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Effects of light pollution on the emergent fauna of shallow marine ecosystems: Amphipods as a case study Texto completo
2015
Navarro-Barranco, Carlos | Hughes, Lauren Elizabeth
Light pollution from coastal urban development is a widespread and increasing threat to biodiversity. Many amphipod species migrate between the benthos and the pelagic environment and light seems is a main ecological factor which regulates migration. We explore the effect of artificial lighting on amphipod assemblages using two kind of lights, LED and halogen, and control traps in shallow waters of the Great Barrier Reef. Both types of artificial light traps showed a significantly higher abundance of individuals for all species in comparison to control traps. LED lights showed a stronger effect over the amphipod assemblages, with these traps collecting a higher number of individuals and differing species composition, with some species showing a specific attraction to LED light. As emergent amphipods are a key ecological group in the shallow water environment, the impact of artificial light can affect the broader functioning of the ecosystem.
Mostrar más [+] Menos [-]Fate of Deepwater Horizon oil in Alabama’s beach system: Understanding physical evolution processes based on observational data Texto completo
2015
Hayworth, Joel S. | Prabakhar Clement, T. | John, Gerald F. | Yin, Fang
The impact of MC252 oil on northern Gulf of Mexico (GOM) beaches from the 2010 Deepwater Horizon (DWH) catastrophe was extensive along Alabama’s beaches. While considerable amount of cleanup has occurred along these beaches, as of August 2014, DWH oil spill residues continue to be found as surface residual balls (SRBs), and also occasionally as submerged oil mats (SOMs). Four years of field observations informing the fate and transport of DWH SRBs in Alabama’s beach system are presented here, along with a conceptual framework for describing their physical evolution processes. The observation data show that SRBs containing MC252 residues currently remain in Alabama’s beach system, although their relationship to SOMs is not fully known. Based on our field observations we conclude that small DWH SRBs are likely to persist for several years along the Alabama shoreline.
Mostrar más [+] Menos [-]Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs Texto completo
2015
Cerezo, Maria Isabel | Agusti, Susana
One way organic pollutants reach remote oceanic regions is by atmospheric transport. During the Malaspina-2010 expedition, across the Atlantic, Indian, and Pacific Oceans, we analyzed the polycyclic aromatic hydrocarbon (PAH) effects on oceanic microbial food webs. We performed perturbation experiments adding PAHs to classic dilution experiments. The phytoplankton growth rates were reduced by more than 5 times, being Prochlorococcus spp. the most affected. 62% of the experiments showed a reduction in the grazing rates due to the presence of PAHs. For the remaining experiments, grazing usually increased likely due to cascading effects. We identified changes in the slope of the relation between the growth rate and the dilution fraction induced by the pollutants, moving from no grazing to V-shape, or to negative slope, indicative of grazing increase by cascade effects and alterations of the grazers' activity structure. Our perturbation experiments indicate that PAHs could influence the structure oceanic food-webs structure.
Mostrar más [+] Menos [-]Baseline monitoring of organic sunscreen compounds along South Carolina's coastal marine environment Texto completo
2015
Bratkovics, Stephanie | Wirth, Edward | Sapozhnikova, Yelena | Pennington, Paul | Sanger, Denise
Organic ultraviolet filters (UV-F) are increasingly being used in personal care products to protect skin and other products from the damaging effects of UV radiation. In this study, marine water was collected monthly for approximately one year from six coastal South Carolina, USA sites and analyzed for the occurrence of seven organic chemicals used as UV filters (avobenzone, dioxybenzone, octocrylene, octinoxate, oxybenzone, padimate-o and sulisobenzone). The results were used to examine the relationship between beach use and the distribution of UV-F compounds along coastal South Carolina, USA. Five of the seven target analytes were detected in seawater along coastal South Carolina during this study. Dioxybenzone and sulisobenzone were not detected. The highest concentrations measured were >3700ng octocrylene/L and ~2200ng oxybenzone/L and beach use was greatest at this site; a local beach front park. Patterns in concentrations were assessed based on season and a measure of beach use.
Mostrar más [+] Menos [-]Numerical analysis of particulate organic waste diffusion in an aquaculture area of Gokasho Bay, Japan Texto completo
2015
Zhang, Junbo | Kitazawa, Daisuke
Particulate organic waste, originating from fish cultured in cages, often brings about negative effects on the structure of bottom sediments. These effects result in deterioration of the aquatic environment. In the present study, a three-dimensional numerical model was coupled with developed submodels of fish cage drag and aquaculture waste diffusion to simulate the hydrodynamic environment and distribution of particulate organic waste. Numerical simulation results showed that fish cages exerted an influence on both the velocity and direction of water current; the reduction of water current velocity was a maximum of approximately 38%. The contribution of fish fecal matter was dominant during winter (ca. 80%), whereas waste fish feed was the main source in other seasons. The distribution of organic waste near the sea bottom indicated that organic waste not only loaded mainly on the sea floor just beneath the fish cages but also diffused towards the coastlines.
Mostrar más [+] Menos [-]Wetland plants as indicators of heavy metal contamination Texto completo
2015
Phillips, D.P. | Human, L.R.D. | Adams, J.B.
In this study metal accumulating abilities of three emergent macrophytes (Phragmites australis, Typha capensis and Spartina maritima) were investigated in the urbanised Swartkops Estuary. Plants and sediment samples were collected at seven sites along the banks of the main channel and in adjacent canals. Sediments and plant organs were analysed, by means of atomic absorption spectrometry, for four elements (Cd, Cu, Pb, and Zn). Metal concentrations in the sediments of adjacent canals were found to be substantially higher than those at sites along the banks of the estuary. These differences were reflected in the plant organs for Pb and Zn, but not for Cu and Cd. All three species exhibited significantly higher concentrations of metals in their roots. These species are therefore suitable for use as indicators of the presence and level of heavy metal contaminants in estuaries.
Mostrar más [+] Menos [-]Assessment of sediment contamination and sampling design in Savona Harbour, Italy Texto completo
2015
Paladino, Ombretta | Massabò, Marco | Fissore, Francesca | Moranda, Arianna
A method for assessing environmental contamination in harbour sediments and designing the forthcoming monitoring activities in enlarged coastal ecosystems is proposed herein. The method is based on coupling principal component analysis of previous sampling campaigns with a discrete optimisation of a value for money function. The objective function represents the utility derived for every sum of money spent in sampling and chemical analysis. The method was then used to assess actual contamination and found to be well suited for reducing the number of chemicals to be searched during extended monitoring activities and identifying the possible sources of contamination. Data collected in Savona Harbour (Porto Vado), Italy, where construction of a new terminal construction is planned, were used to illustrate the procedure. 23 chemicals were searched for within a total of 213 samples in 68 sampling points during three monitoring campaigns. These data were used to test the procedure. Subsequently, 28 chemicals were searched for within 14 samples in 10 sampling points and collected data were used to evaluate the experimental error and to validate the proposed procedure.
Mostrar más [+] Menos [-]Accumulation and distribution of trace metals within soils and the austral cordgrass Spartina densiflora in a Patagonian salt marsh Texto completo
2015
Idaszkin, Yanina L. | Lancelotti, Julio L. | Bouza, Pablo J. | Marcovecchio, Jorge E.
Concentrations of Cd, Cu, Fe, Pb, and Zn were determined in soils and in below- and above-ground structures of Spartina densiflora in a Patagonian salt marsh (San Antonio, Río Negro, Argentina). Also, the relationship between trace metal concentrations in soils and plants was investigated to improve our knowledge regarding the ability of this plant species to take up and accumulate trace metals from the soil. Our results indicate that, within the studied salt marsh, soil trace metal concentrations follow a decreasing concentration gradient toward the sea. They show moderate pollution and a potentially negative biological effect in one site of the salt marsh. While below-ground structures reflect the soil metal concentration pattern, this is not so evident in above-ground concentrations. Also, S. densiflora is able to absorb a limited amount of metals present in the soil, the soil bioaccumulation factor being lower in sites where soil metal concentration is higher.
Mostrar más [+] Menos [-]Antibiotics in typical marine aquaculture farms surrounding Hailing Island, South China: Occurrence, bioaccumulation and human dietary exposure Texto completo
2015
Chen, Hui | Liu, Shan | Xu, Xiang-Rong | Liu, Shuang-Shuang | Zhou, Guang-Jie | Sun, Kai-Feng | Zhao, Jian-Liang | Ying, Guang-Guo
The occurrence, bioaccumulation, and human dietary exposure via seafood consumption of 37 antibiotics in six typical marine aquaculture farms surrounding Hailing Island, South China were investigated in this study. Sulfamethoxazole, salinomycin and trimethoprim were widely detected in the water samples (0.4–36.9ng/L), while oxytetracycline was the predominant antibiotic in the water samples of shrimp larvae pond. Enrofloxacin was widely detected in the feed samples (16.6–31.8ng/g) and erythromycin–H2O was the most frequently detected antibiotic in the sediment samples (0.8–4.8ng/g). Erythromycin–H2O was the dominant antibiotic in the adult Fenneropenaeus penicillatus with concentrations ranging from 2498 to 15,090ng/g. In addition, trimethoprim was found to be bioaccumulative in young Lutjanus russelli with a median bioaccumulation factor of 6488L/kg. Based on daily intake estimation, the erythromycin–H2O in adult F. penicillatus presented a potential risk to human safety.
Mostrar más [+] Menos [-]Spatial and vertical distributions of heavy metals and their potential toxicity levels in various beach sediments from high-background-radiation area, Kerala, India Texto completo
2015
Suresh, G. | Ramasamy, V. | Sundarrajan, M. | Paramasivam, K.
The spatial and vertical distribution of heavy metals and the sediment characteristics of beaches in Kerala, India (the upper surface sediments and the first, second and third one-foot-thick strata) were assessed in this study. The concentrations of most of the studied metals were highest at sampling site S1 (Cochin). The measured concentrations were compared with background and toxicological reference values. The results show that definite adverse biological effects are possible at most of the sampling sites due to the high Pb levels. Three different indexes were calculated to investigate the potential toxicity level. Most of the studied metals and all calculated indexes were highest in the third foot of sediment. Multivariate statistical analyses were performed and suggested that particular heavy metals, e.g., Pb, Cd, Cr and Ni, may represent contamination from a common source. The Cd and Pb concentrations and all the calculated index values show a relationship with the content of organic matter. The results of the present study suggest the recommendation that a systematic analysis is needed to monitor heavy metal levels in the studied area.
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