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The effects of coastal development on sponge abundance, diversity, and community composition on Jamaican coral reefs Texto completo
2015
Stubler, Amber D. | Duckworth, Alan R. | Peterson, Bradley J.
Over the past decade, development along the northern coast of Jamaica has accelerated, resulting in elevated levels of sedimentation on adjacent reefs. To understand the effects of this development on sponge community dynamics, we conducted surveys at three locations with varying degrees of adjacent coastal development to quantify species richness, abundance and diversity at two depths (8–10m and 15–18m). Sediment accumulation rate, total suspended solids and other water quality parameters were also quantified. The sponge community at the location with the least coastal development and anthropogenic influence was often significantly different from the other two locations, and exhibited higher sponge abundance, richness, and diversity. Sponge community composition and size distribution were statistically different among locations. This study provides correlative evidence that coastal development affects aspects of sponge community ecology, although the precise mechanisms are still unclear.
Mostrar más [+] Menos [-]Organic pollution in surficial sediments of Tripoli harbour, Lebanon Texto completo
2015
Merhaby, Dima | Net, Sopheak | Halwani, Jalal | Ouddane, Baghdad
Tripoli harbour is among the most important ports on the Mediterranean Sea eastern basin. The persistent organic pollutants (POPs) were monitored (28 PCBs, 16 PAHs and 18 Me-PAHs) in 15 stations of Tripoli harbour basins, which are influenced by anthropogenic activities. Total PAHs concentrations ranged from 243 to 2965μgkg−1dw, total Me-PAH concentrations ranged from 54 to 1638μgkg−1dw, while total PCB levels ranged from 18 to 302μgkg−1dw. PCBs profiles were dominated by four and six-chlorinated congeners while the PAHs were dominated by four and five rings. For identifying pollution emission sources of PAHs, different ratios were used. The results show that the pollution origin was predominated by pyrogenic process related to the deposition of coal dust and the combustion of biomass and coal. Based on Sediments Quality Guidelines the biological adverse effects on aquatic ecosystems were expected rarely to occasionally for PAHs and PCBs contamination.
Mostrar más [+] Menos [-]Investigation of trophic level and niche partitioning of 7 cetacean species by stable isotopes, and cadmium and arsenic tissue concentrations in the western Pacific Ocean Texto completo
2015
Liu, J. Y. | Chou, L.-S. | Chen, M.-H.
A total of 24 stranded or bycatch cetaceans, including Balaenoptera omurai, Lagenodelphis hosei, Kogia sima, Stenella attenuata, Grampus griseus, Neophocaena phocaenoides, and Sousa chinensis, were collected from 2001 to 2011 in Taiwan. Using the muscular δ13C and δ15N data, three ecological groups were identified as the oceanic baleen whale, the neritic, and the coastal toothed whale groups, coinciding with their taxonomy, feeding habits and geographical distribution. A horizontal inshore to offshore distribution was found for the sympatric neritic toothed dolphins, G. griseus, K. sima, S. attenuata, and L. hosei in the outermost offshore waters, accompanying their growth. For the first time we identify Taiwan’s Chinese white dolphin, S. chinensis, as an exclusive fish eater. Cd and As bioaccumulated in the G. griseus, L. hosei and S. attenuata increase as they grow. Prey-derived As- and Cd-induced health threats were found in L. hosei, and G. griseus.
Mostrar más [+] Menos [-]Optimization of elutriation device for filtration of microplastic particles from sediment Texto completo
2015
Zhu, X.
The increasing presence of plastic pollution in marine ecosystems has become a major concern. In the environment, plastics break down into smaller and smaller pieces of microplastics. Methods of microplastic recovery are needed to reduce the dangers they can pose to a variety of organisms. An elutriation device was manufactured and optimized to achieve maximum microplastic recovery. The parameters flow rate and diameter of elutriation column were varied and their domain of variation was determined. A composite factorial experimental design was generated using MODDE 10.1 and was undergone. The optimal values of flow rate and column diameter were determined to be 385Lh−1 and 5.06cm respectively, under constraints, to achieve a maximum feasible microplastics recovery percentage of 50.2%. The elutriation process can be improved through further testing, and can be tested in the field to compare its efficiency to that of manual microplastics filtration.
Mostrar más [+] Menos [-]Remediation of Acid Mine Drainage-Impacted Water Texto completo
2015
RoyChowdhury, Abhishek | Sarkar, Dibyendu | Datta, Rupali
The formation of acid mine drainage (AMD), a highly acidic and metal-rich solution, is the biggest environmental concern associated with coal and mineral mining. Once produced, AMD can severely impact the surrounding ecosystem due to its acidity, metal toxicity, sedimentation and other deleterious properties. Hence, implementations of effective post-mining management practices are necessary to control AMD pollution. Due to the existence of a number of federal and state regulations, it is necessary for private and government agencies to come up with various AMD treatment and/or control technologies. This review describes some of the widely used AMD remediation technologies in terms of their general working principles, advantages and shortcomings. AMD treatment technologies can be divided into two major categories, namely prevention and remediation. Prevention techniques mainly focus on inhibiting AMD formation reactions by controlling the source. Remediation techniques focus on the treatment of already produced AMD before their discharge into water bodies. Remediation technologies can be further divided into two broad categories: active and passive. Due to high cost and intensive labor requirements for maintenance of active treatment technologies, passive treatments are widely used all over the world. Besides the conventional passive treatment technologies such as constructed wetlands, anaerobic sulfate-reducing bioreactors, anoxic limestone drains, open limestone channels, limestone leach beds and slag leach beds, this paper also describes emerging passive treatment technologies such as phytoremediation. More intensive research is needed to develop an efficient and cost-effective AMD treatment technology, which can sustain persistent and long-term AMD load.
Mostrar más [+] Menos [-]A Review of Groundwater Arsenic in the Bengal Basin, Bangladesh and India: from Source to Sink Texto completo
2015
Chakraborty, Madhumita | Mukherjee, Abhijit | Ahmed, Kazi Matin
The groundwater of the Bengal basin, in Bangladesh and West Bengal state of India, is found to be severely polluted by non-point sourced, geogenic arsenic (As), which has been regarded as the largest public health concern in the human history. The geomorphology and geology of the aquifers play very important role in the three dimensional existence of the As in the groundwater. The provenance of the groundwater As of Bengal basin may be hypothesized to be sourced to the Himalayan orogenic belt, where the contaminant might have originated by deep-seated tectono-magmatism and subsequently introduced to the surficial system by exhumation. Later, sedimentary processes transported the As-laden sediments from the orogenic belt to the peripheral foreland basin of Bengal where, under conducive biogeochemical environment, the As is released from the solid-phase to the circulating groundwater. Ferric hydroxides and pyrite are considered to be the two most important host minerals for As, although clay minerals may also act as important substrates for the sorbed As. The mobilized As then exists in the groundwater until a suitable geochemical sink is available. The mobilization process may be related to reductive-dissolution of metal oxides and hydroxides that exist in the unconsolidated sediments of the Bengal basin. Other mechanisms like pyrite oxidation, redox cycling in surficial soils, and competitive ion exchange are also accepted as potential mechanisms for arsenic mobilization, and multiple processes may simultaneously contribute to the mobilization of As. The processes are significantly complicated by redox disequilibria in the Bengal basin aquifers. These inorganic processes may have been significantly catalyzed and accentuated by microbially mediated activities. The tertiary source of groundwater As is the irrigation return flow from the agricultural fields.
Mostrar más [+] Menos [-]Influence of nutrients pollution on the growth and organic matter output of Ulva prolifera in the southern Yellow Sea, China Texto completo
2015
Zhou, Yuping | Tan, Liju | Pang, Qiuting | Li, Feng | Wang, Jiangtao
The influence of nutrients on the growth of Ulva prolifera was studied in the SYS by field experiments. The wet weight of U. prolifera gradiently increased from 11.94% to 25.92% in proportion to contents of DIN supply, which indicated DIN content was essentially decisive for the output of U. prolifera blooms. Continuous nutrient supply could promote the growth of U. prolifera, indicated by the increase of growth rate from 10.46% of the batch culture to 42.17% of the in situ culture. The higher P utilized rate in all treatments showed P was the potential limited factor for the growth of U. prolifera. Moreover, it was calculated about 4.1×105t organic matter was begot by U. prolifera in the whole Yellow Sea based on the statistical relationship between output of U. prolifera and DIN content. This work could be convenient to evaluate biomass and prepare enough tools to manage U. prolifera.
Mostrar más [+] Menos [-]Arsenic fractionation in estuarine sediments: Does coastal eutrophication influence As behavior? Texto completo
2015
Sá, Fabian | Sanders, Christian J. | Patchineelam, Sambasiva Rao | Machado, Eunice da Costa | Lombardi, Ana Teresa
The Paranaguá Estuarine Complex (PEC) includes the naturally oligotrophic (NO) Mel Island which is surrounded by sea grasses, a naturally eutrophic (NE) Benito Inlet adjacent to mangrove wetlands and the highly impacted eutrophic (IE) Paranaguá Bay, home of one of Brazil’s largest ports. The results from this study indicate that reactive As and pyrite increase with sediment depth near Paranaguá port in the IE region. At the NE region, near a mangrove fringe, the reactive As, Fe, Mn and pyrite remained relatively high along the sediment column while near the sea grasses at NO the As contents were low. The degree of trace metal pyritization (DTMP) and the degree of pyritization (DOP) was highest at the IE site, slightly increasing with depth. These baseline results indicate that influence of trophic conditions and presence of marine vegetation may be directly related to As behavior in coastal systems.
Mostrar más [+] Menos [-]Reducing microplastics from facial exfoliating cleansers in wastewater through treatment versus consumer product decisions Texto completo
2015
Chang, Michelle
Microplastics (<5mm) have been discovered in fresh and saltwater ecosystems, sediments, and wastewater effluent around the world. Their ability to persist and accumulate up food chains should be a concern as research is still experimenting with techniques to assess their long-term effects on the environment. I sought to characterize the microbeads found in facial exfoliating cleansers so as to better understand how to reduce this source of pollution through consumer use and wastewater treatment solutions. By sampling products from national-grossing cosmetic personal care brands, I was able to gather information on the size, color, volume, mass, and concentration of polyethylene beads in the cleansers. From that data, I modeled onto a consumer survey the estimated volume of microplastics entering a wastewater stream. Through inquiry, I learned the practices of two local wastewater treatment facilities. My findings show that consumer decisions and treatment protocols both play crucial parts in minimizing microplastic pollution.
Mostrar más [+] Menos [-]A review of the status and development of Kuwait’s fisheries Texto completo
2015
Al-Husaini, M. | Bishop, J.M. | Al-Foudari, H.M. | Al-Baz, A.F.
The status of Kuwait’s fisheries landings and relative abundance for major species was reviewed using research data from Kuwait Institute for Scientific Research and landing data from the Kuwait’s Central Statistical Bureau. Landing data showed significant decreases for major commercial species such as zobaidy (Pampus argenteus), suboor (Tenualosa ilisha), hamoor (Epinephelus coioides), newaiby (Otolithes ruber) and hamra (Lutjanus malabaricus) while abundance data for the shrimp Penaeus semisulcatus showed significant reduction in the recent years mainly because of overfishing. The catch-rate data showed continuous decline for major species such as zobaidy, newaiby and hamoor, which indicate that stock abundances of these species are low. The reduction in stock abundance in context with changes in habitat quality, particularly the effects of reduced discharge of the Shatt Al-Arab, is discussed.
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