Assessment of the effects of a marine urban outfall discharge on caged mussels using chemical and biomarker analysis

To assess the presence of endocrine disruptors in treated marine outfall discharges and their possible effects, mussels (Mytilus galloprovincialis) were caged in the environmental mixing zone of the outfall of the Santander sanitation system and in one control area. After 30, 60 and 90 days, samples were collected to perform chemical analyses (metals, anionic surfactants, alkylphenols, bisphenol A, phthalates and estrogenic hormones), biomarkers of general stress (lysosomal membrane stability-LMS, histopathology) and biomarkers of endocrine disruption (vitellogenin-like proteins and gonad index). There were no significant differences between outfall and control sites on contaminant levels, except for 4-tert-octylphenol which was higher in the outfall site. Bacteriological counts were higher in the outfall area. No relevant differences in biomarkers were detected between treated and control mussels. A significant reduction in LMS occurred in both groups after 90 days caging, indicating a stress situation possibly related to caging or to post-spawning reproductive state.     

Characterization of spatial patterns in river water quality using chemometric pattern recognition techniques

This study employed three chemometric data mining techniques (factor analysis (FA), cluster analysis (CA), and discriminant analysis (DA)) to identify the latent structure of a water quality (WQ) dataset pertaining to Kinta River (Malaysia) and to classify eight WQ monitoring stations along the river into groups of similar WQ characteristics. FA identified the WQ parameters responsible for variations in Kinta River's WQ and accentuated the roles of weathering and surface runoff in determining the river's WQ. CA grouped the monitoring locations into a cluster of low levels of water pollution (the two uppermost monitoring stations) and another of relatively high levels of river pollution (the mid-, and down-stream stations). DA confirmed these clusters and produced a discriminant function which can predict the cluster membership of new and/or unknown samples. These chemometric techniques highlight the potential for reasonably reducing the number of WQVs and monitoring stations for long-term monitoring purposes.     

Macrobenthic community structure in the northern Saudi waters of the Gulf, 14 years after the 1991 oil spill

The 1991 Gulf oil spill heavily impacted the coastal areas of the Saudi waters of the Arabian Gulf and recent studies have indicated that even 15 years after the incident, macrobenthos had not completely recovered in the sheltered bays in the affected region such as, Manifa Bay. This study investigates the community conditions of macrobenthos in the open waters in one of the impacted areas, Al-Khafji waters, about 14 years after the spill. Diversity measures and community structure analyses indicate a healthy status of polychaete communities. The BOPA index reveals that oil sensitive amphipods were recolonized in the study area. This confirms that the benthic communities of the oil spill impacted area had taken only <14 years to recover in the open waters of the impacted areas. The study also reveals the existence of three distinct polychaete communities along the depth and sediment gradients.     

Rapid increase in copper concentrations in a new marina, San Diego Bay

Concentrations of copper in water rose rapidly following the introduction of boats to a new marina in San Diego Bay. Two months after the marina reached half its capacity, a majority of water samples exceeded chronic and acute criteria for dissolved copper, and copper concentrations in several samples exceeded the highest concentrations observed in another marina that has been listed as an impaired water body. A box model suggested that a small fraction of the leached copper was sequestered in sediment. Copper concentrations in water entering the marina from the bay was more than half the chronic concentration limit, so only 50% of marina boat capacity could be accommodated without exceeding the chronic criterion more than 50% of the time. Copper concentrations in water may increase rapidly following boat introduction in small marinas, but could return to pre-introduction levels by controlling boat numbers or reducing use of copper-based paints.     

Evaluation of the presence of major anionic surfactants in marine sediments

The contamination of aquatic environments has become the focus of increasing regulation and public concern due to their potential and unknown negative effects on the ecosystems. The present work develops a monitoring and statistical study, based on the analysis of variance test (ANOVA) and the multivariable analysis, both for insoluble soap and LAS in order to compare the behavior of different anionic surfactants in this environmental compartment. First, a novel and successfully validated methodology to analyze insoluble soap in these samples is developed. The matrix effect and the comparison of different extraction techniques were also performed. The optimized analytical methodologies were applied to 48 representative samples collected from the Almeria Coast (Spain) and then a statistical analysis to correlate anionic surfactant concentration and several variables associated with marine sediment samples was also developed. The results obtained showed relevant conclusions related to the environmental behavior of anionic surfactants in marine sediments.     

A Paddock to reef monitoring and modelling framework for the Great Barrier Reef: Paddock and catchment component

Targets for improvements in water quality entering the Great Barrier Reef (GBR) have been set through the Reef Water Quality Protection Plan (Reef Plan). To measure and report on progress towards the targets set a program has been established that combines monitoring and modelling at paddock through to catchment and reef scales; the Paddock to Reef Integrated Monitoring, Modelling and Reporting Program (Paddock to Reef Program). This program aims to provide evidence of links between land management activities, water quality and reef health. Five lines of evidence are used: the effectiveness of management practices to improve water quality; the prevalence of management practice adoption and change in catchment indicators; long-term monitoring of catchment water quality; paddock & catchment modelling to provide a relative assessment of progress towards meeting targets; and finally marine monitoring of GBR water quality and reef ecosystem health. This paper outlines the first four lines of evidence.     

Relationship between metal enrichments and a biological adverse effects index in sediments from Todos Santos Bay, northwest coast of Baja California, México

In 1992 and 2004, heavy metals concentrations were measured in surficial sediments from Todos Santos Bay, located in Ensenada, Baja California, Mexico. The aim was to search for relationships between metal enrichment factors and a biological adverse effects index. Unlike Ni, the elements Cd, Cu and Zn showed significant correlations (p<0.05) between enrichment factors and the biological adverse effects index. Cu showed a 0.74:1 relationship, which means that any enrichment above 0.74 could represent biological adverse effects. On the other hand, Cd and Zn enrichments must be >5.5 and >1.5, respectively, in order for the sediments to be considered toxic. In general, data showed that most of the metal concentrations in Todos Santos Bay sediments could not cause adverse effects to biota. Only Ensenada's harbor and the zone next to a dredging dumping site showed metal enrichments that could be toxic.     

Ecosystem under pressure: ballast water discharge into Galveston Bay, Texas (USA) from 2005 to 2010

Ballast water exchange processes facilitate the dispersal and unnatural geographic expansion of phytoplankton, including harmful algal bloom species. From 2005 to 2010, over 45,000 vessels (≈ 8000 annually) travelled across Galveston Bay (Texas, USA) to the deep-water ports of Houston (10th largest in the world), Texas City and Galveston. These vessels (primarily tankers and bulkers) discharged ≈ 1.2 × 10(8) metrictons of ballast water; equivalent to ≈ 3.4% of the total volume of the Bay. Over half of the ballast water discharged had a coastwise origin, 96% being from US waters. Galveston Bay has fewer non-indigenous species but receives a higher volume of ballast water discharge, relative to the highly invaded Chesapeake and San Francisco Bays. Given the magnitude of shipping traffic, the role of Galveston Bay, both as a recipient and donor region of non-indigenous phytoplankton species is discussed here in terms of the invasibility risk to this system by way of ballast water.     

Heavy metal pollution in sediments of a typical mariculture zone in South China

The heavy metal inventory and the ecological risk of the estuarine sediments in Hailing Bay, an important maricultural zone along the southern coast of China, were investigated. Results show that the surface sediments were mainly polluted by As (2.17-20.34 mg/kg), Ni (1.37-42.50mg/kg), Cu (1.21-58.84 mg/kg) and Zn (11.69-219.22 mg/kg). Furthermore, the aquafarming zone was significantly more polluted than the non-aquafarming zone, and cluster analysis suggested additional sources of heavy metal input in the aquafarming zone. As, Cr, Cu, Ni, Pb and Zn were mainly present in the non-bioavailable residual form in the surface sediments, whereas Cd was predominantly in the highly mobile acid soluble and reducible fractions. The ecological risk of the polluted sediments stemmed mainly from Cd, and from As, Cu and Pb to less degrees. The highest potential risks occurred near the aquaculture base, indicating the need to control heavy metal inputs from aquafarming activities.     

Benthic recovery after fish farming cessation: a "beyond-BACI" approach

The development of a benthic environment after fish-farming cessation was examined. To ascertain whether recovery occurred, several abiotic (granulometry, acid-volatile sulfides, total phosphorus and redox potential) and biotic (polychaete abundance) variables were monitored using a "beyond-BACI" approach. Before the cessation of farming, the geochemical conditions and polychaete assemblages differed among the impacted and control sites. After cessation, an improvement of the geochemical conditions was achieved. A significant tendency toward a recovery of the polychaete assemblage in the impacted area was observed, but significant differences still remained compared with the control sites. The acid-volatile sulfide level was responsible for these differences. The abundance of polychaete families associated with organically enriched sediments diminished at the impacted site after cessation, whereas the abundance of some sensitive and omnivorous families increased. The "beyond-BACI" approach provided a wider framework than other approaches, enabling us to differentiate the natural variability from those changes induced by the fish farm and farming cessation.