Bioaccumulation of polychlorinated biphenyls in ranid frogs and northern water snakes from a hazardous waste site and a contaminated watershed

Livers of bullfrogs (Rana catesbeiana) from a polychlorinated biphenyl (PCB) contaminated watershed and hazardous waste site located in Pickens County, South Carolina, contained significantly higher concentrations of PCBs (2.33 and 2.26 ppm, respectively) than those from a reference site (0.05 ppm). Green frogs (R. clamitans) from the two contaminated sites also accumulated higher levels of PCBs (2.37 and 3.88 ppm, respectively) than those from the reference site (0.02 ppm). No temporal variation was observed in PCB concentrations of bullfrogs or green frogs from the contaminated sites between 1992 and 1993. Levels of PCBs in the livers of northern water snakes (Nerodia sipedon) were significantly higher in snakes from the contaminated watershed (13.70 ppm) than in those from the waste site (2.29 ppm) and two reference sites (2.50 and 1.23 ppm). When compared to frogs, significantly higher bioaccumulation occurred in water snakes from the contaminated watershed. No significant differences in PCB levels were found with respect to sex or body size (snout-vent length (SVL) or body mass) for frogs or snakes. PCBs were detected also in eggs of both frogs and snakes. Results of this study provide baseline data and document the bioaccumulation of PCB residues in frog and snake tissues; however, the significance of these tissue residues to reproduction, survival, growth/development, and population dynamics in contaminated habitats is unknown.     

Practices,attitudes and motives for domestic waste recycling

SUMMARY

Solid household waste management in Malaysia has reached a critical stage. Increasing population, urbanization and changing patterns of lifestyle have instigated the phenomenon. The 15 000 tonnes of garbage produced daily are thrown into 230 landfills nationwide, where 80% of them have only two years of life span left. Although recycling programmes were launched as early as 1990, only 5% of the wastes are recycled. The purpose of the present research was to ascertain the current management of household solid waste, attitude and motivational factors towards recycling. Data were collected using interview survey on 150 households in an urban residential area. The findings demonstrated that the respondents had very low awareness and knowledge regarding local domestic waste management. Separation of organic and non-organic wastes was rarely practised by 76% of the respondents. Most waste was thrown away, except for newspaper and aluminium cans which were regularly recycled, while furniture, and electrical items were reused by giving away or trading-in. The attitude of the respondents towards recycling was modest. Of the five motivational factors, intrinsic satisfaction and individual commitment were more important reasons for recycling than convenience, economic motivation and societal commitment. The results of the study indicated that, in order to overcome the solid waste crisis, the conscience of the individual needs to be raised through environmental awareness and concern, inculcation of sustainable consumption practices and education on waste management.     

Flexibility,learning, and irreversibility in environmental decisions: A bayesian approach

The Bayes decision is characterized and studied for a two-period decision problem involving a proposed resource development project. It is assumed that development is irreversible and that expectations about benefits and costs during the second period vary with experiences resulting from the first-period action. The amount and types of learning achieved depend upon the particular action taken during the first period. Flexible sequential decision procedures are compared with fixed once-and-for-all decisions. It is shown that under this specification, optimal development decisions are not necessarily more conservative when a sequential procedure is used. The possibility of reneging on a fixed decision is formally specified and studied.     

Modeling natural attenuation of petroleum hydrocarbon contamination using alternate electron acceptors: Case study comparing bioplume iii with BIOSCREEN

Natural attenuation holds great promise as a cost‐effective means of remedying groundwater contamination at petroleum spill sites: this is particularly true at sites with sufficient background concentrations of alternate electron acceptors (nitrate and/or sulfate). The study reported in this article compared the results of a new Environmental Protection Agency (EPA) numerical model (BIOPLUME III) with an updated EPA analytical model (BIOSCREEN Version 1.4) used to predict natural attenuation at an underground fuel spill site in Oklahoma. High background sulfate concentrations were shown to result in unrealistic predictions from both BIOSCREEN and BIOPLUME III. BIOSCREEN could be easily used with a data set not significantly enlarged from that used in a routine leaking fuel tank investigation. BIOPLUME III was much more difficult to use and did not yield reliable results. Results of this study indicate that the additional complexity of the BIOPLUME III model is not justified for simple sites.     

Transfer of development rights,growth management,and landscape conservation in Virginia

Urban sprawl in Virginia has led to the loss of wildlife habitat and agricultural land, reduced water quality, and to severe traffic congestion. We conducted a survey to identify the tools being used by the state's localities to manage growth and protect land from development, and the factors that influence interest in particular planning goals and strategies. More specifically, we sought to explore the level of interest in using the transfer of development rights (TDR). Almost every locality in Virginia has stated goals of protecting green space and agricultural land but very few have pursued a TDR programme since it became legal to do so in 2006. However, the main tools being used by planning departments are of limited effectiveness, particularly with regard to ensuring permanent or even long-term land preservation. More broadly, they are reflective of a reactive response to individual development proposals rather than a proactive, comprehensive approach to planning.     

Mitochondrial control region sequence analyses indicate dispersal from the US East Coast as the source of the invasive Indo-Pacific lionfish Pterois volitans in the Bahamas

Lionfish are popular aquarium fish from the Indo-Pacific that have invaded the western Atlantic. Two species, Pterois volitans and P. miles, were well established along the United States east coast before the first lionfish were reported from the Bahamas in 2004, where they quickly dispersed throughout the archipelago by 2007. The source of the Bahamian lionfish invasion has been in question because of the hypothesized low connectivity between Florida and Bahamas reef species as well as the temporal lag in their arrival in the Bahamas. Mitochondrial control region haplotypes (680 bp) were determined and analyzed for lionfish specimens from the Bahamas, North Carolina, and two sites within their native range (Indonesia and the Philippines). Exact tests, pairwise F _st and AMOVA analyses all showed no significant differentiation between the Bahamas and North Carolina specimens. The similarity between the Bahamas and North Carolina lionfish was also reflected in a minimum spanning network and neighbor-joining distance tree generated from the data. Sequence analyses also revealed the presence of only Pterois volitans, as no P. miles were detected in the Bahamian sample. These results indicate that the source of the Bahamian lionfish is egg and larval dispersal from the United States east coast population, and support previous models of reef fish dispersal that suggest a low level of connectivity between the Bahamas and east coast of Florida.