Feeding enhancement by social attraction in the Sandwich Tern

Summary A controversy exists over the relative roles of feeding enhancement and predation in shaping the flocking behavior of birds. We examined social attraction among foraging Sandwich Terns, Sterna sandvicensis, in the Gulf of Mexico. The prediction that foraging terns would coalesce at a spot where another bird dove was supported. Approach took place within seconds, occurred over a distance of at least 500 m, and lasted about 10 to 20 s after the food source dissipated. Although social attraction appears to play a major role in the feeding of the terns, this need not be construed as evidence against a similarly important role for predation in shaping social foraging behavior.     

Cleanup of fractured rock aquifers: Implications of matrix diffusion

As contamination moves through a fractured rock aquifer, it tends to diffuse from the flowing fracture water into the rock's essentially stagnant pore water. This process tends both to retard a contamination plume's advance through a fractured rock aquifer and to substantially increase the difficulty of purging contamination from the aquifer. A mathematical model has been developed to evaluate the potential impact of this phenomenon upon water quality restoration in fractured rock aquifers. The numerical modeling reveals that cleanup of fractured rock aquifers will, in many cases, require many decades, even centuries, to achieve, particularly where substantial improvements in water quality are sought. The parameters which most strongly govern the degree to which matrix diffusion prolongs the aquifer restoration process are the rock's matrix porosity, fracture spacing, and matrix diffusivity, the chemical identity of the contaminant(s), and the length of time the aquifer has been contaminated.Since sedimentary rocks tend to have both relatively high matrix porosities and matrix diffusivities, it can be particularly difficult to purge contamination from sedimentary rock aquifers. Crystalline rocks, in contrast, typically have lower matrix porosities and matrix diffusivities, and therefore undergo more rapid cleanup. However, even in crystalline rocks, attainment of very high degrees of water quality improvement may be problematic. Numerical modeling also indicates that conventional groundwater pump and treat programs are not likely to be very effective in speeding up aquifer restoration if the rate limiting step in the process is diffusion of contaminants from the rock matrix.     

Evaluation of the content of Zn,Cu, Ni and Pb as well as the enzymatic activity of forest soils exposed to the effect of road traffic pollution

Environmental Science and Pollution Research - The paper evaluates the contents of total forms of selected heavy metals (Zn, Cu, Ni and Pb) as well as the activity of catalase (CAT), dehydrogenases...     

Preferences for alternative risk management policies at the United States major nuclear weapons legacy sites

A survey of 1351 people who lived within 50 miles of one of six US Department of Energy nuclear weapon sites showed that the vast majority of residents prefer strong public health surveillance and land use controls. The sample was stratified so that the same number of responses was obtained at each site. The strongest correlates of wanting the DOE to restrict on-site activities and maintain and expand its surveillance programs were worries about DOE activities on the site, as well as how those activities could damage the off-site environment. Notably, the exceptions, that is, those who demanded less from the DOE and were not particularly worried about the DOE's activities, tended to live near the site, many worked there or knew people who did, and had high socio-economic status, and trusted the DOE. The findings are mostly, but not entirely, consistent with expectations drawn from the risk perception and organizational trust literatures. The challenge is how to establish a stewardship program that represents a consensus among state and local government, community advisory boards and the public that remediation can go on at the same time that some waste is managed on-site until suitable technologies can be safely deployed, which at some sites means 100 years or in perpetuity.     

Role of Wild Game in the Diet of Recreationists in South Carolina

Risk assessors have devoted considerable attention to the consumption of fish in the diet of recreational and subsistence anglers, but little attention has been directed toward the percentage that wild game contributes to total protein intake for people who engage in hunting and fishing. While recall studies have limitations, the relative errors should be similar for different types of fish and game. We interviewed 454 people attending the Palmetto Sportsmen's Classic in South Carolina to determine their consumption patterns of domesticated animals, fish (both wild-caught and commercial) and wild game. The percentage of people who consumed each type of meat was: chicken (98%); beef (95%); wild-caught fish (79%); deer (79%); restaurant fish (73%); pork (71%); dove (47%); commercial fish (41%); wild turkey (40%), duck, squirrel and self-caught quail (about 25% each); restaurant quail (10%); and raccoon (11%). Although a similar proportion of white respondents and black respondents consumed wild game overall (90%), there were ethnic differences in the number of meals of wild-caught fish and game. Black respondents ate more wild-caught fish, rabbit, raccoon and squirrel, and less deer, than did white respondents. Wild-caught fish and game made up 50% of the meat and fish diet of black sportsmen, but only 32% for whites. Wild-caught fish and game were being eaten disproportionately more by low-income black respondents, while more deer was consumed by higher-income black respondents. The data suggest that managers and planners should take into account age, ethnicity and income when (1) conducting exposure assessments, (2) considering consumption patterns for wild-caught fish and game and (3) managing risk from wild-caught fish and game. The data will be especially useful to policy makers and risk managers who are designing consumption advisories, for risk communicators in identifying the target audience and for managers designing long-term stewardship for sites with contamination.     

Guidance for determining the best disposition of large tracts of decommissioned land

Many government agencies and other organizations hold large tracts of surplus land. Some are investigating ways to lower expenses by selling the land or transferring management responsibility. There is no generally recognized process used to decide what land can be decommissioned and what future use would be best. This paper provides guidance for land‐use decisions in the form of a checklist. The checklist questions address both the socio‐economic resources and current land use in the region, and the ecological resources and suitability of the tract itself. The answers will clarify regional public needs and the economic and ecological values of the land.     

Incubation temperature has long-term effects on behaviour of young Pine snakes (Pituophis melanoleucus)

Summary Eggs of pine snakes (Pituophis melanoleucus) were incubated at constant temperatures of 21°, 23°, 26°, 28°, 30° and 32° C to determine behavioural differences as a function of incubation temperature. For all behavioural and physiological measures hatchlings from medium incubation temperatures (26°, 28°) performed tests better than those hatchlings from eggs incubated at low temperatures (21°, 23°). For some behavioural tests hatchlings from eggs incubated at high temperature (30°, 32°) performed less well than medium temperature hatchlings. These differences were not due to ambient temperatures or age of testing since these were held constant. Some of the behavioural differences persisted for 24 weeks.     

Perceptual Indicators of Environmental Health, Future Land Use, and Stewardship

There are important linkages between the health of humans and theenvironment, restoration of degraded lands, and long-term stewardship of public lands, yet most environmental indicators deal only with assessing the physical and biological aspects ofecosystems. In this article, we examine the ratings of perceptionsof several environmental problems for their utility as indicatorsof environmental quality, and examine perceptions of future land use by people interviewed in Santa Fe, New Mexico, near the Department of Energy's (DOE) Los Alamos National Laboratory (LANL). Overall, people with lower incomes rated environmental problems as more severe than others, were more willing to spend federal funds to solve them, and were consistent in their ratingsof severity of environmental problems and their willingness to spend federal funds. Cleaning up LANL and other Department of Energy sites, received the highest rating for expenditure of federal funds. The highest rated future uses for DOE sites were for recreation and for National Environmental Research Parks. People with less education generally gave higher ratings to mostfuture land uses for DOE than did those with more education. However, those with higher education gave higher ratings to nuclear reprocessing, and nuclear material storage. Where there were differences, the people interviewed at Santa Fe rated all environmental problems (except pesticides) as more severe than did those previously interviewed in Albuquerque (located fartherfrom the LANL site), and they were more willing to spend federalfunds on these problems. Ratings for all future land uses did notdiffer between the Santa Fe and Albuquerque respondents. These perception-based indicators show general agreement among peopleliving close and farther away from LANL with respect to cleaningup LANL and the future land uses for the site. These indicators should be considered by regulators, site personnel, and policy makers in future management and land use decisions.     

Evolutionary consequences for ecological risk assessment and management

The human health risk assessment (HRA) paradigm is being used as a basis for developing ecological risk assessment (ERA). The modification of the HRA paradigm to ERA will be most useful in an ecotoxicological sense, to assess the effect of hazards to single indicator species and populations, rather than to ecosystems. However, even for single species and population assessments, there are major differences in HRA and ERA. One such difference derives from the HRA tenet that human impairment at any age is important, and that each individual is important. For ERA, individuals are less important, and it is the population and its survival and interactions that are of concern. One exception is in the case of endangered species where every individual is critical because of its potential impact on survival and genetic diversity of the species. We suggest that ERA must take into account the relative reproductive value of the potentially impacted individuals in assessing hazards. This will involve adding additional steps to evaluate the value of the individual to current population levels, assessing reproductive value, and assessing recovery potential. Although ecologists recognize the importance of these factors, we suggest that they should be integral parts of ecological risk assessment.