Circulation of the Western Antarctic Peninsula: Implications for Biological Production

The western Antarctic Peninsula (wAP) continental shelf is characterized by large persistent populations of Antarctic krill ( Enphausia superba) and by regions of enhanced concentrations of marine mammals and other predators (hot spots). This study focused on understanding the role of ocean circulation in providing retention/connectivity of wAP Antarctic krill populations and in maintaining biological hot spot regions. Numerical Lagrangian particle tracking simulations obtained from the Regional Ocean Modeling System (ROMS) configured for the wAP region provided quantitative estimates of retention, immigration and emigration from the wAP continental shelf. Additional simulations with a one-dimensional temperature-dependent growth model for krill embryos and early larval stages allowed mapping of the Lagrangian trajectories into krill developmental stages. The simulated particle trajectories showed preferred sites for across-shelf transport, with Marguerite Trough being a primary pathway for movement into Marguerite Bay, Crystal Sound, and the inner shelf regions. Residence times for the biological hot spots were 18 to 27 days for Alexander Island and Crystal Sound and almost 35 days for Laubeuf Fjord (biological hot spot regions). Particles released in the Bellingshausen Sea (remote source) were transported to the wAP shelf with a time scale consistent with the time required for Antarctic krill embryos to develop into larvae (120 days). The trajectories of floats released along the wAP shelf inside the 500-in isobath (local source) showed retention times on the order of 3 months and low connectivity among different release sites on the mid to inner shelf, suggesting that local reproduction and development can be important contributors to wAP Antarctic krill populations. Successful completion of the descent-ascent cycle of Antarctic krill embryo-larvae occurred along the outer shelf and in shelf regions where bottom depths were greater than 500 m. Estimated residence times in these areas were 20–30 days, which suggests that krill spawned in the mid and inner shelf are retained in these regions through development to the first feeding stage (calyptopis I). These results suggest that wAP Antarctic krill populations along the outer and mid shelf may be dependent on inputs from upstream sources. Maintenance of populations confined to the inner shelf regions may be dependent on local processes. Simulated trajectories obtained for projected future environmental conditions suggested that the circulation would enhance advection of krill larvae to the shelf but that recruitment and reproduction may be altered, thereby impeding survival of Antarctic krill

Distributions of Krill and Antarctic Silverfish and Correlations with Environmental Variables in the Western Ross Sea, Antarctica

Antarctic krill Euphausia superba, crystal krill E. crystallorophias, and Antarctic silverfish Pleuragramma antarctica are key mid-trophic level species in the Ross Sea, connecting primary production to the upper trophic levels. Distributions of these species were constructed from observations made in the western Ross Sea from 1988 to 2004. Distributions of environmental conditions were obtained from a 5-km resolution circulation model (temperature, mixed layer depth, surface speed) and satellite-derived observations (chlorophyll, sea ice cover). A hierarchy of statistical methods determined correlations and relationships between species and environmental conditions. Each species occupies a localized habitat defined by different environmental characteristics. Antarctic krill are concentrated along the northwestern shelf break in a habitat characterized by deep (\u3e1000 m) bottom depth, warm temperature (1 to 1.25 degrees C), decreased sea ice, and proximity to the shelf break. Crystal krill and Antarctic silverfish are concentrated in Terra Nova Bay. Common characteristics of the habitat for these species are southwesterly location, coastal proximity, and cold temperature (-1.75 to -2 degrees C). The habitat characteristics obtained for the 3 species provide a basis for projecting potential distribution changes in response to environmental change and for delineating regions of the Ross Sea for focused management and selection of marine protected areas that support ecosystem-level conservation plans. © The authors 2017

General Hydrography of the Beagle Channel, a Subantarctic Interoceanic Passage at the Southern Tip of South America

The Beagle Channel (BC) is a long and narrow interoceanic passage (∼270 km long and 1–12 km wide) with west-east orientation and complex bathymetry connecting the Pacific and Atlantic oceans at latitude 55°S. This study is the first integrated assessment of the main oceanographic features of the BC, using recent oceanographic observations from cruises, moored instruments and historical observations. The waters transported into the BC are supplied mainly by the Cape Horn Current, which carries Subantarctic Water (SAAW) at depth (100 m below surface) along the Pacific Patagonian continental shelf break. SAAW enters the continental shelf via a submarine canyon at the western entrance of the BC. The SAAW is diluted by fresh, nutrient depleted (nitrate, phosphate and silicic acid) Estuarine Water (EW) from Cordillera Darwin Ice Field (CDIF) forming modified SAAW (mSAAW). Freshwater inputs from the CDIF generate a two-layer system with a sharp pycnocline which delimits the vertical distribution of phytoplankton fluorescence (PF). Two shallow sills (<70 m) along the BC contribute to EW and mSAAW mixing and the homogenization of the entire water column east of the sills, coherent with Bernoulli aspiration. The central section of the BC, extending ∼100 km toward the east, is filled by a salty (31–32) variety of EW. In winter, this central section is nearly vertically homogeneous with low nutrient concentrations (0.9–1.1 μM PO4 and 7.5–10 μM NO3) and PF. The temporal variability of seawater temperature from 50 to 195 m in the central section of the BC was found to be mostly dominated by the annual and semiannual cycles and influenced by tidal forcing. The middle section of the BC was less influenced by oceanic inputs and its basin-like structure most likely favors retention, which was observed from the weakly stratified water column at the mooring site. Toward the east, the central section bathymetry is disrupted at Mackinlay Strait where another shallow sill separates the middle channel from the shallow eastern entrance that connects to the Atlantic Ocean. In this section, a weakly stratified two-layer system is formed when the eastward surface outflow (salty-EW) flows over a deeper, denser tongue of oceanic mSAAW.Fil: Giesecke Astorga, Claudio Ricardo. Universidad Austral de Chile; ChileFil: Martín de Nascimento, Jacobo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; ArgentinaFil: Piñones, Andrea. Universidad Austral de Chile; ChileFil: Höfer, Juan. Pontificia Universidad Católica de Valparaíso; ChileFil: Garcés Vargas, Jose. Universidad Austral de Chile; ChileFil: Flores Melo, Elizabeth Ximena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Alarcón, Emilio. Universidad Austral de Chile; ChileFil: Durrieu de Madron, Xavier. Centre National de la Recherche Scientifique; FranciaFil: Bourrin, François. Centre National de la Recherche Scientifique; FranciaFil: González, Humberto E.. Universidad Austral de Chile; Chil

Competencias, TIC e Innovación. Nuevos escenarios para nuevos retos

[ES] Coordinadores: José Manuel Ríos Ariza y Julio Ruíz PalmeroISBN: 978‐84‐676‐5943‐6Depósito Legal: SE‐3771‐2011Editorial: MADAño de edición: 2011Nº Edición: 1ªLugar edición: Alcalá de Guadaíra (Sevilla)Nº páginas: 140Idioma: EspañolRaposo Rivas, M. (2012). Competencias, TIC e Innovación. Nuevos escenarios para nuevos retos. REDU. Revista de Docencia Universitaria. 10(2):467-470. https://doi.org/10.4995/redu.2012.6118OJS46747010

Observing change in pelagic animals as sampling methods shift: the case of Antarctic krill

Understanding and managing the response of marine ecosystems to human pressures including climate change requires reliable large-scale and multi-decadal information on the state of key populations. These populations include the pelagic animals that support ecosystem services including carbon export and fisheries. The use of research vessels to collect information using scientific nets and acoustics is being replaced with technologies such as autonomous moorings, gliders, and meta-genetics. Paradoxically, these newer methods sample pelagic populations at ever-smaller spatial scales, and ecological change might go undetected in the time needed to build up large-scale, long time series. These global-scale issues are epitomised by Antarctic krill (Euphausia superba), which is concentrated in rapidly warming areas, exports substantial quantities of carbon and supports an expanding fishery, but opinion is divided on how resilient their stocks are to climatic change. Based on a workshop of 137 krill experts we identify the challenges of observing climate change impacts with shifting sampling methods and suggest three tractable solutions. These are to: improve overlap and calibration of new with traditional methods; improve communication to harmonise, link and scale up the capacity of new but localised sampling programs; and expand opportunities from other research platforms and data sources, including the fishing industry. Contrasting evidence for both change and stability in krill stocks illustrates how the risks of false negative and false positive diagnoses of change are related to the temporal and spatial scale of sampling. Given the uncertainty about how krill are responding to rapid warming we recommend a shift towards a fishery management approach that prioritises monitoring of stock status and can adapt to variability and change

Observing change in pelagic animals as sampling methods shift: the case of Antarctic krill

Understanding and managing the response of marine ecosystems to human pressures including climate change requires reliable large-scale and multi-decadal information on the state of key populations. These populations include the pelagic animals that support ecosystem services including carbon export and fisheries. The use of research vessels to collect information using scientific nets and acoustics is being replaced with technologies such as autonomous moorings, gliders, and meta-genetics. Paradoxically, these newer methods sample pelagic populations at ever-smaller spatial scales, and ecological change might go undetected in the time needed to build up large-scale, long time series. These global-scale issues are epitomised by Antarctic krill (Euphausia superba), which is concentrated in rapidly warming areas, exports substantial quantities of carbon and supports an expanding fishery, but opinion is divided on how resilient their stocks are to climatic change. Based on a workshop of 137 krill experts we identify the challenges of observing climate change impacts with shifting sampling methods and suggest three tractable solutions. These are to: improve overlap and calibration of new with traditional methods; improve communication to harmonise, link and scale up the capacity of new but localised sampling programs; and expand opportunities from other research platforms and data sources, including the fishing industry. Contrasting evidence for both change and stability in krill stocks illustrates how the risks of false negative and false positive diagnoses of change are related to the temporal and spatial scale of sampling. Given the uncertainty about how krill are responding to rapid warming we recommend a shift towards a fishery management approach that prioritises monitoring of stock status and can adapt to variability and change

Vad innebär det att förskolans verksamhet ska vila på vetenskaplig grund? : En kvalitativ studie om förskollärares upplevelser och reflektioner

Introduction: What is meant by the need for education to rest on a scientific basis? According to Skolverket is at the heart of successful school development in education on scientific basis and proven experience. Theoretical starting points: In this section I will highlight the theoretical concepts that include in the work on the scientific basis. The theoretical concepts are: research-based approach, scientific basis, evidence, knowledge, systematic quality work, collegial learning, lifelong learning. Previous research: In this section I will explain what the research says that education should rest on a scientific basis. Then describe what the research says about school development. Then summarize Fröbels pedagogical philosophy and finally summarize the curriculum theory of the preschool. Forskningen säger att Purpose and issues: The purpose of this essay is to seek answers to what it means to preschool shall rest on a scientific basis and how to apply this to the business. Methods: The study is based on a qualitative data collection. The choice is based on the qualitative method is more appropriate for my study because the research question is about examining how preschool teachers perceive meaning with a scientific basis and how they understand their activities in relation to school laws and curriculum. Results: The result showed that preschool teachers experienced a lack of time, support from preschool managers and too little training. Also, the difficulty of transturning research into practice. Discussion: In the discussion section I discuss what came up in the results linked to previous research. I am debating that the results showed that in preschool It becomes more focus on the organizational, that the business will go around and work, instead of focusing on pedagogical issues and how to work research-based. Keywords: research-based approach, scientific basis, evidence, knowledge, systematic quality work, collegial learning, lifelong learnin

Modeling Environmental Controls on the Transport and Fate of Early Life Stages of Antarctic Krill (\u3cem\u3eEuphausia superba\u3c/em\u3e) on the Western Antarctic Peninsula Continental Shelf

A one-dimensional, temperature-dependent model was used to simulate the descent–ascent cycle of the embryos and early larval stages of Antarctic krill to determine which regions of the western Antarctic Peninsula (wAP) continental shelf support successful completion of this cycle under present environmental conditions and those projected to occur as a result of climate change. The transport and fate of the embryo and larva under present and modified conditions was investigated with Lagrangian particle tracking simulations. The two modeling studies were implemented using temperature and density (embryo–larva model) and circulation distributions (Lagrangian particle tracking) obtained from a high resolution version of the Regional Ocean Modeling System configured for the wAP shelf region. Additional simulations used temperature and circulation distributions obtained from simulations that were forced with increased wind speed and increased transport of the Antarctic Circumpolar Current (ACC), both projected to possibly occur with climate change in the wAP region. Simulations using present conditions showed that successful completion of the descent–ascent cycle occurred along the outer shelf and on the shelf in regions with bottom depths of 600–700 m. Estimated residence times for the shelf regions that support success of the embryo and larva were 20–30 days. Thus, krill spawned in the mid and inner shelf regions can be retained in these regions through development to the first feeding stage (calyptopis 1). Increased winds and ACC transport resulted in more onshelf transport of Circumpolar Deep Water (CDW), which increased the volume of warm (1–1.5 °C) water at depth. These conditions supported a moderate increase in success of the krill embryo and larva, but only for limited areas of the shelf where hatching depths decreased by 10–30 m

Modeling the remote and local connectivity of Antarctic Krill Populations along the Western Antarctic Peninsula

The abundance and distribution of Antarctic krill Euphausia superba over the western Antarctic Peninsula (wAP) continental shelf suggest that these populations are maintained by inputs from upstream sources via advection of individuals that originated in the Bellingshausen Sea, in addition to local spawning and retention. The objective of our study was to evaluate these 2 mechanisms (remote and local inputs) and the consequences for wAP Antarctic krill populations. The relative effect of local versus remote connectivity was investigated using Lagrangian particle tracking experiments. Particles released in the Bellingshausen Sea were transported to the wAP shelf in 120 d, which is consistent with the time required for Antarctic krill eggs to develop into late-stage larvae. An estimated 23% of the particles released along the shelf break crossed the outer shelf and were transported to the mid and inner regions of the wAP shelf via 3 pathways that provide conduits for onshore intrusions of Circumpolar Deep Water (CDW). Of the particles that moved onto the wAP shelf, 54% were transported to inner shelf regions that are associated with areas of enhanced biological production. Of the particles at the outer shelf ~33% continued transport northeastward with the Antarctic Circumpolar Current. Particles released in the mid and inner shelf showed limited connectivity and low export from the shelf (\u3c20%). The Lagrangian experiments indicate that Antarctic krill populations in the Marguerite Bay region of the wAP continental shelf are maintained by local and remote inputs of larvae. Regions influenced by intrusions of CDW are more dependent on remote inputs of Antarctic krill larvae

Tidally Forced Saltwater Intrusions might Impact the Quality of Drinking Water, the Valdivia River (40° S), Chile Estuary Case

The Valdivia River estuary (VRE) located in south-central Chile is known as one of the largest estuarine ecosystems on the Pacific coast. This research aims to determine the intra-tidal and sub-tidal variability of saline intrusions into the VRE between November 2017 and March 2019 derived from salinity sensors located along the VRE. Complementary hydrographic measurements were conducted during flood and ebb conditions of the spring and neap tides for each of the four seasons of the year along the central axis of the VRE. The results of the salinity time series showed that saline intrusions (values greater than 0.5 Practical Salinity Units) occurred ~20 km from the estuary mouth, when the total flow of the Cruces and Calle-Calle rivers (main tributaries of the estuary) was low, around 280&ndash;300 m3 s&minus;1. During the same period, the best co-variability was observed between the saline intrusions and the mixed-semidiurnal tide and the fortnightly and monthly periods of the tide. Regression analyses indicated that salinity intrusion length (L) is best correlated to discharge (D) with a fractional power model L &alpha; D&minus;1/2.64 (R2 = 0.88). The decreasing discharge trend, found between 2008&ndash;2019, implies that saline water intrusions would negatively impact the Valdivia&rsquo;s main drinking water intake during the low rainfall season under future climate conditions