The role of research in coastal westlands management: Salt Marshes of Santoña and Noja (Spain)

Coastal environments, such as marshes, dunes, or estuaries, are characterized by their high natural values that usually cause them to be subjected to high protection levels, affecting activities taking place within them. This is why the action in these spaces must be based on the use of proper techniques and approaches, which integrate ecology with practical engineering necessities. In this context, the Department of Sciences and Techniques of the Water and Environment of the University of Cantabria, through methods developed in the natural reserve of the Salt Marshes of Santoña and Noja, proposes the use of a working methodology based on the discipline of “ecosystem management” combined with the “adaptive management” methodologies; the application of mathematical, statistical, and specific predictive instruments; and the utilization of an “ecologic niche” as a union between the scientific knowledge of the littoral environments and the true actuation scale of the projects and activities carried out within them.     

HPLC-FLD determination of 4-nonylphenol and 4-<Emphasis Type="Italic">tert</Emphasis>-octylphenol in surface water samples

A simple, sensitive and reliable HPLC-FLD method for the routine determination of 4-nonylphenol, 4-NP and 4-tert-octylphenol, 4-t-OP content in water samples was developed. The method consists in a liquid–liquid extraction of the target analytes with dichloromethane at pH  3.0–3.5 followed by the HPLC-FLD analysis of the organic extract using a Zorbax Eclipse XDB C8 column, isocratic elution with a mixed solvent acetonitrile/water 65:35, at a flow rate of 1.0 mL/min and applying a column temperature of 40°C. The method was validated and then applied with good results for the determination of 4-NP and 4-t-OP in Ialomi?a River water samples collected each month during 2006. The concentration levels of 4-NP and 4-t-OP vary between 0.08–0.17 μg/L with higher values of 0.24–0.37 μg/L in the summer months for 4-NP, and frequently <0.05 μg/L but also between 0.06–0.09 μg/L with higher values of 0.12–0.16 μg/L in July and August for 4-t-OP and were strongly influenced by sesonial and anthropic factors. The method was also applied on samples collected over 2 years 2007 and 2008 from urban wastewaters discharged into sewage or directly into the rivers by economic agents located in 30 Romanian towns. Good results were obtained when the method was used for analysis of effluents discharged into surface waters by 16 municipal wastewater treatment plants, during the year 2008.     

Even sampling designs generation by charges repulsion simulation

Evenly distributed sampling design is generally considered as an efficient sampling design. It is widely used in sampling for the environmental survey. In this paper, we present a novel method for generating N evenly distributed samples within a given irregular polygon via simulating the movements of some ideal homogeneous point charges. Initially, charges are randomly put into the sampling region; then, they are freed and held orderly; and after enough runs, the charges will finally reach a stable state with all of them having a zero resultant force and velocity; and so they distribute evenly within the region. Their layout can thus be considered as an evenly distributed sampling design. The main advantages of this method are: (1) it is easy to understand and implement; (2) it is efficient in both running and generating better designs. Analysis and experimental results indicate that this method is an efficient and robust method for generating even sampling designs for 2D polygonal sampling region.     

Socio-economic features of commercial fishery in the bordering upper Danube River area of Serbia

The multidisciplinary socio-economic study of fisheries in the bordering part of the Danube River between Serbia and Croatia (at the following sites: Apatin, Ba?ka Palanka, Ba?ko Novo Selo, Bezdan, and Sombor) that was performed in order to investigate various aspects of fish resource utilization (management, policy of protection and exploitation of freshwater fishery resources, present fisheries legislation, catch statistics), was realized during 2004 and 2005. Data were collected via survey with a structured interview. Socio-economic circumstances, together with ecological factors, have had an influence on the fish stock and number of commercial fishermen. Awareness of the occurring problems, both economic and ecological ones, is apparent, regardless of whether it is assessed in the field of commercial or recreational fishing. Fishery sector in Serbia is in a prolonged process of transition, with the enforcement of fishing regulations, but also the lack of control that leaves space for illegal commercial fishing. The statements, consciousness, experience and behavior of commercial fishermen represent a good basis for planning the sustainable development of fishing in this section of the Danube River.     

Occurrence and characterization of selected organochlorine contaminants in outdoor dust collected from Xinxiang,a fast developing city in North China

As facile “environmental media”, the outdoor dust may reflect the changes of contaminants in environment more promptly. In the present study, selected organochlorine contaminants (OCs) include hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), and pentachlorobenzene (PeCB) were detected in 20 outdoor dust samples collected from Xinxiang City. The concentrations of ΣHCHs, ΣDDTs, HCB, and PeCB in dust were in the range of 0.18–5.05 ng/g dry weight, 0.44–13.50 ng/g dry weight, 0.13–51.61 ng/g dry weight and ND-0.74 ng/g dry weight, respectively. Long-range transport, historical use, and recent impact of impure pesticides might be the main sources of OCs in the outdoor dust. The results of this study indicated that impure pesticide application maybe an important source of DDTs and HCB in the environment.     

Determination of polychlorinated biphenyls and total mercury in two fish species (<Emphasis Type="Italic">Esox lucius</Emphasis> and <Emphasis Type="Italic">Carassius auratus</Emphasis>) in Anzali Wetland,Iran

The Anzali Wetland is one of the most important ecosystems in the north of Iran, and parts of it were registered as a Ramsar site in 1975. However, even though, due to many problems, including eutrophication produced by inflow of excess nutrients and organic materials, the wetland was also listed on the Montreux Record indicating the need to take urgent remedial action. This study was conducted to study the levels of polychlorinated biphenyls (PCBs) and total mercury (THg) in two fish species (Esox lucius and Carassius auratus) as bio-indicators of the ecosystem condition in eastern part of Anzali Wetland. The sampling was carried out in six different periods between years 2009 and 2010. The results showed that the amounts of PCBs in the muscle of northern pike were below the detection limit of gas chromatography, whereas the average concentration in goldfish was 0.449 mg/kg wet weight. Some possible reasons for the higher levels of PCBs in goldfish in comparison with pike have been discussed. No significant (p < 0.05) correlation was observed between PCBs and biological factors (weight, length, lipid content) for both species. On the other hand, the mean concentration of THg in the muscle of pike and goldfish were 182.22 and 75.27 ng/g dry weight, respectively. Although these concentrations were below US-EPA criterion for human consumption (0.3 mg/kg), it pointed up a significant deterioration of the ecosystem condition during the past years. Finally, statistical analysis revealed a significant correlation between THg with weight and an insignificant correlation with length for pike specimens.     

Fish scales as indicators of wastewater toxicity from an international water channel Tung Dhab drain

The effect of wastewater exposure on scales and chromatophores of freshwater fish Channa punctatus was studied using wastewater dilutions (60–100%) from an international water channel Tung Dhab drain at an interval of 15 and 30 days. The exposed fish showed significant alterations such as uprooted and damaged lepidonts and dispersal of chromatophores. These observations strongly suggest that fish scales can be successfully employed as indicators of wastewater pollution.     

Development of geomorphologic instantaneous unit hydrograph for a large watershed

Hill torrents cause a lot of environmental and property damage in Pakistan every year. Proper assessment of direct runoff in the form of hill torrents is essential for protection of environment, property, and human life. In this paper, direct surface runoff hydrograph (DSRH) was derived for a large catchment using the geomorphologic instantaneous unit hydrograph concept. The catchment with hill torrent flows in semi-arid region of Pakistan was selected for this study. It was divided into series of linear cascades and hydrologic parameters required for Nash's conceptual model, and were estimated using geomorphology of the basin. Geomorphologic parameters were derived from satellite images of the basin and ERDAS and ArcGIS were used for data processing. Computer program was developed to systematically estimate the dynamic velocity, its related parameters by optimization and thereby to simulate the DSRH. The data regarding rainfall-runoff and satellite images were collected from Punjab Irrigation and Power Department, Pakistan. Model calibration and validation was made for 15 rainfall-runoff events. Ten events were used for calibration and five for validation. Model efficiency was found to be more than 90% and root mean square error to be about 5%. Impact of variation in model parameters (shape parameter and storage coefficient) on DSRH was investigated. For shape parameter, the number of linear cascades varied from 1 to 3 and it was found that the shaper parameter value of 3 produced the best DSRH. Various values of storage coefficient were used and it was observed that the value determined from geomorphology and the dynamic velocity produced the best results.     

International Environmental Agreements: Design of Optimal Transfers Under Heterogeneity

International environmental agreements (IEAs) can coordinate abatement of transboundary pollutants. This paper investigates how heterogeneous countries facing a stock pollutant might structure such an agreement. In particular, we examine how an IEA might be implemented with a set of monetary transfers. The focus is on transfers that are time invariant, linear in emissions, and consistent with budget balance. There is a range of such schemes that would induce efficient emissions. We provide a simple and intuitive characterization of these penalties and describe how specific proposals might be chosen in order to facilitate compliance and implementation. Our proposals are illustrated with a simple example. We show that heterogeneity reduces the scope for penalty schemes to jointly satisfy desirable properties.     

Optimal Expansion Strategy for a Sewer System under Uncertainty

Because of fast urban sprawl, land use competition, and the gap in available funds and needed funds, municipal decision makers and planners are looking for more cost-effective and sustainable ways to improve their sewer infrastructure systems. The dominant approaches have turned to planning the sanitary sewer systems within a regional context, while the decentralized and on-site/cluster wastewater systems have not overcome the application barriers. But regionalization policy confers uncertainties and risks upon cities while planning for future events. Following the philosophy of smart growth, this paper presents several optimal expansion schemes for a fast-growing city in the US/Mexico borderlands—the city of Pharr in Texas under uncertainty. The waste stream generated in Pharr is divided into three distinct sewer sheds within the city limit, including south region, central region, and north region. The options available include routing the wastewater to a neighboring municipality (i.e., McAllen) for treatment and reuse, expanding the existing wastewater treatment plant (WWTP) in the south sewer shed, and constructing a new WWTP in the north sewer shed. Traditional deterministic least-cost optimization applied in the first stage can provide a cost-effective and technology-based decision without respect to associated uncertainties system wide. As the model is primarily driven by the fees charged for wastewater transfer, sensitivity analysis was emphasized by the inclusion of varying flat-rate fees for adjustable transfer schemes before contracting process that may support the assessment of fiscal benefits to all parties involved. Yet uncertainties might arise from wastewater generation, wastewater reuse, and cost increase in constructing and operating the new wastewater treatment plant simultaneously. When dealing with multiple sources of uncertainty, the grey mixed integer programming (GIP) model, formulated in the second stage, can further allow all sources of uncertainties to propagate throughout the optimization context, simultaneously leading to determine a wealth of optimal decisions within a reasonable range. Both models ran for three 5-year periods beginning in 2005 and ending in 2020. The dynamic outputs of this analysis reflect the systematic concerns about integrative uncertainties within this decision analysis, which enable decision makers and stakeholders to make all-inclusive decisions for sanitary sewer system expansion in an economically growing region.