Differentiated impacts of environmental policies on the Colombian Frontier: coercive conservation and containment of illicit activities in the Pacific and the Ariari region

ABSTRACT

This article, through the use of political ecology perspectives on coercive conservation, aims to explain how in two separate Colombian Natural Parks and buffer zones, environmental policies designed to (re)take control of the frontier, have produced a similar territorial differentiation in the contention of illicit activities. Los Farallones in the Colombian Pacific and La Macarena/Puerto Rico in the Ariari region have experienced different stages of the armed conflict and are at the center of this analysis. I argue that in the contexts of both conflict escalation (1998–2007) and conflict de-escalation (2008–2016), the State in its attempt to control the frontier has not only had military intervention in areas of conservation but has also reinforced environmental programs that attack illegal mining and coca, producing both a territorially differentiated containment of illicit activities and an uneven progression of the illicit frontier.     

Heavy metals and organic carbon in sediments from the Tuy River basin,Venezuela

The Tuy River basin, located in north-central Venezuela with an annual average temperature of 27°C and precipitation of 140 cm, was selected to conduct a geochemical study of bottom sediments, with the object of establishing the natural and human influences in the abundance and distribution of Fe, Mn, Cr, Co, Cu, Ni, Pb, Zn and organic carbon. The basin is lithologically divided into two sub-basins, north and south. The north sub-basin drains a iow-grade metasedimentary terrain with a population density of 800 persons km^–2 and approximateiy 600 industrial sites, while the south sub-basin in underlain by metavolcanic and ultramafic rocks, with a population density of less than 10 persons km^–2.Stream bottom sediment samples (150) were collected during the years of 1979–1986 in 16 unpolluted sites and 13 polluted sites. The sediments were air dried at room temperature and sieved through a 120 stainless steel mesh (125 m). Samples of grain size smaller than 125 m were analysed, the heavy metals being determined by atomic absorption spectrometry and the organic carbon (Corg) by dry combustion.The higher concentrations of heavy metals and organic carbon found in the pristine areas were in the south sub-basin, especially in those areas with higher annual precipitation and tropical forest. This indicated that the metavolcanic and ultramafic rocks yield higher concentrations of heavy metals than the metasedimentary rocks. It was also noted that the higher concentrations of Cr and Ni are associated with the ultramafic rocks. The results obtained from the sediment samples collected in the polluted sites showed that the elements Pb, Zn and Corg are enriched up to 4 times as a result of ail the human activities taking place in the basin. Organic carbon is an excellent indicator of domestic wastewater, Pb and Zn are good indicators of the automotive traffic and industrial effluents. The concentrations of each heavy metal did not show any significant correlation with grain size fractions; however, the concentration of organic carbon did show a negative correlation with grain size. The lithological, climatic and vegetation influence in the abundance of heavy metals and organic carbon in stream sediments clearly indicates the necessity of establishing background levels for the area under study when carrying out studies in environmental geochemistry.     

Fly ash content and distribution in lake sediments around a large power station: inferences from magnetic susceptibility analysis

The bulk magnetic susceptibility of sediments from artificial and natural lakes around a large coal-fired power station in NE Spain has been measured. Higher magnetic susceptibility values are found in lake sediments located SE of the power station. This distribution of susceptibility values is compatible with environmental and meterological studies of emissions from the power station, which indicate a dominant SE plume direction. Mineralogical studies, by means of X-ray diffraction and scanning electron microscopy, show that the highest susceptibility values found in the sediments are caused by magnetic iron spinels in the fly ash that is transferred to the environment by the power station particulate emissions. After the quantitative mineralogical studies of fly ash, two different methods of fly ash content determination in the sediments have been devised, showing very similar results. The low background magnetic susceptibility of the sediments in the study area and the high susceptibility resulting from the input of magnetic fly ash particles allows both delimitation of the polluted area around the power station, and quantification of the fly ash input into the natural sediments.     

Sequestration of pyrrolizidine alkaloids by larvae ofTellervo zoilus (Lepidoptera: Ithomiinae) and their role in the chemical protection of adults against the spiderNephila maculata (Araneidae)

Summary Life stages of the primitive Australian ithomiine butterflyTellervo zoilus and its larval hostplant, the apocynaceous vineParsonsia straminea, were quantitatively assayed for pyrrolizidine alkaloids (PAs). PAs were found in all stages, mainly as N-oxides, being most concentrated in larvae and freshly-emerged adults. Although adults feed at various confirmed PA sources this probably does not compensate for losses, as wild-caught adults had considerably lower concentrations of PAs. The main alkaloid present in both freshly-emerged adults and in leaves of the host-plant was lycopsamine (1b), stored by butterflies in the N-oxide form. Its presence in higher proportion, in relation to intermedine (1a), in larvae, pupae and adults ofTellervo in relation to the host-plants suggests the inversion of intermedine to lycopsamine by the insects. No 14-member ring macrocyclic PAs were detected in either food-plant or butterflies. Several other PAs were found in wild-caught adults reflecting visits to other PA sources. PAs were also found in high concentrations in freshly-emerged individuals of the danaineEuploea core bred onParsonsia straminea. Wild-caughtDanaus affinis had high PA levels acquired from adult feeding. Freshly emergedEuploea raised onIschnocarpus frutescens andDanaus raised onIschnostemma carnosum (both PA-free) were preyed on by the orb weaving spiderNephila maculata, and showed no PAs. In all cases where PAs were present, most butterflies were liberated, usually cut out of the web unharmed, byNephila. The spider's response was not closely linked to PA concentration, however, and may also depend on hunger levels and previous experience with PA-containing butterflies. All control and other non-PA containing butterflies were consumed although rejection of some body parts of freshly-emergedDanaus affinis suggests that compounds other than PAs may be involved.     

Chemical defense: incorporation of diet-derived pyrrolizidine alkaloid into the integumental scales of a moth (<Emphasis Type="Italic">Utetheisa ornatrix</Emphasis>)

Summary. Evidence is presented that pyrrolizidine alkaloid acquired by Utetheisa ornatrix (Lepidoptera, Arctiidae) as a larva from Crotalaria foodplants is incorporated in part into the scales of the adult. A single forewing of a male or female moth may contain in the order of 6 to 13 g monocrotaline in its scale cover or about 1 to 2% of the moths systemic monocrotaline content. Based on estimates of the number of scales per forewing, the monocrotaline content of individual scales is calculated to be in the order of 0.1 and 0.2 ng monocrotaline per male and female scale, respectively. This amounts to concentrations of about 1 and 3%, values roughly at a par with the average systemic concentration (0.5-0.6%) previously determined for monocrotaline in Utetheisa. It is argued that the presence of pyrrolizidine alkaloid in the moths scale coating could account for the promptness with which adult Utetheisa are rejected by spiders. It is suggested further that chemical impregnation of scales with substances deterrent to predators may be more widespread among insects than generally assumed.     

Diving behaviour of Little Penguins from four colonies across their whole distribution range: bathymetry affecting diving effort and fledging success

Little Penguins, Eudyptula minor, breed in several small colonies in New Zealand and Australia. In this study, we compare the birds’ diving performances at different sites situated throughout their breeding range. Environmental conditions and breeding success vary drastically amongst colonies, but all birds feed on similar types of prey and face similar limitations on their foraging range. We examined several diving parameters and calculated the proportion of foraging zone available during breeding to examine whether oceanographic and geographic factors in the foraging zone can explain variations in diving behaviour and fledging success among the different colonies. In colonies with high fledging success, Penguin Island and Oamaru, penguins made shallow dives <50 m depth and had lower diving effort. More than 90% of the foraging zone was in waters <50 m depth in these colonies. Motuara Island also has shallow waters with 95% <50 m depth, but the fledging success was low. Phillip Island has only 42% of waters <50 m and comparatively low fledging success. Thus, penguins dived deeper and showed a higher diving effort in colonies with lower fledging success (Motuara Island and Phillip Island), indicating that they were disadvantaged compared to conspecifics from other colonies that dived shallower and with a lesser diving effort. We concluded that bathymetry is an important factor, but not the only one, which influences fledging success.     

Maternal quality and differences in milk production and composition for male and female Iberian red deer calves (Cervus elaphus hispanicus)

Several theories predict a sex-biased investment either through unbalanced sex ratios in offspring or through differences in provisioning. According to them, one would expect an optimisation in indirect fitness, or else a compensation for increased mortality of one sex. In addition, biases in provisioning may also arise as a consequence of weight-dependent non-adaptive nutrient demands by offspring. This study examines milk provisioning and sex biases in offspring sex ratio together with maternal quality variables. Mothers of higher quality (weight and age) showed greater milk provisioning ability (in terms of production) resulting in greater calf weight gain. Mothers of sons produced greater yields of milk, milk protein, fat and lactose than mothers of daughters, and increased percentage of protein after controlling for higher male birth weight. In contrast, mothers of males did not differ from mothers of females in age or any body weight variables related to maternal quality. These results suggest that differences in milk production and composition for sons and daughters are rather a mechanism to optimise indirect fitness than a mechanism to compensate for increased mortality in male calves, or a consequence of greater weight-dependent nutrient demands by heavier male calves. Results also suggest that biases in milk provisioning may occur without biases in offspring sex ratio, and furthermore, in contrast to the prediction that biases should be relative to the mean investment of the population, that milk provisioning biases might not be relative.Communicated by F. Trillmich     

Imposex in the commercial snail Bolinus brandaris in the northwestern Mediterranean

A survey of the degree of imposex in populations of the commercial muricid Bolinus brandaris (L.) was carried out at six locations along the Catalan Coast (NW Mediterranean). Imposex was found to be a widespread phenomenon; the occurrence of a penis was observed in all females studied with the exception of those from St. Carles (South of Catalunya) where only 37% were affected. Other indices such as Relative Penis Length (RPL) and Vas Deferens Sequence (VDS) were applied; RPL varied from 4.5% in St. Carles--the least affected area--to 29.8% in the vicinity of Barcelona; similar results were obtained for VDS. Tissue organotin residues ranged from 6 to 140 ng g(-1) w.w. as Sn. Despite legislation restricting the use of tributyltin (TBT) in antifouling paints, this paper evidences the occurrence of organotin pollution far from the source, with levels of both TBT and triphenyltin (TPhT) high enough to cause environmental concern.