Monitoring of DNA damage in haemocytes of freshwater mussel Sinanodonta woodiana sampled from the Velika Morava River in Serbia with the comet assay

This study was undertaken to investigate the potential of the freshwater mussel Sinanodonta woodiana for detection of genotoxic pollution of the environment. Study was performed at two sites in the Velika Morava River, from May 2010 to February 2011. The alkaline comet assay on haemocytes was used, and the olive tail moment (OTM) was chosen as a measure of DNA damage. The specimens held on acclimation under controlled laboratory conditions for 10 d were used as a control. Chemical analysis revealed the presence of phosphates and increased concentrations of zinc, copper and nickel at both sites during the entire sampling period. The values of OTM in mussels collected from the environment, significantly correlated with the concentration of zinc (r = 0.6248), temperature (r = 0.7006) and dissolved oxygen (r = 0.7738). Seasonal variations in genotoxic response were observed, with the highest OTM values obtained during summer months. Preliminary results of the in vitro study indicated the effect of water temperature on genotoxic response to zinc and cadmium in S. woodiana suggesting that the presence of genotoxic pollutants during months with lower temperature could be under-estimated. Obtained results indicate that S. woodiana could be a valuable tool for active biomonitoring of aquatic environments and emphasizes the importance of seasonal genotoxic monitoring with this organism.     

Evaluating Spatio-temporal Complexities of Forest Management: An Integrated Agent-based Modeling and GIS Approach

The objective of this study is to integrate agent-based modeling and geographic information systems (GIS) for examining how interactions within forest management lead to patterns of land-cover change. Specifically, this study evaluates how management agents behave in the presence of variable timber prices, harvesting costs, and accessibility to timber and how their actions influence the spatial characteristics of the forest landscape over time. The GIS calculates the average harvested patch size, number of patches, and total harvested area as measures of emergent patterns resulting from agent actions. The results from the agent-based GIS model reveal that good economic conditions lead to few but large harvested patches, while deteriorating conditions will see more patches of smaller size if forest companies have access to high-quality timber. This study emphasizes the need for a complex systems approach to forest management as the model illustrates how system elements interact in a manner to produce emergent spatial patterns over time.     

Optimizing the SO2 total emission control strategy: case study—Bor (Serbia)

Mumbai, a megacity of India, and its adjacent marine environment, though heavily stressed from various anthropogenic interferences, harbor ~146 km² of mangrove cover. Manori creek, in the close vicinity of Mumbai, sustains relatively better mangrove formations. A creek habitat had been evaluated for its biological and environmental characteristics, and is compared with similar but relatively lesser stressed Mandovi estuary (~475 km south of Mumbai). Several evidences of deteriorating environment of Manori creek have been described with respect to Water quality index and various biotic community structures. Water quality index of <55 indicated unacceptable aquatic conditions of Manori creek. Dominance of Avicennia marina and poor abundance and diversity of mangrove and associated biological features indicate highly stressed environment. Dominance of stress-tolerant phytoplankton spp. such as Skeletonema costatum and benthic fauna such as Polychaeta further supported the view. The data presented in the present document would help in developing rational approach towards conservation, protection, and sustainable development of mangrove-dominated creek and estuarine wetlands.     

Biomonitoring of heavy metals in fish from the Danube River

The Croatian part of the Danube River extends over 188 km and comprises 58 % of the country’s overall area used for commercial freshwater fishing. To date, the heavy metal contamination of fish in the Croatian part of the Danube has not been studied. The main purpose of this study was to determine heavy metal levels in muscle tissue of sampled fish species and to analyze the measured values according to feeding habits of particular groups. Lead ranged from 0.015 μg^?1 dry weight in planktivorous to 0.039 μg^?1 dry weight in herbivorous fish, cadmium from 0.013 μg^?1 dry weight in herbivorous to 0.018 μg^?1 dry weight in piscivorous fish, mercury from 0.191 μg^?1 dry weight in omnivorous to 0.441 μg^?1 dry weight in planktivorous fish and arsenic from 0.018 μg^?1 dry weight in planktivorous to 0.039 μg^?1 dry weight in omnivorous fish. Among the analyzed metals in muscle tissue of sampled fish, only mercury exceeded the maximal level (0.5 mg kg^?1) permitted according to the national and EU regulations determining maximum levels for certain contaminants in foodstuffs, indicating a hazard for consumers of fish from the Danube River.     

Effective advocacy: the psychological mechanisms of environmental issue framing

ABSTRACT

While environmental issues are among the most serious threats to human security, they tend to rank toward the bottom of Americans’ priorities for political action. To redress this, environmental organizations strategically frame their mobilization communications in an attempt to garner the public’s support. Advocacy research groups encourage the use of motivational, economic and personal frames because of their ability to mobilize support through distinct psychological processes: efficacy, psychological proximity and emotion. An experimental study is conducted that tests the extent to which these mechanisms mediate environmental frames’ effects on support for an environmental campaign. Results of this study lead to the conclusion that motivational frames are unable to elicit efficacy in the target audience, thus proving ineffectual at influencing attitudes or behaviors. Economic and personal frames are more successful, aligning the audience’s attitudes with the message and operating through psychological proximity, sadness and anger to induce behavioral support for the environmental campaign.     

Characterization of trace metal particles deposited on some deciduous tree leaves in an urban area

In 1996 and 1997 horse chestnut (Aesculus hippocastanum L.) and Turkish hazel (Corulys colurna L.) leaves were sampled at 2 m height in the Belgrade Botanic Garden, located in an urban area with heavy traffic. Using a scanning electron microscope with an energy dispersive X-ray spectroscopy (SEM-EDAX), the size, size distribution, morphology and chemical composition of individual particles were examined on the adaxial and abaxial surfaces of leaf discs of both species. The majority of particles observed on leaves belonged to a class of fine particles (D < 2 microm). Morphological and chemical composition indicated that the most abundant particles were soot and dust with minor constituents such as Pb, Zn, Ni, V, Cd, Ti, As and Cu. Using an electrochemical technique (DPASV), it was possible to measure trace metal concentrations (Pb, Cu, Zn) in a water-soluble fraction of deposits on each single leaf. Trace metal contents in the leaf deposits, increased during the vegetation period for both species and were considerably higher in A. hippocastanum due to different epidermal characteristics. The higher trace metal concentrations in deposits in 1997 reflected greater atmospheric pollution in the Belgrade urban area.