Satellite telemetry reveals behavioural plasticity in a green turtle population nesting in Sri Lanka

Satellite transmitters were deployed on ten green turtles (Chelonia mydas) nesting in Rekawa Sanctuary (RS-80.851°E 6.045°N), Sri Lanka, during 2006 and 2007 to determine inter-nesting and migratory behaviours and foraging habitats. Nine turtles subsequently nested at RS and demonstrated two inter-nesting strategies linked to the location of their residence sites. Three turtles used local shallow coastal sites within 60 km of RS during some or all of their inter-nesting periods and then returned to and settled at these sites on completion of their breeding seasons. In contrast, five individuals spent inter-nesting periods proximate to RS and then migrated to and settled at distant (>350 km) shallow coastal residence sites. Another turtle also spent inter-nesting periods proximate to RS and then migrated to a distant oceanic atoll and made forays into oceanic waters for 42 days before transmissions ceased. This behavioural plasticity informs conservation management beyond protection at the nesting beach.     

Levels and trends of industrial chemicals (PCBs, PFCs, PBDEs) in archived herring gull eggs from German coastal regions

Background

Polychlorinated biphenyls [PCBs], perfluorinated compounds, and polybrominated diphenyl ethers [PBDEs] were retrospectively analyzed in archived herring gull (Larus argentatus) eggs from the North and the Baltic Sea over the last 20 years. The aim was to assess temporal trends and effects of regulatory measures.

Results

PCBs (sum of 7 congeners) were highest in eggs from the North Sea island Trischen, i.e., 3,710 to 20,760 ng/g lipid weight [lw] compared to 2,530 to 11,650 ng/g lw on the North Sea island Mellum and 4,840 to 9,190 ng/g lw on the Baltic Sea island Heuwiese. During the study period, PCBs decreased significantly. Concentrations of PFOS ranged between 46 and 170 ng/g wet weight [ww] at Trischen, 39 to 99 ng/g ww at Mellum, and 20 to 159 ng/g ww at Heuwiese. Since 2000 and 2003, concentration levels decreased in eggs from Mellum and Heuwiese, respectively. Perfluorooctanoic acid was the dominant perfluorinated carboxylic acid in the North Sea eggs (Trischen 2.0 to 74 ng/g ww; Mellum 2.6 to 118 ng/g ww), whereas perfluoroundecanoate [PFUnA] and perfluorodecanoate [PFDA] (means 3.9 ± 3.6 ng/g and 2.9 ± 2.3 ng/g ww, respectively) dominated in the Baltic Sea eggs. At all three locations, longer-chained perfluorinated carboxylic acids (perfluorononanoate, PFDA, PFUnA, perfluorododecanoate) increased during the monitoring period. PBDE concentrations (sum of 35 congeners) in eggs were in the ranges of 282 to 2,059 ng/g lw (Mellum), 116 to 1,722 ng/g (Trischen), and 232 to 2,021 ng/g lw (Heuwiese). Congeners associated with commercial Penta- and Octa-BDE formulations decreased during the study period. No decrease was observed for technical Deca-BDE.

Conclusion

Effects of regulatory measures were apparent for PCBs and Penta- and Octa-BDE, while no consistent trend is noticeable for PFOS.     

Flexible foraging strategies in a diving seabird with high flight cost

How central-place foragers change search strategy in response to environmental conditions is poorly known. Foragers may vary the total distance travelled and how far they range from the central place in response to variation in the distribution of their prey. One potential reason as to why they would extend the length of their foraging trip and its distance from the colony would be to increase prey quality or quantity, despite incurring higher transit costs. To test this trade-off hypothesis in a species with high flight costs, we recorded the foraging behaviour of razorbills (Alca torca) using state-of-the-art techniques that log both individual horizontal (flight activity) and vertical (dive activity) movements. We show that the distance that razorbills travelled to foraging locations increased with sea-surface temperature, which may relate to higher prey quality or quantity. This relation is supported by an indirect index of patch quality, based on dive profiles, which also increased with travel distance from the colony. Furthermore, we show that this index was highest during the daily peak in diving activity, around midday. Taken together, these results suggest that razorbills are capable of adjusting their search strategies sensitively in response to proximate environmental cues.     

Linking socio-economic factors, environment and land cover in the German Highlands, 1945-1999

Land-cover changes are caused by human activities and natural ecological processes. Thus, our study uses an interdisciplinary approach to research land-cover changes. We present a method to (i) link socio-economic/environmental factors and land-cover changes, (ii) identify indicators of land-cover changes, and (iii) distinguish between socio-economic and environmental indicators associated with local types of overall land-cover changes. The study was conducted in the Lahn-Dill Highlands, Germany, a typical marginal rural landscape. In this region, we investigated land-cover changes occurring over the period 1945-1999. Land-cover data were derived from multi-temporal aerial photographs. Types of overall land-cover changes characterising the districts within the study area were differentiated. With the help of redundancy analysis (RDA), we analysed the relationships between land-cover changes and widely available socio-economic/environmental factors. The results reveal that both individual land-cover changes at patch level and types of overall land-cover changes characterising districts are correlated with socio-economic and environmental factors. Whereas the stable environmental factors are drivers of land-cover changes in our rural study area, socio-economic factors introduced into the analysis mostly result from land-cover changes. We identified correlative socio-economic indicators that cannot explain land-cover changes, but that in combination with the environmental factors can be used to greatly facilitate the reconstruction of past land-cover changes and thus lead to a better knowledge of land-cover history. Based on the types of overall land-cover changes, the results of the study can be adopted for the study of land-cover changes in other regions.     

Uncertainty analysis of climate change mitigation options in the forestry sector using a generic carbon budget model

Industrialized countries agreed on a reduction of greenhouse gas emissions under the Kyoto Protocol. Many countries elected forest management activities and the resulting net balance of carbon emissions and removals of non-CO₂ greenhouse gases by forest management in their climate change mitigation measures. In this paper a generic dynamic forestry model (FORMICA) is presented. It has an empirical basis. Several modules trace C pools relevant for the Kyoto Protocol and beyond: biomass, litter, deadwood and soil, and harvested wood products. The model also accounts for the substitution of fossil fuels by wood products and bioenergy.     

Impact of curve construction and community dynamics on the species-time relationship

The species-time relationship (STR) describes how the species richness of a community increases with the time span over which the community is observed. This temporal scaling provides insight into theoretical questions on species diversity patterns as well as applied questions on the appropriate time scale for biodiversity assessments. To better understand STRs, we discuss the methods used to construct STRs in the literature and derive the impact of curve construction on STR properties. Using vegetation data from Mount St. Helens, Washington, USA, we illustrate the sensitivity of the STR to construction under colonization-dominated dynamics. This study highlights the importance of considering the type of STR when interpreting, comparing, and applying STRs, particularly in disturbed or successional systems.     

Gasförmige Stickstoffemissionen im Lebensweg von Getreide zur Energiebereitstellung

The reduction of energy-based environmental pollution is a declared goal of governmental action in all industrialised countries. In this context, the aim of this paper is to investigate the emissions of volatile nitrogen species with regard to their resulting environmental impacts by the example of the heat provision from whole cereal crops as a substitute for light oil products. First, the applied methodology of a Life Cycle Assessment is discussed. The emissions of volatile nitrogen species and their resulting environmental impacts are subsequently quantified putting a special focus on the emissions of gases from biogenic sources in the agroecosystem. The comparison of heat provision based on whole cereal crops versus light oil over the entire life cycle shows that heat from biomass results in a lower environmental impact regarding the anthropogenic greenhouse effect, but a higher one with respect to eutrophication, acidification and the depletion of the stratospheric ozone layer. These results may change if the energy crops are produced extensively during agricultural processes, if other mitigation measures are undertaken or if the emissions from the combustion in the biomass-fired boiler are reduced.     

Fish consumption reduces transfer of BDE47 from dam to murine offspring

Fish and seafood are important contributions to a healthy diet, but also contain persistent organic pollutants (POPs) like polybrominated diphenylethers (PBDEs) and polychlorinated biphenyls (PCBs). Discrepancies have been found between intake and accumulated levels of POPs, where fish consumers have had similar levels of POPs to the general population. Similarly fish oil consumption has been found to reduce accumulation of POPs. This study examined the accumulation of BDE47 or PCB153 in mice fed diets with different nutritional composition, using female mice with pre-weanling pups exposed through gestation and lactation. A fish-based diet was compared to a standard casein-based rodent diet. All diets had low background levels of environmental contaminants and were spiked with BDE47 or PCB153 to levels representing a realistic (∼0.004 μmol kgbw⁻¹ d) or a high dietary exposure (∼1.3 μmol kgbw⁻¹ d). Accumulation of BDE47 or PCB153 in offspring tissues after 18 d lactation reflected the maternal exposure levels. However, the pups of dams fed a fish-based diet had consistently lower BDE47 accumulation in liver, fat and stomach than pups from casein-fed dams. Similarly the pups of dams fed a high dose of PCB153 in a fish diet also accumulated less PCB153 than pups of the dams fed a casein diet, although not significant. In conclusion, the fish based diets seemed to reduce transfer of BDE47 and PCB153 from dams to pups. The study highlights that in-depth knowledge about nutritional impact on toxicokinetics is of great interest to vulnerable consumers.     

Chemical extractions and predicted free ion activities fail to estimate metal transfer from soil to field land snails

This study investigates the relevance of several soil chemical extractions (calcium chloride, acetic acid, citric acid and a four-step sequential procedure) and predicted free metal ion activities in the soil solution to characterise the transfer of trace metals (Cd, Pb, and Zn) from soil to snail soft tissues over a large smelter-impacted area (Metaleurop Nord, Nord-Pas-de-Calais, France). The study was first performed on six snail species together and then specifically on Cepaea sp. and Oxychilus draparnaudi. When the six species were considered together, the accumulation of metals depended mostly on the species. When significant, total or extractable metal concentrations, or the predicted free ion activities, accounted for less than 7% of the variation of the metal concentrations in the snail tissues. Species-specific analyses showed that extractable concentrations explained approximately 25% of the variation of the metal concentrations in O. draparnaudi, and up to 8% in Cepaea snails. When using total soil concentrations and soil properties as explanatory variables, the models were generally slightly better, explaining up to 42% of the variance. The soil extraction procedures and predicted free ion activities used in this study did not accurately estimate the metal transfer from soil to snails and could not be used in risk assessment.