Anelio Aguayo-Lobo

Rare piebald and partially leucistic Antarctic fur seals, Arctocephalus gazella, at Cape Shirreff, Livingston Island, Antarctica

We document five cases of unusual colouration in Antarctic fur seals, Arctocephalus gazella, at Cape Shirreff, Livingston Island, from 1991–1992 to 2005–2006 austral summer seasons. This is the first time that these colour patterns have been reported for this species. These included four rare light coloured animals and one piebald individual. The incidence of this atypical colouring was low and the lack of resightings in previous and subsequent seasons suggests that these morphs are not common in Antarctic fur seals. Although the causes of these atypical light colour patterns are uncertain the subject is interesting for study and more observations on these atypical colourations are required for a proper assessment of the ecological and physiological implications of this condition in otariids can be conducted in the future.

Filopatría de la ballena jorobada (Megaptera novaeangliae Borowski, 1781), al área de alimentación del estrecho de Magallanes

Humpback whales migrate annually between high latitude feeding grounds and low latitude breeding grounds, exhibiting a marked degree of fidelity to migratory destinations. Southeastern Pacific humpback whales migrate between the reproductive area located principally off Ecuador and Colombia and the feeding area located around the Antarctic Peninsula. Previous studies suggested a second feeding area for this population in the Magellan Strait. This study evaluates the site fidelity of humpback whales to the Magellan Strait feeding area using photo-identification data obtained during 10 sighting cruises carried out in three austral summer seasons (2002-2003 to 2004-2005). If the Magellan Strait is a second feeding area for some whales of this population, a high return rate of the same animals photo- identified to this area than by chance would be expected. The site fidelity of humpback whales in different austral summer seasons shown a high return rate ( =78.9%). Furthermore no significant differences were found in the return rate between female and males or between different class/age categories. Finally, the high return rate humpback whale, indicate that Magellan Strait is another feeding ground at least for a part of the Southeastern Pacific humpback whales population.

Eventos reproductivos del león marino común, Otaria flavescens (Shaw 1800), en el norte de Chile (Pacífico suroriental)

Studies on the development of the breeding season of southern sea lions have been carried out primarily in populations from Uruguay and Argentina, western south Atlantic; scarce information has been published from populations of Peru and Chile. The objective of this contribution is to describe the development of the breeding season of the southern sea lion, during two consecutive seasons in the area of Punta Negra, north of Chile. The development of the reproductive events in the Punta Negra colony presented a high annual synchronization, extending from the third week of December till May, with a climax of the reproductive events in February, being the dynamics during the breeding period similar to that informed for other colonies, although with an out of fase in the breeding season with the Atlantic populations of sea lion. We conclude that the development of the reproductive events during the both breeding seasons presented a high annual synchronization, with an average out of fase of 2.0-2.5 days, being representative for most of the northern area of Chile, in the southeastern Pacific Ocean.

Vagrant Antarctic fur seals, Arctocephalus gazella, in southern Chile

The Antarctic fur seal, Arctocephalus gazella, in the eastern South Pacific Ocean, first reported on Hoste Island, Cape Horn in 1973, and then on the Juan Fernandez Archipelago in 1982 and 1983, was recorded again in October and December 2009 on the southern coast of Chile. Three different individuals were seen simultaneously on a single day at Punta Dungenes, Magellan Strait, and a fourth individual was sighted at the northeastern coast of Almirantazgo Sound, Tierra del Fuego. These records represent the first sightings of live Arctocephalus gazella in southern Chile. Although it is difficult to establish both their origin and rationale for dispersion outside of their distribution range, the substantial breeding population recovery in South Georgia and food shortages during the breeding and post-breeding season are suggested as possible explanations.

Albino Weddell seal at Cape Shirreff, Livingston Island, Antarctica

To our knowledge, this paper is the first record/report of a juvenile light-coloured Weddell seal (Leptonychotes weddellii) at Cape Shirreff, Livingston Island in January 1998, determining that it was an albino individual. Based on available literature, three cases of albino seals have been reported exclusively for Harbour seal pups, and no albino has been reported for Antarctic pagophilic true seals. Therefore, this is the first confirmed case of albinism in Antarctic pagophilic true seals species, indicating that this phenomenon is indeed of a rare occurrence.

Occurrence and distribution of Chilean dolphin (Cephalorhynchus eutropia) in coastal waters of central Chile

Abstract The Chilean dolphin, Cephalorhynchus eutropia, is an endemic species distributed along the central‐southern coast of Chile. Biological and ecological knowledge about this species is insufficient; it is catalogued as Data Deficient “DD” by the World Conservation Union. This study provides information on the species’ occurrence and distribution along the central Chilean coast from January 2000 to March 2001. Monthly land‐based surveys were performed within the study area, which was divided by the Maule River outlet, with the northern area more influenced by an estuarine system than the southern one. Chilean dolphins were sighted in 83% of surveys. The relative abundance was significantly higher in the northern than the southern area (13.6 dolphins/h versus 3.5 dolphins/ h). Three behaviour categories were recorded (feeding, socialising, and travelling) in both areas, however, these were more frequently observed in the northern area. We suggest that the area located north of Maule River is the preferred zone for Chilean dolphins within the study area. This study shows a year‐round occurrence of Chilean dolphin in the study area which is possibly a critical habitat for this species. Further research focused on population structure assessment and residence patterns of the species in the study area is required.

Population genetic structure of the South American Bryde's whale

A genetic analysis based on mitochondrial DNA control region sequences was conducted to investigate both species identity and populations genetic structure of South American Brydes whales. The genetic analysis was based on historical, biopsy and stranding samples from Chile (n= 10) and Brazil (n= 8). For comparative purposes published sequences of the Brydes whales from different localities of the Indian and Pacific Oceans (including Peru, n= 24) were incorporated into the analysis. Results of the phylogenetic analysis identified the Brydes whales of South Ameri ca as Balaenoptera brydei. No statistically significant genetic differentiation was found between Chilean and Peruvian Brydes whales. However, striking differences were found between western South Atlantic (Brazil) and eastern South Pacific (Peru and Chile) animals. In addition, striking genetic differences were found between all South American localities and those from the western North Pacific, Fiji and Java. These results suggest movement of B. brydei in the eastern South Pacific in the latitudinal range corresponding to Chile and Peru. These results also suggest no or very limited mov ement of whales between the South Pacific and the South Atlantic Oceans. This is consistent with the notion that B. brydei is not distributed further south of approximately 40oS on both sides of South America.

Trophic Ecology of Humpback Whales (Megaptera novaeangliae) in the Magellan Strait as Indicated by Carbon and Nitrogen Stable Isotopes

National Commission for Scientific and Technological Research (CONICYT) Chilean Antarctic Institute (INACH) CEQUA Foundation Foundation BIOMAR

CARACTERÍSTICAS OCEANOGRÁFICAS Y BIOLÓGICAS DE LAS COMUNIDADES DEL PLANCTON Y NECTON DEL ÁREA MARINA COSTERA PROTEGIDA FRANCISCO COLOANE: UNA REVISIÓN

The objective of this study was to make a review of the current state of knowledge on the Coastal Marine Protected Area (CMPA) Francisco Coloane in terms of the physical and chemical oceanography, the phyto-zooplankton compositions and the fish, birds and marine mammals species present, and provide temperature and salinity data collected during a marine survey carried out the 2012 fall season. Surface temperatures fluctuate between 2.0 and 9.0°C. Salinity varies between 23 and 30.9 PSU. The most oxygenated waters and those of highest pH were recorded within Seno Ballena (320-340 µmoles Kg -1 ; 8.11 units of pH). In spring nutrient levels indicate low surface concentrations, except for phosphate, the phytoplankton is dominated by diatoms and the zooplankton is composed of copepods and meroplanktonic larvae with high abundance levels in the Jeronimo Channel. The family of fish most representative is the Nototheniidae, and among marine birds and mammals, the Magellan penguin and the humpback whale are the most sighted. The review indicates that it is necessary to make further studies on physical oceanography and the benthic community of CMPA.

Occurrence of dwarf minke whales (Balaenoptera acutorostrata subsp.) around the Antarctic Peninsula

The occurrence of dwarf minke whales (Balaenoptera acutorostrata subsp.) around the Antarctic Peninsula was examined based on 406 sightings of minke whales recorded during the Chilean Antarctic Scientific Expeditions and other opportunistic cetacean surveys. Identification of the species was made only for the whales sighted in the proximity of the vessels when the specific diagnostic characters could be confirmed. Of the 406 sightings, 296 were assigned to Antarctic (519 individuals), nine (11 individuals) to dwarf and 101 to unidentified minke whales (149 individuals). Dwarf minke whales were identified by the reported external diagnostic characters for this species. Seven animals occurred around the South Shetland Island and four in the Gerlache Strait. In addition, another two animals were identified as dwarf minke whales in the Bellinghausen Sea in winter 1993, being these the most southern records for this species. These results confirm the occurrence of dwarf minke whales around the Antarctic Peninsula during the summer seasons, as well as in the Bellinghausen Sea in winter. The geographical range of these sightings was comprised between 61°03′ and 69°25′S and between 55°29′ and 86°53′W. These results also suggest that some dwarf minke whales remain in the Antarctic during the austral winter.