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Concept: Madre de Dios Region


Madre de Dios is located in the southeastern Amazonian region of Peru. Rodents have been estimated to be the reservoirs for up to 50 % of emerging zoonotic pathogens, including a host of viruses, bacteria, and parasites. As part of a larger study involving both human and animal research, this study serves to obtain a broader understanding of the key challenges and concerns related to health and rodent-borne illnesses from the perspective of the people living in these communities.

Concepts: Medicine, Epidemiology, Bacteria, Microbiology, Amazon River, Brazil, Peru, Madre de Dios Region


Gold mining has rapidly increased in western Amazonia, but the rates and ecological impacts of mining remain poorly known and potentially underestimated. We combined field surveys, airborne mapping, and high-resolution satellite imaging to assess road- and river-based gold mining in the Madre de Dios region of the Peruvian Amazon from 1999 to 2012. In this period, the geographic extent of gold mining increased 400%. The average annual rate of forest loss as a result of gold mining tripled in 2008 following the global economic recession, closely associated with increased gold prices. Small clandestine operations now comprise more than half of all gold mining activities throughout the region. These rates of gold mining are far higher than previous estimates that were based on traditional satellite mapping techniques. Our results prove that gold mining is growing more rapidly than previously thought, and that high-resolution monitoring approaches are required to accurately quantify human impacts on tropical forests.

Concepts: Amazon River, Tropical rainforest, Amazon Basin, Recession, Peru, Tropical and subtropical moist broadleaf forests, Madre de Dios Region, Peruvian Amazon


A new species of the genus Sturisoma from the Madre de Dios River, upper Madeira, Peru, is described. The new species can be differentiated from its congeners by the following characteristics: dorsolateral stripe reaching to less than half, or only half length of caudal peduncle (v. absence of dorsolateral stripe or, if present, spanning more than half caudal-peduncle length); premaxillary teeth longer than dentary teeth (v. dentary teeth longer); sexually mature adult males having well-developed odontodes on the sides of the head and a broader snout (v. adult males lacking well-developed hypertrophied odontodes or, if present, rostrum is same width as females' or immature males'); by having the ventral portion of the rostrum conspicuously darker than ventral surface of the body (v. rostrum light, with same colour as ventral portion of body, except in Sturisoma barbatum); by lacking the lateral process of the sphenotic (v. lateral process of sphenotic well-developed, except in Sturisoma tenuirostre); a dark spot on the first three branched pectoral-fin rays (v. brown spot absent, except in S. barbatum); and the frontal bone contributing less than half of dorsal border of the orbital ridge (v. extensive participation of the frontal, except in Sturisoma guentheri). Furthermore, the new species has 18-20 plates in the median series, which differentiates it from Sturisoma rostratum (21-22), and Sturisoma monopelte (21); and 14-15 coalescent plates, which differentiates it from S. tenuirostre (16-17). It is further differentiated from Sturisoma brevirostre by presence of an enlarged rostrum (v. rostrum not enlarged). A discussion regarding status of the type series and geographic distribution of Sturisoma rostratum is offered, and an identification key for all Sturisoma species is presented.

Concepts: Skull, Amazon River, Absenteeism, Animal anatomy, Madre de Dios Region, Loricariidae, Loricariinae, Sturisoma


Artisanal and small-scale gold mining (ASGM) is a major contributor to deforestation and the largest anthropogenic source of atmospheric mercury worldwide. Despite significant information on the direct health impacts of mercury to ASGM miners, the impact of mercury contamination on downstream communities has not been well characterized, particularly in Peru’s Madre de Dios region. In this area, ASGM has increased significantly since 2000 and has led to substantial political and social controversy. This research examined the spatial distribution and transport of mercury through the Madre de Dios River with distance from ASGM activity. This study also characterized risks for dietary mercury exposure to local residents who depend on fish from the river. River sediment, suspended solids from the water column, and fish samples were collected in 2013 at 62 sites near 17 communities over a 560 km stretch of the Madre de Dios River and its major tributaries. In areas downstream of known ASGM activity, mercury concentrations in sediment, suspended solids, and fish within the Madre de Dios River were elevated relative to locations upstream of mining. Fish tissue mercury concentrations were observed at levels representing a public health threat, with greater than one-third of carnivorous fish exceeding the international health standard of 0.5 mg kg(-1). This study demonstrates that communities located hundreds of kilometers downstream of ASGM activity, including children and indigenous populations who may not be involved in mining, are at risk of dietary mercury exposure that exceed acceptable body burdens. This report represents the first systematic study of the region to aid policy decision-making related to ASGM activities in Peru.

Concepts: Sediment, Gold, Mercury, Amazon River, Mercury poisoning, Indigenous peoples, Peru, Madre de Dios Region


Artisanal and small-scale gold mining (ASGM) has been an important source of income for communities in the Madre de Dios River Basin in Peru for hundreds of years. However, in recent decades, the scale of ASGM activities in the region has increased dramatically, and exposures to a variety of occupational and environmental hazards related to ASGM, including mercury, are becoming more widespread. The aims of our study were to: (1) examine patterns in the total hair mercury level of human participants in several communities in the region and compare these results to the 2.2 µg/g total hair mercury level equivalent to the World Health Organization (WHO) Expert Committee of Food Additives (JECFA)’s Provisional Tolerable Weekly Intake (PTWI); and (2), to measure the mercury levels of paco (Piaractus brachypomus) fish raised in local aquaculture ponds, in order to compare these levels to the EPA Fish Tissue Residue Criterion of 0.3 µg Hg/g fish (wet weight). We collected hair samples from 80 participants in four communities (one control and three where ASGM activities occurred) in the region, and collected 111 samples from fish raised in 24 local aquaculture farms. We then analyzed the samples for total mercury. Total mercury levels in hair were statistically significantly higher in the mining communities than in the control community, and increased with increasing geodesic distance from the Madre de Dios headwaters, did not differ by sex, and frequently exceeded the reference level. Regression analyses indicated that higher hair mercury levels were associated with residence in ASGM communities. The analysis of paco fish samples found no samples that exceeded the EPA tissue residue criterion. Collectively, these results align with other recent studies showing that ASGM activities are associated with elevated human mercury exposure. The fish farmed through the relatively new process of aquaculture in ASGM areas appeared to have little potential to contribute to human mercury exposure. More research is needed on human health risks associated with ASGM to discern occupational, residential, and nutritional exposure, especially through tracking temporal changes in mercury levels as fish ponds age, and assessing levels in different farmed fish species. Additionally, research is needed to definitively determine that elevated mercury levels in humans and fish result from the elemental mercury from mining, rather than from a different source, such as the mercury released from soil erosion during deforestation events from mining or other activities.

Concepts: Gold, Salmon, Mercury, Aquaculture, Mercury poisoning, Minamata disease, Peru, Madre de Dios Region


The giant otter (Pteronura brasiliensis) is an endangered semi-aquatic carnivore of South America. We present findings on the demography of a population inhabiting the floodplain of Manu National Park, south-eastern Peru, arising from 14 annual dry season censuses over a 16 year period. The breeding system of territorial groups, including only a single breeding female with non-reproductive adult ‘helpers’, resulted in a low intrinsic rate of increase (0.03) and a slow recovery from decades of hunting for the pelt trade. This is explained by a combination of factors: (1) physiological traits such as late age at first reproduction and long generation time, (2) a high degree of reproductive skew, (3) small litters produced only once a year, and (4) a 50% mortality between den emergence and age of dispersal, as well as high mortality amongst dispersers (especially males). Female and male giant otters show similar traits with respect to average reproductive life-spans (female 5.4 yrs., male 5.2 yrs.) and average cub productivity (female 6.9, male 6.7 cubs per lifetime); the longest reproductive life spans were 11 and 13 years respectively. Individual reproductive success varied substantially and depended mainly on the duration of dominance tenure in the territory. When breeding females died, the reproductive position in the group was usually occupied by sisters or daughters (n = 11), with immigrant male partners. Male philopatry was not observed. The vulnerability of the Manu giant otter population to anthropogenic disturbance emphasises the importance of effective protection of core lake habitats in particular. Riverine forests are the most endangered ecosystem in the Department of Madre de Dios due to the concentration of gold mining, logging and agricultural activities in floodplains, highlighting the need for a giant otter habitat conservation corridor along the Madre de Dios River.

Concepts: Male, Reproduction, Female, Otters, Mustelidae, Pantanal, Madre de Dios Region, Giant Otter


After a 20 years hiatus, we describe a new species, Polietina ponti sp. nov., from Madre de Dios, Tambopata River, Peru. Additionally, we propose Polietina nigra Couri Carvalho, 1996 as a junior synonym of Polietina prima (Couri Medeiros, 1990). A previous phylogenetic hypothesis was updated with the inclusion of the new taxon described here, which yielded a single most parsimonious tree that is similar to a previously published hypothesis (Pyrellina marsya (Pyrellina distincta (Deltotus facetus ((Polietina steini (Polietina ponti sp. nov., P. prima (P. bicolor, P. minor, P. univittata)(P. flavithorax, P. major)))(P. flavidicincta (P. rubella (P. concinna (P. orbitalis, P. wulpi)))))))). The identity of Polietina vouchers with nucleotide sequences registered in the GenBank were also verified and corrected.

Concepts: Species, Madre de Dios Region, Madre de Dios River, Tambopata River, Puerto Maldonado


This study examines the role multilevel governance plays in the adoption of sustainable landscape management initiatives in emerging arrangements aimed at reducing emissions from deforestation and forest degradation (REDD+). It sheds light on the challenges these multiple layers of actors and interests encounter around such alternatives in a subnational jurisdiction. Through transcript analysis of 93 interviews with institutional actors in the region of Madre de Dios, Peru, particularly with regard to five sites of land-use change, we identified the multiple actors who are included and excluded in the decision-making process and uncovered their complex interactions in forest and landscape governance and REDD+ arrangements. Madre de Dios is a useful case for studying complex land-use dynamics, as it is home to multiple natural resources, a large mix of actors and interests, and a regional government that has recently experienced the reverberations of decentralization. Findings indicate that multiple actors shaped REDD+ to some extent, but REDD+ and its advocates were unable to shape land-use dynamics or landscape governance, at least in the short term. In the absence of strong and effective regional regulation for sustainable land use alternatives and the high value of gold on the international market, illegal gold mining proved to be a more profitable land-use choice. Although REDD+ created a new space for multilevel actor interaction and communication and new alliances to emerge, the study questions the prevailing REDD+ discourse suggesting that better coordination and cooperation will lead to integrated landscape solutions. For REDD+ to be able to play a role in integrated landscape governance, greater attention needs to be paid to grassroots actors, power and authority over territory and underlying interests and incentives for land-use change.

Concepts: Ecosystem, Emergence, Complexity, Actor, Madre de Dios Region


Anopheline specimens were collected in 2011 by human landing catch, Shannon and CDC traps from the malaria endemic localities of Santa Rosa and San Pedro in Madre de Dios Department, Peru. Most specimens were either Anopheles (Nyssorhynchus) benarrochi B or An. (Nys.) rangeli, confirmed by polymerase chain reaction-restriction fragment length polymorphism-internal transcribed spacer 2 (PCR-RFLP-ITS2) and, for selected individuals, ITS2 sequences. A few specimens from Lupuna, Loreto Department, northern Amazonian Peru, were also identified as An. benarrochi B. A statistical parsimony network using ITS2 sequences confirmed that all Peruvian An. benarrochi B analyzed were identical to those in GenBank from Putumayo, southern Colombia. Sequences of the mtDNA COI BOLD region of specimens from all three Peruvian localities were connected using a statistical parsimony network, although there were multiple mutation steps between northern and southern Peruvian sequences. A Bayesian inference of concatenated Peruvian sequences of ITS2+COI detected a single clade with very high support for all An. benarrochi B except one individual from Lupuna that was excluded. No samples were positive for Plasmodium by CytB-PCR.

Concepts: DNA, Malaria, Anopheles, Mosquito, Amazon River, Andes, Peru, Madre de Dios Region


Exposure to mercury, a toxic metal, occurs primarily from inhaling mercury vapors or consuming methylmercury-contaminated fish. One third of all anthropogenic mercury emissions worldwide are from artisanal gold mining, which uses mercury to extract gold. Although recent reports suggest that the Madre de Dios region in Peru (with >30,000 artisanal miners) has extensive mercury contamination, residents had never been assessed for mercury exposure. Thus, our objective was to quantify mercury exposure among residents of an artisanal mining town in Madre de Dios and to assess risk factors for exposure.

Concepts: Gold, Mercury, California Gold Rush, Mining, Mercury poisoning, Gold mining, Peru, Madre de Dios Region