ABSTRACT Data from the Geostationary Operational Environmental Satellite 16 (GOES-16) are used to study the number of clear nights over Colombia in order to identify potential sites for astronomical observations. First, we compare data from the Advanced Baseline Imager (ABI) with in-situ observations from an all-sky camera in order to validate the cloud cover information from the ABI retrievals. Then, we extend the analysis of the GOES-16 cloud cover fields to quantify the number of hours with low values of cloud cover for each pixel and each day of 2018 for a region that includes Colombia. A clear night is defined as one with five or more consecutive hours with a low fraction of cloud cover. We select the potential sites as those with more than 80 clear nights and with an altitude higher than 2000 m above sea level (m.a.s.l.). Our analyses showed that nine sites fulfil these conditions: five are in Colombia, three are in Ecuador and one in Venezuela. From our sample, eight out of the nine sites are in the Andes Mountains. The results suggest that the most suitable site for astronomical observations in Colombia is located near to Laguna de la Cocha, in the department of Nariño, with 135 clear nights in 2018 (about 37% of the year), followed by a site near to Lago de Tota, with 117 clear nights (about 32% of the year), located near the centre of the country. Exploration of regions outside Colombia showed that the Ecuadorian Andes has locations with approximately 48% of clear nights during the studied year. We conclude that the use of GOES images to measure the number of clear nights in order to select potential astronomical site locations has a great potential.

This study explored the population biology and reproduction of Tozeuma carolinense in Laguna de Términos, Campeche, southwestern Gulf of Mexico, collected bimonthly from June 2009 to June 2010. The sample of 2,109specimens analysed had a sex ratio of 0.39 males per female. On average, females were significantly larger (6.16 ± 2.02 mm carapace length, CL) than males (4.42 ± 0.70 mm CL). Recruitment was continuous, with the highestpercentages of juveniles during June 2009 and June 2010. The estimated asymptotic length with the von Bertalanffy model was 10.13 mm CL for females and 6.62 mm CL for males. Longevity was 6 months for females and 5 monthsfor males, with males having a higher mortality (Z = 1.08) than females (Z = 0.85). The reproduction was continuous, with highest incidence of berried specimens from August 2009 to April 2010. The estimated size at sexual maturity for females was 6.67 ± 1.30 mm CL. There was a significant correlation between female size and the number of embryos, with a mean fecundity of 268 ± 131 embryos. During the incubation period females lost 46% of the embryos.

One of the most recurring discussions among people is the real impact of global warming and human activity on our natural resources. It is hard to identify and quantify the impact generated by each one. Laguna de Aculeo located in Paine city, Chile. It was one of the most attractive and beautiful places to visit in the summer. Today, It has been completely drying up. This research evaluates weather and hydrologic values registered by government weather and water levels stations. The purpose is to evaluate if there has been a change in precipitation, temperature, and water level trend. The analysis consists of the evaluation of the statistical parameters, and legal water withdrawals and fines imposed. The results of this study indicate that the cause of the drought of the lake is generated by climatic and anthropogenic factors. However, the changes in precipitation and temperature over the years are not significant for drying a lake. Therefore, it is possible to assume that human activities are arguably the greatest cause of impact on Laguna de Aculeo. Finally, we present tools, strategies, and practical solutions to prevent, control, and restore lake water level.

Burying the Dead during the Maya Postclassic period: Saxe, Binford and Goldstein’s continued relevance to mortuary analysis

Water quality monitoring activities is a vital part in assessing the status of certain bodies of water such as the Laguna de Bay. The lake has been a significant natural resource as a catchment of an expansive watershed providing various ecological and economic values. It is the largest inland water body in the Philippines and the third largest in South East Asia. Water quality monitoring network is a critical element in the assessment, restoration and protection of Laguna de Bay. This paper measured some important physico-chemical properties of four selected sites from Laguna de Bay such as temperature, pH, electrical conductivity, alkalinity, dissolved oxygen levels, and phosphate and ammonia concentrations. Water Quality Index (WQI) utilizing Weighted Arithmetic Water Quality Index Method was also evaluated.

Abstract Understanding why social relationships vary among conspecifics is central to studies of animal behaviour. For many species, patterns of space use provide important insights into social behaviour. To characterize the social organization of the highland tuco-tuco (Ctenomys opimus), we used visual observations and radiotelemetry to quantify spatial relationships among adults in a population at Laguna de los Pozuelos, Jujuy Province, Argentina. Specifically, we sought to confirm anecdotal reports that these subterranean rodents are social, meaning that adults share burrow systems and nest sites. Our data indicate that the animals live in spatially distinct groups, although the number of individuals per group varies markedly. Although these relationships were robust with regard to location (above vs. below ground) and type of data (visual vs. telemetry), some groups identified during the daytime fissioned during the night. We suggest that the population of C. opimus at Pozuelos is facultatively social, meaning that individuals display predictable, adaptive differences in social relationships with conspecifics. More generally, our findings add to the growing number of subterranean species of rodents recognized as social, thereby generating new opportunities for comparative studies of these animals aimed at assessing the causes and consequences of variation in social organization.

Abstract. The use of Sentinel-3 Ocean and Land Color Instrument (OLCI) images in estimating chlorophyll-a (total and class-differentiated)a concentration is promising owing to Sentinel-3’s 21 bands. This was investigated for the case of Laguna de Bay (or Laguna Lake), Philippines. Field surveys were conducted on 13–17 November 2018 using FluoroProbe, a submersible fluorimeter capable of quantifying concentrations of spectral classes of microalgae. These were regressed with reflectance data obtained from 10-day composite Sentinel-3 reflectance images as well as ten empirical algorithms (indices) for OLCI. Compared to band reflectance, the 10 indices yielded stronger correlations, especially with R665/R709, R674/R709, and (1/R665-1/R709)xR754 with the following respective correlation values: −0.623, −0.646, and 0.628. Multiple regression results indicates that 48% of the variability of total chl-a concentration is explained by five explanatory (reflectance) variables (R412, R443, R560, R681, and R754) with RMSE of 2.814 μg/l. In contrast, the two indices R674/R754 and (1/R665-1/R709)xR754 accounted for about 46% of the variability of total chl-a concentration with RMSE of 2.475 μg/l. For diatoms and bluegreen microalgae, R560/R665 and (1/R665-1/R709)xR754 constitute the models with R2 of 0.21 and 0.435, and RMSE of 2.516 and 2.163 ug/l, respectively. Green microalgal concentration is jointly described by three indices: R560/R665, R674/R754, and R709-R754, with R2 = 0.182 and RMSE = 1.219 μg/l. From cryptophytes, the model comprising of R560/R665, (1/R665-1/R709)xR754, and R709-R754 produced an R2 = 0.289 and RMSE = 0.767 μg/l. It can be said that the empirical algorithms can be used for Sentinel-3 OLCI data providing acceptable estimations of total and spectral class-differentiated chl-a concentration.

Rapid degradation of freshwater ecosystems threatens water supply for human populations and natural landscapes. At diverse time scales, this process has been clearly associated with climatic and anthropogenic forcings. The question remains, however, how tropical lakes have responded to these two sources of variability. We present a multiproxy record from Lake San Lorenzo, Lagunas de Montebello National Park, tropical Mexico, spanning the last ~3400 years. We used multi‐elemental concentrations, and Cladocera and pollen assemblages along the record to reconstruct regional and local environmental variability, aiming to infer the factors and processes involved in the evolution of the lacustrine system. A principal component analysis on the pooled biological and geochemical evidence allowed the inference of the main changes in lake level and productivity. At millennial scales, the development of the lake system has been closely associated with regional moisture availability, with wetter (drier) time intervals associated with high (low) lake stands. According to Ti concentrations, from ~3400 to 1000 cal. a BP, regional conditions followed a trend towards drier conditions, with littoral cladoceran assemblages suggesting high lake productivity. The extreme regional droughts reportedly associated with the cultural collapse of the Maya civilization manifested in our study area through both high lake productivity and the lowest lake levels of the record. Through the last ~800 years, the regional moisture availability has increased, with the water body becoming deeper and larger. Overall, our record offers evidence of a highly variable system strongly coupled with regional climates, but also very sensitive to local disturbances associated with human occupation. Lake San Lorenzo has been highly resilient to external pressures and has previously recovered from conditions probably alike those associated with the ongoing modern deterioration process. Nevertheless, such recovery involves a complex network of interactions amongst natural and human factors.

We present a high-resolution record of Late Glacial and Early Holocene mercury (Hg) accumulation within the sediments of Laguna de Los Anteojos, a small headwater alpine lake in Venezuela. Our sediment core spans the Older Dryas (OD) and Younger Dryas (YD) climate reversals, providing new insight into the effects of abrupt climatic transitions on atmospheric Hg deposition. Sediment Hg concentrations and accumulation rates (fluxes) increased sharply after regional deglaciation and then peaked immediately prior to onset of both the OD and YD. Mercury concentrations and fluxes then decreased through cold OD and YD conditions. Both Hg concentrations and fluxes increased rapidly with warming, rising two-fold in about 100 years after the OD and nearly four-fold in about 500 years during the latter-half of the YD. This lake-sediment record of Hg dynamics during the Glacial–Holocene transition suggests atmospheric Hg cycling is affected by abrupt climate change.

Micrathyria paulsoni sp. nov. is described on specimens collected in Veracruz, México ( 19.1593-97.0045), Holotype male 9 July 2000, Laguna de Santo Domingo, Huatusco, leg E. González-Soriano L. E. González-Figueroa [in Colección Nacional de Insectos (CNIN), Instituto de Biología, UNAM] and compared with similar species. By its enlarged hamular process, this species belong to the so-called Micrathyria didyma group.

New geochemical results for two obsidian types, Laguna del Diamante and Arroyo Paramillos, naturally available in the Laguna del Diamante locality, a seasonally accessible highland wetland emplaced in the current border between Argentina and Chile at 3300 masl (34°S), are presented. A total of 1219 archeological artifacts from 41 sites located on both sides of the Andes have been assigned to these sources. The artifacts were analyzed by non-destructive, energy-dispersive X-ray fluorescence (ED-XRF). Archeological distributions of these obsidian types are assessed through GIS spatial analysis. Results show a great asymmetry in the distribution of these sources toward the two Andean slopes: the Laguna de Diamante chemical type shows a fairly local use pattern, being concentrated almost entirely in Cordillera sites, but the Paramillos shows a less homogeneous distribution and tends to be more concentrated in the sites that are in the western natural corridor. Although these lands were accessed and occupied from diverse demographic nodes in lower-altitude settings, the spatial analysis of obsidian artifacts reinforces the argument of dominant geographic vectors of access connecting with the western valleys and lowlands of Chile.

ABSTRACT Polylepis: forests are the world’s highest forests in terms of elevation and host a unique biodiversity of plants and animals. Unfortunately, these forests are rapidly disappearing due to human impact and are one of the most threatened ecosystems of South America. This paper deals with liverwort diversity in Polylepis forests of Ecuador. Liverworts are very diverse in tropical forests and are sensitive indicators of changes in humidity conditions. By comparing species richness, species composition and composition of functional groups of liverworts in dry and humid Polylepis forest, we explore how liverwort diversity of Polylepis forests is affected by climatic conditions differing in humidity. We inventoried liverwort diversity in Polylepis pauta forest of Lagunas de Mojanda reserve characterized by a relatively dry climate and in the páramo of Papallacta with a humid climate. In each site, we sampled liverworts on 10 P. pauta trees and surrounding soil. Species richness was highest in the humid forest and species composition in the two sites differed significantly. The two sites also had very different patterns of functional groups, with smooth mats dominating the liverwort flora of Mojanda while rough mats prevailed at Papallacta. This underscores the importance of bryophyte life forms as climate indicators in tropical forests. A phytogeographic comparison of the two sites showed a higher number of northern Andean taxa in the humid forest. The greater representation of species with restricted ranges in humid Polylepis forest shows the importance of these forests for conservation.

The present research work is of simple descriptive non-experimental design and was carried out with the purpose of determining the proximal analysis of proteins, iron and calcium in dry samples of Nostoc sphaericum “cushuro” from the Laguna de Conococha, District of Catac, Province of Huaraz, Department of Ancash. The analysis of results was performed in the Excel 2016 program, through descriptive statistical parameters as average and standard deviation. For the determination of proximal analysis in 100g of pulverized Nostoc sphaericum “cushuro”, the Kjeldahl method was used, finding 26.68 ± 0.01% protein, 0.21 ± 0.03% fat, 5.77 ± 0.11% crude fiber, 11.23 ± 0.42% moisture, 7.77 ± 0.01% ash. For the determination of iron, the colorimetric method based on reactions with orthoferantothroline was used, finding 15.72 ± 2.07 mg/100g of dry sample, and for calcium the complexometric method was applied by titration with ethylenediamine tetraacetic acid (EDTA), obtaining 1224.4 mg of Ca/100g of dehydrated “cushuro” as a result. It is concluded that dehydrated Nostoc sphaericum “cushuro” is important in the diet because of its high protein, iron and calcium content and indispensable for its use in the treatment of anemia, malnutrition and osteoporosis.

Few studies have dealt with small lakes in the Philippines, particularly aspects of their governance, which translate to information deficit on the status of administration of many lakes in the country. At the core of governance in any lake is its administrative agency, and in the eight crater lakes of San Pablo City, it is the Laguna Lake Development Authority (LLDA). Under this context, this article examines the administrative performance of the LLDA on the eight small lakes (i.e., Sampaloc Lake, Bunot Lake, Palakpakin Lake, Calibato Lake, Mohicap Lake, Pandin Lake, Yambo Lake, and Tadlac Lake) of the Laguna de Bay Region. The study evaluates the agency using four criteria deemed fundamental in managing, conserving, and developing small lakes: (1) having an approved management and development plan (MDP); (2) regulating fish pens and cages; (3) implementing the shoreline easement; and (4) conducting maintenance activities. Using data from interviews, site observations, documents, reports, and other secondary sources, the study contends that the LLDA’s performance is ambivalent because its management of the small lakes can be characterized as slow and lacking in follow-through in the MDP issue; unsatisfactory in the regulation of aquastructure and shoreline easement; but decent in water quality monitoring, clean-up operations, and fingerlings dispersal. On the whole, the assessment exemplifies the inconsistent actions of the LLDA and underscores the long-term commitment and accountability of the agency in governing the crater lakes.

Abstract. The mission of the European Space Agency’s Sentinel-3 satellite is to provide data for land and ocean monitoring purposes. Sentinel- 3’s Ocean and Land Colour Instrument (OLCI) data are being used largely for monitoring offshore and coastal waters but can also be used for inland waters including lakes. It has a spatial resolution of 300 meters, a temporal resolution of 2–3 days and contains 21 spectral bands. Laguna de Bay, with a surface area of around 930 km2, suffers from periodic algal blooms resulting from excessive nutrient inputs from surrounding watersheds. This study aims to assess the applicability of Sentinel-3 OLCI for estimating chlorophylla (chl-a) concentration in Laguna Lake. Several chl-a estimation algorithms (i.e., band ratios and indices) were tested for Sentinel 3 OLCI images and compared with in-situ data obtained using a chl-a sensor. A regression model comprising of individual spectral bands, band ratios, and band indices for chl-a estimation as independent variables was developed, yielding an adjusted R2 of 0.759 and RMSE of 1.19 ug/L. The model consists of R620, R674/R708, and RED/NIR. A map was produced showing the spatial distribution of chl-a in Laguna Lake, with most of the portion of the lake having a concentration ranging from 7.5 ug/L to 15 ug/L. This shows that Sentinel 3 OLCI images can be utilized for accurately estimating chl-a in Laguna Lake.

El trabajo presenta una reflexión en torno al potencial actual de las colecciones arqueológicas y especialmente del acervo de los museos para las investigaciones arqueológicas. Se parte de un ejemplo concreto como fue el diagnóstico realizado en 2012 por parte del equipo del LAPPU en el Museo Regional de Rocha Milton de los Santos en relación con las investigaciones arqueológicas y patrimoniales en el Área protegida Laguna de Rocha (República Oriental del Uruguay) para a posteriori realizar algunas consideraciones teóricas. El objetivo es brindar reflexiones que puedan a futuro tomarse en cuenta para la definición de acciones de gestión, medidas de conservación y el desarrollo de estrategias de musealización de estas colecciones. Entendemos que mientras se sigan realizando intervenciones arqueológicas y generando colecciones científicas, es necesario, de forma paralela, analizar continuamente desde la propia disciplina el rol que se juega en la construcción del patrimonio y en la conformación de los acervos y discursos dentro de los museos.

Nutrient loadings and deforestation decrease benthic macroinvertebrate diversity in an urbanised tropical stream system

Humid montane forests are challenging environments for human habitation. We used high-resolution fossil pollen, charcoal, diatom and sediment chemistry data from the iconic archaeological setting of Laguna de los Condores, Peru to reconstruct changing land uses and climates in a forested Andean valley. Forest clearance and maize cultivation were initiated during periods of drought, with periods of forest recovery occurring during wetter conditions. Between AD 800 and 1000 forest regrowth was evident, but this trend was reversed between AD 1000 and 1200 as drier conditions coincided with renewed land clearance, the establishment of a permanent village and the use of cliffs overlooking the lake as a burial site. By AD 1230 forests had regrown in the valley and maize cultivation was greatly reduced. An elevational transect investigating regional patterns showed a parallel, but earlier, history of reduced maize cultivation and forest regeneration at mid-elevation. However, a lowland site showed continuous maize agriculture until European conquest but very little subsequent change in forest cover. Divergent, climate-sensitive landscape histories do not support categorical assessments that forest regrowth and peak carbon sequestration coincided with European arrival.

We present a list of amphibian species from the protected area Barra de la Laguna de Rocha (BLR), Uruguay. Fifteen monthly three-day field trips were performed between September 2011 and March 2013. During each field trip, active searches of individuals and auditive samplings were performed at seven selected sites. We recorded 19 species of amphibians belonging to five families: Bufonidae (4 especies), Hylidae (5), Leptodactylidae (7), Microhylidae (1) y Odontophrynidae (2). Comparing these data with historical records (obtained from cientific collections and literature), eight species represented new records for the study site. The species richness in the area represents 39.6% of the total richness recorded for Uruguay. We highlight the presence of Melanophryniscus montevidensis (Philippi 1902), a locally and globally threatened species. Information on BLR's amphibian species composition could help in the implementation of the management plan for this conservation unit, as well as to stimulate future studies in the area.

This study investigates different provisioning services in the peri-urban landscapes of Manila conurbation through a case study of two villages in the Jala-Jala municipality of the Laguna de Bay area in the Philippines. Laguna de Bay is an ecologically productive and important watershed for the urban and peri-urban areas of Manila for the provision of food, freshwater, and other materials. However, the lake and its ecosystem are under threat because of rapid urbanization and associated land-use changes. This study is based on a semi-quantitative survey conducted with 90 households in two villages: Special District and Paalaman. It was aimed to capture how provisioning services in the locality are connected with local livelihoods. The results obtained from the study suggest that landscapes in this peri-urban area still has considerable provisioning ecosystem services associated with local biodiversity and that this dependence on provisioning services and their relationship to peri-urban landscapes and biodiversity should be addressed for sustainable landscape management. The results have important implications for the conservation potential of biodiversity on which local livelihoods depend, in urban and peri-urban ecosystems.