Bridging information domains to improve ecological understanding of biological invasions in a marine ecosystem

We devised a practical method for integrating information on 2 marine invasive species using 3 different approaches: standardized ecological monitoring, online-reporting databases, and surveys of anglers and crabbers. Focusing on 2 recently introduced species with different characteristics, the Asian shore crab (Hemigrapsus sanguineus) and Chinese mitten crab (Eriocheir sinensis), in the Hudson-Raritan watershed of New York and New Jersey, we used sensitivity analyses to explore the relative contribution of each information source to knowledge of species abundance and distribution. All 3 information sources contributed something unique to understanding abundance and distribution of the introduced crabs. Online and survey data on Asian shore crabs significantly affected predictions of abundance, whereas monitoring data did not. When survey data were omitted, abundance estimates were unchanged over time, but when they were included, the model predicted an increased abundance in 2012. All 3 data sets for the Asian shore crab significantly affected estimates of species coverage; surveys had the biggest influence, increasing range size by 4097.25 km². For the catadromous Chinese mitten crab, ecological monitoring data collected in freshwater shortly after the original sighting significantly shaped model estimates for abundance and documented the establishment phase of the mitten crab in an area outside the spatial scope of the surveyed resource users. However, the survey data significantly enlarged mitten crab range-size estimates by 6498.01 km². By demonstrating that data integration produced an image of the invasion process that would not have emerged had we used any 1 method individually, model results provide evidence for the advantages of an interdisciplinary approach.     

Environmental pollution of China to foreign investors: detrimental or beneficial?

Environmental Science and Pollution Research - This study investigates the dynamic linkage among foreign direct investment, energy consumption, and environmental pollution of China spanning from...     

Global justice and the opportunity costs of conservation

Opportunity costs can represent a significant portion of the costs associated with conservation projects and frequently outstrip other kinds of cost. They are typically understood to refer to the benefits someone would have obtained if conservation projects had not required them to give up current activities, such as farming or hunting or if the land had been available for uses other than conservation. This familiar way of identifying opportunity costs is flawed, however, because it threatens to condone, or take advantage of, the injustices that many people face that affect their opportunities. I integrated ideas from the political theory of global justice to examine how the analysis of opportunity costs illustrates the importance of considering conservation and issues of global justice together, rather than thinking about them in isolation. I distinguish four baselines for defining opportunity costs. A status quo baseline defines opportunity costs by asking what people would have earned had a conservation project not happened. A willingness to accept baseline defines them by asking people what it would take to make them indifferent to whether a conservation project takes place or not. An antipoverty baseline suggests that opportunity costs have been met when people affected by a project are not left in poverty. An egalitarian baseline suggests opportunity costs have been met when people are not left in relative disadvantage, with worse than average opportunities. I argue that the egalitarian baseline is the most acceptable from the point of view of justice. Such a baseline would suggest that, in practice, many of the world's poor are being unjustly treated, or even exploited, as a result of conservation activities.     

Correlation between nectar supply and aggression in territorial honeyeaters: causation or coincidence?

Summary A fundamental prediction of food-based economic models of territoriality is that animals will not defend territories if food is so abundant that defense will not improve access to food. Several studies of nectar-feeding birds support this prediction, with territoriality being rare or absent in years when nectar was particularly abundant. However, these results could potentially be an artefact of changes in bird density with nectar availability, and in at least some cases the correlations between territory defense and nectar availability could be purely coincidental. This paper reports the first experimental test of whether cessation of territory defense in nectar-feeding birds results from a direct response to abundance of nectar. New holland honeyeaters Phylidonyris novaehollandiae and white-cheeked honeyeaters P. nigra show pronounced changes in their levels of territorial aggression over the 7–8 months that they breed. These changes are predictable from economic considerations in that the birds are least aggressive in the months when nectar is extremely abundant. I tested whether the birds were responding to changes in nectar availability by providing sugar-water feeders at neutral locations that were easily accessible to territory holders, but far enough away from territories that intrusion rates were unaffected. I tested for responses at two time scales feeders were put out for 48-h periods in 1987, and were left out continuously from January to October 1988. The only effect was that territory holders visited feeders instead of flowers when floral nectar was scarce. They continued to defend their territories aggressively at those times, showed seasonal changes in aggressiveness similar to birds on a site without feeders, and did not shift their territories toward feeders. I conclude that the observed changes in aggressiveness are not responses to changes in nectar availability, and suggest alternative explanations.     

The behaviour of residual contaminants at a former station site,Antarctica

In 1994, New Zealand's only mainland Antarctic base, Vanda Station, was removed from the shores of Lake Vanda, in the McMurdo Dry Valleys region of southern Victoria Land, Antarctica. Residual chemical contamination of the station site has been identified, in the form of discrete fuel spills, locally elevated Pb, Zn, Ag and Cd concentrations in soil and elevated Cu, Ni, Co and phosphate concentrations in suprapermafrost fluids in a gully formerly used for domestic washing water disposal. Pathways for contaminant transfer to Lake Vanda, potential environmental impacts and specific remediation/monitoring options are considered. While some contaminants (particularly Zn) could be selectively leached from flooded soil, during a period of rising lake level, the small area of contaminated soils exposed and low level of contamination suggests that this would not adversely affect either shallow lake water quality or the growth of cyanobacteria. Phosphate-enhanced growth of the latte may, however, be a visible consequence of the minor contamination occurring at this site.     

A boundary value approach for estuarine water quality modelling with results for Jamaica Bay,New York

Results of water quality modelling for Jamaica Bay, a New York estuary with a large hydraulic circulation, are presented. The two-dimensional topology is approximated by a set of coupled one-dimensional subsystems. The long term steady state water quality problem is then reformulated as a multi-point boundary value problem for ordinary differential equations. Piecewise constant dispersion parameters are estimated from salinity data.A sequential algorithm based on parallel shooting is developed for solving the multipoint problem. The method, which simplifies handling of feedforward and feedback reaction kinetics, is equivalent to employing a high order finite difference technique with the subsequent enhanced accuracy.Results of model verification for uncoupled variables — salinity, coliform, total soluble phosphorus, and coupled variables for nitrogen (organic and ammonia) and BOD-DO for Jamaica Bay are discussed.     

Risk-taking by female ducks: intra- and interspecific tests of nest defense theory

We tested several predictions of nest defense theory by observing variation in flushing distance and probability of nest abandonment within and between six species of waterfowl. In these species, only the females incubate eggs and attend offspring. First, we examined whether flushing distance by females varied in relation to clutch size, stage of incubation, and time of season, after controlling for the number of visits made to nests by observers. Revisits by observers appeared to affect flushing distance by females for reasons unrelated to the relative value of the current clutch. We found that as incubation progressed, females allowed observers to approach more closely before flushing from the nest. In some species, females with larger clutches allowed closer approaches to nests before flushing which was also consistent with nest defense theory. In contrast, time of season (Julian date) did not relate to flushing distance for any species. When species were compared, we found that species with moderate to high yearly mortality and high reproductive output per breeding attempt (e.g., northern shoveler and blue-winged teal) were less likely to abandon nesting attempts and exhibited riskier behavior (remained at nests when approached closely by observers) than species that had lower yearly mortality (e.g., mallard). Our results show that flushing distance and patterns of nest abandonment by female ducks conform to several predictions of nest defense theory.Correspondence to: M.R.L. Forbes     

Early amniocentesis: Experience of 222 consecutive patients, 1987–1988

Early amniocentesis from 9 to 14 weeks' gestation provides a safe and accurate method of prenatal diagnosis of cytogenetic and biochemical disorders. There was a 100 per cent success rate in culturing the amniotic cells from 222 samples obtained between 9 and 14 weeks' gestation. Follow-up of the patients to delivery revealed an abortion rate of 1·4 per cent. Among the 207 live- and stillborn infants, only one had a congenital abnormality (bilateral talipes equino-varus) and no infant had respiratory distress syndrome or pneumonia. Eleven pregnancies were terminated following the detection of a chromosomal, biochemical, or congenital abnormality (5·0 per cent). However, before the procedure of early amniocentesis becomes routine clinical practice, it requires appraisal by a randomized clinical trial.     

Crash risk perception of sleepy driving and its comparisons with drink driving and speeding: Which behavior is perceived as the riskiest?

Objective: Driver sleepiness is a major crash risk factor but may be underrecognized as a risky driving behavior. Sleepy driving is usually rated as less of a road safety issue than more well-known risky driving behaviors, such as drink driving and speeding. The objective of this study was to compare perception of crash risk of sleepy driving, drink driving, and speeding.

Methods: Three hundred Australian drivers completed a questionnaire that assessed crash risk perceptions for sleepy driving, drink driving, and speeding. Additionally, the participants' perceptions of crash risk were assessed for 5 different contextual scenarios that included different levels of sleepiness (low, high), driving duration (short, long), and time of day/circadian influences (afternoon, nighttime) of driving.

Results: The analysis confirmed that sleepy driving was considered a risky driving behavior but not as risky as high levels of speeding (P < .05). Yet, the risk of crashing at 4 a.m. was considered as equally risky as low levels of speeding (10 km over the limit). The comparisons of the contextual scenarios revealed driving scenarios that would arguably be perceived as quite risky because time of day/circadian influences were not reported as high risk.

Conclusions: The results suggest a lack of awareness or appreciation of circadian rhythm functioning, particularly the descending phase of circadian rhythm that promotes increased sleepiness in the afternoon and during the early hours of the morning. Yet, the results suggested an appreciation of the danger associated with long-distance driving and driver sleepiness. Further efforts are required to improve the community's awareness of the impairing effects from sleepiness and, in particular, knowledge regarding the human circadian rhythm and the increased sleep propensity during the circadian nadir.