Impact of the intensive shrimp farming on the water quality of the adjacent coastal creeks from Eastern China

The effects of shrimp aquaculture on the adjacent water bodies over a crop cycle period were evaluated by studying the water quality of inlet and outlet creeks located within Xuwei Salt Field, Lianyungang City of Jiangsu Province. The characterization of the water consisted of the evaluation of the variation of 10 parameters along the inlet and outlet creeks and during the period of March-September. These parameters were pH, temperature, dissolved oxygen, nutrients (ammonium, nitrite, nitrate and inorganic phosphorus), Chlorophyll a, chemical oxygen demand (COD) and total organic carbon (TOC). Average concentrations of inorganic nitrogen (1.5 mg/l), inorganic phosphorus (0.024 mg/l), Chlorophyll a (0.0025 mg/l), COD (5.77 mg/l) and TOC (6.57 mg/l) at the discharge site in the outlet creek were significantly higher than in the inlet creek (0.33, 0.012, 0.0018, 4.72 and 3.68 mg/l, respectively). There were no significant differences between the inlet and outlet creeks in pH, temperature and DO. With a water quality criteria based on local laws, a significant pollution was observed in the area, with inorganic nitrogen being the most significant pollutant, followed by COD and inorganic phosphorus.     

Surface flow boundary conditions in modeling land subsidence due to fluid withdrawal

Land subsidence due to subsurface fluid (water, gas, oil) withdrawal is often predicted by either finite element or finite difference numerical models based on coupled poroelastic theory, where the soil is represented as a semi-infinite medium bounded by the traction-free (ground) surface. One of the variables playing a most important role on the final outcome is the flow condition used on the traction-free boundary, which may be assumed as either permeable or impermeable. Although occasionally justified, the assumption of no-flow surface seems to be in general rather unrealistic. A permeable boundary where the fluid pressure is fixed to the external atmospheric pressure appears to be more appropriate. This paper addresses the response, in terms of land subsidence, obtained with a coupled poroelastic finite element model that simulates a distributed pumping from a horizontal aquifer confined between two relatively impervious layers, and takes either a permeable boundary surface, i.e., constant hydraulic potential, or an impermeable boundary, i.e., a zero Neumann flow condition. The analysis reveals that land subsidence is rather sensitive to the flow condition implemented on the traction-free boundary. In general, the no-flow condition leads to an overestimate of the predicted ground surface settlement, which could even be 1 order of magnitude larger than that obtained with the permeable boundary.     

Monitoring chemical contamination levels in the Mediterranean based on the use of mussel caging

Within the framework of the biointegrator network (RINBIO), 92 man-made cages containing mussels (Mytilus galloprovincialis), distributed over 1800 km of the French Mediterranean coast, made it possible to assess chemical contamination by heavy metals (Cd, Hg, Zn, Pb, Cu, Ni, Cr, As) and organic compounds (DDT, PCBs, HAP). The caging technique was adopted to compensate for the scarcity of natural shellfish stocks in the Mediterranean and to enable comparison of the sites regardless of their physicochemical and trophic characteristics. Models linking a biometric parameter (the condition index) to pollutant levels make it possible to adjust raw data on contamination for a reference individual, by making a clear distinction between physiological factors (growth) and environmental ones. The results demonstrate significant levels of pollutants in sites heretofore unsampled; the pollution occurs at limited areas, and the sources have been identified. Moreover, average contamination levels are comparable to those measured in wild species and in other areas. Overall, the research demonstrates the reliability of this methodological approach for monitoring marine pollution, especially in the Mediterranean.     

An assessment of the pollutant status of surficial sediment in Cork Harbour in the South East of Ireland with particular reference to polycyclic aromatic hydrocarbons

Surface sediment from three polluted sites within Cork Harbour, Ireland, and from a relatively clean reference site were collected and analysed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), brominated flame retardants (BFRs), organotins (OTs), and heavy metals. PAHs were determined to be the most abundant class of contaminant. Concentrations of the sum (Sigma) of the 21 PAHs measured from the Harbour sites (2877.70 ng g(-1), 1000.7 ng g(-1) and 924.40 ng g(-1) dry weight respectively) were significantly higher than that of the sediment from the reference site (528.30 ng g(-1) dry weight). An inner harbour site, Douglas being the more contaminated of the three harbour sites. A similar pattern was observed with the other contaminants however, these compounds, with the exception of the heavy metals, all tended to be detected at concentrations on or below detection limits.     

Plastic debris ingestion by sea turtle in Paraíba, Brazil

Coastal gill net entanglement and debris intake are important threats to the survival of sea turtles. Two sea turtles (Lepidochelys olivacea and Chelonia mydas) were found stranded along the coast of Paraíba. After necropsy, plastic debris were found in the stomach. The debris is described. This is the first record of this sort of problem for the Paraíba littoral.     

GEOLOGICAL INVESTIGATIONS IN THE WESTERN KWENLUN AND THE KARAKORUM-HIMALAYA

The vast unexplored territory of Western China and the adjoining regions of Central Asia, are still so little known, and contain so many problems of the highest scientific significance, that any contribution of an authoritative nature is hailed with gratification. So much of the workin the past has been done by