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Inter-annual variability of wet season freshwater plume extent into the Great Barrier Reef lagoon based on satellite coastal ocean colour observations Full text
2012
Schroeder, Thomas | Devlin, Michelle J. | Brando, Vittorio E. | Dekker, Arnold G. | Brodie, J. E. (Jon E.) | Clementson, Lesley A. | McKinna, Lachlan
Riverine freshwater plumes are the major transport mechanism for nutrients, sediments and pollutants into the Great Barrier Reef (GBR) lagoon and connect the land with the receiving coastal and marine waters. Knowledge of the variability of the freshwater extent into the GBR lagoon is relevant for marine park management to develop strategies for improving ecosystem health and risk assessments. In this study, freshwater extent has been estimated for the entire GBR lagoon area from daily satellite observations of the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2002 and 2010. To enable a reliable mapping of freshwater plumes we applied a physics-based coastal ocean colour algorithm, that simultaneously retrieves chlorophyll-a, non-algal particulate matter and coloured dissolved organic matter (CDOM), from which we used CDOM as a surrogate for salinity (S) for mapping the freshwater extent.
Show more [+] Less [-]Toxic metal (Pb, Cd and Hg) levels in the nearshore surface sediments from the European and Anotolian Shores of Bosphorus, Turkey Full text
2012
Balkıs, Nuray | Aktan, Yelda | Balkıs, Neslihan
In this study, some toxic metal such as Pb, Cd and Hg analyzes have been done in the nearshore surface sediments. Sediment samples have been collected from five parts from the European and Anotolian Shores of the Bosphorus during 2003–2004. Total Pb, Cd and Hg contents vary between <0.01μgg⁻¹ and 238μgg⁻¹; <0.01μgg⁻¹ and 0.92μgg⁻¹; 0.001μgg⁻¹ and 0.45μgg⁻¹, respectively. Contamination Factor (CF) values of Pb and Cd range between 1 and 3 whilst CF values of Hg are lower than 1 in all the stations. It means that there are no Hg metal enrichment by natural or anthropogenic inputs contrary to moderately contamination for Pb and Cd metals throughout the Bosphorus sediments.
Show more [+] Less [-]Comprehensive assessment of heavy metal contamination in sediment of the Pearl River Estuary and adjacent shelf Full text
2012
Yang, Yongqiang | Chen, Fanrong | Zhang, Ling | Liu, Jinsong | Wu, Shijun | Kang, Mingliang
Total metal concentrations (Cr, Ni, Cu, Zn, and Pb), acid volatile sulfide and simultaneously extracted metals (AVS–SEM), and heavy metal fractionation were used to assess the heavy metals contamination status and ecological risk in the sediments of the Pearl River Estuary (PRE) and adjacent shelf. Elevated concentrations at estuarine sites and lower concentrations at adjacent shelf sites are observed, especially for Cu and Zn. Within the PRE, the concentration of heavy metals in the western shore was mostly higher than that in the middle shore. The metals from anthropogenic sources mainly occur in the labile fraction and may be taken up by organisms as the environmental parameters change. A combination of total metal concentrations, metal contamination index and sequential extraction analysis is necessary to get the comprehensive information on the baseline, anthropogenic discharge and bioavailability of heavy metals.
Show more [+] Less [-]Spread of Alsidium corallinum C. Ag. in a Tyrrhenian eutrophic lagoon dominated by opportunistic macroalgae Full text
2012
Lenzi, Mauro | Gennaro, Paola | Renzi, Monia | Persia, Emma | Porrello, Salvatore
In 2007, the Rhodophyceae Alsidium corallinum C. Ag., a marine taxon, bloomed in the eutrophic lagoon of Orbetello (Tuscany, Italy) for the first time, becoming the dominant species in spring and summer. In November, its biomass collapsed. The hypothesis examined in this study is that the bloom expressed a relatively low eutrophic level of the ecosystem after intense disposal of accumulated sedimentary organic matter (OM) by dystrophic processes in the two years preceding the bloom. To verify the hypothesis, we compared water physical–chemical variables, sediment redox (Eh) and OM, and standing crops of macroalgae and seagrass from the database of routine monitoring between 2005 and 2008. We also used dissolved nutrient data obtained in 2007 and 2008, as well as data on chlorophyll and total suspended matter in the water column during the microalgal bloom of 2007, and C, N and P content in thalli of the Chlorophycea Chaetomorpha linum and the Rhodophyceae Gracilariopsis longissima and A. corallinum obtained in 2007. In 2007, unusually low values of dissolved inorganic nitrogen (DIN) were recorded. Combined with stable values of soluble reactive phosphorus (SRPs), low DIN led to a reduction of about one order of magnitude in the DIN:SRP atomic ratio with respect to the past and to 2008. G. longissima accumulated C, N and P more than the other species and A. corallinum proved to be less demanding. Sediment OM was lower in the autumn of years characterized by dystrophy, confirming that summer dystrophic events coincided with maximum energy dissipation in this ecosystem. However, as soon as OM and DIN values increased (2008), the vegetation shifted towards blooms of G. longissima and C. linum, while A. corallinum almost disappeared. The results sustain the hypothesis that the bloom of A. corallinum was due to a decline in DIN that limited G. longissima, and to intense turbidity of the water caused by microphytes that developed after the dystrophic event of summer 2006. The latter probably limited the development of C. linum, which could only develop at the edges of the lagoon.
Show more [+] Less [-]Evaluation of the ecotoxicity and biological efficacy of ship’s ballast water treatment based on hydroxyl radicals technique Full text
2012
Zhang, Nahui | Zhang, Zhitao | Bai, Mindong | Chen, Cao | Meng, Xiangying | Tian, Yiping
Ballast water has been identified as one of the key pathways for the movement of species between different ecosystems. The purpose of this study is to evaluate the biological efficacy and the potential toxicological impact of a proposed ballast water treatment using hydroxyl radicals as the main active substances. Living biomass of organisms kept in treated water for 2days met the requirement stated in the International Maritime Organization (IMO) Ballast Water Convention (Regulation D-2), and no re-growth was observed over a period of 5days. Aquatic toxicity tests of three trophic levels for the treated ballast water were performed. The results indicated that the toxicological risk of the discharge water to the receiving environment was not significant.
Show more [+] Less [-]Distribution and sources of organochlorine pesticides in sediments of the coastal East China Sea Full text
2012
Lin, Tian | Hu, Limin | Shi, Xuefa | Li, Yuanyuan | Guo, Zhigang | Zhang, Gan
Forty-two surface sediment samples collected from the southern coastal East China Sea (ECS) were analyzed for organochlorine pesticides (OCPs). The results showed high concentrations of DDTs and parent DDT fractions in the nearshore area, suggesting that there is still a fresh input of these species from non-point sources, probably due to the recent usage of relevant products. However, for HCHs, the high concentrations with elevated β-HCH fraction were focused at the local major river estuaries, indicating that soils-released HCH input was mainly from the major river runoffs. The distribution and composition of OCPs in the coastal ECS could be more prominently controlled by the direct regional inputs rather than the general natural sorption process on particulate organic carbon. DDTs and chlordane are more important for their potential ecotoxicological risk on neighboring benthic community in the nearshore region and the local major river estuaries.
Show more [+] Less [-]Reproductive characteristics and steroid levels in the scleractinian coral Oculina patagonica inhabiting contaminated sites along the Israeli Mediterranean coast Full text
2012
Armoza-Zvuloni, Rachel | Kramarsky-Winter, Esti | Rosenfeld, Hanna | Shore, Laurence S. | Segal, Roee | Sharon, Daniel | Loya, Yossi
In this study we compared reproductive characteristics and steroid hormone levels in the non-indigenous scleractinian coral, Oculina patagonica, inhabiting contaminated vs. uncontaminated reference sites along the Israeli Mediterranean coast. Our results indicate significantly higher steroid levels in both seawater and coral tissue samples from contaminated sites as compared to reference sites, suggesting that corals tend to accumulate steroids from the surrounding waters. Despite their higher steroid levels, corals from the contaminated sites showed reproductive potential comparable to those of the reference sites. Interestingly, a clear distinction could be seen between corals exposed to pollution for long vs. short durations, with the latter showing a failure to complete gametogenesis. This suggests that reproduction in O. patagonica is susceptible to acute rather than chronic stress. The involvement of adjustment/adaptation processes may explain this species tolerance, and may reflect the ability of O. patagonica to successfully invade new areas in the Mediterranean Sea.
Show more [+] Less [-]Marine biosecurity: The importance of awareness, support and cooperation in managing a successful incursion response Full text
2012
Piola, Richard F. | McDonald, Justin I.
Shipping is almost certainly the most prevalent human-mediated transport vector for non-indigenous species (NIS) within the marine environment. The Royal Australian Navy (RAN) has long acknowledged the importance of sound environmental management and in recent years has taken a proactive approach to addressing risks associated with marine biosecurity. primarily as a result of biofouling on Navy vessel returning from overseas operations. This paper describes two case studies that highlight the effectiveness of the RAN marine biosecurity management framework in identifying an unwanted marine species on Navy vessels, and the successful biosecurity management program that ensued. In particular, the early detection and identification of a suspect NIS, the quick response to the discovery and the collaborative approach adopted between the RAN and the Government regulatory agency (Western Australian Department of Fisheries) charged with coordinating the incursion response serves as a model for how future incursion responses should be reported and managed.
Show more [+] Less [-]Ascidian introductions through the Suez Canal: The case study of an Indo-Pacific species Full text
2012
Rius, Marc | Shenkar, Noa
Although marine biological invasions via the Suez Canal have been extensively documented, little is known about the introduction of non-indigenous ascidians (Chordata, Ascidiacea), a group containing particularly aggressive invasive species. Here, we used a multidisciplinary approach to study the introduction of the ascidian Herdmania momus into the Mediterranean Sea. We reviewed its taxonomy and global distribution, and analyzed how genetic variation is partitioned between sides of the Suez Canal. The taxonomic revision showed that H. momus currently has a wide Indo-Pacific distribution. Genetic data indicated two well-differentiated colonization histories across the eastern Mediterranean. Our findings suggest that the range expansion of H. momus has been greatly facilitated by the combined effect of human-mediated transport and the species’ ability to adapt to different environments. The integrative approach presented here is critical to attain a holistic understanding of marine biological invasions, especially when studying groups with a poorly resolved taxonomy.
Show more [+] Less [-]Likely effects of construction of Scroby Sands offshore wind farm on a mixed population of harbour Phoca vitulina and grey Halichoerus grypus seals Full text
2012
Skeate, Eleanor R. | Perrow, Martin R. | Gilroy, James J.
Scroby Sands offshore wind farm was built close to a haul-out and breeding site for harbour seal, a species of conservation concern. An aerial survey programme conducted during a five-year period spanning wind farm construction, revealed a significant post-construction decline in haul-out counts. Multivariate model selection suggested that the decline was not related to the environmental factors considered, nor did it mirror wider population trends. Although cause and effect could not be unequivocally established, the theoretical basis of hearing in pinnipeds and previous studies suggested that extreme noise (to 257dB re 1μ Paₚₚ @ 1m) generated by pile-driving of turbine bases led to displacement of seals. A lack of full recovery of harbour seal during the study was also linked to their sensitivity to vessel activity and/or rapid colonisation of competing grey seal. Any impact of offshore wind farm development upon pinnipeds would be much reduced without pile-driving.
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