Antarctic Science

The data presented provides new information on the distribution of Antarctic squids and on the summer diet of the emperor penguins. The diet of 58 adult emperor penguins (Aptenodytes forsteri) on the fast ice of the Drescher Inlet, Vestkapp Ice Shelf (72°52′S, 19°25′W) in the eastern Weddell Sea was investigated. Prey consisted principally of squid, fish, krill, amphipods and isopods. Squids were identified by the lower beaks and allometric equations were used to estimate the squid biomass represented. Beaks occurred in 93% of the stomach samples. Each sample contained a mean of 27 beaks (range 1–206). Ninety-two percent of the squids could be identified by the lower beaks and belonged to four families (Onychoteuthidae, Psychroteuthidae, Neoteuthidae and Gonatidae). The most abundant squid was Psychroteuthis glacialis which occurred in 52 samples with lower rostral lengths (LRL) ranging from 1.4–7.2 mm. Forty-five samples contained Alluroteuthis antarcticus (LRL range 1.8–5.8 mm), 1...

Reproductive allocation (reproductive biomass relative to vegetative biomass) and seed production were measured for samples of the two native phanerogams occurring in Antarctica. Material collected on South Georgia (subantarctic), Signy Island (northern maritime Antarctic) and Léonie Island (southern maritime Antarctic) allowed an initial comparison of reproduction over a wide latitudinal range. Sizes of vegetative and reproductive structures of Colobanthus quitensis were smaller in Signy Island samples than those from South Georgia or Léonie Island. This pattern was reflected in the pattern of seed production. Vegetative and reproductive structures of Deschampsia antarctica were generally similar in size at both maritime Antarctic sites, but larger at subantarctic South Georgia. Seed production was similar in each season assessed and at all three sites. In most samples of both species there were close relationships between reproductive and vegetative biomass, and seed output and re...

... It may also be used as a supplementary text on graduate courses concerned with high latitude geography, meteorology, and climatology. ERIK RASMUSSEN began his career as a meteorologist at the age of 17, in 1952, as flight forecaster in Kastrup Airport, Copenhagen. ...

"Como todos sabemos, hace unos 20.000 años el planeta vivió el Último Máximo Glacial. La Patagonia y gran parte de los Andes se cubrieron de hielo, Argentina y Brasil tuvieron climas templados: América entera fue como un soplo blanco y prolongado del polo sur. Hoy, pasados 20.000 años, la Antártica parece cubrirnos nuevamente, pero esta vez con la clara voz de la ciencia.

Se cumplen ya siete versiones de este encuentro de investigación polar latinoamericana, que naciera casi como la reunión de unos pocos locos interesados en la Antártica y que es ahora un congreso y con toda propiedad. Los títulos de los simposios que forman este congreso (Sistemas de observación antárticos terrestres y costeros; Genómica de microorganismos antárticos: avances y desafíos; Ecofisiología vegetal; Glaciología y Cambio Climático; Nuevos avances en el estudio de las aves antárticas; Evolución de la biota del Meso-Cenozoico; y Océano Austral) demuestran el alto nivel y especificidad que hemos alcanzado. Si a esto agregamos el número de trabajos presentados (más de 160) y la excelencia de las conferencias, podemos afirmar que el Congreso Latinoamericano de Ciencia Antártica tiene una calidad difícil de igualar.

Es paradójico que un lugar tan lejano como la Antártica sirva para congregar a personas de países tan diversos como Rusia, China, Corea del Sur, con quienes los países latinoamericanos suelen compartir en la isla Rey Jorge. Igual de curioso es que tengamos la misma blanca excusa para reunirnos como estamos haciendo ahora en la hermosa ciudad de La Serena. Junto al Congreso Latinoamericano tienen lugar otras reuniones que vale la pena nombrar: Reunión de la Red Latinoamericana de Microbiología Antártica, Reunión de la Red Latinoamericana de Investigación en Plantas Antárticas y Mesa Redonda de APECS Latinoamérica. También quisiera destacar que junto a este congreso, hemos organizado la XXIV Reunión de Administradores de Programas Antárticos Latinoamericanos (RAPAL), para que los diversos operadores tengan la oportunidad de interiorizarse en los temas y avances científicos polares y así cuenten con mayores antecedentes al momento de tomar decisiones que digan relación con el desarrollo de la actividad antártica futura.

Esta confluencia nos lleva a decir que la Antártica es nuestra ventana para ver el mundo. En realidad, no sólo para verlo, sino que para participar en él. Fenómenos como el agujero de ozono ayer y el calentamiento global hoy, han puesto los ojos del mundo en el Continente Blanco y nuestros países están contribuyendo, en una forma reconocida internacionalmente, al avance del conocimiento científico en estas problemáticas.

La vocación antártica de nuestros países nace, sin duda, de la cercanía que tenemos con dicho continente. Pero este es sólo un punto de partida. El desafío siguiente es asegurar que lo que hacemos en esas altas latitudes sea algo significativo para los ciudadanos de nuestros respectivos países (a fin de cuentas, son los principales financistas de nuestras tareas) y también para la comunidad internacional. El nivel de este congreso nos dice que vamos por buen camino, porque si establecemos reglas claras, que estimulen la competencia y el respeto por estándares reconocidos por la comunidad científica, entonces, los resultados serán de provecho no sólo para cada una de nuestras naciones, sino también para el amplio foro polar y científico.

Es una enorme alegría que en este congreso se premie el Espíritu Antártico del Dr. Francisco Hervé. Con “Pancho” hemos compartido muchas veces y en todas hemos aprendido algo. Su trayectoria ha sido ejemplar en cada uno de los aspectos de la vida académica: como científico, como profesor y como divulgador, además de ser una excelente persona. La geología y las ciencias de la Tierra en la Antártica no tendrían el desarrollo que tienen en Chile sin el aporte fundamental y prolongado del Dr. Hervé."

Little information is available regarding predator-prey interactions in High-Antarctic coastal systems. In this study, the predation of Trematomus bernacchii (Pisces: Nototheniidae) on Adamussium colbecki (Mollusca: Pectinidae) is described and the related impact on the population structure of the mollusc is hypothesized. Fishes and scallops were collected during several expeditions between 1990/91 and 1997/98 summers, in nearshore waters at Terra Nova Bay (Antarctica). Adamussium colbecki was the main food item of T. bernacchii and an ontogenetic prey-size selection was observed. The predation was mainly on medium size classes of the scallop. These were lacking in the A. colbecki population sampled in the same period suggesting that the impact of fish-feeding on the size structure of the natural population of the mollusc may be substantial. Two size classes of the Adamussium population were not preyed on. Large adults avoid predation either because of the limits for mouth gape in t...

A new basal actinopterygian fish, Donnrosenia schaefferi gen. et sp. nov., is described from the Middle Devonian (Givetian) Aztec Siltstone of southern Victoria Land, Antarctica. Donnrosenia gen. nov. is characterized by the large parietals which are of almost equivalent size to the frontals, very small
intertemporals, a small accessory operculum situated dorsally to the prominent anterodorsal process of the suboperculum, a deep dentary with anterior flexure, porous ornamentation on the clavicle, an elongate body form with macromeric squamation, an absence of paired fringing fulcra on the fins, and pectoral lepidotrichia which are unsegmented for much of their length. A phylogenetic analysis based on dermalskeletal features of Devonian actinopterygians indicates that Donnrosenia gen. nov. is the sister taxon to Howqualepis from the Middle Devonian of Victoria, Australia, and is embedded within a possible clade containing the actinopterygians from the Gogo Formation, Western Australia. This supports the concept of an endemic radiation of East Gondwanan actinopterygians, and reinforces the already strong biogeographical similarities between the Middle Devonian palaeofaunas of Australia and Antarctica.

The main water body at Hope Bay, Boeckella Lake, was sampled at four sites for phytoplankton during summer 1991 to assess the influence of nutrients from nearby penguin rookeries on both phytoplankton density and composition. The site located at the base of the rookeries had total phosphorus values comparable to those reported from the most eutrophic Antarctic lakes. During the ice-free period most of the Chlorophyceae and Cyanophyceae recorded were concentrated at this site. Phytoplankton density increased strongly in the area opposite to the rookeries where ice began to form; an under-ice bloom of Ochromonas aff. ovalis (Chrysophyceae) was observed in this area.

This overview examines available circum-Antarctic glacial history archives on land, related to developments after the Last Glacial Maximum (LGM). It considers the glacial-stratigraphic and morphologic records and also biostratigraphical information from moss banks, lake sediments and penguin rookeries, with some reference to relevant glacial marine records. It is concluded that Holocene environmental development in Antarctica differed from that in the Northern Hemisphere. The initial deglaciation of the shelf areas surrounding Antarctica took place before 10 000 14C yrs before present(BP), and was controlled by rising global sea level. This was followed by the deglaciation of some presently ice-free inner shelf and land areas between 10 000 and 8000 yr BP. Continued deglaciation occurred gradually between 8000 yr BP and 5000 yr BP. Mid-Holocene glacial readvances are recorded from various sites around Antarctica. There are strong indications of a circum-Antarctic climate warmer than...