Effects of mercury on the feeding behavior of the mummichog, Fundulus heteroclitus from a polluted habitat

Fish living in contaminated environments may exhibit reduced growth which may be due, in part, to the impact of toxicants on prey capture ability. We studied the effects of methylmercury (meHg) and mercuric chloride (Hg) on feeding of Fundulus heteroclitus from Piles Creek, a polluted habitat in Linden, New Jersey. We found that exposure to 0·01 mg/liter of meHg for one week had less impact on the prey capture rate than exposure to a similar concentration of Hg. Exposure to 0·01 mg/liter for two weeks or to 0·02 mg/liter for one week, of either meHg or Hg, produced significant reductions in feeding rate, compared to controls. In general, the fish were affected to a greater degree by exposure to Hg than to meHg. This is the reverse of the usual order of toxicity, but is in keeping with previous observations on this population, in which we have noted that gametes and embryos had developed tolerance to meHg, but were more susceptible to Hg.     

Climates of urbanization: local experiences of water security,conflict and cooperation in peri-urban South-Asia

ABSTRACT

This article explores changing water (in)securities in a context of urbanization and climate change in the peri-urban spaces of four South-Asian cities: Khulna (Bangladesh), Gurugram and Hyderabad (India), and Kathmandu (Nepal). As awareness of water challenges like intensifying use, deteriorating quality and climate change is growing, water security gets more scientific and policy attention. However, in peri-urban areas, the dynamic zones between the urban and the rural, it remains under-researched, despite the specific characteristics of these spaces: intensifying flows of goods, resources, people, and technologies; diversifying uses of, and growing pressures on land and water; and complex and often contradictory governance and jurisdictional institutions. This article analyses local experiences of water (in-)security, conflict and cooperation in relation to existing policies. It uses insights from the analysis of the case studies as a point of departure for a critical reflection on whether a ‘community resilience’ discourse contributes to better understanding these cases of water insecurity and conflict, and to better policy solutions. The authors argue that a community resilience focus risks neglecting important insights about how peri-urban water insecurity problems are experienced by peri-urban populations and produced or reproduced in specific socio-economic, political and policy contexts. Unless supported by in-depth hydro-social research, such a focus may depoliticize basically political questions of water (re) allocation, prioritization, and access for marginalized groups. Therefore, the authors plead for more critical awareness among researchers and policy-makers of the consequences of using a ‘community resilience’ discourse for making sense of peri-urban water (in-)security.

Key policy insights

• There is an urgent need for more (critical) policy and scientific attention to peri-urban water insecurity, conflict, and climate change.

• Although a changing climate will likely play a role, more attention is needed to how water insecurities and vulnerabilities in South Asia are socially produced.

• Researchers and policy-makers should avoid using depoliticized (community) resilience approaches for basically socio-political problems.

     

Determination of groundwater potential by using geoelectrical method and petrographic analysis in Rawalakot and adjacent areas of Azad Kashmir,sub-Himalayas,Pakistan

The current study is carried out for the determination of groundwater potential in District Rawalakot Azad Jammu and Kashmir (AJ&K) Pakistan by using electrical resistivity method and petrographic analysis of the area. The tape-compass-clinometers method was used in section measurement to understand the facies and depositional environment. The electrical resistivity survey was carried out in the project area in sub-Himalayan Siwaliks system of Pakistan to overcome water scarcity in a few regions. The area was chartered with the Schlumberger configuration up to the AB/2 depth of 150 m. The ABEM Terrameter SAS 4000 (Sweden) and accessories were used to acquire vertical electrical soundings in 24 locations. The results obtained through the 2D and 3D isoresistivity maps of apparent resistivity for 15, 45, and 130 m spacings, the 3D isoresistivity maps of transverse resistance and anisotropy, the VES curve types, and the measured stratigraphic section of surface rocks revealed the confined or semi-confined type aquifers within sedimentary formations. The petrographic analysis indicates the clues of the secondary porosity and fluid migrations through the rocks.     

Long-term seismic observations along Myanmar–Sunda subduction margin: insights for 2004 Mw > 9.0 earthquake

International Journal of Earth Sciences - The present study investigates the temporal variation of few seismic parameters between the Myanmar (Zone I), Andaman–Nicobar–Northwest Sumatra...     

Assessing the effect of future landslide on ecosystem services in Aqabat Al-Sulbat region,Saudi Arabia

Natural Hazards - Co-occurrence events of droughts and heatwaves characterized by abnormal low soil moisture (SM) and high temperatures may cause more significant impacts on society and natural...     

Assessing the long-term planform dynamics of Ganges–Jamuna confluence with the aid of remote sensing and GIS

Natural Hazards - The confluence of the Ganges, Jamuna, and Padma rivers is one of the most dynamic in the world, an internationally important research area because of the confluence of two of the...