Artículos de revistas: "Patagonia fjords"

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Díaz-Rosas, Francisco, Catharina Alves-de-Souza, Emilio Alarcón, Eduardo Menschel, Humberto E. González, Rodrigo Torres y Peter von Dassow. "Abundances and morphotypes of the coccolithophore <i>Emiliania huxleyi</i> in southern Patagonia compared to neighbouring oceans and Northern Hemisphere fjords". Biogeosciences 18, n.º 19 (8 de octubre de 2021): 5465–89. http://dx.doi.org/10.5194/bg-18-5465-2021.

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Abstract. Coccolithophores are potentially affected by ongoing ocean acidification, where rising CO2 lowers seawater pH and calcite saturation state (Ωcal). Southern Patagonian fjords and channels provide natural laboratories for studying these issues due to high variability in physical and chemical conditions. We surveyed coccolithophore assemblages in Patagonian fjords during late spring 2015 and early spring 2017. Surface Ωcal exhibited large variations driven mostly by freshwater inputs. High-Ωcal conditions (max. 3.6) occurred in the Archipelago Madre de Dios. Ωcal ranged from 2.0–2.6 in the western Strait of Magellan and 1.5–2.2 in the inner channel and was subsaturating (0.5) in Skyring Sound. Emiliania huxleyi was the only coccolithophore widely distributed in Patagonian fjords (> 96 % of total coccolithophores), only disappearing in the Skyring Sound, a semi-closed mesohaline system. Correspondence analysis associated higher E. huxleyi biomasses with lower diatom biomasses. The highest E. huxleyi abundances in Patagonia were in the lower range of those reported in Norwegian fjords. Predominant morphotypes were distinct from those previously documented in nearby oceans but similar to those of Norwegian fjords. Moderately calcified forms of E. huxleyi A morphotype were uniformly distributed throughout Patagonia fjords. The exceptional R/hyper-calcified coccoliths, associated with low Ωcal values in Chilean and Peruvian coastal upwellings, were a minor component associated with high Ωcal levels in Patagonia. Outlying mean index (OMI) niche analysis suggested that pH and Ωcal conditions explained most variation in the realized niches of E. huxleyi morphotypes. The moderately calcified A morphotype exhibited the widest niche breadth (generalist), while the R/hyper-calcified morphotype exhibited a more restricted realized niche (specialist). Nevertheless, when considering an expanded sampling domain, including nearby southeast Pacific coastal and offshore waters, even the R/hyper-calcified morphotype exhibited a higher niche breadth than other closely phylogenetically related coccolithophore species. The occurrence of E. huxleyi in naturally low pH–Ωcal environments indicates that its ecological response is plastic and capable of adaptation.

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Dowdeswell, J. A., E. K. Dowdeswell y C. Rodrigo. "Pockmarks in the fjords of Chilean Patagonia". Geological Society, London, Memoirs 46, n.º 1 (2016): 109–10. http://dx.doi.org/10.1144/m46.159.

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Ross, Lauren, Iván Pérez-Santos, Brigitte Parady, Leonardo Castro, Arnoldo Valle-Levinson y Wolfgang Schneider. "Glacial Lake Outburst Flood (GLOF) Events and Water Response in A Patagonian Fjord". Water 12, n.º 1 (16 de enero de 2020): 248. http://dx.doi.org/10.3390/w12010248.

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As a result of climate change, the frequency of glacial lake outburst floods (GLOF) is increasing in Chilean Patagonia. Yet, the impacts of the flood events on the physics and biology of fjords is still unknown. Current velocities, density, in-situ zooplankton samples, and volume backscatter (Sv) derived from an acoustic profiler were used to explore the response of circulation and zooplankton abundance in a Patagonian fjord to GLOF events in 2010 and 2014. Maximum Sv was found both during the GLOFs and in late winter to early spring of 2010 and the fall and summer of 2014. The increase in Sv in late winter and spring of 2010 corresponded to multiple zooplankton species found from in-situ net sampling. In addition, diel vertical migrations were found during this seasonal increase both qualitatively and in a spectral analysis. Concurrently with zooplankton increases, wind forcing produced a deepening of the pycnocline. Zooplankton abundance peaked in the fjord when the pycnocline depth deepened due to wind forcing and throughout the entire spring season, indicating that mixing conditions could favor secondary production. These results were corroborated by the 2014 data, which indicate that weather events in the region impact both fjord physics and ecology.

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de la Torriente, Ana, Renato A. Quiñones, Diego A. Miranda-Urbina y Fidel Echevarría. "South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia". ICES Journal of Marine Science 67, n.º 2 (16 de octubre de 2009): 294–303. http://dx.doi.org/10.1093/icesjms/fsp235.

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Abstract de la Torriente, A., Quiñones, R. A., Miranda-Urbina, D. A., and Echevarría, F. 2010. South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia. – ICES Journal of Marine Science, 67: 294–303. The South American sea lion (Otaria flavescens) is a pinniped known to interact with fisheries, potentially damaging gear and lowering catches. Predation by O. flavescens and spiny dogfish (Squalus acanthias) on artisanal southern hake (Merluccius australis) catches in fjords of Chilean Patagonia is estimated and compared. Observations were made in the Gulf of Ancud and Comau Fjord in southern Chile from October 2005 to September 2006. Losses of southern hake catches to O. flavescens predation were 1.6% of the total catch of the species, and to spiny dogfish predation were slightly higher, at 3.3%. The predation of both species on southern hake catches varied throughout the year, but was lower in summer. Both predators showed a preference for adult southern hake over juveniles. There was no significant relationship between predation on southern hake catches by the sea lion and the availability of adult and juvenile southern hake on longlines (AHCL). However, there was a significant relationship (p < 0.05) between AHCL and spiny dogfish predation. Most O. flavescens interaction events (81.4%) were during longline retrieval. Our results showed minimal interactions between O. flavescens and the artisanal southern hake fishery in the area, so with the present abundance of O. flavescens, there is no justification for reducing the sea lion population by hunting.

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Soto, Eulogio H. y Guillermo San Martín. "New reports and a new species of Syllidae (Annelida) from Chilean Patagonia". Journal of the Marine Biological Association of the United Kingdom 98, n.º 7 (24 de julio de 2017): 1599–607. http://dx.doi.org/10.1017/s0025315417001242.

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The Syllidae subfamilies Eusyllinae, Anoplosyllinae and Autolytinae, as well as the incertae sedis genera (Aguado et al., 2012), were studied from samples collected in shallow water from fjords and channels in Chilean Patagonia. One new species Paraehlersia kawesqar sp. nov. is described. The genus Nudisyllis Knox & Cameron, 1970 is recorded for the first time for Chile, while the species Brachysyllis infuscata (Ehlers, 1901a) and Syllides japonica Imajima, 1966 are recorded for the first time for continental Chile. Finally, Syllides articulosa Ehlers, 1897 and Epigamia sp. are also reported. The majority of the species were found inside tubes of the polychaete worm Chaetopterus cf. variopedatus (Renier, 1804) – a new habitat for syllid polychaetes. This work is an important contribution to the knowledge of syllids in Chile and to the polychaete fauna of the Patagonian region generally.

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Viddi, Francisco A., Rodrigo Hucke-Gaete, Juan P. Torres-Florez y Sandra Ribeiro. "Spatial and seasonal variability in cetacean distribution in the fjords of northern Patagonia, Chile". ICES Journal of Marine Science 67, n.º 5 (10 de enero de 2010): 959–70. http://dx.doi.org/10.1093/icesjms/fsp288.

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Abstract Viddi, F. A., Hucke-Gaete, R., Torres-Florez, J. P., and Ribeiro, S. 2010. Spatial and seasonal variability in cetacean distribution in the fjords of northern Patagonia, Chile. – ICES Journal of Marine Science, 67: 959–970. Compared with other Chilean coastal areas, little is known about the diversity and distribution of cetaceans in northern Patagonian fjords. Between December 2000 and November 2001, surveys on platforms of opportunity were undertaken in southern Chile to evaluate species richness and the spatial and seasonal distribution of cetaceans. Nine species were recorded, blue, humpback, and minke whales, Peale's dolphin, Chilean dolphin, killer whale, false killer whale, bottlenose dolphin, and Cuvier's beaked whale. The pattern of cetacean distribution displayed significant seasonal differences, with most baleen whales (mysticetes) observed during late summer and autumn, and toothed cetaceans (odontocetes) mostly during spring. Generalized additive models, used to assess the spatial distribution of cetaceans, showed that mysticetes were distributed disproportionately along a north–south gradient, in open gulfs with oceanic influence, and close to shore. In contrast, odontocetes were observed mainly within narrow channels, areas with complex coastal morphology, peaking at different water depths. These findings, although from a single year of data, increase our understanding of habitat determinants of cetacean distribution in southern Chile. The results have the potential to be applied to coastal conservation and management in the region.

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Friedlander, Alan M., Enric Ballesteros, Jennifer E. Caselle, Mathias Hüne, Alyssa M. Adler y Enric Sala. "Patterns and drivers of benthic macroinvertebrate assemblages in the kelp forests of southern Patagonia". PLOS ONE 18, n.º 1 (6 de enero de 2023): e0279200. http://dx.doi.org/10.1371/journal.pone.0279200.

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The kelp forests of southern Patagonia have a large diversity of habitats, with remote islands, archipelagos, peninsulas, gulfs, channels, and fjords, which are comprised of a mixture of species with temperate and sub-Antarctic distributions, creating a unique ecosystem that is among the least impacted on Earth. We investigated the distribution, diversity, and abundance of marine macroinvertebrate assemblages from the kelp forests of southern Patagonia over a large spatial scale and examined the environmental drivers contributing to the observed patterns in assemblage composition. We analyzed data from 120 quantitative underwater transects (25 x 2 m) conducted within kelp forests in the southern Patagonian fjords in the Kawésqar National Reserve (KNR), the remote Cape Horn (CH) and Diego Ramírez (DR) archipelagos of southern Chile, and the Mitre Peninsula (MP) and Isla de los Estados (IE) in the southern tip of Argentina. We observed rich assemblages of macroinvertebrates among these kelp forests, with a total of 185 unique taxa from 10 phyla and 23 classes/infraorders across the five regions. The number of taxa per transect was highest at IE, followed by MP, CH, and KNR, with the lowest number recorded at DR. The trophic structure of the macroinvertebrate assemblages was explained mostly by wave exposure (28% of the variation), followed by salinity (12%) and the KNR region (11%). KNR was most distinct from the other regions with a greater abundance of deposit feeders, likely driven by low salinity along with high turbidity and nutrients from terrigenous sources and glacial melt. Our study provides the first broad-scale description of the benthic assemblages associated with kelp forests in this vast and little-studied region and helps to establish baselines for an area that is currently lightly influenced by local anthropogenic factors and less impacted by climate change compared with other kelp forests globally.

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SOTO, EULOGIO H. y GUILLERMO SAN MARTÍN. "Exogoninae (Annelida: Syllidae) from Chilean Patagonia". Zootaxa 4353, n.º 3 (24 de noviembre de 2017): 521. http://dx.doi.org/10.11646/zootaxa.4353.3.7.

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The subfamily Exogoninae was studied from samples collected in shallow waters of the fjords and channels of the Patagonian region of Chile. Two new species are described: Exogone yagan n. sp. and Erinaceusyllis carrascoi n. sp. The species Exogone heterosetoides, Erinaceusyllis bidentata and Erinaceusyllis perspicax are newly reported to Chile, as well as the genus Erinaceusyllis San Martín, 2005. Parapionosyllis brevicirra, Sphaerosyllis hirsuta and Salvatoria rhopalophora, n. comb., are also reported, with the latter redescribed. Finally, we redescribe Exogone anomalochaeta from Antarctica. Most of the species were found inside tubes of Chaetopterus cf. variopedatus; this habitat is new for Exogoninae. This research is a new taxonomic account of Syllidae in Chile and improves the knowledge of Exogoninae of the Patagonian region.

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Ahumada, Ramón, Elizabeth González, Christian Díaz y Nelson Silva. "Characterization of Baker Fjord region through its heavy metal content on sediments (Central Chilean Patagonia)". Latin American Journal of Aquatic Research 43, n.º 3 (23 de febrero de 2017): 581–87. http://dx.doi.org/10.3856/vol43-issue3-fulltext-20.

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The spatial distribution of heavy metals content (Ba, Cd, Cu, Pb, Sr and Zn) in sediments of the Baker Fjord and surrounding channels in the central region of the Chilean fjords (47°45'S, 48°15'S) is analyzed. The aim of the study was characterized the patterns of abundance and distribution of these metals in surface sediments. The area corresponds to a poorly studied zone with low human activity. Distribution patterns would be influenced by rainfall conditions (local erosion), fluvial (continental sediments carried by rivers), glacier (glacier flour) and estuarine circulation. Cluster analysis allows differentiation among the sampled sites and group with similar characteristics. Finally, the concentrations found were contrasted with average values of metamorphic rocks and show with some certainty that the values found for calendar for this area and the greatest concentrations are the result of natural enrichment.

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Medina-Vogel, Gonzalo, Carlos Calvo-Mac, Nicole Delgado-Parada, Gabriela Molina-Maldonado, Stephanie Johnson-Padilla y Paulette Berland-Arias. "Co-Occurrence Between Salmon Farming, Alien American Mink (Neogale vison), and Endangered Otters in Patagonia". Aquatic Mammals 49, n.º 6 (15 de noviembre de 2023): 561–68. http://dx.doi.org/10.1578/am.49.6.2023.561.

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The southern river otter (Lontra provocax) and the marine otter (Lontra felina) are endangered species that inhabit Chile. In southern Chile, both species cohabit with the American mink (Neogale vison), an invasive exotic species. The Chilean aquaculture industry has grown exponentially since the late 1980s, with salmon farming taking place from central Chile to the Patagonian fjords and channels. This study assessed co-occurrence between otters, mink, and aquaculture in Patagonia by (1) distributing a survey among workers, fisheries personnel, and aquaculture inspectors concerning observations of otters and mink inside or around aquaculture facilities and outcomes; and (2) a geographical assessment of distribution overlap between known otter territory and salmon farming-registered facilities. We recorded the first anecdotal evidence of interaction, described as co-occurrence, among native otters, American mink, and salmon aquaculture in Patagonia, which varied among seasons and seems to be increasing. We also recorded evidence of difficulty in recognition of the three mustelids among respondents. There is a geographically extended interaction between otters and salmon farms in Chile. The evidence of interaction among alien American mink, native endangered otters, and aquaculture is an early alarm for human–wildlife conflict, and further studies are recommended to ensure native otter conservation.

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Bao, Weiyang y Carlos Moffat. "Impact of shallow sills on circulation regimes and submarine melting in glacial fjords". Cryosphere 18, n.º 1 (9 de enero de 2024): 187–203. http://dx.doi.org/10.5194/tc-18-187-2024.

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Abstract. The increased melting and rapid retreat of marine-terminating glaciers is a key contributor to sea-level rise. In glacial fjords with shallow sills common in Patagonia, Alaska, and other systems, these bathymetric features can act as a first-order control on the dynamics. However, our understanding of how this shallow bathymetry interacts with the subglacial discharge from the glacier and impacts the fjord circulation, water properties, and rates of submarine melting is limited. To address this gap, we conduct idealized numerical simulations using a coupled plume–ocean fjord model spanning a wide range of initial ocean conditions, sill depths, and subglacial discharge. A previously documented circulation regime leads to strong mixing and vertical transport over the sill, where up to ∼ 70 % of the colder water from the upper-layer outflow is refluxed into the deeper layer, cooling the incoming warm oceanic water by as much as 1 ∘C and reducing the stratification near the glacier front. When the initial stratification is relatively strong or the subglacial discharge is relatively weak, an additional unsteady circulation regime arises where the freshwater flow can become trapped below the sill depth for weeks to months, creating an effective cooling mechanism for the deep water. We also find that submarine melting often increases when a shallow sill is added to a glacial fjord due to the reduction of stratification – which increases submarine melting – dominating over the cooling effect as the oceanic inflow is modified by the presence of the sill. These results underscore that shallow-silled fjords can have distinct dynamics that strongly modulate oceanic properties and the melting rates of marine-terminating glaciers.

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Cuevas, María José, Konrad Górski, Leonardo R. Castro, Aurélien Vivancos y Malcolm Reid. "Otolith elemental composition reveals separate spawning areas of anchoveta, Engraulis ringens, off central Chile and northern Patagonia". Scientia Marina 83, n.º 4 (3 de diciembre de 2019): 317. http://dx.doi.org/10.3989/scimar.04918.28a.

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The anchoveta (Engraulis ringens) is widely distributed throughout the Humboldt Current (4°30′-44°S). In recent years, its eggs and larvae have also been found inside fjords and channels of northern Patagonia, close to the southern limit of the central-south Chilean fishery zone. Currently, it is unclear whether these southern individuals constitute an independent subpopulation. This study analysed the elemental composition of otoliths from 102 specimens from central Chile and northern Patagonia using laser ablation inductively coupled plasma mass spectrometry. The results indicated that the elemental composition of the otolith cores (Mg, Pb, Zn, Ba) differed significantly between sites, revealing the existence of two discrete spawning zones, one in central Chile and one in northern Patagonia. However, the low significant differences of elemental signatures of otolith edges suggest that either individuals from both areas move between spawning areas and mix at certain periods of the year, or they represent pocket units that form part of a larger stock that moves along the coast.

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Rebolledo, Lorena, Carina B. Lange, Sébastien Bertrand, Práxedes Muñoz, Marco Salamanca, Pablo Lazo, José L. Iriarte, Gabriel Vargas, Silvio Pantoja y Laurent Dezileau. "Late Holocene precipitation variability recorded in the sediments of Reloncaví Fjord (41°S, 72°W), Chile". Quaternary Research 84, n.º 1 (julio de 2015): 21–36. http://dx.doi.org/10.1016/j.yqres.2015.05.006.

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We present reconstructions of late Holocene changes in the source of organic matter and siliceous export production in the Relocanví Fjord (41°S, 72°W), Northern Chilean Patagonia, based on organic carbon content, δ13Corg, N/C ratio, diatom assemblages and biogenic silica contents from three sediment cores. The age models are based on a combination of 210Pb profiles, AMS 14C dating, and on the first occurrence of the diatom Rhizosolenia setigera f. pungens, as a stratigraphic marker in the fjords. The cores span the last 300 to 700 yr. Diatoms dominate the siliceous assemblages in the three cores (98% on average). Our results suggest that precipitation seasonality in the region of Reloncaví was high in CE 1300–1400 and CE 1700–1850, with a clear decreasing trend since CE 1850. The latter trend is in agreement with instrumental records and tree-ring reconstructions. These fluctuations seem to be associated with the Southern Annular Mode (SAM).

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Capella, Juan J., José Z. Abramson, Yerko A. Vilina y Jorge Gibbons. "Observations of killer whales (Orcinus orca) in the fjords of Chilean Patagonia". Polar Biology 37, n.º 10 (3 de julio de 2014): 1533–39. http://dx.doi.org/10.1007/s00300-014-1535-5.

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Castillo-Hidalgo, Gissella, Mauricio F. Landaeta, Eduardo Anaya-Godínez y Claudia A. Bustos. "Larval fish assemblages from channels and fjords of south Pacific Patagonia: effects of environmental conditions". Revista de Biología Marina y Oceanografía 53 (1 de agosto de 2018): 39. http://dx.doi.org/10.22370/rbmo.2018.53.0.1253.

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Chilean Patagonian fjords are characterized by strong stratification and chemical gradients which influence the ichthyoplankton distribution and abundance. Plankton samples were collected through bongo net oblique tows in 40 stations from onboard a bio-oceanographic cruise took place in inner fjords of southern Chile (47° to 51°S). Water column physical data were obtained with a conductivity-temperature-depth profiler (CTD) and turbidity was measured with a portable turbidimeter from 0 to 100 m depth. Stations were distributed by three zones: oceanic, channels and continental waters. A total of 1424 larvae were collected, representing 21 families. Dominant taxa were Maurolicus parvipinnis (31%), Sebastes oculatus (12%), Merluccius australis (11%), Lampanyctodes hectoris (10%), and Bathylagichthys parini (8%). Most of the environmental variability was determined by salinity, mainly in the area where continental waters are discharged. The water column in the oceanic zone presented mixed waters dominated by the myctophid L. hectoris and the sternoptychid M. parvipinnis. No significant effect of turbidity gradients on larval fish assemblages was evident during spring. The channel zone was both more saline, and density stratified with less turbidity, and lower abundance of species. Two ichthyoplanktonic assemblages were evident, one living in oceanic waters, and the other from channels and inner zones.

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Pérez-Santos, Iván, Leonardo Castro, Lauren Ross, Edwin Niklitschek, Nicolás Mayorga, Luis Cubillos, Mariano Gutierrez et al. "Turbulence and hypoxia contribute to dense biological scattering layers in a Patagonian fjord system". Ocean Science 14, n.º 5 (9 de octubre de 2018): 1185–206. http://dx.doi.org/10.5194/os-14-1185-2018.

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Abstract. The aggregation of plankton species along fjords can be linked to physical properties and processes such as stratification, turbulence and oxygen concentration. The goal of this study is to determine how water column properties and turbulent mixing affect the horizontal and vertical distributions of macrozooplankton along the only northern Patagonian fjord known to date, where hypoxic conditions occur in the water column. Acoustic Doppler current profiler moorings, scientific echo-sounder transects and in situ plankton abundance measurements were used to study macrozooplankton assemblages and migration patterns along Puyuhuapi Fjord and Jacaf Channel in Chilean Patagonia. The dissipation of turbulent kinetic energy was quantified through vertical microstructure profiles collected throughout time in areas with high macrozooplankton concentrations. The acoustic records and in situ macrozooplankton data revealed diel vertical migrations (DVM) of siphonophores, chaetognaths and euphausiids. In particular, a dense biological backscattering layer was observed along Puyuhuapi Fjord between the surface and the top of the hypoxic boundary layer (∼100 m), which limited the vertical distribution of most macrozooplankton and their DVM, generating a significant reduction of habitat. Aggregations of macrozooplankton and fishes were most abundant around a submarine sill in Jacaf Channel. In this location macrozooplankton were distributed throughout the water column (0 to ∼200 m), with no evidence of a hypoxic boundary due to the intense mixing near the sill. In particular, turbulence measurements taken near the sill indicated high dissipation rates of turbulent kinetic energy (ε∼10-5 W kg−1) and vertical diapycnal eddy diffusivity (Kρ∼10-3 m2 s−1). The elevated vertical mixing ensures that the water column is well oxygenated (3–6 mL L−1, 60 %–80 % saturation), creating a suitable environment for macrozooplankton and fish aggregations. Turbulence induced by tidal flow over the sill apparently enhances the interchange of nutrients and oxygen concentrations with the surface layer, creating a productive environment for many marine species, where the prey–predator relationship might be favored.

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Iriarte, José L., Silvio Pantoja y Giovanni Daneri. "Oceanographic Processes in Chilean Fjords of Patagonia: From small to large-scale studies". Progress in Oceanography 129 (diciembre de 2014): 1–7. http://dx.doi.org/10.1016/j.pocean.2014.10.004.

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Palma, Sergio, María Cristina Retamal, Nelson Silva y Antonio Canepa. "Siphonophores in fjords and channels in southern Patagonia: biodiversity, spatial distribution and environmental association". Journal of the Marine Biological Association of the United Kingdom 98, n.º 2 (20 de octubre de 2016): 245–59. http://dx.doi.org/10.1017/s0025315416001302.

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This study characterizes the abundance and spatial distribution of siphonophores between the Trinidad Channel (50°06′S) and the Strait of Magellan (52°45′S) in southern Chile, during October–November 2009. Ten species were identified, of which Agalma elegans, Rosacea plicata and Sphaeronectes fragilis are new records for this region. Dominant species showed similar dominance values e.g. Lensia conoidea (26.3%), Dimophyes arctica (24.6%), Lensia meteori (22.2%) and Muggiaea atlantica (20.7%). Eudoxids of L. conoidea and D. arctica represented 97.3% of all eudoxids collected and they were mainly collected in estuarine waters. The highest densities were found in estuarine waters (high vertical stratification and low temperature, salinity and dissolved oxygen values). On the other hand, the lowest densities were found in coastal areas influenced by permanent influx of Sub-Antarctic waters from the Pacific (greater instability and vertical mixing, higher temperatures, salinity and dissolved oxygen values). Temperature and dissolved oxygen were the most important environmental variables. In general, all the dominant species showed a positive association with temperature and a negative association with dissolved oxygen (with the exception of L. meteori). The vertical distribution showed that M. atlantica was mainly distributed in the first 50 m, in association with estuarine waters, while L. conoidea, L. meteori and D. arctica were mainly found in the deeper layer (50–200 m) and in association with modified Sub-Antarctic waters. The comparison of the results obtained in the springs of 1996 and 2009 showed a significant increase in abundance.

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Friedlander, Alan M., Enric Ballesteros, Whitney Goodell, Mathias Hüne, Alex Muñoz, Pelayo Salinas-de-León, Catalina Velasco-Charpentier y Enric Sala. "Marine communities of the newly created Kawésqar National Reserve, Chile: From glaciers to the Pacific Ocean". PLOS ONE 16, n.º 4 (14 de abril de 2021): e0249413. http://dx.doi.org/10.1371/journal.pone.0249413.

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The newly created Kawésqar National Park (KNP) and National Reserve (KNR) in southern Chile consists of diverse terrestrial and marine habitats, which includes the southern terminus of the Andes, the Southern Patagonia Ice Fields, sub-Antarctic rainforests, glaciers, fjords, lakes, wetlands, valleys, channels, and islands. The marine environment is influenced by wide ranging hydrological factors such as glacier melt, large terrigenous inputs, high precipitation, strong currents, and open ocean water masses. Owing to the remoteness, rugged terrain, and harsh environmental conditions, little is known about this vast region, particularly the marine realm. To this end, we conducted an integrated ecological assessment using SCUBA and remote cameras down to 600 m to examine this unique and largely unexplored ecosystem. Kelp forests (primarily Macrocystis pyrifera) dominate the nearshore ecosystem and provide habitat for myriad benthic organisms. In the fjords, salinity was low and both turbidity and nutrients from terrigenous sources were high, with benthic communities dominated by active suspension feeders (e.g., Bivalvia, Ascidiacea, and Bryozoa). Areas closer to the Pacific Ocean showed more oceanic conditions with higher salinity and lower turbidity, with benthic communities experiencing more open benthic physical space in which predators (e.g., Malacostraca and Asteroidea) and herbivorous browsers (e.g., Echinoidea and Gastropoda) were more conspicuous components of the community compared to the inner fjords. Hagfish (Myxine sp.) was the most abundant and frequently occurring fish taxa observed on deep-sea cameras (80% of deployments), along with several taxa of sharks (e.g., Squaliformes, Etmopteridae, Somniosidae, Scyliorhinidae), which collectively were also observed on 80% of deep-sea camera deployments. The kelp forests, deep fjords, and other nearshore habitats of the KNR represent a unique ecosystem with minimal human impacts at present. The KNR is part of the ancestral territory of the indigenous Kawésqar people and their traditional knowledge, including the importance of the land-sea connection in structuring the marine communities of this region, is strongly supported by our scientific findings.

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Briceño, Cristóbal, Leslie A. Knapp, Alejandra Silva, José Paredes, Iván Avendaño, Aliro Vargas, Juan Sotomayor y Alejandro R. Vila. "Detecting an increase in an Endangered huemul Hippocamelus bisulcus population following removal of cattle and cessation of poaching in coastal Patagonia, Chile". Oryx 47, n.º 2 (abril de 2013): 273–79. http://dx.doi.org/10.1017/s0030605312000014.

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AbstractThe conservation of threatened species poses many challenges but through cooperation and pooling of resources, individuals and organizations can work together to achieve better results. Here we describe our experience, working through a governmental and private alliance, studying one of the most threatened mammals in the Southern Cone. The huemul deer Hippocamelus bisulcus, one of two members of the Hippocamelus genus of South America, is endemic to Argentina and Chile and currently inhabits only a small fraction of its former range. Little is known about the huemul because it generally lives in remote areas with a harsh climate and rugged terrain. Using drive counts and fixed width transects over 5 consecutive years (2004–2008) we estimated density and abundance, and examined population changes and social structure, in three coastal huemul populations in the area of the Témpanos and Bernardo fjords of Bernardo O'Higgins National Park, Chile. Our results suggest that synergistic conservation actions, such as cattle removal and poaching control, can lead to the recovery of threatened huemul. The baseline information obtained from our surveys and the lessons learned through this governmental and private alliance will be useful for future monitoring of the huemul in the Patagonian fjords of Chile.

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Pineda-Metz, Santiago E. A. y Américo Montiel. "Seasonal dynamics of meroplankton in a sub-Antarctic fjord (Southern Patagonia, Chile)". Polar Biology 44, n.º 5 (30 de marzo de 2021): 875–86. http://dx.doi.org/10.1007/s00300-021-02823-6.

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AbstractKnowledge of seasonal dynamics and composition of meroplankton (larvae of benthic invertebrates) is rather limited for sub-Antarctic regions. We studied the seasonal dynamics of meroplankton in a sub-Antarctic proglacial basin (Gallegos Sound, Chile), by examining changes in the meroplankton community in relation to hydrographic variables along four sampling cruises between early winter 2010 and late winter 2011. The local meroplankton community was composed of 39 larval morphotypes distributed among 11 major taxa, being polychaetes the best represented (15 larvae morphotypes), and bivalve the most abundant. We found distinct seasonal differences in terms of meroplanktonic composition and abundance, with higher abundance and larval morphotype number during austral spring and late winter, and lower in summer and early winter. The pattern observed for meroplankton was directly related to seasonal variations of fluorescence of chlorophyll a and temperature. We found meroplankton abundances lower than those of other sub- and Polar environments. However, meroplanktonic temporal dynamics showed a common pattern for sub- and Polar fjords, suggesting a strong link between benthic spawning and the occurrence of phytoplankton blooms.

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22

Suazo, Cristián G., Roberto P. Schlatter, Aldo M. Arriagada, Luis A. Cabezas y Jaime Ojeda. "Fishermen's perceptions of interactions between seabirds and artisanal fisheries in the Chonos archipelago, Chilean Patagonia". Oryx 47, n.º 2 (abril de 2013): 184–89. http://dx.doi.org/10.1017/s0030605311001815.

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AbstractInteractions 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 fishermen is critical for the future of community-based conservation of the region's marine resources and biodiversity.

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23

Quiroga, Eduardo, Paula Ortiz, Brian Reid y Dieter Gerdes. "Classification of the ecological quality of the Aysen and Baker Fjords (Patagonia, Chile) using biotic indices". Marine Pollution Bulletin 68, n.º 1-2 (marzo de 2013): 117–26. http://dx.doi.org/10.1016/j.marpolbul.2012.11.041.

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24

Valdés-Castro, Valentina, Humberto E. González, Ricardo Giesecke, Camila Fernández y Verónica Molina. "Assessment of Microbial Community Composition Changes in the Presence of Phytoplankton-Derived Exudates in Two Contrasting Areas from Chilean Patagonia". Diversity 14, n.º 3 (7 de marzo de 2022): 195. http://dx.doi.org/10.3390/d14030195.

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Patagonian fjords and channels in southern Chile are heterogeneous ecosystems characterized by the interaction of estuarine and marine waters influencing physical-chemical conditions and biological assemblages. Besides salinity, microbial communities from estuarine and marine origin are naturally subjected to changing organic matter quality and variable nutrient concentrations. In this study, we tackle the response of the bacterial community from estuarine and marine origins associated with two size classes (<0.7 µm and <1.6 µm) to the addition of sterile phytoplankton-derived exudates (PDE) compared to control conditions (no addition). Picoplanktonic cell abundance, active bacterial composition analyzed through 16S rRNA sequencing, changes in dissolved organic carbon (DOC) and δ13C were determined over 5 and 15 days after PDE addition. Our results showed that the active marine bacteria were richer and more diverse than their estuarine counterparts, and were dominated by Alphaproteobacteria and Gammaproteobacteria, respectively. PDE addition in both the fractions and the sample origin resulted in an enrichment throughout the incubation of Rhodobacteracea and Cryimorphaceae families, whereas Epsilonproteobacteria (Arcobacteraceae) were mainly favored in the estuarine experiments. Picoplankton abundance increased with time, but higher cell numbers were found in PDE treatments in both size classes (>2 × 105 cell mL−1). In all the experiments, DOC concentration decreased after eight days of incubation, but shifts in δ13C organic matter composition were greater in the estuarine experiments. Overall, our results indicate that despite their different origins (estuarine versus marine), microbial communities inhabiting the fjord responded to PDE with a faster effect on marine active bacteria.

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25

Meier, Aravena, Grießinger, Hochreuther, Soto-Rogel, Zhu, Pol-Holz, Schneider y Braun. "Late Holocene Glacial Fluctuations of Schiaparelli Glacier at Monte Sarmiento Massif, Tierra del Fuego (54°24′S)". Geosciences 9, n.º 8 (3 de agosto de 2019): 340. http://dx.doi.org/10.3390/geosciences9080340.

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The Magallanes–Tierra del Fuego region, Southern Patagonia (53–56°S) features a plethora of fjords and remote and isolated islands, and hosts several thousand glaciers. The number of investigated glaciers with respect to the multiple Neoglacial advances is based on a few individual studies and is still fragmentary, which complicates the interpretation of the glacial dynamics in the southernmost part of America. Schiaparelli Glacier (54°24′S, 70°50′W), located at the western side of the Cordillera Darwin, was selected for tree-ring-based and radiocarbon dating of the glacial deposits. One focus of the study was to address to the potential dating uncertainties that arise by the use of Nothofagus spp. as a pioneer species. A robust analysis of the age–height relationship, missing the pith of the tree (pith offset), and site-specific ecesis time revealed a total uncertainty value of ±59 years. Three adjacent terminal moraines were identified, which increasingly tapered towards the glacier, with oldest deposition dates of 1749 ± 5 CE, 1789 ± 5 CE, and 1867 ± 5 CE. Radiocarbon dates of trunks incorporated within the terminal moraine system indicate at least three phases of cumulative glacial activity within the last 2300 years that coincide with the Neoglacial phases of the Southern Patagonian Icefield and adjacent mountain glaciers. The sub-recent trunks revealed the first evidence of a Neoglacial advance between ~600 BCE and 100 CE, which so far has not been substantiated in the Magallanes–Tierra del Fuego region.

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26

Hüne, Mathias, Alan M. Friedlander, Enric Ballesteros, Jennifer E. Caselle y Enric Sala. "Assemblage structure and spatial diversity patterns of kelp forest-associated fishes in Southern Patagonia". PLOS ONE 16, n.º 9 (20 de septiembre de 2021): e0257662. http://dx.doi.org/10.1371/journal.pone.0257662.

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Knowledge of the ecology of the fish fauna associated with kelp (primarily Macrocystis pyrifera) forests in Southern Patagonia is scarce, especially in how abiotic and biotic variables influence their structure, diversity, and distribution. This information is important for the management and conservation of this unique ecosystem, which has minimal anthropogenic impacts at present. We analyzed data from 122 quantitative underwater transects conducted within kelp forests at 61 stations from Chile’s southern Patagonian fjords to the Cape Horn and Diego Ramirez archipelagos and the southern tip of Argentina, including the Mitre Peninsula and Isla de los Estados. In total, 25 fish species belonging to 13 families were observed. Multivariate analysis indicated that there are significant differences in fish assemblage structure among locations and wave exposures, which was driven primarily by Patagonotothen sima and Paranotothenia magellanica, which occurred on exposed and semi-exposed stations. P. cornucola was mainly distributed across sheltered stations of the Kawésqar National Park. Temperature, salinity, depth, and kelp density influenced fish assemblage structure, with the highest diversity in areas with the lowest temperature and greater depth at Isla de los Estados. In contrast, species richness, diversity, abundance, and biomass were all lower in areas with high density of the understory kelp Lessonia spp., which might be driven by the absence of P. tessellata, P. squamiceps and P. cornucola, the most important species in terms of occurrence, abundance, and biomass. Our study provides the first broad-scale description of the fish assemblages associated with kelp forests along the southern cone of South America based on non-invasive visual transects, improving our knowledge of the distribution of fish assemblages across several environmental conditions in this vast and little-studied area.

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27

Toledo, Pamela, Edwin J. Niklitschek, Audrey M. Darnaude, Félix P. Leiva, Chris Harrod, Sergio Lillo, Vilma Ojeda et al. "The trophic ecology of partial migration: insights from Merluccius australis off NW Patagonia". ICES Journal of Marine Science 77, n.º 5 (18 de junio de 2020): 1927–40. http://dx.doi.org/10.1093/icesjms/fsaa065.

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Abstract Partial migration, where migrant and resident organisms coexist within the same population, has been found in many fishes. Although it seems obvious that different life cycles exploit habitats and food webs differently, few assessments about the trophic consequences of partial migration are available. To unveil part of this complexity, we combined otolith chemistry with stable isotope analyses data for hind-casting Merluccius australis habitat use and diet composition at age. By providing detailed information about lifetime variability in diet, trophic position, and prey demand of four M. australis life-cycle types, we show that these groups feed differentially in estuarine and oceanic habitats throughout their ontogeny. Although trophic positions were similar between habitats for juvenile and subadults, substantial differences between life-cycle types were found regarding lifetime diet and trophic demand. Thus, the more abundant and heavily exploited oceanic stock of M. australis was heavily dependent of estuarine habitats within the Patagonian Fjords System, where it consumes large biomasses of Macruronus magellanicus, Pasiphaea, Sprattus fuegensis, and Euphausiidae at earlier stages. We show ignoring trophic consequences of partial migration and life-cycle diversity may produce highly biased results, both in terms of prey and habitat use, which appears critical for multispecies and ecosystem management approaches.

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28

Mata Almonacid, Pablo y Carolina Medel. "A structure-preserving model for the dynamics of estuarine ecosystems and its application in western Patagonia fjords". Ecological Modelling 466 (abril de 2022): 109871. http://dx.doi.org/10.1016/j.ecolmodel.2021.109871.

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29

Wiff, Rodrigo, Andrés Flores, Angel M. Segura, Mauricio A. Barrientos y Vilma Ojeda. "Otolith shape as a stock discrimination tool for ling (Genypterus blacodes) in the fjords of Chilean Patagonia". New Zealand Journal of Marine and Freshwater Research 54, n.º 2 (12 de diciembre de 2019): 218–32. http://dx.doi.org/10.1080/00288330.2019.1701047.

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30

Försterra, Günter, Vreni Häussermann y Carsten Lüter. "Mass occurrence of the recent brachiopodMagellania venosa(Terebratellidae) in the fjords Comau and Reñihué, northern Patagonia, Chile". Marine Ecology 29, n.º 3 (septiembre de 2008): 342–47. http://dx.doi.org/10.1111/j.1439-0485.2008.00240.x.

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31

Vásquez, Sebastián I., María Belén de la Torre, Gonzalo S. Saldías y Aldo Montecinos. "Meridional Changes in Satellite Chlorophyll and Fluorescence in Optically-Complex Coastal Waters of Northern Patagonia". Remote Sensing 13, n.º 5 (9 de marzo de 2021): 1026. http://dx.doi.org/10.3390/rs13051026.

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Northern Patagonia is one of the largest estuarine systems worldwide. It is characterized by complex geography, including islands, peninsulas, channels, and fjords. Here, the Inner Sea of Chiloé (ISC) is the largest estuarine system extending about 230 km in the meridional direction. Phytoplankton’s long-term dynamics and the main physical drivers of their variability are not well understood yet. Time-space fluctuations of Chlorophyll-a (Chl-a) and Chlorophyll fluorescence (nFLH) within the ISC and their association with meteorological and oceanographic processes were analyzed using high resolution (1000 m) satellite data (2003–2019). Our results revealed a meridional Chl-a and nFLH gradient along the ISC, with higher concentrations north of the Desertores islands where the topography promotes a semi-closed system with estuarine characteristics yearlong. Satellite Chl-a and nFLH were characterized by asynchronous seasonal cycles (nFLH peaks in fall) that differed from the southern ISC where the maximum Chl-a and nFLH occurs in spring-summer. The adjacent coastal ocean influences the southern ISC, and thus, the Chl-a and nFLH variability correlated well with the seasonal variation of meridional winds. The northern ISC was clearly influenced by river discharges, which can bias the Chl-a retrievals, decoupling the annual cycles of Chl-a and nFLH. In situ data from a buoy in Seno Reloncaví reaffirmed this bias in satellite Chl-a and a higher correlation with nFLH, by which the construction of a local Chl-a algorithm for northern Patagonia is essential.

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González, H. E., L. Castro, G. Daneri, J. L. Iriarte, N. Silva, C. A. Vargas, R. Giesecke y N. Sánchez. "Seasonal plankton variability in Chilean Patagonia fjords: Carbon flow through the pelagic food web of Aysen Fjord and plankton dynamics in the Moraleda Channel basin". Continental Shelf Research 31, n.º 3-4 (marzo de 2011): 225–43. http://dx.doi.org/10.1016/j.csr.2010.08.010.

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Garcı́a, Carlos, Viviana González, Carlos Cornejo, Hernán Palma-Fleming y Néstor Lagos. "First evidence of Dinophysistoxin-1 ester and carcinogenic polycyclic aromatic hydrocarbons in smoked bivalves collected in the Patagonia fjords". Toxicon 43, n.º 2 (febrero de 2004): 121–31. http://dx.doi.org/10.1016/j.toxicon.2003.10.028.

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34

Garcı́a, Carlos, Marı́a del Carmen Bravo, Marcelo Lagos y Néstor Lagos. "Paralytic shellfish poisoning: post-mortem analysis of tissue and body fluid samples from human victims in the Patagonia fjords". Toxicon 43, n.º 2 (febrero de 2004): 149–58. http://dx.doi.org/10.1016/j.toxicon.2003.11.018.

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35

Hüne, Mathias y Rodrigo Vega. "Spatial variation in the diet of Patagonotothen tessellata (Pisces, Nototheniidae) from the fjords and channels of southern Chilean Patagonia". Polar Biology 38, n.º 10 (10 de junio de 2015): 1613–22. http://dx.doi.org/10.1007/s00300-015-1726-8.

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36

Flores, Andrés, Rodrigo Wiff, Donald I. Brown y Sebastián Larrea-Meza. "Reproductive traits of female of pink cusk-eel (Genypterus blacodes Schneider, 1801) in the fjords of the Chilean Patagonia". Estuarine, Coastal and Shelf Science 233 (febrero de 2020): 106554. http://dx.doi.org/10.1016/j.ecss.2019.106554.

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37

Seguel, Miriam, Carlos Molinet, Manuel Díaz, Gonzalo Álvarez, Carlos García, Andrés Marín, María Olga Millanao y Patricio A. Díaz. "Paralytic Shellfish Toxins in the Gastropod Concholepas concholepas: Variability, Toxin Profiles and Mechanisms for Toxicity Reduction". Marine Drugs 21, n.º 1 (6 de enero de 2023): 44. http://dx.doi.org/10.3390/md21010044.

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Harmful algal blooms of toxin-producing microalgae are recurrent in southern Chile. Paralytic shellfish poisoning (PSP) outbreaks pose the main threat to public health and the fishing industry in the Patagonian fjords. This study aims to increase understanding of the individual and spatial variability of PSP toxicity in the foot of Concholepas concholepas, Chile’s most valuable commercial benthic invertebrate species, extracted from the Guaitecas Archipelago in Chilean Patagonia. The objective is to determine the effect of pigment removal and freezing during the detoxification process. A total of 150 specimens (≥90 mm length) were collected from this area. The live specimens were transferred to a processing plant, where they were measured and gutted, the foot was divided into two equal parts, and pigment was manually removed from one of these parts. The PSP toxicity of each foot (edible tissue) was determined by mouse bioassay (MBA) and high-performance liquid chromatography with fluorescence detection and postcolumn oxidation (HPLC-FLD PCOX). The individual toxicity per loco, as the species is known locally, varied from <30 to 146 μg STX diHCL eq 100 g−1 (CV = 43.83%) and from 5.96 to 216.3 μg STX diHCL eq 100 g−1 (CV = 34.63%), using MBA and HPLC, respectively. A generalized linear model showed a negative relation between individual weight and toxicity. The toxicological profile showed a dominance of STX (>95%), neoSTX and GTX2. The removal of pigment produced a reduction in PSP toxicity of up to 90% and could represent a good detoxification tool moving forward. The freezing process in the muscle with pigment did not produce a clear pattern. There is a significant reduction (p < 0.05) of PSP toxicity via PCOX but not MBA. Furthermore, the study discusses possible management and commercialization implications of the findings regarding small-scale fisheries.

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Cuevas, L. Antonio, Fabián J. Tapia, José Luis Iriarte, Humberto E. González, Nelson Silva y Cristian A. Vargas. "Interplay between freshwater discharge and oceanic waters modulates phytoplankton size-structure in fjords and channel systems of the Chilean Patagonia". Progress in Oceanography 173 (abril de 2019): 103–13. http://dx.doi.org/10.1016/j.pocean.2019.02.012.

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39

Contreras, Tabit, Leonardo R. Castro, Sandra Montecinos, Humberto E. Gonzalez, Samuel Soto, Maria I. Muñoz y Sergio Palma. "Environmental conditions, early life stages distributions and larval feeding of patagonian sprat Sprattus fuegensis and common sardine Strangomera bentincki in fjords and channels of the northern Chilean patagonia". Progress in Oceanography 129 (diciembre de 2014): 136–48. http://dx.doi.org/10.1016/j.pocean.2014.10.005.

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40

Bertrand, Sébastien, Konrad A. Hughen, Julio Sepúlveda y Silvio Pantoja. "Geochemistry of surface sediments from the fjords of Northern Chilean Patagonia (44–47°S): Spatial variability and implications for paleoclimate reconstructions". Geochimica et Cosmochimica Acta 76 (enero de 2012): 125–46. http://dx.doi.org/10.1016/j.gca.2011.10.028.

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WILLENZ, PHILIPPE, ALEXANDER V. ERESKOVSKY y DENNIS V. LAVROV. "Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia". Zootaxa 4208, n.º 6 (21 de diciembre de 2016): 501. http://dx.doi.org/10.11646/zootaxa.4208.6.1.

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A series of recent expeditions in fjords and canals of Southern Chilean Patagonia allowed the re-collection of Halisarca magellanica Topsent, 1901 and the discovery of a new species, Halisarca desqueyrouxae sp. nov. The material studied was collected at depths ranging from 3 to 30 m at latitudes comprised between 42° and 49°S. Both species share the same habitat and show a morphological plasticity, but differ in their colour. Halisarca magellanica is bright pink to whitish with three morphs whereas H. desqueyrouxae sp. nov. is light brown to beige with two morphs. An extensive investigation in TEM and SEM reveals several differences among cell types with inclusions between both species. Three distinct spherulous cells occur. Type 1 is shared by both species, Type 2 is occasional in H. magellanica but absent from H. desqueyrouxae sp. nov. Type 3 is rare in H. magellanica and occurs abundantly in half of the specimens of H. desqueyrouxae sp. nov. Granular cells are shared by both species but do not occur in all specimens. Microgranular cells are characteristic of H. magellanica. Both species also clearly differ by their endobiotic bacteria. Phylogenetic analysis of cox1 sequences places H. magellanica as a sister group to all other previously published Halisarca species sequences (9.1–9.7% difference) except H. harmelini, while H. desqueyrouxae sp. nov. is placed as a sister group to H. dujardini (2.3% difference).

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Wiff, Rodrigo, Andrés Flores, Dante Queirolo, Mauricio Ahumada, Pedro Apablaza, Santiago Gacitúa, José T. Montero, Stefan Gelcich, Felipe Torres Cañete y Mauricio Lima. "A survey-based approach to constructing an abundance index of the pink cusk-eel (Genypterus blacodes) in the fjords of Chilean Patagonia". Regional Studies in Marine Science 39 (septiembre de 2020): 101445. http://dx.doi.org/10.1016/j.rsma.2020.101445.

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43

Sepúlveda, Julio, Silvio Pantoja y Konrad A. Hughen. "Sources and distribution of organic matter in northern Patagonia fjords, Chile (∼44–47°S): A multi-tracer approach for carbon cycling assessment". Continental Shelf Research 31, n.º 3-4 (marzo de 2011): 315–29. http://dx.doi.org/10.1016/j.csr.2010.05.013.

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Vandekerkhove, Elke, Sébastien Bertrand, Brian Reid, Astrid Bartels y Bernard Charlier. "Sources of dissolved silica to the fjords of northern Patagonia (44-48°S): the importance of volcanic ash soil distribution and weathering". Earth Surface Processes and Landforms 41, n.º 4 (14 de octubre de 2015): 499–512. http://dx.doi.org/10.1002/esp.3840.

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45

Sauter, Tobias. "Revisiting extreme precipitation amounts over southern South America and implications for the Patagonian Icefields". Hydrology and Earth System Sciences 24, n.º 4 (23 de abril de 2020): 2003–16. http://dx.doi.org/10.5194/hess-24-2003-2020.

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Abstract. Patagonia is thought to be one of the wettest regions on Earth, although available regional precipitation estimates vary considerably. This uncertainty complicates understanding and quantifying the observed environmental changes, such as glacier recession, biodiversity decline in fjord ecosystems and enhanced net primary production. The Patagonian Icefields, for example, are one of the largest contributors to sea-level rise outside the polar regions, and robust hydroclimatic projections are needed to understand and quantify current and future mass changes. The reported projections of precipitation from numerical modelling studies tend to overestimate those from in situ determinations, and the plausibility of these numbers has never been carefully scrutinized, despite the significance of this topic to our understanding of observed environmental changes. Here I use simple physical arguments and a linear model to test the plausibility of the current precipitation estimates and its impact on the Patagonian Icefields. The results show that environmental conditions required to sustain a mean precipitation amount exceeding 6.09±0.64 m yr−1 are untenable according to the regional moisture flux. The revised precipitation values imply a significant reduction in the surface mass balance of the Patagonian Icefields compared to previously reported values. This yields a new perspective on the response of Patagonia's glaciers to climate change and their sea-level contribution and might also help reduce uncertainties in the change of other precipitation-driven environmental phenomena.

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46

Linford, Pamela, Iván Pérez-Santos, Paulina Montero, Patricio A. Díaz, Claudia Aracena, Elías Pinilla, Facundo Barrera et al. "Oceanographic processes driving low-oxygen conditions inside Patagonian fjords". Biogeosciences 21, n.º 6 (20 de marzo de 2024): 1433–59. http://dx.doi.org/10.5194/bg-21-1433-2024.

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Abstract. The dissolved oxygen (DO) levels of coastal ocean waters have decreased over the last few decades in part because of the increase in surface and subsurface water temperature caused by climate change, the reduction in ocean ventilation, and the increase in stratification and eutrophication. In addition, biological and human activity in coastal zones, bays, and estuaries has contributed to the acceleration of current oxygen loss. The Patagonian fjord and channel system is one world region where low-DO water (LDOW, 30 %–60 % oxygen saturation) and hypoxia conditions (<30 % oxygen saturation, 2 mL L−1 or 89.2 µmol L−1) are observed. An in situ dataset of hydrographic and biogeochemical variables (1507 stations), collected from sporadic oceanographic cruises between 1970 and 2021, was used to evaluate the mechanisms involved in the presence of LDOW and hypoxic conditions in northern Patagonian fjords. Results denoted areas with LDOW and hypoxia coinciding with the accumulation of inorganic nutrients and the presence of salty and oxygen-poor Equatorial Subsurface Water mass. The role of biological activity in oxygen reduction was evident in the dominance of community respiration over gross primary production. This study elucidates the physical and biogeochemical processes contributing to hypoxia and LDOW in the northern Patagonian fjords, highlighting the significance of performing multidisciplinary research and combining observational and modeling work. This approach underscores the importance of a holistic understanding of the subject, encompassing both real-world observations and insights provided by modeling techniques.

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47

Hucke-Gaete, Rodrigo, Luis Bedriñana-Romano, Francisco A. Viddi, Jorge E. Ruiz, Juan Pablo Torres-Florez y Alexandre N. Zerbini. "From Chilean Patagonia to Galapagos, Ecuador: novel insights on blue whale migratory pathways along the Eastern South Pacific". PeerJ 6 (30 de abril de 2018): e4695. http://dx.doi.org/10.7717/peerj.4695.

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Background The most traditional scheme for migration among baleen whales comprises yearly migrations between productive waters at high latitude summer feeding grounds and warmer waters at lower latitudes where whales calve and mate, but rarely feed. Evidence indicates, however, that large departures from this scheme exist among populations and individuals. Furthermore, for some populations there is virtually no information on migratory pathways and destinations. Such is the case of Chilean blue whales throughout the Eastern South Pacific; hence, the goal of this study was to assess its migratory behavior. Methods Dedicated marine surveys and satellite tagging efforts were undertaken during the austral summer and early autumn on blue whale feeding grounds off Chilean Northern Patagonia (CNP) during 2013, 2015 and 2016. Positional data derived from satellite tags regarding movement patterns and behavior were analyzed using Bayesian switching first-difference correlated random walk models. Results We instrumented 10 CNP blue whales with satellite transmitters and documented individual variation in departure time, northbound migratory routes and potential wintering grounds. The onset of migration occurred from mid/late austral autumn to well into the austral winter. Blue whales moved in various directions, but ultimately converged toward a general NW movement direction along a wide corridor exceeding 2,000 km. Area-Restricted Search behavior was exhibited within fjords and channels of CNP and also South of Galapagos Archipelago (GA) and northern Peru, but never during migration. Interestingly, dive profiles for one whale that reached GA showed a sharp and consistent increase in depth north of 5°S and extreme deep dives of up to 330 m. Discussion Information derived from satellite tagged blue whales in this study is the first of its kind off the Eastern Southern Pacific. Our results provide valuable information on their migratory timing, routes and behavior on their northbound migration, particularly regarding the varied migratory plasticity for this particular population. Our results also highlight the first record of two complete migratory paths between CNP and GA and strengthen the hypothesis that GA waters correspond to a potential wintering destination for CNP blue whales. We further hypothesize that this area might be selected because of its biological productivity, which could provide feeding opportunities during the breeding season. Our results suggest that special efforts should be put forward to identify blue whale critical areas and understand key behavioral aspects in order to provide the basis for their conservation on a regional context (i.e., reducing potential ship strike and promote Marine Protected Area (MPA) implementation in Chile, Ecuador and Peru). Indeed, we suggest joint blue whale conservation efforts at the regional level in order to identify and determine potential threats and impacts and, most importantly, implement prospective management actions.

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Pérez-Santos, Iván, Romanet Seguel, Wolfgang Schneider, Pamela Linford, David Donoso, Eduardo Navarro, Constanza Amaya-Cárcamo, Elías Pinilla y Giovanni Daneri. "Synoptic-scale variability of surface winds and ocean response to atmospheric forcing in the eastern austral Pacific Ocean". Ocean Science 15, n.º 5 (16 de septiembre de 2019): 1247–66. http://dx.doi.org/10.5194/os-15-1247-2019.

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Abstract. In the Southern Hemisphere, macroscale atmospheric systems such as westerly winds and the southeast Pacific subtropical anti-cyclone (SPSA) influence the wind regime of the eastern austral Pacific Ocean. The average and seasonal behaviors of these systems are well known, although wind variability at different time and distance scales remains largely unexamined. Therefore, the main goal of this study was to determine the variabilities of surface winds on a spatiotemporal scale from 40 to 56∘ S, using QuikSCAT, Advanced Scatterometer (ASCAT), and the fifth major global European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA5) surface-wind information complemented with in situ meteorological data. In addition, interactions between the atmospheric systems, together with the ocean–atmosphere response, were evaluated for the period 1999–2018. The empirical orthogonal function detected dominance at the synoptic scale in mode 1, representing approximately 30 % of the total variance. In this mode, low and high atmospheric pressure systems characterized wind variability for a 16.5 d cycle. Initially, mode 2 – which represents approximately 22 % of the variance – was represented by winds from the west/east (43–56∘ S), occurring mostly during spring and summer/fall and winter at an annual timescale (1999–2008) until they were replaced by systems cycling at 27.5 d (2008–2015). This reflects the influence of the baroclinic annular mode in the Southern Hemisphere. Mode 3, representing approximately 15 % of the variance, involved the passage of small-scale low and high atmospheric pressure (LAP and HAP) systems throughout Patagonia. Persistent Ekman suction occurred throughout the year south of the Gulf of Penas and beyond the Pacific mouth of the Strait of Magellan. Easterly Ekman transport (ET) piled these upwelled waters onto the western shore of South America when winds blew southward. These physical mechanisms were essential in bringing nutrients to the surface and then transporting planktonic organisms from the oceanic zone to Patagonian fjords and channels. In the zonal band between 41 and 43∘ S, the latitude of Chiloé Island, upward Ekman pumping and Ekman transport during spring and summer favored a reduced sea surface temperature and increased chlorophyll a (Chl a) levels; this is the first time that such Ekman upwelling conditions have been reported so far south in the eastern Pacific Ocean. The influence of the northward-migrating LAP systems on the ocean–atmosphere interphase allowed us to understand, for the first time, their direct relationship with recorded nighttime air temperature maxima (locally referred to as “nighttime heatwave events”). In the context of global climate change, greater attention should be paid to these processes based on their possible impact on the rate of glacier melting and on the austral climate.

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49

Silva, Nelson y Cristian A. Vargas. "Hypoxia in Chilean Patagonian Fjords". Progress in Oceanography 129 (diciembre de 2014): 62–74. http://dx.doi.org/10.1016/j.pocean.2014.05.016.

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50

BERTOLINO, MARCO, GABRIELE COSTA, ANNA REBOA, GIORGIO BAVESTRELLO, MAURIZIO PANSINI, FEDERICO BETTI, MARZIA BO y GIOVANNI DANERI. "The sponge fauna of the Seno Magdalena and Puyuhuapi Fjord (Chile), with a description of two new species". Zootaxa 4623, n.º 2 (25 de junio de 2019): 306–20. http://dx.doi.org/10.11646/zootaxa.4623.2.5.

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The presence of fjords, islands and channels originating from glacial erosion and ice cap retreat, makes the Chilean benthic biodiversity difficult to explore and study. Our survey of this region allowed the identification of 29 Demospongiae species in total. Two of them are new to science and here described: Biemna lutea sp. nov., and Hamigera cleistochela sp. nov.. Two species (Clathria (Clathria) microxa and Lissodendoryx (Ectyodoryx) patagonica,) are new for the region and the Chilean fjords. Lissodendoryx (Ectyodoryx) patagonica was found for the second time after the original description by Ridley & Dendy, 132 years ago. These results – considering the small number of species identified on the whole – are promising and confirm that the marine biodiversity of Chilean fjords is remarkable but not well known yet.

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