Jaime Ojeda

Filosofía ambiental de campo y conservación biocultural en el Parque Etnobotánico Omora: Aproximaciones metodológicas para ampliar los modos de integrar el componente social ("S") en Sitios de Estudios Socio-Ecológicos a Largo Plazo (SESELP)

This article discusses field environmental philosophy and biocultural conservation methods at the Omora Ethnobotanical Park in the Cape Horn Biosphere Reserve in Chile.

Patrones estacionales y espaciales de la diversidad de moluscos intermareales de bahía Róbalo, canal Beagle, Reserva de la Biosfera Cabo de Hornos, Chile

Resumen es: Los canales subantarticos de Chile son una de las regiones con mayor diversidad de moluscos del oceano Pacifico en el sur de Sudamerica. Esta region pres...

Fishermen's perceptions of interactions between seabirds and artisanal fisheries in the Chonos archipelago, Chilean Patagonia

Interactions between seabirds and commercial fishing activities have been well documented but little information is available regarding the impacts of more traditional fishing practices on seabird populations. We interviewed fishermen, administered questionnaires, and made field-based observations to determine the extent to which artisanal fisheries interact with and affect seabirds in the fjords and channels of the Chonos archipelago in southern Chile. Our surveys indicated a positive perception of seabirds as useful indicators of marine productivity and in their role scavenging fish waste and discards associated with fishing operations. However, the surveys also revealed that fishermen routinely establish seasonal camps for collecting seabird eggs and adults for food or bait and introduce feral predators to seabird breeding colonies on islands. Understanding the traditional practices of fisher- men is critical for the future of community-based conservation of the regions marine resources and biodi-

Estructura del ensamble de peces costeros de los canales y fiordos de la zona central de la Patagonia chilena (48º-52ºS)

Resumen es: La costa de la zona central de la Patagonia (48°-52°S) representa un area particular para evaluar la diversidad y estructura del ensamble de peces, a cau...

Egg masses of the Patagonian squid ( Doryteuthis Amerigo gahi ) attached to giant kelp ( Macrocystis pyrifera ) in the sub-Antarctic ecoregion

Egg masses of the Patagonian squid Doryteuthis (Amerigo) gahi attached to giant kelp (Macrocystis pyrifera) in the Magellanic channels of the sub-Antarctic ecoregion in southern South America is documented for the first time. Of seven egg masses observed between 2008 and 2011, one was taken to the laboratory to be analysed and photographed. Comprising long transparent capsules containing eggs, the masses were strongly attached to the stipes of M. pyrifera. This macroalgae is a potentially important economic resource due to its multiple industrial uses; this study shows that it also serves an important ecological role as a spawning substrate for D. gahi.

Seasonal variations of the photosynthetic activity and pigment concentrations in different reproductive phases of Gigartina skottsbergii (Rhodophyta, Gigartinales) in the Magellan region, sub-Antarctic Chile

Seasonal environmental changes may significantly influence macroalgal diversity and biomass. Cryptogam species richness increases towards the poles, especially in sub-Antarctic environments. Yet, subpolar seaweed biodiversity and ecophysiology remain understudied even though it is essential for the management and sustainability of endemic species of significant economic interest (e.g., Gigartina skottsbergii). We evaluate the seasonality and ecophysiology of the different life phases of the rhodophyte G. skottsbergii by analyzing variation in fluorescence yield and photosynthetic pigment composition. There were significant seasonal differences in maximum relative electron transport rate (rETRmax) between gametophyte and tetrasporophyte phase, and between reproductive and vegetative specimens. Photosynthetic efficiency (α) was not significantly different between reproductive states of G. skottsbergii. We found significant differences in mean concentrations of allophycocyanin (APC), phycocyanin (PC), and chlorophyll a (Chl a) between gametophyte and tetrasporophyte phases. Results obtained provide new insight into seasonal acclimation patterns of an ecologically important species, which can be used for the design of appropriate management and cultivation strategies of G. skottsbergii towards the restoration of natural populations in fragile, subpolar regions where some of the last, relatively undisturbed communities of G. skottsbergii still remain.

Richness, systematics, and distribution of molluscs associated with the macroalga Gigartina skottsbergii in the Strait of Magellan, Chile: A biogeographic affinity study.

Abstract Knowledge about the marine malacofauna in the Magellan Region has been gained from many scientific expeditions that were carried out during the 19th century. However, despite the information that exists about molluscs in the Magellan Region, there is a lack of studies about assemblages of molluscs co-occurring with macroalgae, especially commercially exploitable algae such as Gigartina skottsbergii, a species that currently represents the largest portion of carrageenans within the Chilean industry. The objective of this study is to inform about the richness, systematics, and distribution of the species of molluscs associated with natural beds in the Strait of Magellan. A total of 120 samples from quadrates of 0.25 m2 were obtained by SCUBA diving at two sites within the Strait of Magellan. Sampling occurred seasonally between autumn 2010 and summer 2011: 15 quadrates were collected at each site and season. A total of 852 individuals, corresponding to 42 species of molluscs belonging to Polyplacophora (9 species), Gastropoda (24), and Bivalvia (9), were identified. The species richness recorded represents a value above the average richness of those reported in studies carried out in the last 40 years in sublittoral bottoms of the Strait of Magellan. The biogeographic affinity indicates that the majority of those species (38%) present an endemic Magellanic distribution, while the rest have a wide distribution in the Magellanic-Pacific, Magellanic-Atlantic, and Magellanic-Southern Ocean. The molluscs from the Magellan Region serve as study models for biogeographic relationships that can explain long-reaching patterns and are meaningful in evaluating possible ecosystemic changes generated by natural causes or related to human activities.

Estado actual del desarrollo de la ecología urbana en grandes ciudades del sur de Chile

RESUMEN Mediante una revision bibliografi ca se determino el estado actual del conocimiento sobre la ecologia urbana en las grandes ciudades del sur de Chile: Temuco, Valdivia, Osorno, Puerto Montt y Punta Arenas. Esta revision revelo la escasez de estudios sobre ecologia urbana en donde los procesos de urbanizacion se incrementan considerablemente, desconociendose los impactos que este fenomeno pueda generar sobre sus ecosistemas. Puerto Montt es la ciudad con mayor incremento poblacional urbano y, a la vez, la ciudad con menor cantidad y diversidad de estudios realizados. Los principales impactos generados por el proceso de urbanizacion sobre el paisaje son la contaminacion de cuencas hidrografi cas, contaminacion atmosferica, perdida de biodiversidad nativa y aumento de especies exoticas. Se entregan recomendaciones para aumentar y conservar la biodiversidad local dentro de los paisajes urbanos del sur de Chile, asi como tambien se senalan las lineas de investigacion necesarias por realizar.

Genetics, Gene Flow, and Glaciation: The Case of the South American Limpet Nacella mytilina

Glacial episodes of the Quaternary, and particularly the Last Glacial Maximum (LGM) drastically altered the distribution of the Southern-Hemisphere biota, principally at higher latitudes. The irregular coastline of Patagonia expanding for more than 84.000 km constitutes a remarkable area to evaluate the effect of Quaternary landscape and seascape shifts over the demography of near-shore marine benthic organisms. Few studies describing the biogeographic responses of marine species to the LGM have been conducted in Patagonia, but existing data from coastal marine species have demonstrated marked genetic signatures of post-LGM recolonization and expansion. The kelp-dweller limpet Nacella mytilina is broadly distributed along the southern tip of South America and at the Falkland/Malvinas Islands. Considering its distribution, abundance, and narrow bathymetry, N. mytilina represents an appropriate model to infer how historical and contemporary processes affected the distribution of intraspecific genetic diversity and structure along the southern tip of South America. At the same time, it will be possible to determine how life history traits and the ecology of the species are responsible for the current pattern of gene flow and connectivity across the study area. We conducted phylogeographic and demographic inference analyses in N. mytilina from 12 localities along Pacific Patagonia (PP) and one population from the Falkland/Malvinas Islands (FI). Analyses of the mitochondrial gene COI in 300 individuals of N. mytilina revealed low levels of genetic polymorphism and the absence of genetic differentiation along PP. In contrast, FI showed a strong and significant differentiation from Pacific Patagonian populations. Higher levels of genetic diversity were also recorded in the FI population, together with a more expanded genealogy supporting the hypothesis of glacial persistence of the species in these islands. Haplotype genealogy, and mismatch analyses in the FI population recognized an older and more complex demographic history than in PP. Demographic reconstructions along PP suggest a post-LGM expansion process (7.5 ka), also supported by neutrality tests, mismatch distribution and maximum parsimony haplotype genealogies. Migration rate estimations showed evidence of asymmetrical gene flow from PP to FI. The absence of genetic differentiation, the presence of a single dominant haplotype, high estimated migration rates, and marked signal of recent demographic growth, support the hypothesis of rapid post-glacial expansion in N. mytilina along PP. This expansion could have been sustained by larval and rafting-mediated dispersal of adults from northernmost populations following the Cape Horn Current System. Marked genetic differentiation between PP and FI could be explained through differences in their respective glacial histories. During the LGM, Pacific Patagonia (PP) was almost fully covered by the Patagonian Ice Sheet, while sheet coverage in the FI ice was restricted to small cirques and valleys. As previously recorded in the sister-species N. magellanica, the FI rather than represent a classical glacial refugium for N. mytilina, seems to represent a sink area and/or a secondary contact zone. Accordingly, historical and contemporary processes, contrasting glacial histories between the analyzed sectors, as well as life history traits constitute the main factors explaining the current biogeographical patterns of most shallow Patagonian marine benthic organisms.

Ciclos de vida de insectos dulceacuícolas y cambio climático global en la ecorregión subantártica de Magallanes: investigaciones ecológicas a largo plazo en el Parque Etnobotánico Omora, Reserva de Biosfera Cabo de Hornos (55° S)

El Parque Etnobotanico Omora, ubicado en la ecorregion subantartica y en la Reserva de Biosfera Cabo de Hornos (55° S) es el sitio mas austral de la red LTSER-Chile. El Parque protege la cuenca hidrografica del rio Robalo, que provee de agua a Puerto Williams, la capital de la Provincia Antartica Chilena. El ano 2008, se inicio un estudio a largo plazo sobre la diversidad, historias de vida y distribucion de insectos acuaticos asociados al rio Robalo, y otros cursos de agua en la isla Navarino. Estos estudios son de gran interes para la red LTSER-Chile y la ciencia mundial por tres razones: 1) las caracteristicas climaticas unicas de los ecosistemas dulceacuicolas de la ecorregion subantartica de Magallanes, que contrastan con aquellas del Hemisferio Norte; 2) las respuestas de los insectos dulceacuicolas y sus ciclos de vida son muy sensibles a la temperatura, y bajo condiciones de gradientes termicos del gradiente altitudinal del rio Robalo se pueden hacer predicciones bajo distintos escenarios de Cambio Climatico Global; y 3) los ciclos de vida de insectos dulceacuicolas han sido muy poco estudiados en el suroeste de Sudamerica, e incorporando el gradiente latitudinal con estudios similares de respuestas fenologicas de los insectos dulceacuicolas incorporando otros sitios de la Red LTSER-Chile permitiria evaluar senales tempranas de esta biota al cambio climatico global.