Field comparison of passive sampling and biological approaches for measuring exposure to PAH and alkylphenols from offshore produced water discharges

Polycyclic aromatic hydrocarbons (PAH) and alkylphenols (AP) that are present in routine discharges of produced water (PW) from the offshore industry continue to cause concern. The suitability of biological methods and chemical based passive samplers to determine exposure to these compounds was tested by deploying them around an oil installation and at reference locations in the North Sea. PAH and AP were analysed either as parent compounds in passive samplers and mussel tissue or as metabolites in fish bile. Generally the pattern of exposure relative to proximity to the discharge was represented by mussels, SPMDs and fish for PAH. Fish and SPMDs showed good correlation for PAH accumulations, whereas some differences were apparent between mussels and SPMDs. POCIS was the only technique tested that could accurately measure the most abundant AP in PW. The advantages of biologically independent measures of exposure for inclusion in discharge monitoring studies are outlined.     

Macrobenthic community response to copper in Shelter Island Yacht Basin, San Diego Bay, California

We examined Cu contamination effects on macrobenthic communities and Cu concentration in invertebrates within Shelter Island Yacht Basin, San Diego Bay, California. Results indicate that at some sites, Cu in sediment has exceeded a threshold for “self defense” mechanisms and highlight the potential negative impacts on benthic faunal communities where Cu accumulates and persists in sediments. At sites with elevated Cu levels in sediment, macrobenthic communities were not only less diverse but also their total biomass and body size (individual biomass) were reduced compared to sites with lower Cu. Cu concentration in tissue varied between species and within the same species, reflecting differing abilities to “regulate” their body load. The spatial complexity of Cu effects in a small marina such as SIYB emphasizes that sediment-quality criteria based solely on laboratory experiments should be used with caution, as they do not necessarily reflect the condition at the community and ecosystem levels.     

Bacterioplankton dynamics along the gradient from highly eutrophic Pearl River Estuary to oligotrophic northern South China Sea in wet season: implication for anthropogenic inputs

Bacterioplankton abundance (BA) and biomass (BB) from the eutrophic Pearl River Estuary (PRE) to the oligotrophic northern South China Sea (NSCS) were studied in the wet season. BA was significantly higher (p < 0.05) in PRE (12.51 ± 3.52 × 10⁸ cells L⁻¹), than in the continental shelf neritic province (CSNP, 4.95 ± 2.21 × 10⁸ cells L⁻¹) and in the deep oceanic province (OP, 3.16 ± 1.56 × 10⁸ cells L⁻¹). Nutrient-replete PRE waters (DIN > 100 μM and PO₄ > 1 μM) resulted in high chl a and BB, whereas nutrient-depleted offshore waters (DIN <5 μM and PO₄ < 0.5 μM) had low biomass. Temperature (>26 °C) was not the controlling factor of BA. BB was significantly correlated with chl a biomass both in PRE and NSCS. The bacteria to phytoplankton biomass (BB/PB) ratio increased clearly along the gradient from near-shore PRE (0.15) to offshore CSNP (0.93) and deep OP (2.75), indicating the important role of small cells in the open ocean compared to estuarine and coastal zones.     

Harmful algal bloom species and phosphate-processing effluent: field and laboratory studies

In 2002, the Florida Department of Environmental Protection began discharging phosphate-processing effluent into Bishop Harbor, an estuary within Tampa Bay. Because of concerns that the effluent would serve as a nutrient source for blooms of the toxic dinoflagellate Karenia brevis, a field monitoring program was established and laboratory bioassays were conducted. Several harmful algal bloom (HAB) species, including Prorocentrum minimum and Heterosigma akashiwo, were observed in bloom concentrations adjacent to the effluent discharge site. Blooms of diatoms were widespread throughout Bishop Harbor. K. brevis was observed with cell concentrations decreasing with increasing proximity to the effluent discharge site. Bioassays using effluent as a nutrient source for K. brevis resulted in decreased cell yields, increased growth rates, and increased time to log-phase growth. The responses of HAB species within Bishop Harbor and of K. brevis to effluent in bioassays suggested that HAB species differ in their response to phosphate-processing effluent.     

Sorption behavior of phenanthrene in Yangtze estuarine sediments: sequential separation

In the present study, phenanthrene was chosen as the probe compound for determining the sorption of PAHs in sediments from Yangtze estuary and nearby coastal area, China. Sorption isotherms were fitted well by the Freundlich and dual models, respectively. Selected sediments were further sequentially separated to remove the carbonate and organic carbon (OC). Calculated OC sorption capacity values based on both H₂O₂ oxidization and 375 °C combustion methods were similar and comparable to the K_oc values estimated by the empirical linear sorption equations. Both sorption models and sorption data using sequentially separated samples achieve the similar conclusions: (1) the partition behavior dominated by OC in sediments with f_oc > 0.01; (2) for sediments with 0.001 < f_oc < 0.01, OC dominated sorption at relatively high aqueous concentration; whereas mineral phase adsorption dominated sorption at lower concentration especially when C_w/S_w was in the range of 0.0001-0.001 in natural aqueous system.     

Metal concentrations in water and sediments from tourist beaches of Acapulco, Mexico

A survey on the metal concentrations (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, Zn) in beach water and sediments is reported from the tourist destination of Acapulco city on the Pacific coast of Mexico. The concentration of dissolved trace metals (DTMs) in beach water and acid leachable trace metals (ALTMs) in sediments indicated that they are anthropogenic in nature due to the increased tourist activities in the crowded beach locations. The statistical analysis indicates Fe and Mn play a major role as metal scavengers in both the medium (water and sediment) and the higher value of other metals is site specific in the study area, indicating that they are transported from the local area. Comparison results suggest that the beach water quality has deteriorated more than the sediments and special care needs to be taken to restore the beach quality.     

Impacts of maintenance dredged material disposal on macrobenthic structure and secondary productivity

The results of a monitoring programme to assess the spatial impacts associated with ongoing dredged material disposal activity at a dispersive, coastal disposal site (southwest UK) are described. Benthic impacts were assessed using benthic community structure and secondary productivity estimates.Analyses of univariate indices (including secondary production) and multivariate community structure revealed differences between stations inside and those outside the disposal site were minimal. Generally, stations within and outside the disposal site were characterised by the same species. Regression models indicated that the variability in biological structure and secondary production was predominantly accounted for by natural variables (e.g., depth, sediment granulometry) with only a small amount of residual variability being due to contaminant variables. Thus, the elevated levels of certain contaminants in the vicinity of the disposal area were not sufficient to result in significant ecological or ecotoxicological changes. We ascribe such findings partly to the dispersive nature of the disposal site.     

Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico

Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g⁻¹), followed by Selenium (10.92 μg g⁻¹). The mean concentration of toxic metal Cadmium was 6.12 μg g⁻¹ and 1.01 μg g⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn > Se > Ni > Cu > Mn > Cd > Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.