Conservation overstretch and long-term decline of wildlife and tourism in the Central African savannas

When in 2010 the world's governments pledged to increase protected area coverage to 17% of the world's land surface, several Central African countries had already set aside 25% of their northern savannas for conservation. To evaluate the effectiveness of this commitment, we analyzed the results of 68 multispecies surveys conducted in the seven main savanna national parks in Central Africa (1960–2017). We also assembled information on potential drivers of large herbivore population trends (rainfall and number of rangers) and on tourist numbers and revenues. In six out of the seven parks, wild large herbivore populations declined dramatically over time, livestock numbers increased severalfold, and tourism, the pillar under a once thriving local wildlife industry, collapsed. Zakouma National Park (Chad) stood out because its large herbivore populations increased, an increase that was positively correlated with rainfall and number of rangers (a proxy for management inputs). With increasing insecurity and declining revenues, governments find themselves confronted with too few resources to protect vast areas. To deal with this conversation overstretch, we propose to extend the repeatedly promoted solutions––scaled up funding, enhanced management––with a strategic retreat, focusing scarce resources on smaller areas to save wildlife in the Central African savannas.     

Alkane biodegradation and dynamics of phylogenetic subgroups of sulfate-reducing bacteria in an anoxic coastal marine sediment artificially contaminated with oil

For 503 days, unoiled control and artificially oiled sediments were incubated in situ at 20m water depth in a Mediterranean coastal area. Degradation of the aliphatic fraction of the oil added was followed by GC-MS. At the same time, terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA encoding genes was used to detect dynamics in the sulfate-reducing bacteria (SRB) community in response to the oil contamination. Specific polymerase chain reaction (PCR) primer sets for five generic or suprageneric groups of SRB were used for PCR amplification of DNA extracted from sediments. During the experiment, hydrocarbons from C(17) to C(30) were significantly degraded even in strictly anoxic sediment layers. Of the five SRB groups, only two groups were detected in the sediments (control and oiled), namely the Desulfococcus-Desulfonema-Desulfosarcina-like group and the Desulfovibrio-Desulfomicrobium-like group. Statistical analysis of community patterns revealed dynamic changes over time within these two groups following the contamination. Significant differences in community patterns were recorded in artificially oiled compared with control sediments. Cloning and sequencing of 16S rRNA encoding genes performed after 503 days showed that many of the most abundant sequences were closely related to hydrocarbonoclastic SRB which could have played an active role in the observed biodegradation of aliphatic hydrocarbons. Results from the present study provide useful information on the dynamics of dominant SRB in heavily oil-contaminated sediments and their potential for anaerobic biodegradation for the treatment of spilled oil in anoxic marine environments.     

Environmental evaluation of transfer and treatment of excess pig slurry by life cycle assessment

Slurry management is a central topic in the agronomic and environmental analysis of intensive livestock production systems. The objective of this study is to compare the environmental performance of two scenarios of collective slurry management for the disposal of excess nitrogen from animal manure. The scenarios are the transfer of slurry and its injection to crop land, and the treatment of slurry in a collective biological treatment station. The study is based on a real case in the West of France, where a group of farmers is developing a collective plan for the disposal of almost 7000 m(3) of excess pig slurry. The evaluation is carried out by Life Cycle Assessment, where emissions and resource consumption are quantified and aggregated into four environmental impact categories: eutrophication, acidification, climate change, and non-renewable energy use. Ammonia emitted is the most important contributor to acidification and eutrophication, while methane contributes most to climate change. Both ammonia and methane are mostly emitted during the storage of slurry and, in the case of the treatment scenario, also during composting the solid fraction of the slurry. The two management strategies are similar with respect to climate change, whereas eutrophication and acidification are twice as large for treatment relative to transfer. Electricity needed for the treatment process is the main contributor to non-renewable energy use for the treatment scenario, while the transfer scenario represents a net energy saving, as energy saved by the reduction of mineral fertiliser use more than compensates for the energy needed for transport and injection of slurry. The overall environmental performance of transfer is better than that of treatment, as it involves less acidification, eutrophication and non-renewable energy use. The method employed and the results obtained in this study can provide elements for a transparent discussion of the advantages and disadvantages of contrasting excess slurry management scenarios as well as the identification of the main aspects determining their environmental performance.     

Towards a multidisciplinary and integrated strategy in the assessment of adverse health effects related to air pollution: the case study of Cracow (Poland) and asthma

Complex interaction between anthropogenic activities, air quality and human health in urban areas, such as in Cracow sustains the need for the development of an interdisciplinary and integrated risk-assessment methodology. In such purpose, we propose a pilot study performed on asthmatics and based on a combined use of a biomarker, such as metallothionein 2A (MT-2A) in the characterization of human exposure to one or a mixture of pollutants and of Geographical Information Systems (G.I.S.) which integrates climatic and urban anthropogenic parameters in the assessment of spatio-temporal dispersion of air pollutants. Considering global incidence of air pollution on asthma and on peripheral blood lymphocytes MT-2A expression should provide a complementary information on biological risks linked to urban anthropogenic activities. Such study would help for the establishment of a sustainable development in urban areas that can maintain the integrity of air quality and preserve human health.     

In vitro biodegradation of Arabian Light 250 by a marine mixed culture using fertilizers as nitrogen and phosphorous sources

The improved in vitro bioremediation of Arabian Light crude oil in synthetic sea water by a mixed culture of bacteria is reported. Effects of fish meal, meat meal 80 % proteins and sophorolipids on the biodegradation were evaluated during a three-week incubation using GC/FID and GC/MS analysis of the remaining oil. Fish meal and more particularly meat meal 80 % proteins used at 0,5 mg.ml⁻¹ involve no nitrogen and phosphorous limits when used as sole source of nutrients. Biodegradation processes in the first four days of the incubation supplemented with sophrolipids are accelerated two fold over controls.     

Semiochemicals mediating host-finding behaviour in the phoretic association between Macrocheles saceri (Acari: Mesostigmata) and Scarabaeus species (Coleoptera: Scarabaeidae)

Summary. Phoresy is an interspecific association where mobile organisms ensure small and/or wingless organisms to colonize patchy distributed environment. Macrocheles saceri (Acari: Mesostigmata) is a phoretic mite which specialized on Scarabaeus dung beetles (Coleoptera: Scarabaeidae). Variation for phoretic load and sites for mite fixation on beetle body has been tested according to Scarabaeus species. The number of setae on beetle body cannot explain the observed patterns in mite fixation. Evidence was provided that the semiochemicals of the host cuticle play a kairomonal role in the host finding behaviour of phoretic mites. In addition semiochemicals ensure host discrimination.     

Influence of n-alkanes and petroleum on fatty acid composition of a hydrocarbonoclastic bacterium: Marinobacter hydrocarbonoclasticus strain 617

This study concerns the effects of various long-chain n-alkanes, n-alkane mixtures and Arabian Light crude oil on the fatty acid (FA) composition of a sedimentary marine bacteria (Marinobacter hydrocarbonoclasticus strain 617), growing under aerobic conditions. The cultures with n-alkanes, as compared with soluble carbon sources, led to greater amounts of saturated and methyl branched FA (mainly belonging to a delta10 series). We observed the appearance or increase of saturated and unsaturated FA with the same carbon chain length (CCL) as the n-alkane carbon source (maximum for n-alkane CCL corresponding to the 'range' of the de novo synthesized fatty acids). We also observed a strong control of the oddness/evenness of the CCL of the FA by the oddness/evenness of the n-alkane. A n-alkane utilization index, (saturated + branched)/monounsaturated fatty acids (SAFA + BFA/MUFA) enabled discriminating between soluble carbon sources and hydrocarbons.     

Prenatal identification of an isochromosome for the short arm of the Y i(Yp), by cytogenetic and Molecular analyses

A case of 45,X/46,X,+mar mosaicism was detected in a male fetus (27 weeks' gestation) referred for karyotype analysis following the observation of a short femur at the ultrasound scan. Analysis of 12 Y-chromosome loci by fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR) demonstrated that the marker chromosome is of Y origin and corresponds to an authentic isochromosome for the short arm of the Y chromosome, i(Yp). The breakpoint on this marker is in YQ11·1 close to the centromere. The present report illustrates the importance of FISH and PCR techniques as a complement to cytogenetic methods for accurate identification and characterization of chromosome rearrangements in prenatal diagnosis.     

Tuna food habits related to the micronekton distribution in French Polynesia

Stomach content analyses are commonly used to study both fish feeding behaviour and trophic conditions. However, the interpretation of such data depends on fish foraging behaviour for a given environment and how representative the stomach contents are to the prey distribution. Tuna feeding behaviour was studied within the context of a research programme conducted in French Polynesia. Tuna prey distribution was characterised using acoustic measurements and pelagic trawls; thereafter, this distribution was compared with the stomach contents of tuna caught using an instrumented longline. Acoustic, pelagic trawling and stomach content analyses give complementary elements to describe the pelagic trophic habitat and to better understand tuna-prey relationships. The classic concept of a reduced food availability for tunas in the tropical pelagic environment seems relative. Tunas able to dive enough during daytime to exploit the migrant micronektonic species secure a source of regular food. This is particularly true of bigeye tuna (Thunnus obesus), which have ecophysiological capacities for this purpose. The behaviour of albacore tuna (T. alalunga), which dive >400 m in depth, remains less clear, as little is known about their vertical behaviour. Lastly, yellowfin tuna (T. albacares), which are distributed in more superficial waters, can better exploit the biomass of juvenile fish and crustaceans exported from the reefs. Analysis of the stomach fullness of tuna caught by longline, a passive gear, generally showed an empty state. This result suggests that most tuna foraging on large prey aggregations present in the study area are quickly satiated and escape longline capture and sampling. A consequence is that studies of tuna feeding behaviour based on longlining may be biased, particularly when large aggregations of prey are present such as in convergence zones. Another potential consequence is that longline tuna catch rates could differ according to prey richness. Longline tuna catch rates may sometimes reflect the relative abundance of prey rather than relative tuna abundance. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00227-001-0776-3.