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The biogeographic history of the Southern Ocean (SO) fauna is complex and poorly studied, especially the areas of endemism. We reanalyzed the data of Marques & Peña Cantero (2010), along with other geographical records of endemic benthic hydroids below 45°S. A Parsimony Analysis of Endemicity (PAE) based on 5° latitude by 5° longitude matrix with 61 species resulted in eight areas of endemism. We discuss these results in the context of different hypotheses of the evolution of the SO fauna and previously proposed biogeography patterns.

Para emplear la captura por unidad de esfuerzo (CPUE) como índice de abundancia se debe realizar normalmente un proceso de estandarización que consiste en aislar desde las series de tiempo de CPUE todos aquellos efectos exógenos a las variaciones temporales de la abundancia. Dentro del conjunto de efectos exógenos, como aquellos generados por modificaciones en la eficiencia de las embarcaciones pesqueras, variaciones en las estrategias de pesca y variaciones ambientales, la elección de estos últimos ha sido considerada una de las etapas más difícil, arbitraria y menos documentada, debido a que los efectos ambientales varían en diferentes escalas temporales de forma autocorrelacionada y no aleatoria, influenciando a la CPUE por medio de un proceso causa-efecto. Los modelos de función de transferencia (MFT) fueron construidos para describir estadísticamente la relación causa-efecto entre dos series de tiempo y se proponen en este artículo como una herramienta valida para i) discriminar efectos ambientales que influencian la CPUE y ii) describir la forma en que estos efectos deben ser incluidos en un modelo lineal generalizado (MLG). Se analizó la CPUE de krill antartico para el período agosto 1989-julio 1999, y como posibles efectos causales el índice de Oscilación Antartico (IOA) y las Presiones Atmosféricas al Nivel del Mar (PANM). El MFT muestra que las PANM bajo un desfase anual (PANM12), influencian la CPUE de krill antartico; mientras que la IAO no tiene un efecto significativo. La utilización de la PANM12 en un MLG incrementó en 31% la explicación de la devianza respecto a la serie sin desfase. Se concluye que los MFT son herramientas promisorias para incluir efectos ambientales en la estandarización de la CPUE resultando en índices de abundancia menos sesgados y más precisos.The use of the catch per unit effort (CPUE) as an index of abundance usually requires a standardization process consisting of isolating all those exogenous factors from temporal variations in abundance from the CPUE time-series. These exogenous factors include those generated by modifications in fishery vessel efficiency, variations in fishing strategies, and environmental fluctuations. The selection of the latter has been considered to be one of the most difficult, arbitrary, and poorly documented stages since the environmental effects vary on different temporal scales in autocorrelated and non-random manners, influencing the CPUE through a cause-effect process. Transfer function models (TFM) were constructed to describe statistically the cause-effect relationship between two time-series and herein we propose that TFM are a valid tool for: i) discriminating environmental effects that influence the CPUE and ii) describing how these effects should be included in a generalized lineal model (GLM). We analyzed the Antarctic krill CPUE from August 1989 to July 1999, and as possible causal effects, the Antarctic Oscillation Index (AOI) and atmospheric pressure at sea level (APSL). TFM shows that the APSL, with an annual lag (APSL12), influences the CPUE of Antarctic krill, whereas the AOI did not have a significant effect. The use of APSL 12 in the GLM increased the explanation of the deviance by 31% as compared with the APSL with no lag. We concluded that TFM constitute a promising tool for including environmental effects in the standardization of the CPUE that would result in less biased and more accurate indexes of abundance.

The vast majority of the mid-ocean ridge system and of the continental margins around the globe have not yet been explored. A relatively small number of vent and seep sites have been analysed and are the focus of long-term research programmes. However, the exploration of new areas will certainly provide the discovery of new vent and seep sites. Furthermore, the study of these key locations will lead to the description of new species and improve our understanding of the abundance, diversity, and distribution of species from chemosynthetically-driven systems around the world's oceans. It is the aim of ChEss to develop an exploration field phase to discover new deep-water hydrothermal vents and cold seeps at key locations, to describe their fauna, and to study the processes driving these ecosystems. The main objective is to obtain a thorough understanding of the biogeography of chemosynthetic ecosystems at a global scale. This goal can only be reached through international cooperation, which will be coordinated by the ChEss scientific steering committee. The southern oceans are the less studied regions for deep-water chemosynthetic sites. Mainly, the Indian Ocean Ridges, the southern Mid-Atlantic Ridge, the East Scotia Ridge, and the Chile Rise for vents; and the continental margins of Brazil, Peru, Chile and Africa for seeps, are crucial for the biogeographic puzzle of chemosynthetic systems.La mayor parte del sistema de dorsales oceánicas y los márgenes continentales de nuestro planeta todavía no han sido explorados. Un número limitado de fuentes hidrotermales y frías han sido estudiadas y son el objeto de programas de investigación a largo término. Sin embargo, la exploración de nuevas áreas quimiosintéticas llevará sin lugar a dudas a descubrir nuevas fuentes hidrotermales y coladuras frías. Además, el estudio de estas localidades llevará a descripciones de nuevas especies, así como a un mayor y más completo conocimiento sobre la abundancia, la diversidad y la distribución de especies de sistemas quimiosintéticos, alrededor de los oceános del mundo. Uno de los componentes principales de ChEss es un programa de campo a largo término para el descubrimiento y la exploración de nuevas fuentes hidrotermales y surgencias frías en áreas claves, así como la descripción de su fauna y el estudio de los procesos que dirigen a dichas comunidades. El objetivo principal es obtener un conocimiento sólido sobre la biogeografía de ecosistemas quimiosintéticos de profundidad a escala global. Este objetivo sólo se puede alcanzar a través de cooperación internacional, la cual será coordinada por el comité científico internacional de ChEss. En cuanto a sistemas quimiosintéticos de profundidad se refiere, los océanos del hemisferio sur engloban las regiones menos exploradas del planeta. Las dorsales del Océano Indico, el sur de la dorsal Atlántica, la dorsal ártica de Scotia y la dorsal de Chile para fuentes hidrotermales, así como los márgenes continentales de Brasil, Perú, Chile y Africa para surgencias frías, son esenciales para resolver el puzle biogeográfico de sistemas quimiosintéticos.

The biogeographic history of the Southern Ocean (SO) fauna is complex and poorly studied, especially the areas of endemism. We reanalyzed the data of Marques & Peña Cantero (2010), along with other geographical records of endemic benthic hydroids below 45ºS. A Parsimony Analysis of Endemicity (PAE) based on 5º latitude by 5º longitude matrix with 61 species resulted in eight areas of endemism. We discuss these results in the context of different hypotheses of the evolution of the SO fauna and previously proposed biogeography patterns. [ABSTRACT FROM AUTHOR]

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The article presents a research study on subantarctic rocky reef communities. It describes the community structure in the Magellan Strait in the Magellan Region and the South Shetland Islands in Antarctica. Results comparing community characteristics on benthic assemblages in these sites are offered, discussing the physical structure, dominant macroalgae and sessile community structure. It explores the significance of the study on extending ecological studies of seaweed forests in the northern hemisphere sites.

The use of the catch per unit effort (CPUE) as an index of abundance usually requires a standardization process consisting of isolating all those exogenous factors from temporal variations in abundance from the CPUE time-series. These exogenous factors include those generated by modifications in fishery vessel efficiency, variations in fishing strategies, and environmental fluctuations. The selection of the latter has been considered to be one of the most difficult, arbitrary, and poorly documented stages since the environmental effects vary on different temporal scales in autocorrelated and non-random manners, influencing the CPUE through a cause-effect process. Transfer function models (TFM) were constructed to describe statistically the cause-effect relationship between two time-series and herein we propose that TFM are a valid tool for: i) discriminating environmental effects that influence the CPUE and ii) describing how these effects should be included in a generalized lineal model (GLM). We analyzed the Antarctic krill CPUE from August 1989 to July 1999, and as possible causal effects, the Antarctic Oscillation Index (AOI) and atmospheric pressure at sea level (APSL). TFM shows that the APSL, with an annual lag (APSL12), influences the CPUE of Antarctic krill, whereas the AOI did not have a significant effect. The use of APSL12 in the GLM increased the explanation of the deviance by 31% as compared with the APSL with no lag. We concluded that TFM constitute a promising tool for including environmental effects in the standardization of the CPUE that would result in less biased and more accurate indexes of abundance. [ABSTRACT FROM AUTHOR]