Fate of organo‐heavy metal complexes of sludges from domestic wastes in soils: A simplified modelization

Simplified models provided information on the binding ability of organic acids with trace elements, the distribution of the formed organo‐heavy metal complexes at different pH, and the biological stability (biodegradation ability) of these complexes.     

Contrasting diel patterns in vertical movement and locomotor activity of whale sharks at Ningaloo Reef

Activity patterns of animals often relate to environmental variables such as food availability and predation pressure. Technological advances are providing us with new tools to monitor and better understand these activity patterns. We used animal-attached data loggers recording acceleration and depth to compare activity patterns and vertical habitat use of whale sharks (Rhincodon typus) at Ningaloo Reef, Western Australia. Whale sharks showed a moderate reverse diel vertical migration but exhibited a clear crepuscular pattern in locomotory activity. Peak activity occurred at sunset, whereas vertical movement peaked prior to this. Typical ram surface filter feeding could be identified and occurred primarily during sunset and the first hours of night. At such times, direct observations indicated whale sharks were feeding on tropical krill swarms. Kinematic analysis of postural data and data from vertical movement suggests that whale sharks at Ningaloo spend ~8 min per day actively ram surface filter feeding. Considering the high biomass present in krill schools, it is estimated that whale sharks at Ningaloo have a similar energy intake as those at other aggregation sites. Diel patterns in activity and diving behaviour suggest that whale sharks have tuned their diving behaviour in anticipation of the formation of these high-density patches which appear to only be periodically, but predictably available at sunset. Our results confirm that diel patterns in vertical habitat selection and vertical movements do not necessarily reflect patterns in activity and foraging behaviour. Direct quantification of activity and behaviour is required in gaining accurate representation of diel activity patterns.     

Experimental evidence that workers recognize reproductives through cuticular hydrocarbons in the ant Odontomachus brunneus

Eusociality is characterized by a reproductive division of labor, wherein workers respond to the presence of reproductive individuals by refraining from reproduction themselves and restricting the reproductive efforts of others. Our understanding of how eusociality is maintained therefore depends on characterizing the mechanism by which workers detect the presence of a reproductive. Variations in cuticular hydrocarbons correspond to changes in reproductive ability in ants, and experimental studies are beginning to reveal the function of hydrocarbons as signals. In this study, we compare the cuticular hydrocarbon profiles of dominant and reproductive workers and queens of the ant Odontomachus brunneus with profiles of non-reproductive workers. Using split/reunification tests we document the existence of worker policing in both queenless and queenright colonies; supernumerary reproductives were treated aggressively by nestmates. Finally, we induce aggression and replicate queen-like submissive nestmate responses by supplementing the hydrocarbon profile of workers with (Z)-9-nonacosene, a compound that was significantly more abundant on the cuticles of reproductives. In three bioassays, we compare this manipulation to various control manipulations of the hydrocarbon profile and demonstrate that workers gauge the reproductive activity of nestmates through changes in their cuticular hydrocarbon profiles.     

Variation, levels and profiles of organochlorines and brominated flame retardants in great tit (Parus major) eggs from different types of sampling locations in Flanders (Belgium)

Small-scale geographical variation in the occurrence of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) was investigated using the eggs of a terrestrial residential songbird species, the great tit (Parus major). In addition, we investigated the influence of the type of sampling location on the presence of these pollutants. To achieve this, 10 different sampling locations in Flanders (Belgium) were classified into 3 groups based on the extent of urbanisation, industrialisation and agriculture. The higher variance among sampling locations for the levels and profiles of PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. Levels of PCBs and PBDEs were significantly higher in the industrialised sampling locations compared to the other locations. Sum PCB and sum PBDE levels reached up to 6050 and 79 ng/g lipid weight, respectively. PCBs and PBDEs were highly positively correlated for all groups, suggesting similar exposure pathways and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs up to 2683 ng/g lipid weight) were detected in the rural sampling locations situated in a residential area. This suggests that local historical usage of OCPs by inhabitants may be an important source of contamination in Flanders. Contamination profiles differed also among the sampling locations. The rural sampling locations had a higher contribution of lower brominated BDE congeners, whereas the industrialised locations had a higher contribution of higher brominated congeners. The differences in contamination profiles among the sampling locations are probably due to differences in exposure. In conclusion, our results showed that the characteristics of a sampling location influence both the levels and profiles of PCBs, OCPs and PBDEs.     

Preen oil as the main source of external contamination with organic pollutants onto feathers of the common magpie (Pica pica)

We investigated the possible sources of contamination with organic pollutants, such as polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyltrichloroethane (DDT) and metabolites, and polybrominated diphenyl ethers (PBDEs), in and onto tail feathers of a large songbird, the common magpie (Pica pica). Although feathers are potentially useful as a non-destructive biomonitor for organic pollutants, concentrations may be influenced by external contamination onto the feather surface. In a first approach, a group of magpies was captured after the completion of moult. The third tail feather was pulled out and a blood sample was taken. Most PCBs, DDTs and some PBDEs could be quantified in one single tail feather, indicating that the applicability of feathers goes beyond monitoring with predatory birds, as shown previously. Nevertheless, correlations between levels in serum and feathers were found significant in three cases only (i.e. CB 170, CB 180 and CB 187). This finding may be attributed to different factors, such as varying diet, condition, sample size or external contamination. In a second approach, cadavers of magpies were collected throughout Flanders. The preen gland was removed and the first, third and fifth tail feathers were pulled out at both sides. No significant differences were found among tail feathers within an individual. We compared three washing procedures to remove external contamination with organic pollutants from these feathers: deionised water, acetone and a surfactant/acetone solution. Right feathers were washed and left feathers were kept as control. Concentrations in the resulting washes were found highest in the acetone solutions. Furthermore, feathers washed with acetone or with a surfactant/acetone solution had significantly lower mean concentrations than the control feathers. Highest correlations with levels in preen gland were obtained for the control feathers. Consequently, the source of external contamination with organic pollutants onto feathers seems to be endogenous, originating from the preen gland. This is in great contrast to the extensive airborne pollution that has been reported for most heavy metals. In summary, the results of the current study highlight the usefulness of feathers for non-destructive biomonitoring of organic pollutants.     

Polybrominated diphenyl ethers in domestic indoor dust from Canada, New Zealand, United Kingdom and United States

Because of the similarities in European and North American dietary exposure, it has been suggested that the order of magnitude higher body burdens in North Americans may be due to international variations in exposure via ingestion of indoor dust. Furthermore, ingestion of indoor dust has been suggested as a possible source of PBDEs in the blood serum of New Zealanders. Hence, polybrominated diphenyl ethers (PBDEs) were measured in domestic indoor dust from: Amarillo/Austin, Texas, US; Birmingham, UK; Toronto, Canada; and Wellington, New Zealand. Concentrations of BDE 209 in two UK samples were - at 520,000 and 100,000 ng g(-1) - the highest ever recorded in a domestic (or office) indoor dust sample. Median concentrations in ng g(-1) were: in Canada 620 and 560 for Sigmatri-hexa-BDEs and BDE 209 respectively; in New Zealand 96, BDE 209 not determined; in the UK 59 and 2,800; and in the US 1600 and 1300. With respect to BDE 209, concentrations were in the order: UK approximately US>Canada. For Sigmatri-hexa-BDEs, the order of concentrations was US approximately Canada>New Zealand approximately UK. Combined with principal component analysis of congener patterns, this suggests that, while North American dusts are contaminated by both Deca- and Penta-BDE commercial formulations, UK dusts are contaminated predominantly by Deca-BDE. The Octa-BDE formulation appears of minimal importance in accordance with available market demand figures. Despite the commercial formulations of PBDEs never having been manufactured in, nor imported into New Zealand, their presence in dusts from that country suggests international trade in PBDE-containing goods is an important pathway effecting their global distribution.     

Personality, individual differences, and demographic antecedents of self-reported household waste management behaviours

The present study sought to extend recent conceptual frameworks of waste management behaviours by examining personality, individual differences, and socio-demographic antecedents of self-reported waste recycling, reuse, and reduction behaviours. A total of 203 participants from a British community sample completed a questionnaire consisting of measures of their self-reported waste management behaviour, Machiavellianism, political cynicism, the Big Five personality traits, and socio-demographics. The results of structural equation modelling showed that individuals who were less Machiavellian, less politically cynical, older, and more conscientious were more likely to report positive waste management behaviours. In combination, these predictors explained 22.0% of the variance in waste management behaviours. Thus, these variables may improve the predictive validity of existing conceptual models of waste management behaviours. The results are discussed in relation to those models.     

Stakeholder Opinions on the Assessment of MPA Effectiveness and Their Interests to Participate at Pacific Rim National Park Reserve,Canada

As the number of marine protected areas (MPAs) is globally increasing, information is needed on the effectiveness of existing sites. Many protected area agencies however have limited resources and are unable to evaluate MPA effectiveness. An evaluation conducted entirely by the managing agency may also lack credibility. Long-term monitoring and evaluation programs should ideally offer opportunities for participation of diverse groups in the selection of evaluation indicators and their assessment. A participatory approach has the potential to enhance evaluation capacity, to increase credibility and acceptance of results, to strengthen relationships between managers and local stakeholders, and to address more locally relevant information. Using a case study approach, this paper investigates diverse stakeholder groups’ opinions on the design of an evaluation and their interest to participate in an assessment. Respondents were most interested in the assessment of MPA achievements and outcome indicators. Most groups identified a range of government agencies and stakeholders that should participate in an assessment but only half of all respondents were interested to participate in monitoring activities. Most frequently mentioned limitations for more participation were a lack of time and money, but also governance shortcomings such as limited participation possibilities and not paying enough credit to stakeholders’ input. Participation interest was also influenced by occupation, place of residency, and familiarity with the marine environment. Differences exist among stakeholders about suitable evaluators and preferred monitoring partners, which could affect the credibility of evaluation results and affect monitoring activities.     

Spatial elements of mortality risk in old-growth forests

For many species of long-lived organisms, such as trees, survival appears to be the most critical vital rate affecting population persistence. However, methods commonly used to quantify tree death, such as relating tree mortality risk solely to diameter growth, almost certainly do not account for important spatial processes. Our goal in this study was to detect and, if present, to quantify the relevance of such processes. For this purpose, we examined purely spatial aspects of mortality for four species, Abies concolor, Abies magnifica, Calocedrus decurrens, and Pinus lambertiana, in an old-growth conifer forest in the Sierra Nevada of California, USA. The analysis was performed using data from nine fully mapped long-term monitoring plots. In three cases, the results unequivocally supported the inclusion of spatial information in models used to predict mortality. For Abies concolor, our results suggested that growth rate may not always adequately capture increased mortality risk due to competition. We also found evidence of a facilitative effect for this species, with mortality risk decreasing with proximity to conspecific neighbors. For Pinus lambertiana, mortality risk increased with density of conspecific neighbors, in keeping with a mechanism of increased pathogen or insect pressure (i.e., a Janzen-Connell type effect). Finally, we found that models estimating risk of being crushed were strongly improved by the inclusion of a simple index of spatial proximity. Not only did spatial indices improve models, those improvements were relevant for mortality prediction. For P. lambertiana, spatial factors were important for estimation of mortality risk regardless of growth rate. For A. concolor, although most of the population fell within spatial conditions in which mortality risk was well described by growth, trees that died occurred outside those conditions in a disproportionate fashion. Furthermore, as stands of A. concolor become increasingly dense, such spatial factors are likely to become increasingly important. In general, models that fail to account for spatial pattern are at risk of failure as conditions change.