Walter Sielfeld

Distribution and abundance of the South American sea lion Otaria flavescens (Carnivora: Otariidae) along the central coast off Chile

Se estimo la distribucion y la abundancia poblacional del lobo marino comun Otaria flavescens en la costa de Chile central durante los meses de enero y febrero de 2007. Adicionalmente, se analizaron los cambios en la abundancia de esta especie durante el periodo 1970-2007. Los censos poblacionales se basaron en fotografias tomadas desde embarcaciones menores o desde avionetas. Se contabilizaron un total de 16301 lobos marinos (IC = 16209-16375) en 33 colonias (6 reproductivas y 27 no reproductivas). Despues de corregir por la proporcion de animales en el agua y por crias no registradas al momento del censo, se estimo una abundancia promedio de 18179 (95 % CI = 17777-18851) lobos marinos en el area de estudio. El analisis de tendencia poblacional presento que desde 1970 a 1985 la abundancia-lobo marino com-mostro una tendencia positiva de aproximadamente 2.1 % ano-1. Sin embargo, entre 1985 a 1997, y entre 1997 a 2007, el numero de lobos marinos muestra una tendencia estable o ligeramente negativa de 0.4 ± 0.1 % ano-1 y 0.5 ± 0.1 % ano-1, respectivamente. Se sugiere que la sobreexplotacion y la declinacion de las principales pesquerias en la zona central de Chife podria haber impactado negativamente la distribucion y abundancia del lobo marino comun en el area de estudio.

Primer registro de Etropus ectenes Jordan, 1889, Bothus constellatus Jordan & Goss, 1889, Achirus klunzingeri (Steindachner, 1880) y Symphurus elongatus (Günther, 1868) (Pisces, Pleuronectiformes) en Chile, con comentarios sobre la distribución de los lenguados chilenos

RESUMEN. Se comunican los primeros registros de los Pleuronectiformes Achirus klunzingeri (Soleidae), Etropusectenes y Bothus constellatus (Bothidae) y Symphurus elongatus (Cynoglossidae) en aguas de chilenas. Las caracteris-ticas morfologicas de los especimenes estudiados se confrontan con descripciones previas. Se discute su distribucionen el Pacifico sur oriental y aquella del orden en aguas chilenas. Palabras claves: Pleuronectiformes, nuevos registros, Etropus ectenes , Bothus constellatus , Achirus klunzingeri , Symphurus elongatus , norte de Chile. First records of Etropus ectenes Jordan, 1889, Bothus constellatus Jordan & Goss,1889, Achirus klunzingeri (Steindachner, 1880) and Symphurus elongatus (Gunther,1868) (Pisces: Pleuronectiformes) in Chile, with comments on the distribution of theChilean flounders ABSTRACT. The first records of the Pleuronectiformes Achirus klunzingeri (Soleidae), Etropus ectenes and Bothusconstellatus (Bothidae), and Symphurus elongatus (Cynoglossidae) in chilean waters are reported. The morphologicalcharacteristics of the studied specimens are compared with previous descriptions. Their distribution in the SoutheasternPacific and that of the order in Chilean waters are discussed.

Habitat overlap of Paralabrax humeralis (Cuvier & Valenciennes, 1828), Hemilutjanus macrophthalmos (Tschudi, 1845), and Acanthistiuspictus (Tschudi, 1845) (Pisces; Serranidae) in the rocky subtidal south of Iquique, Chile

A simple SCUBA diving survey was used to study the habitat use and coexistence of three spe- cies in the family Serranidae with sympatric distribution patterns along the rocky subtidal south of Iquique. Depth and microhabitat were recorded for each sampled individual. Samples were taken at 15 different beaches through SCUBA diving in the deepest areas of the first rocky fringe, herein referred to as the transi- tion zone. The data were analyzed according to depth and frequency of use (microhabitat, habitat) for each species and considering three size classes. Dendograms were created to interpret the similarities in the use of beaches, microhabitat, and habitat. The results showed the species to be independent in their use of the micro- habitat and habitat. The most abundant species was the roving Paralabrax humeralis whose habitat was mostly associated with Lessonia trabeculata. Hemiluthjanus macrophthalmos and Acanthistius pictus are cav- ity specialists, although their microhabitat use differed according to the size of the cavity: H. macrophthalmos occupied larger caves (> 0.5 m) and A. pictus mostly smaller cavities (< 0.5 m). The lack of juvenile A. pictus individuals seems to indicate the use of an alternative ecosystem. The distribution patterns of these Serranids varied throughout the study area, indicating a dependence on the geomorphology of the substrate and the pres- ence of the structural species L. trabeculata.

Antennarius avalonis (Antennariidae, Lophiiformes) in the southeast Pacific

Specimens of Antennarius avalonis captured in the north of Chile are described. The information is compared with the data presented by previous authors. The distribution of the southeast Pacific species and those known from the continental and insular coasts of Chile is compared.

Coastal Wetlands of Northern Chile

The coastal wetlands of the northern zone, being the focus of water presence in an extremely arid area, are particular ecosystems that shelter and serve as a refuge for exclusive flora and fauna species, and at the same time have been strongly associated with the history of the population and use of the territory by humans. This chapter analyzes the composition, diversity and abundance of flora and avifauna species of the coastal wetlands associated with the mouths of the rivers and streams of the northern zone of Chile and discusses their conservation status. The vegetation associated with these ecosystems tends to follow an order in fringes, presenting itself from the littoral zone to the submerged, natants, emerged/surfaced, and free floating species, marshy ones and finally shrubs. In terms of species, a total of 69 species are recognized in 4 classes. Out of these species, 80% are native and 14% introduced, with only three species being endangered. In the case of birds, there is a presence of 194 species, and the Lluta wetland is the one with the greatest representation of this group (154 spp.). Most of these species are residents of wetlands (140 spp.), but there are also visiting species (26 spp.), as well as accidental ones (28 spp.). Out of all of the avifauna recorded in these wetlands, 32 species are endangered. In general terms, the development of mining and agricultural activities, urbanization and modification of the water flows associated with the coastal wetlands of northern Chile are the main threats to this type of ecosystems, and should be considered in the regional conservation strategies for avifauna, flora and biodiversity in general.

Annual, seasonal and daily variation in the abundance of the South American sea lion Otaria flavescens in two breeding colonies in northern Chile

Los estudios de variaciones de abundancia de las poblaciones a distintas escalas temporales permiten comprender como dichas poblaciones fluctuan en el tiempo y cuales son los factores que influyen sobre dichas variaciones. Se analizaron los patrones de abundancia del lobo marino comun (SASL, Otaria flavescens) a escalas diaria, mensual y anual en 2 loberas reproductivas del norte de Chile. Adicionalmente, se evaluo el efecto de El Nino sobre los patrones anuales de la especie. La abundancia de lobos marinos en Punta Negra (PN) disminuyo desde 1994 a 2011, mientras que en Punta Patache (PP) aumento, aunque el numero de crias fue proporcionalmente bajo. Los resultados demuestran un efecto importante de El Nino sobre la abundancia de lobos marinos, especialmente para hembras + juveniles en PN. La abundancia mensual de hembras y juveniles fue mayor en invierno, mientras que para machos adultos y subadultos no se encontro ningun patron. Finalmente, durante el dia la abundancia incrementa hasta llegar a un maximo hacia fines de la tarde, especialmente en el caso de hembras y juveniles. No se encontraron diferencias en los patrones de abundancia entre las epocas reproductiva y no reproductiva para ninguna de las clases de sexo/edad. Este estudio muestra que la abundancia en PP y PN muestra periodicidades anuales, mensuales y diarias, y que dichas periodicidades estan condicionadas tanto por factores intrinsecos (e.g., epoca reproductiva) como extrinsecos (e.g., hora del dia, El Nino). A escala anual, los resultados indican que aun a una escala local, las tendencias de abundancia en 2 colonias pueden ser diferentes.

Estudio poblacional y genético de la tortuga Chelonia mydas agassizii (Sauria: Cheloniidae) en la Playa Chinchorro, Arica, Chile

Observations on Chelonia mydas agassizii have been carried out on a monthly basis for the last 2 years along the Chinchorro beach in Arica (northern Chile), with the aim of monitoring and describing genetic and population parameters in this group of turtles. Eighteen Ch. mydas agassizii individuals were captured and marked from December 2011, to July 2013. These individuals had long carapace of 47 to 75.7 cm, of which 11 were identified as females and the rest were of undetermined sex (individuals of smaller sizes). We were only able to recapture one of such individuals 6 months later in the same feeding area. Sequencing of the mtDNA Control Region showed 4 haplotypes: 3 that had never been described before and one observed in several regions of the Pacific (Japan, Mexico and Ecuador). This information suggests that Ch. mydas agassizii may stay in the same feeding zone for months. Nevertheless, the genetic information did not indicate any association between the individuals captured from the Chinchorro Beach and a nesting area in the Pacific.