PCBs) was undertaken in Milford Haven Waterway (MHW) and a reference site in the Tywi Estuary (St Ishmael/Ferryside) during 2007–2008. Bioindicator species encompassed various uptake routes—Fucus vesiculosus (dissolved contaminants); Littorina littorea (grazer); Mytilus edulis and Cerastoderma edule (suspension feeders); and Hediste (=Nereis) diversicolor (sediments). Differences in feeding and habitat preference have subtle implications for bioaccumulation trends though, with few exceptions, contaminant burdens in MHW were higher than the Tywi reference site, reflecting inputs. Elevated metal concentrations were observed at some MHW sites, whilst As and Se (molluscs and seaweed) were consistently at the higher end of the UK range. However, for most metals, distributions in MH biota were not exceptional. Several metal-species combinations indicated increases in bioavailability upstream, which may reflect the influence of geogenic/land-based sources—perhaps enhanced by lower salinity. TBT levels in MH mussels were below OSPAR toxicity thresholds and in the Tywi were close to zero. Phenyltins were not accumulated appreciably in M. edulis, whereas some H. diversicolor populations appear subjected to localized (historical) sources. PAHs in H. diversicolor were distributed evenly across most of MHW, although acenaphthene, fluoranthene, pyrene, benzo(a)anthracene and chrysene were highest at one site near the mouth; naphthalenes in H. diversicolor were enriched in the mid-upper Haven (a pattern seen in M. edulis for most PAHs). Whilst PAH (and PCB) concentrations in MH mussels were mostly above reference and OSPAR backgrounds, they are unlikely to exceed ecotoxicological thresholds. Bivalve Condition indices (CI) were highest at the Tywi reference site and at the seaward end of MH, decreasing upstream—giving rise to several significant (negative) relationships between CI and body burdens. Despite the possible influence of salinity gradient as a complicating factor, multivariate analysis indicated that a combination of contaminants could influence the pattern in condition (and the biomarkers metallothionein and TOSC). Integrating bioaccumulation data with biological and biochemical endpoints is seen as a useful way to discriminate environmental quality of moderately contaminated areas such as MHW and to prioritise cause and effect investigations.

Construction and Evaluation of a Low Cost Interface for the Determination of Elemental Speciation by Gas Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometry (GC‐ICP‐MS)

Abstract The construction and evaluation of a low cost, easily demountable interface to couple capillary gas chromatography to inductively coupled plasma mass spectrometry detection is described. Using this interface, the capillary column can be maintained at a high temperature through to the tip of the torch injector using a transfer line heated by a combination of hot argon and electrical resistance. The interface is suitable for analytes with boiling points up to 230°C, allowing for the analysis of low and high boiling analytes in a single injection. The system was evaluated by the determination of the butyltin species in a marine sediment CRM using conventional calibration with tripropyltin dichloride as the internal standard and the measurement of methylmercury in a tuna fish CRM via species‐specific isotope dilution analysis. Detailed information on the design and construction of the interface are included to facilitate its construction and use by other workers.

PAH, PCB, TPH and mercury in surface sediments of the Delaware River Estuary and Delmarva Peninsula, USA

Surface sediment concentrations of polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB), total petroleum hydrocarbons (TPH) and mercury, were compared from two areas with contrasting land use history, the industrial Delaware Estuary and the rural Delmarva Peninsula (USA). TPH in the Delaware (38-616mg/kg) and saturate/aromatic fractions suggested petroleum/industrial sources compared to biogenic sources in the Delmarva coastal control (<34-159mg/kg). Within the Delaware the ∑PAH18 ranged from 3749 to 22,324μg/kg with isomeric ratios indicative of petroleum combustion source/s, conversely, those in the Delmarva (5-2139μg/kg) also yielded relatively higher perylene that were consistent with natural background levels derived from vegetation/coal combustion source/s. ∑PCB(tri-hepta) concentrations in the Delmarva (0.6-6.5μg/kg) were less than the threshold effect concentration (TEC), whereas the Delaware had received much higher PCB loading (18.1-136.8μg/kg) as evidenced by a significantly higher amounts in some samples (>TEC).

Molecular characterisation of dissolved organic matter (DOM) in ground waters from the Aspo underground research laboratory, Sweden : a novel "finger printing" tool for palaeohydrological assessment

The molecular signature of dissolved organic matter (DOM) in groundwaters can be used as a tool when investigating the palaeohydrological response of groundwater systems in relation to changes in recharge environment, and also for examining groundwater compartmentalisation, mixing and transport at underground repositories for radioactive waste. The DOM in groundwaters from two compartmentalised bodies of groundwater of distinctly different origin within the Aspo Underground Research Laboratory (URL), Sweden and in Baltic seawater has been isolated using tangential flow ultrafiltration (TUF) and diafiltration. Recoveries of DOM ranged from 34.7 to 0.1 mg/L with substantial differences in the concentrations of the groundwaters collected only 120 m apart. Analysis by infrared spectroscopy (IR) and pyrolysisgas chromatography-mass spectrometry (Py-GC-MS) of the isolated DOM revealed that the groundwaters contained abundant alkylphenols which may represent heavily decomposed proteins or lignins originating from biopolymers contained within soils. The difference in the distribution and relative abundance of major pyrolysis products groups such as alkyphenols confirmed that the groundwater and Baltic seawater DOM samples were chemically distinct indicating minimal infiltration of marine groundwater derived by recharge from the Baltic or earlier Littorina Sea within the two compartmentalised groundwater bodies.