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In this contribution to the subfamily Pseudophyllinae in the Neotropics, we focus on reviewing the status of the genus Brachyauchenus and its four included species. After this revision, the genus remains monotypic, including only B. castaneus (type species), so it is necessary to provide a new diagnosis, since the current has characteristics of species that in the past was moved to Triencentrus, in addition to the characteristics of the species that are being excluded here. B. castaneus is redescribed to complement the characteristics of the genus, the unknown female is described, and new distribution data are provided, refuting the presence of this species in Bogotá, Colombia, its type locality. Brachyauchenus festae and B. minutus are grouped into the new genus Mikrischyrum n. gen. (Platyphyllini) which is similar to Baliophyllum and Drepanoxiphus, and a key is provided to differentiate these species. Brachyauchenus varicosus is being moved to the genus Stenoschema (Pleminiini), restricting the distribution of Brachyauchenus to the center and north of the eastern slope of the Colombian Andes and the new genus in Panama and the Peruvian Amazon. A map is included with the distribution data of the species studied here. Finally, the variation of the coloration of some species and the current taxonomic panorama of the tribe Platyphyllini are discussed.

This article presents a grasp of the Inter-American Court of Human Rights’ most important case law of 2020. As is developed within the paper, during 2020, the Court made important developments on Inter-American case-law which will have relevant incidence for the region. Many of the major developments that will be studied in this paper concern the right to nondiscrimination; economic, social and cultural rights; detention conditions, and some important advances on rights protection within the COVID-19 context.

La Universidad de Concepción es una Corporación Educacional sin fines de lucro, creada por iniciativa de la comunidad local en 1919 y definida como una institución tolerante, pluralista y dedicada al Servicio Público. A través de su historia, ha estado vinculada al progreso social, cultural y económico del país, siendo en la actualidad la tercera universidad en importancia académica en Chile. La Universidad de Concepción es reconocida por su gran contribución en la formación de profesionales, creación de conocimientos y vinculación con la sociedad, generando múltiples aportes en las artes plásticas, literatura, política, música, ciencia y tecnología. La cooperación multi e interdisciplinaria adquiere cada vez mayor importancia ante los grandes retos impuestos por el actual modelo neoliberal y la globalización tecno-económica, donde la vinculación de la Universidad con la sociedad y sus instituciones aparece como un factor decisivo y estructurante de sus actividades y proyección futura hacia una sociedad sustentable.

Tribe Platyphyllini Brunner von Wattenwyl, 1895 Comments. This tribe comprises 19 genera and 73 valid species, with a continental distribution between Brazil and Mexico, and a unique insular and monotypic genus, Antillophyllum Beier, 1960, from Jamaica (Cigliano et al., 2021). Platyphyllini differs from the other tribes by the following characteristics: 1. Anterior margin of pronotum convex and usually projected forward. 2. Striae of the mesosternum in a mid-caudal direction, extending from the anterior margin, into the lateral portion of the transverse sulcus, wich is usually long. 3. Metafurcal furrow as a groove with paired holes in a widely separated internal process. 4. Costal margin of tegmina uniformly narrowed, anal margin more strongly curved than the costal margin, which is slightly straight. 5. Main veins frequently indistinct, very fine, and densely reticulated, giving a stippled appearance to the tegmina. 6. Male terminalia without conspicuous modifications, with some exceptions in some species of Triencentrus and Xiphophyllum Beier, 1960. 7. Ovipositor as long as hind femur or longer, wide, usually straight or slightly curved, and with some denticulations on the dorsal margin., Published as part of Cadena-Castañeda, Oscar J., Rodríguez, Nixon Oscar Parra, Res, Gustavo Costa Tava-, Rodríguez, Diana Marcela Trujillo & Arias, Ronald Fernando Quintana, 2021, Studies on Neotropical Pseudophyllinae: The status of the genus Brachyauchenus Brunner von Wattenwyl, 1895 and its species (Orthoptera: Tettigoniidae: Pseudophyllinae: Platyphyllini), pp. 546-562 in Zootaxa 5027 (4) on page 548, DOI: 10.11646/zootaxa.5027.4.4, http://zenodo.org/record/5453427, {"references":["Brunner von Wattenwyl, C. (1895) Monographie der Pseudophylliden. Verhandlungen der Kaiserlich-Koniglichen Zoologisch- Botanischen Gesellschaft in Wien. 45, 282 pp.","Beier, M. (1960) Orthoptera Tettigoniidae (Pseudophyllinae II). In: Mertens, R., Hennig, W. & Wermuth, H. (Eds.), Das Tierreich. 74, Walter de Gruyter & Co., Berlin, pp. 396.","Cigliano, M. M., Braun, H., Eades, D. C. & Otte, D. (2021) Orthoptera Species File. Version 5.0 / 5.0. Available from: http: // Orthoptera. SpeciesFile. org (accessed 12 June 2021)"]}

Stenoschema varicosus (Piza, 1980) n. comb. (Fig. 8) Comments. Piza (1980) describes this species within the genus Brachyauchenus, and its existence remained unknown for a long time to entomologists due to the restricted diffusion of the journals in which Piza published his contributions. It was so difficult to achieve some contributions of the author, that in the review of tettigonids from the Salvador de Toledo Piza Jr collection, this species was cataloged as a “phantom species” because the references were not available (Chamorro-Rengifo & Braun, 2010). Recently, some of Piza’s contributions were made available online, but even the identification task is arduous; due to the brief descriptions and, in many cases, without drawings of the diagnostic characters. Brachyauchenus varicosus (Platyphyllini) is here transferred to Stenoschema (Pleminiini). The characters observed in the type specimens compare more with the diagnostic characteristics of this genus than Brachyauchenus. When comparing the other species described in Stenoschema, it is confirmed that this species is not synonymous with any of the other species already described and remains a valid taxon. Thus, Stenoschema has seven valid species, with a mainly Amazonian distribution, but also with some records from the Andes and Atlantic Forest (Cigliano et al., 2021). The habitus and other characters are typical of the taxa of the tribe Pleminiini, as mentioned by Braun (2012), in a scrutiny of the Orthoptera Species File.

Stenoschema varicosus (Piza, 1980) n. comb. (Fig. 8) Comments. Piza (1980) describes this species within the genus Brachyauchenus, and its existence remained unknown for a long time to entomologists due to the restricted diffusion of the journals in which Piza published his contributions. It was so difficult to achieve some contributions of the author, that in the review of tettigonids from the Salvador de Toledo Piza Jr collection, this species was cataloged as a “phantom species” because the references were not available (Chamorro-Rengifo & Braun, 2010). Recently, some of Piza’s contributions were made available online, but even the identification task is arduous; due to the brief descriptions and, in many cases, without drawings of the diagnostic characters. Brachyauchenus varicosus (Platyphyllini) is here transferred to Stenoschema (Pleminiini). The characters observed in the type specimens compare more with the diagnostic characteristics of this genus than Brachyauchenus. When comparing the other species described in Stenoschema, it is confirmed that this species is not synonymous with any of the other species already described and remains a valid taxon. Thus, Stenoschema has seven valid species, with a mainly Amazonian distribution, but also with some records from the Andes and Atlantic Forest (Cigliano et al., 2021). The habitus and other characters are typical of the taxa of the tribe Pleminiini, as mentioned by Braun (2012), in a scrutiny of the Orthoptera Species File., Published as part of Cadena-Castañeda, Oscar J., Rodríguez, Nixon Oscar Parra, Res, Gustavo Costa Tava-, Rodríguez, Diana Marcela Trujillo & Arias, Ronald Fernando Quintana, 2021, Studies on Neotropical Pseudophyllinae: The status of the genus Brachyauchenus Brunner von Wattenwyl, 1895 and its species (Orthoptera: Tettigoniidae: Pseudophyllinae: Platyphyllini), pp. 546-562 in Zootaxa 5027 (4) on pages 558-559, DOI: 10.11646/zootaxa.5027.4.4, http://zenodo.org/record/5453427, {"references":["Piza Jr., S. T. (1980) Especies novas de Pseudophyllinae especialmente do Brasil (Orthoptera, Tettigoniidae). Anais da Escola Superior de Agricultura \" Luiz de Queiroz \" (Universidade de Sao Paulo), 37 (1), 209 - 222. https: // doi. org / 10.1590 / S 0071 - 12761980000100014","Chamorro-Rengifo, J. & Braun, H. (2010) The Tettigoniidae (Orthoptera) described by Salvador de Toledo Piza Jr. and deposited in the collection of the University of Sao Paulo, Escola Superior de Agricultura \" Luiz de Queiroz \", Brazil. Zootaxa, 2635, 41 - 66. https: // doi. org / 10.11646 / zootaxa. 2635.1.3","Cigliano, M. M., Braun, H., Eades, D. C. & Otte, D. (2021) Orthoptera Species File. Version 5.0 / 5.0. Available from: http: // Orthoptera. SpeciesFile. org (accessed 12 June 2021)","Braun, H. (2012) Species Brachyauchenus varicosus Piza, 1980 In: Cigliano, M. M., Braun, H., Eades, D. C. & Otte, D. (2021) Orthoptera Species File. Version 5.0 / 5.0. Available from: http: // Orthoptera. SpeciesFile. org (accessed 12 June 2021)"]}

Brachyauchenus castaneus Brunner von Wattenwyl, 1895 (Figs. 1–6) http://lsid.speciesfile.org/urn:lsid: Orthoptera.speciesfile.org:TaxonName:5035 Redescription. Male. General coloration reddish-brown (Fig. 1); in life, the face is grayish-green (when preserved in alcohol, this coloration disappears); in museum specimens, the face is reddish-brown (Fig. 1C). Dorsal surface of the stridulatory area of both wings distinctly black, bordered by a light-yellow line (Figs. 1B, 2A, 2B). Costal area of the tegmina is blurred and outlined by black regions, forming yellowish triangular portions that contrast with the rest of the tegmina (Fig. 1A). Body covered by abundant hairs on all its surface (Fig. 1). Head. Frons and vertex smooth, quite narrow fastigium; in dorsal view, a little bit shorter than the margins of the antennal sockets, and dorsally sulcate. Lateral ocelli reduced and not very visible between antennal basins and fastigium; frontal ocellus very reduced, inconspicuous being only a small diffuse point between the antennal sockets; eyes rounded both in lateral or frontal view; antennal scape with a spine at the apex on the dorsal margin, pedicel unarmed. Pronotum notably granulated, pronotal disc flat, with deep grooves, with anterior margin projected onto the neck and with a more conspicuous distal granulation; posterior margin straight (Fig. 1B); ventral margin of lateral lobes thick, remarkably widening from the anterior to the posterior border, and separated from the propleura (Figs. 1A, 1B). Sternum. Proesternum armed with two triangular and conspicuous spines; mesosternum rectangular, and with a tubercle elevated on each margin of the lateral lobe; metasternum without elevated tubercles. Legs. Fore-femur ventrally armed with four spines only on the inner margin; fore-tibia armed with seven spines on each ventral margin. Mid-femur with five ventral spines on the outer margin and mid-tibia with seven ventral spines on each ventral margin. Hind femur with seven ventral spines on the outer margin; hind tibia with ten dorsal spines on each margin, and twelve spinules on the ventral margins. All genicular lobes armed, except the outer genicular lobe of the mid-femur; all spines of the femora and hind tibiae black (Fig. 1A, 1C). Wings not surpassing the apex of the abdomen, reaching the sixth or seventh abdominal segment. Veins M and R of the tegmina never converge, and Rs vein originating near the apex of the tegmina (Figs. 1A, 1B). Left stridulatory file (= vein A1) short, almost straight, but with the distal third (towards the anal margin) notably sinuous, bearing 155‒160 elongated and flattened teeth (Fig. 2C). When the tegmina are at rest position, the stridulatory file is covered under the pronotum (Fig. 2A). Mirror on the right tegmen ovoid and small (Fig. 2B); non-functional stridulatory file of the right tegmen ventrally in the form of a fold with few and small visible denticulations. Hindwings faded brown. Abdomen. Tenth tergite unmodified, without prolongation nor any ornamentation, cupuliform (Figs. 2D, 2F), with the division between the tenth tergite and the epiproct little differentiated (Fig. 2G). Epiproct ovoid, membranous and strongly attached to the paraprocts, with a longitudinal groove on the dorsal region and rounded posterior border (Fig. 2G). Cerci tumescent, cylindrical with a small distal inward spine (Fig. 2D). Subgenital plate mostly rectangular, narrow, notably longer than wide, and with a deep and narrow U-shaped notch (Fig. 2E), styli as long as the subgenital plate, upcurved and club-shaped (Figs. 2E, 2F). Male genitalia. Lateral edges produced into two lobes corresponding to the lw.vl.; up.vl reduced in dorsal view; df narrow, dl with divergent lateral margins from the distal portion to the base, internally with various microstructures like small denticulations; ti tubular and with two distal-lateral regions with microstructures like small scales; ejv ovoid and connected by a small conduit internally to the ejd. Female (nov). Similar in shape and color to the male (Fig. 4), but the tegmina reach only the fifth abdominal segment (Fig. 4A, 4B). Tenth tergite with a slightly concave posterior margin, flanked by two small prolongations; epiproct with a semicircle shape, wider than long and with a rounded posterior border (Fig. 5A); cerci cylindrical, progressively tapering towards the apex (Figs. 5A, 5B). Subgenital plate triangular, at the apex with a small notch (Fig. 5C). Ovipositor a little longer than the hind femur, slightly curved, and with an acuminated apex (Fig. 5B). Dorsal valve with serrulations from the middle to the apex, and ventral margin of the lower valve convex (Fig. 5B). Variation. The studied specimens did not show significant variations, the number of spines on the legs did not vary in number. A female had the hind femur with black and gray spots (Fig. 6), which, when placed in alcohol, disappeared, acquiring the same coloration as the rest of the body, as happened with museum specimens. Possibly this coloration is lost post-mortem, as occurs with the coloration of the face. Type specimen. Holotype. Male, Colombia, Sta. Fe de Bogotá, Alen Linding. Code. 4808 Naturhistorisches Museum Wien (NMW). Specimens examined. 1 male and 1 female, Colombia, Boyacá, Coper, Vereda Turtur, Sector San Ignacio, 1600 m. 5°25’32.03”N, 74° 0’15.24”W. December 2015. O.J. Cadena-Castañeda leg. (CAUD) 1 male, Cundinamarca, Pacho, 1680 m. 5° 9’14.32”N, 74° 9’8.61”W. October 2009 (CAUD). 1 female, Santander, Oiba, 1790m. 6°14’12.21”N, 73°16’58.55”O (CAUD). 1 male and 1 female, Santander, Charalá, Virolín, 6°17’14,10”N, 73°9’10,7”W. ICN-OR 00973 and ICN-OR 00984 (ICN). 1 male, Santander, San José de Suaita, 1500m. 9 May 1999, 6.167 6, -73.4672 (Det. H. Braun, December, 2009) (ICN). Measurements (mm). Male / Female: LB: 30–33/38–40, Pr: 6.5–7/8–8.5, Teg: 21–23/27–29, HF: 16– 16.5/17–18, HT: 17.5–18/19–20, SP: 4.5–5/2–2.5, Ov: 20–21. Comments. The female of the species is reported and described for the first time, with additional material (until now only the male type specimen was known). According to the specimens collected in Coper, Boyacá, it was observed that they have twilight and nocturnal activity, being present in the vegetation and tree trunks at the understory level, preferring humid areas. When they were collected, the male sang, and due to the visible movement of its wings and the fact that the sound was not audible to a large extent, its song must be mostly ultrasonic. Unfortunately, it was not possible to record the specimen on that occasion. With specimens collected in Santander, it was observed that, during the day, they prefer to be between holes in the trunks, with the forelegs and the antennae arranged forward and the mid and hind legs backward (Fig. 6). The type locality of the species was originally Santa Fe de Bogotá (former name of the capital of Colombia, now known only as Bogotá) (Chamorro-Rengifo et al., 2011). However, the place is above 2500–2650 m., with a cold climate, unlike the other reliable records of the specimens studied here, of middle lands with a warm climate between Cundinamarca, Boyacá, and Santander (Fig. 9). Possibly, the type specimen could be collected in midland localities near Bogotá. However, at that time, collectors used to mention that the specimens were sampled in more recognized towns or cities of Colombia, even if the collection places were many kilometers away from the locality mentioned on the specimens labels, with flora, elevation, and conditions very different (Rehn, 1930). A recent case that corroborates the statement presented here, concerns Bactrophora dominans Westwood, 1842. The locality of this species is “ Santa Fe de Bogotá ”, but this species inhabits the Amazon rainforests and localities of the Guyanese shield, where the biomes are opposite to those found in the Bogotá savanna, or the rest of the Cundiboyacense highlands. For this reason, that record was not taken into account by entomologists (Rehn, 1930; Silva et al., 2021), and, for the same reason, we discarded the presence of B. castaneus in the forests that surround the city of Bogotá., Published as part of Cadena-Castañeda, Oscar J., Rodríguez, Nixon Oscar Parra, Res, Gustavo Costa Tava-, Rodríguez, Diana Marcela Trujillo & Arias, Ronald Fernando Quintana, 2021, Studies on Neotropical Pseudophyllinae: The status of the genus Brachyauchenus Brunner von Wattenwyl, 1895 and its species (Orthoptera: Tettigoniidae: Pseudophyllinae: Platyphyllini), pp. 546-562 in Zootaxa 5027 (4) on pages 549-556, DOI: 10.11646/zootaxa.5027.4.4, http://zenodo.org/record/5453427, {"references":["Brunner von Wattenwyl, C. (1895) Monographie der Pseudophylliden. Verhandlungen der Kaiserlich-Koniglichen Zoologisch- Botanischen Gesellschaft in Wien. 45, 282 pp.","Chamorro-Rengifo, J., Cadena-Castaneda, O. J., Braun, H., Montealegre-Z, F., Romero, R. I., Serna Marquez, F. H. & Gonzales, R. (2011) Checklist and new distribution records of katydids (Orthoptera: Tettigoniidae) from Colombia. Zootaxa, 3023 (1), 1 - 42. https: // doi. org / 10.11646 / zootaxa. 3023.1.1","Silva, D. S. M., Tavares, G. C, Fianco, M. & Gonzalez, J. M. (2021) First report of the rare arboreal grasshopper Bactrophora dominans Westwood, 1842 (Insecta, Orthoptera, Caelifera, Romaleidae) from Brazil. Check List, 17 (3), 895 - 903. https: // doi. org / 10.15560 / 17.3.895"]}

Se analizan los modelos de gestión del agua y la utilidad de la mediación ambiental en los casos de conflictividad sobre los recursos hídricos de España y Brasil y su aplicabilidad a Chile. Se parte de la experiencia de España, que establece las cuencas hidrográficas como las bases territoriales de la administración. En España, se crean en 1926 por Real Decreto las Confederaciones Sindicales Hidrográficas, instituciones adscritas al Ministerio de Fomento para “el aprovechamiento intensivo, máximo de los recursos hidráulicos de las cuencas de nuestros grandes ríos”, que establece las cuencas hidrográficas como las bases territoriales de la administración. La trasposición de la Directiva Marco del Agua conservó la Demarcación Hidrográfica como base territorial de gestión, incorporando la participación social activa e integra de los implicados como principio crucial para la gestión sostenible. Brasil y Chile están entre los 14 países del mundo con más disponibilidad de agua. Sin embargo, ambos tienen problemas de escasez relativa. En Chile la gestión responde a la demanda, y las zonas de mayor oferta de recursos hídricos no coinciden con las áreas de mayor población y actividad económica. Ambos países muestran enfoques de gestión diferentes, siendo el brasileño más afín al europeo al definir la cuenca hidrográfica como unidad de gestión. Los principales resultados obtenidos son: 1. El agua es vital, pero su compleja gestión suele desembocar en conflictos socioambientales y económicos entre diferentes actores; 2. Posibilitar procesos participativos eficientes requiere estrategias que incentiven el interés en la información y compromiso de los implicados en la búsqueda de la mejor resolución de los conflictos. 3. Se propone la Mediación Ambiental como una estrategia adecuada para la resolución de conflictos en torno al agua.

Triaenogryllacris horaciotrianai Cadena-Castañeda n. sp. (Fig. 6, Map. 1) http://lsid.speciesfile.org/urn:lsid: Orthoptera.speciesfile.org:TaxonName:512290 Etymology. In memory of the social leader Horacio Triana, defended the Serranía de las Quinchas Natural Park, located between the departments of Boyacá and Santander (in the Middle Valley of the Magdalena River) to prevent the entry of illegal armed groups. A community leader in the village of El Carmen, in the municipality of Otanche, located in western Boyacá, who was assassinated on July 20, 2018. Type material. Holotype. Female. Colombia, Boyacá, Coper, Vereda Turtur, sector San Ignacio. 5.428 4, -73.990 2. 1500 m. 15 January 2018. O.J. Cadena-Castañeda (CAUD)., Published as part of Cadena-Castañeda, Oscar J., Díaz, Carlos Julio Arango, Guez, Nixon Oscar Parra Rodrí- & García, Alexander García, 2020, Studies on raspy crickets: New Triaenogryllacris species (Orthoptera: Gryllacrididae), pp. 239-250 in Zootaxa 4896 (2) on pages 247-248, DOI: 10.11646/zootaxa.4896.2.5, http://zenodo.org/record/4381682

Triaenogryllacris Karny, 1937 Redescription. Medium-sized (body length 19-22 mm) (Fig. 1A, 4A). Coloration. Body pink, green, or yellowish (Fig. 1-6). Head completely black (Fig. 1B, 6A) or reddish (Fig. 4D); central ocellus white, red or pink (Fig. 2B, 3B, 4D, 6A). Tegmina whitish, with red veins and hind wings hyaline, with red to brownish veins (Fig. 1A). Head. Space between antennal sockets 1.5 times the wider than the antennal scape; median ocellus as a large spot; maxillary palps elongated with the last segment slightly dilated at the apex; labial palpi robust, the last segment noticeably dilated in a scalene triangle shape and with a truncated apex (Fig. 1B, 4D, 6A). Thorax. Pronotum narrow and smooth, with quadrangular pronotal disc and rectangular lateral lobes; auditory spiracle below the lower margin of the lateral lobe of the pronotum and armed with a conspicuous spine (Fig. 4 B-C, 6B-C). Propleuron armed with a conspicuous and stout spine (Fig. 4D, 6 A-B). Legs. All coxae without spines or tubercles. Fore and mid femora unarmed; hind femur with spines on both ventral edges. Fore and middle tibiae, except the terminal spines, with four pairs of spines. Both sides of hind tibiae are very similarly armed (normally), with three spines on both dorsal edges; ventral edges unarmed. Wings. Well developed, slightly projecting beyond hind knees (Fig. 4 A-B). Tegmina with five anal longitudinal veins (post-cubital veins sensu Karny, 1937). Media vein (M) originating from radius stem, appears as the first branch of radius. Hind wings with Rs vein without connection to M vein, only originating at the beginning of the apical third of R, which bifurcates once (Fig. 1A). Abdomen. Stridulatory apparatus poorly developed. Male. Ninth and tenth abdominal tergite unmodified, sclerotized hooks present between the paraprocts and ventral edge of the tenth tergite, the area between the hooks membranous (Fig. 5 A-B). Cerci simple without branches. Subgenital plate posteriorly with three or two acute median processes, without styli (Fig. 1D, 5 D-F). Female. Subgenital plate posteriorly emarginated and slightly narrower than its base, sternite preceding the subgenital plate with a papilla on each side (Fig. 6 D-E). Ovipositor longer than the hind femur, tip semicircularly rounded (Fig. 6F). Distribution. Colombian and Ecuadorian Andes (Map 1). Taxa included. Triaenogryllacris triaena (Karny, 1929) (type species), T. diaena n. sp. and T. horaciotrianai n. sp., Published as part of Cadena-Castañeda, Oscar J., Díaz, Carlos Julio Arango, Guez, Nixon Oscar Parra Rodrí- & García, Alexander García, 2020, Studies on raspy crickets: New Triaenogryllacris species (Orthoptera: Gryllacrididae), pp. 239-250 in Zootaxa 4896 (2) on pages 240-242, DOI: 10.11646/zootaxa.4896.2.5, http://zenodo.org/record/4381682, {"references":["Karny, H. H. (1937) Orthoptera Fam. Gryllacrididae, Subfamiliae Omnes. Genera Insectorum, 206, 1 - 317.","Karny, H. H. (1929) Ueber einige Gryllacrinen des Madrider Naturwissenschaftlichen Museums (Orth. Tettig.). Eos, Revista espanola de Entomologia, 5 (1), 33 - 80."]}

Subfamily Gryllacridinae Blanchard, 1845 Genus group Triaenogryllacrae Cadena-Castañeda, 2019 Comments. This group was proposed in a recent monograph on the Gryllacrididae classification (Cadena-Castañeda, 2019). It is characterized by a blackish or reddish head, a very well-developed median ocellus (Fig. 1B, 4C, 6A), the subgenital plate of the male without styles and with two or three medium-sized sharp processes (Fig. 1D, 5D), and the females with a pair of papillae on each side of the last abdominal sternite (Fig. 6 D-E). Triaenogryllacrae is represented by the monotypic genus, Triaenogryllacris, and the new species described in this paper, all from Colombian and Ecuadorian Andes (Map 1). The Group is distinguished from the other American genera by the tegmen venation corresponding to Type IV (sensu Karny, 1924) and the strange hindwing venation. The males do not have styli, as in the genera of Hyperbaenini. This character is interpreted as convergence, since both groups are found in different subfamilies, and are separated by many other characters such as the shape of the hind femur tegmina, and pattern of wing venation (Cadena-Castañeda, 2019)., Published as part of Cadena-Castañeda, Oscar J., Díaz, Carlos Julio Arango, Guez, Nixon Oscar Parra Rodrí- & García, Alexander García, 2020, Studies on raspy crickets: New Triaenogryllacris species (Orthoptera: Gryllacrididae), pp. 239-250 in Zootaxa 4896 (2) on page 240, DOI: 10.11646/zootaxa.4896.2.5, http://zenodo.org/record/4381682, {"references":["Cadena-Castaneda, O. J. (2019) A proposal towards classification of the Raspy Crickets (Orthoptera: Stenopelmatoidea: Gryllacrididae) with zoogeographical comments: An initial contribution to the higher classification of the Gryllacridines. Zootaxa, 4605 (1), 1 - 100. https: // doi. org / 10.11646 / zootaxa. 4605.1.1","Karny, H. H. (1924) Beitrage zur malayischen Orthopterenfauna VI. Die Gryllacriden des Buitenzorger Museums. Treubia, 5 (1 - 3), 19 - 105. https: // doi. org / 10.14203 / treubia. v 5 i 1 - 3.1681"]}

Triaenogryllacris triaena (Karny, 1929) (Fig. 1-3, 5F, Map. 1) http://lsid.speciesfile.org/urn:lsid: Orthoptera.speciesfile.org:TaxonName:22109 Type material. Holotype. Ecuador (MNCN). Allotype. Colombia, Antioquia (MNCN). Comments. This species was described in detail by Karny (1929), although, unfortunately, there are no data on the precise localities of the type specimens, so the distribution of this species is incomplete on Map 1, since it can extend even farther south and to the north, in contrast to the records documented here. In the distribution range, based on the observed specimens, three variations or color forms are differentiated (Map 1, see the color code on each locality): 1) The body is yellowish (except for the head, which will always be black in all color forms) and the median ocellus red, as observed in the holotype of Ecuador (Fig. 1) and Colombian specimens from Circasia, Quindío department and Manizales, Caldas department. 2) The body is pink similar to the median ocellus. This color form was recorded at Cali-Dagua road in the Department of Valle del Cauca (Fig. 2). 3) Pink medan ocellus, green legs, pronotum, and abdomen yellowish, with diffuse pink spots. This color form was observed in only one specimen from Chinchina, Caldas (Fig. 3). It is currently unknown if these color forms are regional (although the yellowish form 1 is more widely distributed than the other two color forms) or are conditioned by the micro-habitat and food where the populations live., Published as part of Cadena-Castañeda, Oscar J., Díaz, Carlos Julio Arango, Guez, Nixon Oscar Parra Rodrí- & García, Alexander García, 2020, Studies on raspy crickets: New Triaenogryllacris species (Orthoptera: Gryllacrididae), pp. 239-250 in Zootaxa 4896 (2) on page 242, DOI: 10.11646/zootaxa.4896.2.5, http://zenodo.org/record/4381682, {"references":["Karny, H. H. (1929) Ueber einige Gryllacrinen des Madrider Naturwissenschaftlichen Museums (Orth. Tettig.). Eos, Revista espanola de Entomologia, 5 (1), 33 - 80."]}

We analyzed the abundance of benthic algae in nine forested headwater watersheds in south-central Chile to study the relationship between the variability of the abundance of benthic algae and physicochemical parameters and forest cover factors. Between 10 November 2015 and 18 August 2016, we sampled benthic algae and physicochemical parameters in the streams and characterized forest cover factors in each of the study watersheds. We found that physicochemical parameters and forest cover factors have contrasting effects on abundance. More specifically, the following observations were made: (1) maximum diversity and abundance occurred in watersheds covered with Pinus radiata, (2) seasonal ranks did not influence the abundance of benthic algae, (3) benthic algae abundance is controlled by rank dissimilarities in type of vegetation, solar radiation, volume, density age, canopy openness, native forest area, plantation area and harvested area, and (4) regression analysis of genera exhibited significant variability with physicochemical parameters (water temperature, pH, ammonium, nitrate, phosphorus, solar radiation) and forest cover factors (volume, density, age, native forest area, plantation area and harvested area); however, these effects were not seen in all genera. Factors related to the benthic algae compartment showed the highest sensitivity to forest cover, emphasizing their value as biological indicators of water quality and stream ecological integrity.

The magnitude of hydropower developments in emerging regions threatens the sustainability of their riverine landscapes. Fragmentation of river networks by multiple barriers and the imposition of new hydrological regimes influences the ability of these river ecosystems to absorb and adapt to these developments and other stressors. Direct transfer of paradigms built from a restricted geographical base to a global context is fraught with issues because of regional differences in eco‐hydro‐geomorphology, biological communities, and nonlinear interactions between the two. In this manuscript, some impacts of hydropower development on Chilean riverine ecosystems are presented. To understand the context of hydropower, we provide the political context of energy development in Chile. Interactions between hydropower generation and Chilean river ecosystems with special reference to native Chilean fish fauna are outlined. Three case studies are presented that considers: (a) habitat alteration downstream of the Rucue Dam, (b) the effects of daily hydropeaking in the Biobio River, and (c) mitigation strategies to reduce habitat alteration upstream of the San Pedro Dam. These case studies illustrate the expanding scientific knowledge on Chilean riverine landscapes. Finally, new measures to reduce ecosystem impacts of hydropower development on native Chilean fish communities are outlined. Although specific scientific information is available, developing regional ecohydrological models and improving knowledge of ecosystem and sustainability science is required. The scientific approach on which solutions are sought to address present and future river ecosystem problems in Chile are inherently interdisciplinary nature.

In this paper, we connect ideas of the astrobiological and ecological schools to quantify habitability. We show how habitability indexes, devised using the astrobiologically inspired Quantitative Habitability Theory (QHT), can be embedded into ecological models of trophic levels. In particular, we address the problem of spatial-temporal scales. It turns out that the versatility of QHT allows to treat spatial and temporal scales typical of ecological studies. As a habitability index, we propose a new version of our Aquatic Primary Habitability, devised by some of us and formerly applied to saltwater ecosystems (both ocean and coastal) and now applied to freshwater. Although the aim of the paper is to outline the methodology rather than realism, initial steps for parameterization are considered for lakes of South-Central Chile.

Lake surface water temperature (LSWT) is a crucial water quality parameter that modulates many lake and reservoir processes. Therefore, it is necessary to monitor it from a long-term perspective. Over the last decades, many methods to retrieve LSWT fields from satellite imagery have been developed. This work aims to test, implement and automate six methods. These are performed in the Google Earth Engine (GEE) platform, using 30 m spatial resolution images from Landsat 7 and 8 satellites for 2000–2020. Automated methods deliver long-term time series. Series are then calibrated with in situ data. Two-dimensional (2D) × time data fields are built on the lakes with the calibration, and a subsequent LSWT climatology is derived. Our study area is two urban lagoons with areas smaller than two (2) km2 of the city of San Pedro de la Paz, South-Central Chile. The six methods describe the seasonal variation of LSWT (Willmott’s index of agreement > 0.91, R2 > 0.67). The main difference between series is their bias. Thus, after a simple calibration, all series adequately describe the LSWT. We utilized the Pedro de la Paz lagoons to demonstrate the method’s utility. Our research demonstrates that these adjacent lagoons exhibit comparable LSWT spatial (15.5–17 ∘C) and temporal (7–25 ∘C) trends throughout the year. Differences in geographical pattern might result from the northern island’s heat impact and the existence of the Biobío river to the east. Our work represents an efficient alternative for obtaining LSWT in particular lakes and reservoirs, especially useful in medium and small-sized ones.

Chronic Zoon vulvitis was successfully treated with platelet-rich plasma achieving a considerable reduction of the clinical symptoms and signs of an evident lesion.

Millennium Science Initiative from Chile's Ministry of Economy, Development, and Tourism, through the Millennium Nucleus MUSELS NC120086 Millennium Science Initiative from Chile's Ministry of Economy, Development, and Tourism, through the Millennium Institute of Oceanography (IMO) IC120019 Water Research Center for Agriculture and Mining (CRHIAM) Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDAP 15130015 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1170065 1190805

This paper explores possible strategies to meet iron ore customer requirements (reduce variability and keep Fe% and contaminants such as Al2O3% and P% within the acceptable tolerance) by optimizing the mine plan and scheduling strategy in the rehandling process. The paper aims to obtain more homogenous iron ore grade by redesigning current rehandling strategy and creating selective Run of Mine (ROM) with defined Fe grade and contaminants tolerances in the supply chain process. A new Linear Programming Model was developed and sample data from an Iron Ore operation in Western Australia was used to conduct this analysis. The outcomes indicate that it is possible to achieve better grade results for Fe% and Al2O3% keeping required tonnage targets. Furthermore, the results reflect Low-Grade materials could play a more important role in the weekly schedule and that grade contents could balance alterations of High-Grade products. Although there are extra costs due to rehandling activities, these costs could be offset by selling more consistent products. It is an invitation to mining companies to change current strategy and focus more on the downstream and customer requirements in terms of quality product instead of just quantity.

Se estudiaron las características morfológicas y las variables físicas y químicas de cuatro lagos urbanos de Concepción (Chile) durante un periodo de tres años (2011-2013). Los resultados muestran que los lagos se encuentran en un proceso de eutrofización avanzada, por la excesiva carga de nutrientes (principalmente fósforo y nitrógeno), además de presentar altas concentraciones de conformes fecales y totales en la columna de agua y metales pesados en los sedimentos. El análisis de componentes principales, indica que el fósforo total, amonio, pH, transparencia conductividad y clorofila-a son las variables que mejor explican las condiciones del agua de todos los lagos estudiados. Se recomienda orientar las acciones de gestión de los lagos en disminuir la concentración de fósforo total, sin embargo y dependiendo de las particularidades de cada lago deben ser aplicadas otra serie de medidas complementarías que ayuden a revertir la situación actual de estos sistemas acuáticos. Este trabajo contribuye a la generación de conocimiento limnológico que facilita la toma de decisiones en materia del uso y gestión ambiental de los lagos urbanos de Concepción.

In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36° 54 'S, 71° 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.

The district of Chileans Araucanian Lakes is a group of lakes of glacial origin that are located between 39° and 42°, Lat. S and 71° and 72° Long. W that are characterized by presenting oligotrophic conditions. The last of the chain of lakes of Valdivia Basin River is the Rinihue, a temperate monomitic lake, reason why its study is of great importance, since it reflects any disturbance in the chain. It is relevant to have precise spectra of the photosynthetically active and ultraviolet radiation of the location area to calculate the photosynthetic potential in these lakes. In this paper, an assessment is made about the applicability of the COART radiative transport model in freshwater aquatic systems.

The mechanisms involved in N2O production, consumption and air-sea interactions in fluvial systems are modulated and affected by several factors, including hydrological, chemical and anthropogenic impacts. In recent decades, the basin of the Biobío River (central Chile) has been impacted by an enhanced precipitation deficit and anthropogenic pressure, so the aim of the present work is to understand the spatial and seasonal dynamics of N2O during a megadrought that has been affecting the river since 2010. We also aim to determine the annual contribution of N2O to the atmosphere and the possible response of the Biobío River to projected climatic changes. Seasonal sampling of the water physical-chemical properties was carried out at 15 stations along 280 km of the river and its five tributaries; the stations were distributed between the pristine headwaters (700 m asl) and the outlet of the river at the Pacific Ocean. The longitudinal distribution of oxygen, nutrients, and nitrous oxide evidenced agricultural, urban and industrial impacts on the river water. Headwater areas presented the highest oxygen concentration and the lowest nutrient and N2O concentrations, all of which fluctuated with the variability in water discharge with the different seasons. In the middle river section, where agricultural, industrial and urban activities impacted the river, the nutrient and N2O concentrations increased up to 20 and 1.2 times, respectively, compared to those in the headwaters, and the outlet area showed the highest nutrient and N2O concentrations. Throughout the entire river, N2O oversaturation exhibited a pronounced seasonal cycle with maxima occurring during the dry season. Our results suggest that urban activities had the greatest impact on the Biobío River at its outlet. Furthermore, the inverse relationship between the N2O concentration and water discharge suggests that the predicted future decrease in water discharge may result in higher N2O values in the Biobío River that would expectedly enhance global warming further, through a positive feedback.

This chapter develops the concept of ‘institutional empowerment’ to highlight the ways in which state actors have redefined their strategies as a result of interactions with the Inter-American Human Rights System (IAHRS). The empirical analysis in the chapter assesses the direct and indirect ways that IAHRS decisions have helped strengthen state agencies that are facing difficulties in driving forward human rights policies, particularly as a result of resistance from other sectors of the state itself. This strategic repositioning of state agencies contributes to broader efforts to ensure the greater enjoyment of rights by individuals and groups. Parra-Vera’s examination of a range of concrete cases demonstrates the diversity of the actions of state agencies in the Inter-American System.

The International Waters Science Project Lakes Working Group reviewed 58 Global Environment Facility (GEF) projects that addressed serious environmental and human development issues in transboundary lakes. The lessons learned from the review of these projects were integrated with the intention to contribute to the design and success of future projects. Issues that will continue to impact lake ecosystems and their management include changing agricultural practices, resource extraction, emerging contaminants, energy policies, and water allocation. Future lakes

Quantifying the effect of droughts on ecosystem functions is essential to the development of coastal zone and river management under a changing climate. It is widely acknowledged that climate change is increasing the frequency and intensity of droughts, which can affect important ecosystem services, such as the regional supply of clean water. Very little is understood about how droughts affect the water quality of Chilean high flow rivers. This paper intends to investigate the effect of an, recently identified, unprecedented drought in Chile (2010-2015), on the Biobio River water quality, (36°45'-38°49' S and 71°00'-73°20' W), Central Chile. This river is one of the largest Chilean rivers and it provides abundant freshwater. Water quality (water temperature, pH, dissolved oxygen, electrical conductivity, biological oxygen demand, total suspended solids, chloride, sodium, nutrients, and trace metals), during the drought (2010-2015), was compared with a pre-drought period (2000-2009) over two reaches (upstream and downstream) of the river. Multivariate analysis and seasonal Mann-Kendall trend analyses and a Theil-Sen estimator were employed to analyze trends and slopes of the reaches. Results indicated a significant decreased trend in total suspended solids and a slightly increasing trend in water temperature and EC, major ions, and trace metals (chrome, lead, iron, and cobalt), mainly in summer and autumn during the drought. The reduced variability upstream suggested that nutrient and metal concentrations were more constant than downstream. The results evidenced, due to the close relationship between river discharge and water quality, a slightly decline of the water quality downstream of the Biobio River during drought period, which could be attenuated in a post-drought period. These results displayed that water quality is vulnerable to reductions in flow, through historical and emerging solutes/contaminants and induced pH mobilization. Consequently, seasonal changes and a progressive reduction of river flow affect the ecosystem functionality in this key Chilean river. The outcomes from this research can be used to improve how low flow conditions and the effects of a reduction in the river volume and discharge are assessed, which is the case under the scenario of more frequent drought periods.

El río San Pedro corresponde al sistema fluvial que desagua la cadena de ocho lagos andinos de la cuenca del río Valdivia (Región de los Ríos). Este sistema recorre 40 km entre el desagüe del lago Riñihue y su confluencia con el río Collileufu, donde cambia de nombre a río Calle Calle. En él se proyectó construir la "Central Hidroeléctrica San Pedro", cuyo muro se ubica 14 km aguas abajo del desagüe del lago Riñihue y la cual transforma 12,5 km de río en embalse. Ello generó la necesidad de elaborar un Estudio de Impacto Ambiental, el cual fue desarrollado por el Centro de Ciencias Ambientales Eula Chile (Universidad de Concepción). En relación a la ecología del río, dicho estudio puso especial énfasis en generar el conocimiento de detalle sobre su ictiofauna, con el fin de efectuar una evaluación de impactos especie específica. En este artículo presentamos los fundamentos y aproximaciones metodológicas para llevar a cabo el estudio intensivo, cuyos resultados dan origen a esta publicación monográfica y a la descripción de la distribución, abundancia, uso de hábitat, patrones de desplazamiento, relaciones de longitud-peso, primeros estadíos de vida y estructura genética de la ictiofauna del río San Pedro.

La gran presion generada por el desarrollo socioeconomico del sur de Chile, esta causando cada vez mas un mayor impacto en los lagos y rios alli presentes. Sin embargo, el conocimiento de la estructura ecologica y la capacidad microbiana de autodepuracion de los cuerpos de agua lacustres es escasa, pero esencial para un futuro uso sostenible de los recursos agua y suelo. Se estudio el lago Laja, por ser un cuerpo de agua muy afectado por la extraccion de agua para la generacion de energia hidroelectrica y el riego. Como es caracteristico de la region andina, el lago Laja es oligotrofico limitado por nutrientes nitrogenados. Se encontraron bajas concentraciones de clorofila a y carbono organico particulado (POC), asi como bajas abundancias y biomasa de bacterias (principalmente ultramicrobacteria) y de flagelados heterotroficos. Interrelaciones troficas debiles se determinaron de la relacion bacterias y flagelados heterotroficos. Para las diez enzimas extracelulares estudiadas (fosfatasa, leucina-, arginina-, glicina- y tirosina-aminopeptidasa, a-, b-D-glucosidasa, a-, b-D-galactosidasa, N-acetyl-b-D-glucosaminidasa), con la excepcion de α-β-glucosidase, se analizo un amplio rango de actividad de degradacion sobre la materia organica. Probablemente, debido a la limitacion de nitrogeno, el N-organico hidrolizado por enzimas extracelulares alcanzo una actividad promedio de 45 %, comparada con otros estudios en aguas oligotroficas. El posible efecto de la limitacion de N en la actividad enzimatica extracelular, fue mas pronunciado en las tasas de la actividad enzimatica extracelular especificas, las cuales excedieron en un factor promedio de dos a las de otros cuerpos de aguas oligotroficos. En general, la actividad de todas las enzimas extracelulares microbianas estudiadas resultaron estar dominadas por enzimas externas disueltas libres (hasta el 98 %), mas que por ectoenzimas asociadas a particulas de materia organica (paredes celulares de bacterias, particulas y agregados). De esta manera es posible concluir que los futuros cambios socioeconomicos, reflejados en el incremento de cargas organicas e inorganicas, asi como el efecto del cambio global (cambios en temperaturas y precipitaciones), podrian provocar cambios significativos en la ecologia del lago Laja.

Hydropeaking dam operation and water extractions for irrigation have been broadly stated as alterations to natural flow regimes, which have also been noticed in the Biobio Watershed, in Central Chile, since 1996. In the Biobio River, most of native fish species are endemic and very little is known about them. Their ecological and social values have never been estimated, and there is lack of information about their habitat preferences. Furthermore, changes on fish habitat availability due to natural and/or man-made causes have not been evaluated. In this study, eight native fish species, in a representative reach of the Biobio River, were studied and their preferred habitats were surveyed and characterized. A hydrodynamic model was built and linked to the fish habitat simulation model CASiMiR. Fuzzy rules and fuzzy sets were developed for describing habitat preference of the native fish species. CASiMiR was then used to simulate how physical habitat conditions vary due to flow control (i.e. upstream dams). Results show how overall habitat quality, expressed as weighted usable area (WUA) and hydraulic habitat suitability (HHS), changes and fluctuates due to the dam operation and how the daily hydropeaking is influencing quantity, quality and location of different habitats. The study suggests that the analysed fish are highly susceptible to flow control, as dams are currently operated, and fish habitat improvement suggestions are proposed.

Radiation plays an essential role in the establishment and proliferation of biota in natural environments. The photosynthetic process determines the existence of all life forms, since it supplies the energy that this photobiological process needs for the reaction, it is carried out by absorbing photons in the visible and infrared bands of the electromagnetic spectrum, while ultraviolet (UV) photons and ionizing radiation tends to inhibit it (decreasing, by various mechanisms, its quantum yield). The speed of photosynthesis, measured by the amount of O2 released in the unit of time (or CO2 absorbed) depends on the intensity of the incident light, in the last three decades this radiation has been increased by the decrease of stratospheric ozone in the South latitudes of our planet, for this reason the UV values in the aquatic ecosystems of Chile have been high as well as a considerable increase in the surface temperature of the bodies of water, having possible implications in the primary biological productivity of the ecosystems lakes, especially in Andean lakes. This increase in radiation could be related to the abundance of the different algal groups and the seasonal variability of them, creating favorable conditions for those dominant species considered invasive of these ecosystems. This paper shows the direct relationship between the concentration of ozone (O3) and ultraviolet radiation and how it influences the vertical distribution of the phytoplankton groups in the water column. For the first time it was found in this lake the appearance of a bloom of toxic cyanobacteria.

A multidisciplinary approach is followed for analysis of the effect of changes in land use patterns on the hydrologic response of the Vergara watershed (4340 km2) located in central Chile. Probable future land use scenarios were generated using heuristic rules and logistic regression models, in order to identify and represent the main pressure on the watershed, namely forestation of extensive areas used for agriculture with rapid growing exotic species. The hydrologic response of the watershed was computed with a physically based distributed precipitation-runoff model, which was calibrated and validated for the current period. Results show that mean annual discharge increase with agricultural land use and diminish with introduced forest coverage. Thus, forestation of areas with introduced species like Pinus radiata and Eucalyptus globulus might be regulated in order to protect the water resources of the watershed.

A course for upper division undergraduate students was developed in response to a request for a cross-disciplinary course in environmental sustainability with an emphasis on an international issue. The topic selected for the course focused on the energy needs for Chile and a proposal for five hydropower projects on the Baker and Pascua Rivers in the Patagonia area. Collaborations between the University of Michigan (USA) and the University of Concepcion (Chile) to develop the course led to a plan to offer a parallel course at both universities, with the students of both courses participating in a site visit to Patagonia. The courses were structured to enhance learning through interdisciplinary team-based activities. The courses were taught in a seminar format, with invited lecturers to provide background information on technical, environmental, economic, social, and political issues surrounding hydropower development in general and the proposed projects in particular. The students combined this information with insights obtained during the site visit to prepare a variety of course products, notably an assessment of the concerns of the various affected stakeholder groups. Assessment of the course outcomes is discussed.

Many researchers have shown the importance of water chemistry and benthic habitat characteristics for the conservation of the freshwater macroinvertebrate biodiversity. However, few authors have examined the physical effect of extreme water-level fluctuations in lakes. The present study set out to determine, through a comparative study between a regulated lake (Laja Lake, LL) and an unregulated lake (Icalma Lake, IL) of the Andean zone of southern Chile, how man-made disturbances of the natural hydrological regime affect the structure of the benthic macroinvertebrate community. The results showed LL had very low values for species richness, density and biomass in comparison with IL, and the community was composed mainly of few individuals belonging to opportunistic taxa such as Chironomidae and Naididae. We suggest that the low values in the regulated lake are potentially explained by littoral zone factors driven by the water-level fluctuations such as: desiccation, freezing of the biota, removal of organic particles from the sediment and absence of aquatic macrophytes.

Large dams have provided extensive benefits during the past 60 years but have also resulted in ecological and social consequences that were unexpected or were deemed to have a lower societal importance than the design benefits. The management of large dams is still a relatively new scientific issue, compared to the timeframe necessary to detect and understand all the consequences occurring at the watershed scale. This paper summarizes the unforeseen or unanticipated environmental consequences of these projects and potential ramifications to the overall project performance. The value of a central knowledge base and the importance of a system-wide monitoring program to assess pre- and post-implementation conditions and adapt operational rules are presented. Knowledge developed in several basins is reviewed in the context of future strategies for Chile. Chile has a strong economy, looming energy crisis and is faced with balancing the long-term value of a renowned natural landscape with unique ecology and the largest salmon aquaculture industry in the world against the prospect of low cost hydropower to drive other sectors of the economy. This paper outlines the hydroinformatics technologies and scientifically based management approaches that can be applied to this complex issue.

SUMMARY 1. The Biobo ´o River basin of south-central Chile exhibits the greatest species richness of all rivers in Chile, where it is one of the most important rivers for human use. Use for provision of drinking water, irrigation, sewage effluents, hydropower generation and industry has increased dramatically during the last decade. To help understand the effects of human activities on the Biobo ´o River, we document recent changes in the fish community. 2. In this study, current patterns of distribution and abundance of fishes were compared with the expected longitudinal pattern, and to historical data from studies conducted before the rapid development of the last decade. Fish distribution, biomass, abundance and diversity were studied at eight sampling stations in the middle and lower zones of the river in both high and low flow seasons. 3. Contrary to the pattern observed in less impacted river systems, species richness (S), diversity (H¢) and abundance [calculated catch per unit effort (CPUE)] all tended to decrease downstream from the uppermost sampling locations. Mean S decreased from 7.9 to 5.4, mean H¢ decreased from 0.7 to 0.4, and mean CPUE decreased from 111 to 43 from hyporithral to potamal locations. 4. Comparison with previous records indicates loss or reduction in distribution of native species, and a concurrent expansion in distribution and abundance of tolerant introduced species (e.g. Gambusia holbrooki, and Cyprinus carpio) over the last 10–15 years. These comparisons suggest a large-scale and long-term effect of recent human impacts on the river.

1. Chilean rivers have a large potential for hydropower development, and they also contain a unique native fish fauna with a high level of endemism. Several diversion hydropower plants have recently been constructed in Chile; however, the response of fish communities to these new hydropower plant designs is not well known. 2. Responses of native and non-native fish to the construction and operation of a new hydropower plant that diverts water from two rivers were quantified. The Laja River is highly regulated and manipulated with three older (40 yr) dam-based hydropower plants and irrigation diversions located upstream from the new facility. In contrast, the Rucue River has no other hydropower facilities and is comparatively undisturbed. 3. Prior to construction, the Laja River had a fish community with lower species richness compared with the Rucue River. The fish community structure in the Laja River was dramatically altered after the new hydropower facility began operation. On the other hand, in the Rucue River, even though abundance of fish declined, there was less of a change in the total fish community structure. The fish community in the Rucue River exhibited greater resistance to change compared with the Laja River. 4. The species most affected were the introduced salmonids and an endangered native species Percilia irwini. 5. Although diversion hydropower designs may have less impact than traditional dam-based hydropower facilities, results of this study indicate that diversion hydropower structures can cause large changes in the fish community. Copyright © 2006 John Wiley & Sons, Ltd.

A baseline study on a temperate, oligotrophic North Patagonian lake (Lake Chapo, Southern Chile) was made prior to the installation of a hydroelectric power station. Throughout one year (September 1986–October 1987) the physical and chemical properties of the lake were investigated monthly from the surface to a depth of 40 m. Lake Chapo is a deep, transparent (Secchi depth: 17–25 m), glacial lake located at 41° 27.5′ S and 72° 30′ W. It has a maximum depth of 298 m, mean depth of 183 m, surface area of 45.3 km2 and water volume of 8.296 km3. The theoretical residence time of the water was 5.5 years. The temperature regime is monomictic with the mixed temperature between 8.1–8.8 °C. Maximum temperature at the surface was 18.7 °C during thermal stratification in summer when the epilimnion had a thickness of about 20 m. The conductivity was low (20.3–23.8 μS cm−1) as was the buffering capacity of a predominantly CO2-carbonate system. The predominant cations were Ca+2? Na+?Mg+2?K+. The phosphorous and nitrogen contents were very low (soluble reactive ortophosphate: 0–1.5 μg P l−1, total phosphorus: 0.3–4 μg P l−1 and nitrate: 0–35 μg N l−1), which is typical of North Patagonian lakes.

The present paper focuses on the biological properties of Lake Chapo prior to the installation of a hydroelectric power station. Most of the biological parameters indicate that the lake is oligotrophic, i.e., it has very low values of chlorophyll a and primary production. The phytoplankton community of 73 species shows a predominance of only a few species in terms of density and biomass. The zooplankton community is poor in species, with one of the lowest densities measured in the North Patagonian lakes. The fish community is dominated by two introduced salmonid species. Comparison with other North Patagonian lakes reveals that Lake Chapo is the most oligotrophic.

Rivers may act as important sinks (filters) or sources for inorganic nutrients between the land and the sea, depending on the biogeochemical processes and nutrient inputs along the river. This study examines the inter-annual variability of dissolved inorganic nitrogen (DIN) seasonal (wet–dry) cycle for the Biobío River, one of the largest and most industrialized rivers of Central Chile (36°45'–38°49' S and 71°00'–73°20' W). Long-term water flow (1990–2012) and water quality datasets (2004–2012) were used along with a one-dimensional reactive transport ecosystem model to evaluate the effects of water flow and N inputs on seasonal pattern of DIN. From 2004 to 2012, annual average nitrate levels significantly increased from 1.73 ± 2.17 μmol L−1 (upstream of the river) to 18.4 ± 12.7 μmol L−1 (in the river mouth); while the annual average oxygen concentration decreased from 348 ± 22 to 278 ± 42 μmol L−1 between upstream and downstream, indicating an additional oxygen consumption. Variability in the mid-section of the river (station BB8) was identified as a major influence on the inter-annual variability and appeared to be the site of a major anthropogenic disturbance. However, there was also an influence of climate on riverine DIN concentrations; high DIN production occurred during wet years, whereas high consumption proceeded during dry years. Extremely reduced river flow and drought during summer also strongly affected the annual DIN concentration, reducing the DIN production. Additionally, summer storm events during drought periods appeared to cause significant runoff resulting in nitrate inputs to the river. The total DIN input reaching the river mouth was 0.159 Gmol yr−1, implying that internal production exceeds consumption processes, and identifying nitrification as one of the predominant processes occurring in the estuary. In the following, the impact on the river of DIN increases as a nutrient source, as well as climate and biogeochemical factors are discussed.