Regulating manure application discharges from concentrated animal feeding operations in the United States

In the United States, reducing pollution from agriculture has received attention due to data suggesting that this is the leading source of impairment of many waterbodies. The federal government revised its regulations governing concentrated animal feeding operations (CAFOs) to enhance governmental oversight over sources of pollution. For the application of manure resulting in pollutant discharges, CAFOs need to implement nutrient management plans. A federal court affirmed the ability of the US federal government to oversee the application of manure from CAFOs that have discharges. Simultaneously, owners and operators of CAFOs who have implemented an appropriate nutrient management plan may forgo securing a permit if their discharges qualify under the agricultural stormwater discharge exemption.     

Photolysis of vinclozolin

Following photolysis of vinclozolin in methanol five products were detected and identified: 3,5-dichlorophenylisocyanate, 3,5-dichloroaniline, methyl 3,5-dichlorophenylcarbamate, 3-(3-chlorophenyl)-5-methyl-5-vinyl-oxazolidine-2,4-dione and methyl (3,5-dichlorophenyl) (2-hydroxy-2-methyl-1-oxo-buten-3-yl) carbamate. The major component identified from photolysis in benzene solution, 3-(3-chlorobiphenyl)-5-methyl-5-vinyl-oxazolidine-2,4-dione, was produced by replacement of one chlorine atom by a solvent molecule.     

Distribution and rate of disappearance of fluorene in pond ecosystems

Fluorene, an energy related polynuclear aromatic hydrocarbon, was applied to several experimental pond ecosystems to effect concentrations of 0.12, 0.5, 2.0, 5.0, and 10.0 mg/L. Water, benthic sediment, and rooted macrophytes were monitored for fluorene residues for 56 days after application. Most of the fluorene at concentrations greater than its water solubility appeared to sublime from the surface of the ponds. The rate of disappearance of fluorene from the water decreased as the application rate increased. This reduction was linked to high concentrations and a flux of fluorene from benthic sediments, macrophytes, and pond surfaces to water columns. Several parameters of photosynthetic primary production were statistically linked to the accelerated disappearance of fluorene from the water.     

Universal access to water and sanitation: Why the private sector must participate

Against the background of the current state of provision of drinking water and sanitation in the world — with one billion lacking safe water, and 2.2 billion not having adequate sanitation — this article argues that private participation is necessary. The most important issues for the management of water utilities in the 21^st century are identified as mobilizing investment for the highly capital intensive operation of water supply and sanitation infrastructure, and achieving efficiency in the delivery of services. The article highlights the issues that need to be raised if private investment is to be seriously considered as an alternative. Case studies, especially from Latin America (Argentina, Chile, Peru, Bolivia), illustrate different modes of private participation, and possible reasons for successes and failures are discussed. The article stresses that regardless of the modality of private sector involvement, on‐going government regulatory responsibility in the water sector is crucial. It suggests that regulatory policy must go beyond just setting tariffs, to develop standards for drinking water quality and waste treatment, as well as other standards. In conclusion, the article recognizes that numerous and increasingly difficult challenges face utilities in fulfilling their responsibility to deliver drinking water of adequate quality, in sufficient quantity, and at affordable prices, as well as safe and sustainable disposal of wastewaters for members of urban and rural communities.     

The role of learning in the acquisition of threat-sensitive responses to predator odours

The supposition that prey animals respond to a predator with an intensity that matches the risk posed by the predator is known as the threat-sensitive predator avoidance hypothesis. Many studies have provided support for this hypothesis; yet, few studies have attempted to determine how such abilities are acquired by prey species. In this study, we investigated whether fathead minnows (Pimephales promelas) could learn to recognize an unknown predator (northern pike, Esox lucius) in such a way that they could match the intensity of their antipredator response with the threat posed by the predator. We exposed pike-naïve minnows to conspecific alarm cues paired with either a high or low concentration of pike odor. The following day, both groups were tested for a response to either high or low concentration of pike odor alone. We found that minnows conditioned with alarm cues paired with a given concentration of pike odor subsequently responded with a higher intensity to higher concentrations of pike odor, and with a lower intensity to lower concentrations of pike odor. These results demonstrate that during a single conditioning trial, minnows learn the identity of the predator in a threat-sensitive manner. Minnows use predator odor concentrations that they experience in subsequent interactions to adjust the intensity of their antipredator behavior.     

Spatial variance in abundance and occupancy of corals across broad geographic scales

Species assemblages vary in structure due to a wide variety of processes operating at ecological and much broader biogeographical scales. Cross-scale studies of assemblage structure are necessary to fully understand this variability. Here, we evaluate the abundance and occupancy patterns of hierarchically sampled coral assemblages in three habitats (reef flat, crest, and slope) and five regions (Indonesia, Papua New Guinea, the Solomon Islands, American Samoa, and the Society Islands) across the west-central Pacific Ocean. Specifically, we compare two alternative models that unify spatial variance and occupancy via the negative binomial distribution. The first assumes a power-law scaling between the mean and variance of abundance; the second assumes a quadratic variance-mean relationship and a constant abundance-invariant aggregation parameter. Surprisingly, the well-established power-law model performs worse than the model assuming abundance-invariant aggregation, for both variance-mean and occupancy-abundance relationships. We also find strong evidence for regional and habitat variation in these relationships and in the levels of aggregation estimated by the abundance-invariant aggregation model. Among habitats, corals on reef flats exhibited lower occupancy and higher levels of aggregation compared to reef crests and slopes. Among regions, low occupancy and high aggregation were most pronounced across all habitats in American Samoa. These patterns may be related to habitat and regional differences in disturbance and recovery processes. Our results suggest that the spatial scaling of abundance and occupancy is sensitive to processes operating among these habitats and at regional scales. However, the consistency of these relationships across species within assemblages suggests that a theoretical unification of spatial variance and occupancy patterns is indeed possible.