Feathers are useful to determine mercury (Hg) contamination. We evaluated the mercury concentration in feathers of Magellanic penguins (Spheniscus magellanicus) age 1.5years to 25years at Punta Tombo, Argentina before and during their molt. Mercury ranged between <1.4 and 367ng/gdryweight, with three extreme high values (8996ng/g, 3011ng/g and 1340ng/g) all in young adults. The median concentration was lowest for juveniles and significantly higher for adults but with high variation among older adults. Males and females had similar mercury loads. Compared with other penguin species, concentrations in Magellanic penguins were low. Mercury levels for Magellanic penguins in the Southwest Atlantic for older adults averaged 206±98ng/g, and serve as a baseline for biomonitoring and/or ecotoxicological studies.

Vertical profiles of dissolved and particulate Mn, Fe, Ni, Cu, Zn, Cd, Pb, and ²³⁴Th were determined in the Hung-Tsai Trough off southwestern Taiwan during 19–23 November, 2004. Except in the case of Cd, the distribution coefficient (Kd) of the trace elements showed a negative correlation with the suspended particle concentration. Based on the average Kd values, the general sequence of particle affinities for the eight trace elements is, from highest to lowest, Fe>Mn≈Pb>Zn≈Th>Cd≈Cu≈Ni. The trace metal data was coupled with the particle removal flux estimated from ²³⁴Th/²³⁸U disequilibrium to investigate metal removal by particle sinking from the euphotic layer. The residence time of trace elements with respect to particle removal from the euphotic layer was estimated. A negative correlation between the residence time and the distribution coefficient for the trace metals was found.

In Stone Town, Zanzibar, sewage treatment is minimal, with a biological oxygen demand reduction to 60% and no removal of bacteria or nutrients. Here, Stone Town’s sewage pollution was studied by measuring Enterococci and NH₄ ⁺ concentrations in seawater and δ¹⁵N of benthic organisms; samples were collected along the Stone Town shoreline and from offshore coral reefs. Public perceptions of sewage pollution were investigated via interviews. Enterococci from the Stone Town shoreline exceeded USEPA guidelines for recreational use. Benthic organisms from two of the four reefs were relatively enriched (δ¹⁵N>10‰), indicative of sewage derived N. δ¹⁵N values of organisms from Stone Town exceeded 16‰. A strong correlation was found between Enterococci and δ¹⁵N across sites, while step-wise regression indicated rainfall and tidal stage as important predictors for bacterial concentrations. These data provide an important impact assessment from which the efficacy of future policy and management change can be assessed.

Rare earth elements (REE) were analyzed in surface sediments from the Guadiana Estuary (SW Iberian Pyrite Belt). NASC (North American Shale Composite) normalized REE patterns show clearly convex curvatures in middle-REE (MREE) with respect to light- and heavy-REE, indicating acid-mixing processes between fluvial waters affected by acid mine drainage (AMD) and seawater. However, REE distributions in the mouth (closer to the coastal area) show slightly LREE-enriched and flat patterns, indicating saline-mixing processes typical of the coastal zone. NASC-normalized ratios (La/Gd and La/Yb) do not discriminate between both mixing processes in the estuary. Instead, a new parameter (EMREE) has been applied to measure the curvature in the MREE segment. The values of EMREE>0 are indicative of acid signatures and their spatial distribution reveal the existence of two decantation zones from flocculation processes related to drought periods and flood events. Studying REE fractionation through the EMREE may serve as a good proxy for AMD-pollution in estuarine environments in relation to the traditional methods.

The impact of typical pollutants upon the fish-farming was assessed by use of a battery of biomarkers in two typical marine aquaculture regions in South China. Biotransformation parameters including 7-ethoxyresorufin-O-deethylase (EROD), aminopyrine N-demethylase (APND), erythromycin N-demethylase (ERND), glutathione-S-transferase (GST) and Malondialdehyde (MDA) were measured in five cultured fish species. Pollutants such as polycyclic aromatic hydrocarbon (PAHs), organochlorinated compounds (OCs), heavy metals and antibiotics (quinolones and sulfonamides) in sediments were characterized. Higher pollutant residue levels were observed in Dapeng Cove. EROD, APND and ERND activities were lower in fish from Dapeng Cove compared with fish from Hailing Island, while it is just on the contrary for GST and MDA. ERND, APND and GST showed sensitivity corresponding to different pollutants. Small fish species seemed to exhibit more sensitive to pollutants. The study further supports usefulness of multi-biomarker approach considering multiple species to define the effects of anthropogenic inputs in marine aquaculture systems.

The keynote paper by Garrett Hardin 44years ago introduced the term ‘tragedy of the commons’ into our language (Hardin, 1968); this term is now used widely, but it is neither universally accepted nor fully understood. Irrespective, the ‘tragedy of the commons’ is an increasing reality for more than 500 million people that rely on the biodiversity resources and services of tropical coral reefs, mangrove forests, seagrass beds and associated fisheries. These natural resources continue to decline despite major advances in our scientific understanding of how ecosystems and human populations interact, and the application of considerable conservation and management efforts at scales from local user communities to oceans. Greater effort will be required to avert increasing damage from over-exploitation, pollution and global climate change; all deriving from increasing exploitation driven by poverty and progress i.e. continuing to expand development indefinitely and extraction of resources at industrial scales. However, the ‘tragedy’ concept has been widely criticized as a simple metaphor for a much larger set of problems and solutions. We argue that the ‘tragedy’ is essentially real and will continue to threaten the lives of millions of people unless there are some major moral and policy shifts to reverse increasing damage to coastal habitats and resources. We agree with the conclusion by Hardin that the solution to the tragedy will not be through the application of natural sciences, but via implementing exceedingly difficult and controversial moral decisions. An extreme example of a moral and controversial direction suggested by Hardin was in re-examining the ‘freedom to breed’ as an inherent human value. The need for ‘moral decisions’ is even greater in 2012.

The Berre Lagoon has been under strong anthropogenic pressure since the early 1950s. The opening of the hydroelectric EDF power plant in 1966 led to large salinity drops. The zooplankton community was mainly composed of two common brackish species: Acartia tonsa and Brachionus plicatilis. Since 2006, European litigation has strongly constrained the input of freshwater, maintaining the salinity above 15. A study was performed between 2008 and 2010 to evaluate how these modifications have impacted the zooplankton community. Our results show that the community is more diverse and contains several coastal marine species (i.e., Centropages typicus, Paracalanus parvus and Acartia clausi). A. tonsa is still present but is less abundant, whereas B. plicatilis has completely disappeared. Strong predatory marine species, such as chaetognaths, the large conspicuous autochtonous jellyfish Aurelia aurita and the invasive ctenophore Mnemiopsis leidyi, are now very common as either seasonal or permanent features of the lagoon.

With many environments worldwide experiencing at least some degree of anthropogenic modification, there is great urgency to identify sensitive indicators of ecosystem stress. Estuarine organisms are particularly vulnerable to anthropogenic contaminants. This study presents bacterial communities as sensitive indicators of contaminant stress. Sediments were collected from multiple sites within inner and outer zones of three heavily modified and three relatively unmodified estuaries. Bacterial communities were censused using Automated Ribosomal Intergenic Spacer Analysis and analysed for a suite of metal and PAH contaminants. Shifts in both bacterial community composition and diversity showed strong associations with sediment contaminant concentrations, particularly with metals. Importantly, these changes are discernable from environmental variation inherent to highly complex estuarine environments. Moreover, variation in bacterial communities within sites was limited. This allowed for differences between sites, zones and estuaries to be explained by variables of interest such as contaminants that vary between, but not within individual sites.

Interannual variability (2003–2008) of meiofaunal assemblages were analyzed in sediments beneath fish cages (Impact group) and in areas not affected by aquaculture activities (Control group). Organisms responded with spatial and seasonal variation in meiofauna assemblages, with an abrupt increase of abundances in locations beneath fish cages throughout the study period. This increase was greater during the last sampling year (2008) and mainly due to high abundances of nematodes. Univariate analyses showed differences between control and impacted sites at both sites, however, only significant variations were found in Los Gigantes, which are consistent with seasonal meiofauna variations throughout the study period. These results are partially explained by differences in current velocity between both sampling areas. The Ne/Co index showed the same trend and it seems to be a reliable index in sediment slightly affected by aquaculture wastes. This index is especially recommended in oligotrophic areas (e.g. Canary Islands) where meiofaunal assemblages are poorly represented in terms of abundances.

This study evaluated the toxicity of dispersant application which is, in nearshore area, a controversial response technique to oil spill. Through an experimental approach with juveniles of Liza aurata, the toxicity of five exposure conditions was evaluated: (i) a chemically dispersed oil simulating dispersant application; (ii) a single dispersant as an internal control of chemically dispersed oil; (iii) a mechanically dispersed oil simulating natural dispersion of oil; (iv) a water soluble fraction of oil simulating an undispersed and untreated oil slick and (v) uncontaminated seawater as a control exposure condition. The relative concentration of PAHs (polycyclic aromatic hydrocarbons) biliary metabolites showed that the incorporation of these toxic compounds was increased if the oil was dispersed, whether mechanically or chemically. However, toxicity was not observed at the organism level since the aerobic metabolic scope and the critical swimming speed of exposed fish were not impaired.