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Variabilidad poblacional en Fisiología de pingüinos en la Península Antártica: Patrones de titudinales y predicciones en un escenario de cambio climático.
Expone: Dr. Andrés Barbosa, Museo Nacional de Ciencias Naturales, CSIC
Autores: Andrés Barbosa(1,2), María José Palacios (2), Francisco Valera (2), Jesús Benzal (2), José Javier Cuervo (1), Josabel Belliure (3), Eva De Mas (2), Julia I. Diaz (4), Veronica D’Amico (5), Virginia Vidal (6), Juana Ortiz (6), Nestor Coria (7), Mercedes Santos (7), Miguel Motas (8), Silvia Jerez (8), Ana Martinez (9), Olga Dolnik (10), Juan José Negro (11), Susana Pedraza (12), Luis Ortega-Mora (12), Francisco Javier Garcia-Peña (13), Santiago Merino (1), Javier Martinez (14), Carlos de la Cruz (15), Carmen Carrillo (2)
(1) Dept. Ecología Evolutiva. Museo Nacional de Ciencias Naturales, CSIC. C/José Gutierrez Abascal, 2. 28806 Madrid, (2) Dept. Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas, CSIC, La Cañada de San Urbano - Almeria, (3) Dept. Ecologia. Universidad Alcala de Henares, Madrid, (4) Centro de Estudios Parasitológicos y de Vectores (CCT-CONICET-UNLP), La Plata, Argentina, (5) Cent
La península antártica y en concreto la costa oeste, es uno de los lugares del planeta donde más y más rápidamente están aumentando las temperaturas debido al cambio climático. Este aumento de las temperaturas está provocando diferentes efectos en cascada tales como la disminución de la concentración y extensión de hielo marino durante el invierno, la disminución de la producción de fitoplancton, la reducción de la abundancia de krill y como consecuencia una reducción de las poblaciones de dos de las especies de pingüinos pigoscélidos que habitan la región como son el pingüino de Adelia (Pygoscelis adeliae) y el pingüino barbijo (Pygoscelis antarctica), a diferencia de lo que ocurre con el pingüino papúa (Pygoscelis papua) el cual mantiene estables sus poblaciones o incluso en expansión. Sin embargo estos cambios no se dan por igual en la región norte y en la sur de la península antártica, siendo especialmente intensos en la zona norte. Por otra parte, dichas regiones muestran un diferencia de temperatura de 2,5ºC. Estas características junto con una mayor actividad humana en la región norte ya sea por el establecimiento de un mayor número de estaciones científicas o por la mayor presencia de turistas, establece un gradiente latitudinal que puede afectar a los pingüinos de diferente manera a lo largo de la península. En los últimos años dentro de las actividades del proyecto PINGUCLIM, hemos llevado a cabo 5 expediciones a bordo del buque Las Palmas en las que se han muestreado 6 poblaciones de las tres especies de pingüinos pigoscélidos. A partir de las ellas se han determinado las variaciones geográficas existentes en diferentes aspectos de su fisiología, desde la variación en la presencia/ausencia de parásitos y patógenos, su respuesta inmunitaria, las variaciones en la dieta, variación en compuestos incorporados en la dieta y con importancia fisiológica como carotenos, la expresión de rasgos indicadores de calidad como la coloración del pico en el caso del pingüino papúa, variación en la presencia de contaminantes y por último variaciones en indicadores de estrés ambiental. Los resultados en general confirman la presencia de claros gradientes latitudinales mostrando en la región norte de la península antártica mayor abundancia y riqueza de parásitos, mayores valores en los parámetros inmunitarios estudiados, mayores niveles de carotenos y coloración del pico en el pingüino papua y unos mayores niveles de metales pesados. Estos resultados permiten establecer predicciones de la dirección del cambio en estas variables si las temperaturas continúan incrementándose debido al cambio climático.
The ESASSI project: shelf-slope interactions in the South Scotia Ridge region
Expone: Dr. Damià Gomis, IMEDEA, Universitat de les Illes Balears - CSIC
Autores: D. Gomis (1), M. Flexas (1), M. Palmer (1), G. Jordà (1), A. H. Orsi (2), S. A. Yvon-Lewis (2)
(1) IMEDEA (Univ. de les Illes Balears - CSIC), Mallorca, Spain, (2) Texas A&M University, College Station, USA
Ecosystem modelling, validation, and network characteristics of the Ross Sea, Antarctica
Expone: Dr. M.H. Pinkerton, National Institute of Water and Atmospheric Research, New Zealand
Autores: M.H. Pinkerton (1), J. Bradford-Grieve (1) (1) National Institute of Water and Atmospheric Research (NIWA), Private Bag 14901, Wellington 6241, New Zealand
The Ross Sea, Antarctica has been affected by human activity probably less than any other ocean in the world and may represent the last opportunity to observe a continental shelf ecosystem with its full complement of piscine predators. The Ross Sea has the most extensive continental shelf in Antarctic waters and mainly because of this is a major hotspot for species such as Adelie penguins, crystal krill, Antarctic toothfish, and Antarctic silverfish. We present an end-to-end food web model of the Ross Sea and validation data derived from the recent New Zealand International Polar Year Census of Antarctic Marine Life (IPY-CAML) voyage to the Ross Sea. End to end trophic models have several purposes: (1) to force the critical assembly of data on all components of the ecosystem in a form where they may be combined; (2) to test whether our current understanding of the ecosystem structure and function is complete and internally consistent; (3) to formalise our conceptual model of ecosystem interconnectedness, requiring explicit acknowledgement of assumptions and parameterisations; (4) to characterise the ecosystem and facilitate between-ecosystem comparisons. Information required to develop end-to-end models is typically incomplete. A novel method is presented to adjust the initial parameter set to give a balanced model taking into account the estimates of parameter uncertainty and the large range of magnitude (>6 orders of magnitude) in trophic flows between groups. Using the new method, parameters for biomass, production rate, growth efficiency, diet fractions, and other transfers of biomass between groups were adjusted simultaneously. We found that changes to the initial set of parameters needed to obtain balance were reasonably small. Data for the validation of the trophic model of the Ross Sea were collected during the New Zealand IPY-CAML survey of the Ross Sea region in February/March 2008. Diet and trophic linkages of species were measured by two approaches: (1) gut contents analysis, especially of the fish community; (2) stable isotope analysis. The former provides a detailed “snap-shot” of diet in terms of species, whereas the latter gives a longer-term average indication of trophic position. The stable isotope dataset includes more than a thousand measurements of demersal fishes (22 species), nearly 200 cephalopod samples, over 400 pelagic invertebrate samples, as well as samples of benthic invertebrates, phytoplankton and sedimentary organic material. We use the balanced and validated model to characterise the ecosystem of the Ross Sea in terms of factors such as proportion of top predators, total biomass, total net primary production, system throughput, trophic level transfer efficiency, omnivory indices, and relative ecological importance of species.
The ESASSI project is the Spanish contribution to the Synoptic Antarctic Shelf-Slope Interaction study (SASSI), one of the core projects of the International Polar Year. Major objectives of the project were: 1) To elucidate the fate of the Antarctic Slope Front (ASF) when it enters the South Scotia Ridge (SSR) from the Weddell Sea; the western coast of the Antarctic Peninsula is the only region in Antarctica where the ASF is not present, and the SSR region west of the South Orkney Islands is where the ASF gets lost. 2) To determine the export of renovated intermediate and deep waters from the Weddell Sea into the South Scotia Sea across the gaps of the SSR located to the west of the Orkney Islands. In that region the Weddell Gyre waters are shallower, colder and fresher than the waters that reach the eastern gaps of the SSR after surrounding the Orkney Plateau; hence, although in terms of volume the eastern gaps account for most of the export, in terms of the renovation of Scotia Sea waters the western gaps might play a significant role. 3) To characterize the role played by shelf-slope interactions in the fate of the ASF and in the exchange of heat, nutrients, and other biochemical parameters between the continental shelves and the open ocean. The ESASSI-08 oceanographic cruise carried out in January 2008 was the major milestone of ESASSI. The sampling strategy of the cruise consisted of 11 full-depth CTD sections across the northern and southern slopes of the SSR between Elephant and Orkney Islands and along-track ADCP measurements. The sections extended from shelf waters to open sea and the profiles were gathered at an unprecedented spatial resolution over the slope (about 2 nm). Water samples for chemical and biological analysis were also collected at each station; the analyzed parameters included water mass tracers (CFCs), dissolved oxygen, nutrients, and carbon-related parameters. Additionally, two moored lines equipped with T,S sensors and currentmeters were deployed on the northern flank of the SSR on February 2009 and recovered one year later. This presentation intends to be a summary of the work carried out so far. First we will show section distributions for the most important variables in order to draw an overall picture of the dynamics of the region. Then we will focus on the path of the ASF and suggest possible causes for the observed progressive weakening as it crosses the SSR. The quantification of the outflow of intermediate and deep waters has been addressed by applying an inverse model to temperature and salinity profiles initialized with ship ADCP velocities. From the output of the model we will give estimates of velocities and fluxes across different sections of the SSR and for different water masses. Finally, we will show some plots illustrating the temporal variability of shelf-slope interactions in the northern flank of the SSR.
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