In the Eastern South Pacific (ESP), blue whale (Balaenoptera musculus subsp.) aggregations have been described for two feeding areas (in northern and southern Chile) and in the Eastern Tropical Pacific (ETP). However, despite the knowledge of these areas, little is known about the seasonal movements of blue whales between them. Comparisons of 1074 individual blue whales, photographed across these regions from 1992 to 2019, resulted in re-sightings of 107 individuals. Photo-identification comparisons were conducted using the Southern Hemisphere Blue Whale Catalog, a collaborative platform for sharing photo-identification data among 21 research groups from 7 nations. A total of 92 matches were found within the southern Chile feeding area and 13 matches within the northern Chile feeding area. High site fidelity was found for the southern Chile feeding area (return rates >= 43%). The longest interval between the first and last sighting was 17 years. There was no exchange between northern and southern Chile feeding areas. Two matches revealed long-distance connectivity and migration of blue whales from southern Chile to the Gal & aacute;pagos Islands in the southern ETP. There were no matches between Chile and the Costa Rica Dome, farther north in the ETP, a location known for the year-round presence of blue whales. The results highlight the importance of collaboration to understand blue whale movements and migration patterns. Our results provide valuable ESP and ETP region-wide data toward understanding population structure and informing conservation and management strategies, population assessments, and/or delineating biologically important areas.

Several legal acts mandate that management agencies regularly assess biological populations. For species with distinct markings, these assessments can be conducted noninvasively via capture-recapture and photographic identification (photo-ID), which involves processing considerable quantities of photographic data. To ease this burden, agencies increasingly rely on automated identification (ID) algorithms. Identification algorithms present agencies with an opportunity-reducing the cost of population assessments-and a challenge-propagating misidentifications into abundance estimates at a large scale. We explored several strategies for generating capture histories with an ID algorithm, evaluating trade-offs between labor costs and estimation error in a hypothetical population assessment. To that end, we conducted a simulation study informed by 39 photo-ID datasets representing 24 cetacean species. We fed the results into a custom optimization tool to discern the optimal strategy for each dataset. Our strategies included choosing between truly and partially automated photo-ID and, in the case of the latter, choosing the number of suggested matches to inspect. True automation was optimal for datasets for which the algorithm identified individuals well. As identification performance declined, the optimization recommended that users inspect more suggested matches from the ID algorithm, particularly for small datasets. False negatives (i.e., individual was resighted but erroneously marked as a first capture) strongly predicted estimation error. A 2% increase in the false negative rate translated to a 5% increase in the relative bias in abundance estimates. Our framework can be used to estimate expected error of the abundance estimate, project labor effort, and find the optimal strategy for a dataset and algorithm. We recommend estimating a strategy's false negative rate before implementing the strategy in a population assessment. Our framework provides organizations with insights into the conservation benefits and consequences of automation as conservation enters a new era of artificial intelligence for population assessments.

A collaborative research program (the Alfaguara Project) has collected information on Chilean blue whales (Balaenoptera musculus) off Isla Grande de Chiloe, in southern Chile, through eight aerial and 85 marine surveys. A total of 363 individual blue whales was photo-identified from 2004 to 2010. Approximately 20% of all catalogued individuals were resighted within the same season and 31% were resighted between years. Recaptures of photo-identified individuals from other areas to the north and south of the main study area support the hypothesis that the feeding ground off southern Chile is extensive and dynamic. The high overall annual return and sighting rates highlight the waters off northwestern Isla de Chiloe and northern Los Lagos as the most important aggregation areas currently known for this species in Chile and one of the largest in the Southern Hemisphere. Observations on feeding and social behaviour also were recorded. These results provide important information on the conservation status of Chilean blue whales and highlight the necessity that long-term photographic identification research and line-transect surveys to monitor health conditions and population trends be continued off northwestern Isla de Chiloe. The high frequency of large vessels in the mouth of the Chacao Channel (along the north side of Isla de Chiloe) and the high number of blue whales in the area raises the possibility of vessel collisions. Therefore, it is necessary to develop and implement a conservation plan for these whales to address this and other potential threats.

Researchers can investigate many aspects of animal ecology through noninvasive photo–identification. Photo–identification is becoming more efficient as matching individuals between photos is increasingly automated. However, the convolutional neural network models that have facilitated this change need many training images to generalize well. As a result, they have often been developed for individual species that meet this threshold. These single‐species methods might underperform, as they ignore potential similarities in identifying characteristics and the photo–identification process among species. In this paper, we introduce a multi‐species photo–identification model based on a state‐of‐the‐art method in human facial recognition, the ArcFace classification head. Our model uses two such heads to jointly classify species and identities, allowing species to share information and parameters within the network. As a demonstration, we trained this model with 50,796 images from 39 catalogues of 24 cetacean species, evaluating its predictive performance on 21,192 test images from the same catalogues. We further evaluated its predictive performance with two external catalogues entirely composed of identities that the model did not see during training. The model achieved a mean average precision (MAP) of 0.869 on the test set. Of these, 10 catalogues representing seven species achieved a MAP score over 0.95. For some species, there was notable variation in performance among catalogues, largely explained by variation in photo quality. Finally, the model appeared to generalize well, with the two external catalogues scoring similarly to their species' counterparts in the larger test set. From our cetacean application, we provide a list of recommendations for potential users of this model, focusing on those with cetacean photo–identification catalogues. For example, users with high quality images of animals identified by dorsal nicks and notches should expect near optimal performance. Users can expect decreasing performance for catalogues with higher proportions of indistinct individuals or poor quality photos. Finally, we note that this model is currently freely available as code in a GitHub repository and as a graphical user interface, with additional functionality for collaborative data management, via Happywhale.com.

AbstractAs species recover from exploitation, continued assessments of connectivity and population structure are warranted to provide information for conservation and management. This is particularly true in species with high dispersal capacity, such as migratory whales, where patterns of connectivity could change rapidly. Here we build on a previous long-term, large-scale collaboration on southern right whales (Eubalaena australis) to combine new (nnew) and published (npub) mitochondrial (mtDNA) and microsatellite genetic data from all major wintering grounds and, uniquely, the South Georgia (Islas Georgias del Sur: SG) feeding grounds. Specifically, we include data from Argentina (npub mtDNA/microsatellite = 208/46), Brazil (nnew mtDNA/microsatellite = 50/50), South Africa (nnew mtDNA/microsatellite = 66/77, npub mtDNA/microsatellite = 350/47), Chile–Peru (nnew mtDNA/microsatellite = 1/1), the Indo-Pacific (npub mtDNA/microsatellite = 769/126), and SG (npub mtDNA/microsatellite = 8/0, nnew mtDNA/microsatellite = 3/11) to investigate the position of previously unstudied habitats in the migratory network: Brazil, SG, and Chile–Peru. These new genetic data show connectivity between Brazil and Argentina, exemplified by weak genetic differentiation and the movement of 1 genetically identified individual between the South American grounds. The single sample from Chile–Peru had an mtDNA haplotype previously only observed in the Indo-Pacific and had a nuclear genotype that appeared admixed between the Indo-Pacific and South Atlantic, based on genetic clustering and assignment algorithms. The SG samples were clearly South Atlantic and were more similar to the South American than the South African wintering grounds. This study highlights how international collaborations are critical to provide context for emerging or recovering regions, like the SG feeding ground, as well as those that remain critically endangered, such as Chile–Peru.

Marine Mammal ScienceVolume 35, Issue 1 p. 284-289 Notes First acoustic recordings of critically endangered eastern South Pacific southern right whales (Eubalaena australis) Ellen Jacobs, Corresponding Author Ellen Jacobs ellenrosejacobs@yahoo.com Department of Bioscience, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Corresponding author (e-mail: ellenrosejacobs@yahoo.com).Search for more papers by this authorMaureen Duffy, Maureen Duffy Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Search for more papers by this authorJessica Magolan, Jessica Magolan Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Search for more papers by this authorBarbara Galletti Vernazzani, Barbara Galletti Vernazzani Centro de Conservacion Cetacea, Casilla 19178, Correo Alonso de Córdova, Vitacura, Santiago, 7639002 ChileSearch for more papers by this authorElsa Cabrera, Elsa Cabrera Centro de Conservacion Cetacea, Casilla 19178, Correo Alonso de Córdova, Vitacura, Santiago, 7639002 ChileSearch for more papers by this authorRafaela Landea, Rafaela Landea Fundación MERI, Avenida Kennedy 5682, Vitacura, Santiago 7650720, ChileSearch for more papers by this authorSusannah Buchan, Susannah Buchan COPAS Sur-Austral, University of Concepción, Barrio Universitario s/n, Concepción 4030000, Chile Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Search for more papers by this authorLaela Sayigh, Laela Sayigh Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A. School of Cognitive Science, Hampshire College, Amherst, Massachusetts 01002, U.S.ASearch for more papers by this author Ellen Jacobs, Corresponding Author Ellen Jacobs ellenrosejacobs@yahoo.com Department of Bioscience, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Corresponding author (e-mail: ellenrosejacobs@yahoo.com).Search for more papers by this authorMaureen Duffy, Maureen Duffy Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Search for more papers by this authorJessica Magolan, Jessica Magolan Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Search for more papers by this authorBarbara Galletti Vernazzani, Barbara Galletti Vernazzani Centro de Conservacion Cetacea, Casilla 19178, Correo Alonso de Córdova, Vitacura, Santiago, 7639002 ChileSearch for more papers by this authorElsa Cabrera, Elsa Cabrera Centro de Conservacion Cetacea, Casilla 19178, Correo Alonso de Córdova, Vitacura, Santiago, 7639002 ChileSearch for more papers by this authorRafaela Landea, Rafaela Landea Fundación MERI, Avenida Kennedy 5682, Vitacura, Santiago 7650720, ChileSearch for more papers by this authorSusannah Buchan, Susannah Buchan COPAS Sur-Austral, University of Concepción, Barrio Universitario s/n, Concepción 4030000, Chile Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.Search for more papers by this authorLaela Sayigh, Laela Sayigh Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A. School of Cognitive Science, Hampshire College, Amherst, Massachusetts 01002, U.S.ASearch for more papers by this author First published: 30 May 2018 https://doi.org/10.1111/mms.12519Citations: 6Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume35, Issue1January 2019Pages 284-289 RelatedInformation

Since 1970, blue whales (Balaenoptera musculus) have been seen feeding in the waters off southern Chile during the summer and autumn (December to May). Investigation of the genetic, acoustic and morphological characteristics of these blue whales shows that they are a distinct but unnamed subspecies, called the Chilean blue whales. Photo-identification surveys have been conducted in the waters off northwestern Isla Grande de Chiloé, southern Chile from 2004-2012 and Isla Chañaral, central Chile in 2012. Over this time, 1,070 blue whales were encountered yielding, after photo-quality control, 318 and 267 unique photographs of the left and right side of the flank respectively. Using mark-recapture analysis of left and right side photographs collected from Isla Grande de Chiloé (2004-2012), open population models estimate that ~570-760 whales are feeding seasonally in this region. POPAN superpopulation abundance estimates for the same feeding ground in 2012 are 762 (95% confidence intervals, CI = 638-933) and 570 (95% CI 475-705) for left and right side datasets respectively, very similar to results from closed population models. Estimates of trend revealed strong variation in abundance, peaking in 2009 and [suggesting] fluctuating use in the survey area over time, likely related to the density of their prey. High inter-annual return rates suggest a degree of site-fidelity of individuals to Isla Grande de Chiloé and that the number of whales using this feeding ground is relatively small.

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11 12 A collaborative research program (the Alfaguara Project) has collected information related to the conservation status 13 of Chilean blue whales (Balaenoptera musculus) off Isla Grande de Chiloe, off southern Chile, through eight aerial 14 and 85 marine surveys. A total of 365 individual blue whales was photo-identified from 2004 to 2010. 15 Approximately 20% of all catalogued individuals were resighted within the same season and 31% were resighted 16 between years. Recaptures of photo-identified individuals from other areas to the north and south of our main study 17 area support the hypothesis that the feeding ground off southern Chile is extensive and dynamic. The high overall 18 annual return and sighting rates highlight the waters off northwestern Isla de Chiloe and northern Los Lagos as the 19 most important aggregation areas known for this species in Chile and the Southern Hemisphere. Observations on 20 feeding and social behavior also were recorded. To monitor the conservation status of these whales, it is essential 21 that long-term photographic identification research and line-transect surveys to monitor health conditions and 22 population trends be continued off northwestern Isla de Chiloe. The high frequency of large vessels in the mouth of 23 the Chacao Channel (along the north side of Chiloe) and the high number of blue whales in the area raises the 24 possibility of vessel collisions. Therefore, it is necessary to develop and implement a conservation plan for these 25 whales to address this and other potential threats. 26 27 28

The status of southern right whales from the eastern South Pacific was assessed by reviewing 79 sightings collected between 1975 and 2010. No reports of southern right whales occurred in May and the majority of sightings were reported between winter and spring (July to November). Groups consisted mostly of one whale (44%) and pairs (45%). Cow/calf pairs represented about 34% (n=27) of the sightings and it is probable that the number of reproductive females in this population could be as low as eight. No significant increase was found in number of sightings or number of individuals but small trend to increase was found for number of calves. Although inconsistent sighting effort over the last 36 years may affect results, our analyses suggest that the population off Chile/Peru is extremely depleted and the current population size may be below 50 mature individuals. Therefore, the eastern South Pacific population clearly qualifies as “critical endangered” under The World Conservation Union (IUCN). We recommend increased cooperative effort to document all sightings and collect individual photoidentification. Furthermore, we urge the implementation of an international/regional action plan for the recovery of the eastern South Pacific population that affords maximum protection to the species in light of increasing anthropogenic activities that continue to degrade Chile-Peru coastal habitats.

There is not published information on a comparative analysis about interchange of individual humpback whales between coastal areas of aggregation of the species along southern Chilean coast.Here we present a comparison of individually photo-identified humpback whales obtained off northwestern Chiloé Island, in Patagonian and Fuegian fjords and in the Strait of Magellan near Carlos III Island , to discover movements and interchange of individuals.Comparison of photographs resulted in conclusive matches of four individuals within the four study locations: two whales from Canal Wide (49°55'S, 74°30'W), one whale from Canal Cockburn (54°18'S, 72°15'W) and a mother-calf pair off northwestern Chiloé Island matched whales found near Carlos III.The minimum linear distance between these summering locations are approximately 80 km from Canal Cockburn to Carlos III, 540 km from Carlos III to Canal Wide, and 1300 km from Carlos III to northwestern Chiloé Island.The trip from Chiloé Island to Strait of Magellan during 38 days in the same summer season represented a minimum mean speed of transit of 34 km/day.This study provides the first evidence of direct connection of individual humpback whales along the coast of southern Chile.

There is not published information on a comparative analysis about interchange of individual humpback whales between coastal areas of aggregation of the species along southern Chilean coast. Here we present a comparison of individually photo-identified humpback whales obtained off northwestern Chiloe Island, in Patagonian and Fuegian fjords and in the Strait of Magellan near Carlos III Island , to discover movements and interchange of individuals. Comparison of photographs resulted in conclusive matches of four individuals within the four study locations: two whales from Canal Wide (49°55’S, 74°30’W), one whale from Canal Cockburn (54°18’S, 72°15’W) and a mother-calf pair off northwestern Chiloe Island matched whales found near Carlos III. The minimum linear distance between these summering locations are approximately 80 km from Canal Cockburn to Carlos III, 540 km from Carlos III to Canal Wide, and 1300 km from Carlos III to northwestern Chiloe Island. The trip from Chiloe Island to Strait of Magellan during 38 days in the same summer season represented a minimum mean speed of transit of 34 km/day. This study provides the first evidence of direct connection of individual humpback whales along the coast of southern Chile.

Several studies have reported that mutations in genes involved in maintenance of genome integrity may be responsible for increased cancer risk. Human RAD51, known to function in DNA repair, interacts with a number of proteins implicated in breast cancer (BC), including BRCA1 and BRCA2. Few studies have investigated the role of RAD51 gene variations in familial BC. To detect potential novel gene defects that may contribute to hereditary BC susceptibility, 143 patients belonging to 143 Chilean families tested for BRCA1 and BRCA2 mutations were screened for mutations in RAD51, using conformational sensitive gel electrophoresis (CSGE) and DNA sequencing. No mutations were detected in the exon or splice-boundary regions of the RAD51 gene in these families. The RAD51 135G>C polymorphism (c.-98G>C, rs1801320) was studied in a case–control design, to evaluate its possible association with BC susceptibility. The frequency of the RAD51 135C allele was established in 143 cases and 247 controls, using restriction fragment length polymorphism–polymerase chain reaction. RAD51 135C genotypes (G/C and C/C) were associated with an increased BC risk only among women with (a) a family history of BC, (b) BRCA1/2 negative (n = 131), and (c) age at onset <50 years (P = 0.020; OR = 2.17, 95% CI = 1.11–4.24). Thus, we propose that RAD51 135G>C polymorphism presents an increased risk of familial BC in women with age < 50 years at diagnosis, and this polymorphism may be a BC risk variant. This finding should be confirmed in other populations.

We report on three types of skin lesions in a population of blue whales, Balaenoptera musculus, off the northwestern coast of Isla Grande de Chiloe, Chile. These lesions were: (1) cookie-cutter shark, Isistius brasilensis, bites, (2) vesicular or blister lesions, and (3) a tattoo-like skin disease. The presence of these lesions was determined by the examining photos collected in 2006 and 2007 for a blue whale photoidentification project. We examined 289 photographs of 68 individuals for lesions. The cookie-cutter shark lesions are common on these blue whales and similar to those reported from other species of cetaceans. Skin peeling or shedding was observed on some whales and is believed to be a normal condition. Based on the photographs examined to date the vesicular lesions are more common than the tattoo-like lesions. The tattoo-like skin lesions was observed just on a single whale in 2007. The blister lesions were common on whales in both 2006 and 2007. The presence of blister lesions in both years may indicate that this “disease” will be present in the population for a long time. It is unknown if these lesions contribute to mortality of blue whales frequenting Chilean waters, but the tattoo-like skin lesions if shown to be a pox virus could cause neonatal and calf mortality. Additional investigations are needed that, as a minimum, must include the histological and genetic examination of the two types of disease from live or dead whales, especially the tattoo-like skin lesions. Until this work is undertaken, it will be impossible to determine if these lesions pose a conservation risk to the blue whales off Chile. INTRODUCTION Almost 3,000 blue whales, Balaenoptera musculus, were killed in the coastal waters of Chile between 1929 and 1971, but very little is known about their biology and ecology. Recently, blue whales have been reported from the waters on the outer coast of Isla Grande de Chiloe (Cabrera, Carlson and Galletti 2005), in the Golfo de Corcovado, and around the Chonos Archipelago, Chile (Hucke-Gaete, Osman, Moreno, Findlay and Ljungblad 2004). These blue whales feed in southern Chilean waters during the austral summer and fall. Blue whales in Chilean waters have been classified as either Antarctic blue whales, Balaenoptera musculus intermedia, or pygmy blue whales, B. m. brevicauda. However, Branch, Abubaker, Mkango, Butterworth (In press) have shown, based on the length frequency of adult females, that blue whales captured off Chile are intermediate in total length between the two described Southern Hemisphere subspecies and therefore probably represent a unique population or even a different subspecies. More data are needed to resolve this question. The purpose of this note is to report on skin lesions observed on blue whales photographed off the northwestern coast of Isla de Chiloe, Chile, in 2006 and 2007. We describe the morphology of these lesions and comment on their possible origin. We also discuss the possible conservation implications that these lesions have for blue whales off Chile. Paper SC/59/SH21 presented to the International Whaling Commission Scientific Committee, June 2007, Anchorage, Alaska, USA. DO NOT CITE WITHOUT THE AUTHORS PERMISSION SC/59/SH21 2 MATERIALS AND METHODS We examined a series of photographs of 68 blue whales taken during the austral summer 2006 and two additional blue whales photographed during February 2007. One of the 2007 whales was a resighting from 2006. These whales were photographed to identify individual whales offshore on the northwestern shore of Isla Grande de Chiloe, Chile. We observed a variety of lesions on these blue whales in the photographs and during our at-sea observations. Examples of skin lesions described in this paper were sent to various researchers working on blue whales in different parts of the world to see if any of them had observed similar types of lesions on the blue whales they study. RESULTS We examined 289 photographs from 68 individual blue whales collected in 2006. Thirty-seven of these individuals had cookie-cutter shark lesions; 52 had vesicular or blister lesions; 17 had linear marks, including some that may be related to blister lesions or tattoo lesions; and 11 had miscellaneous unknown scars or marks. Ten individuals had peeling skin and three had rake marks from killer whales. The identification photographs of blue whales (approximately 80 individuals) collected in 2007 have not been examined in detail. However, two blue whales photographed in February 2007 are included here. One had extensive tattoo-like lesions over a large portion of its body and the other a open lesion that may have resulted from one of the blister lesions. Cookie-cutter shark lesions Cookie-cutter shark bites were recorded from left side photographs of 69.2% of the individuals (n=18) examined (Figure 1). Most of scars had healed but some whales had open wounds. Healed scars usually do not have pigment and the scar area is white. Vesicular or blister lesions Based on the photographs we examined, 52 individual blue whales had either raised lesions or lesions that had opened and were in various stages of healing (Figure 2) The raised or blister-like lesions were about the same size or slightly larger than a cookie-cutter shark bite but the lesion was rounder in shape than the oval bites caused by cookie-cutter sharks (Figure 1). Only one open, raw lesion was the general size of one of these blister lesions was observed in February 2007 (Figure 3). Another commonly observed scar was a round crater-like depression in the skin that is the same size as a blister lesion and therefore may be a healed blister lesion (Figure 4). Tattoo-like skin lesions We photographed one individual with extensive tattoo-like lesions (Figure 5) on 8 February 2007. This whale was not observed again during the 2007 field season. A few other whales may have had this type of lesions too but the lower quality of the photographs prevented us from making a positive determination. Other skin conditions Eleven blue whales were found with various other markings. Ten whales showed signs of peeling skin and others had rake marks from killer whales. In a few photographs, what appears to be a diatom film was observed on the skin of some whales. In some of the whales we could observe a dark diatom film. The pseudostalked barnacle, Xenobalanus globicipitis, was common on the dorsal fin and flukes. One blue whale encountered on 10 March 2006 had many of these barnacles on the trailing edge of its flukes. DO NOT CITE WITHOUT THE AUTHORS PERMISSION SC/59/SH21

Since 2004, a collaborative research program of the Alfaguara Project on blue whales off Isla de Chiloe, Chile, has produce important new information on present day conservation status of this population. This paper presents preliminary findings from 2007 and compares such data with that reported in previous years. Land-based monitoring in 2007 resulted in 36 days of observations with 262.85 h of land-based effort. The maximum number of individuals sighted from land ranged from 2 to 44, with an average of 18.14 individuals per day (SD=12.00 ; CI95% =14.08 22.20). Preliminary results on fifteen of seventeen photo-identification surveys conducted in 2007 resulted in the documentation of 123 blue whale groups comprising 156 individuals. The number of whales encountered does not include animals resighted on same day. Individual photo-identification of left and right side respectively, resulted in 80 individual blue whales, including seven between years and sixteen within year recaptures; and 74 individual blue whales, including nine between years and fourteen within year recaptures. The combined photo-indentification catalogue (2004-2007) is comprised of 143 individual blue whales (left-side) and 137 (right-side). A photoidentification recapture from different areas provides evidence that the blue whale feeding ground off southern Chile is extensive and dynamic. A recapture analysis of 2005 and 2006 whales shows an overall return rate of 10.8% (left side) and 11.4% (right side) highlighting the northwestern Isla de Chiloe as an important long-term feeding area for this population. Of the 80 individuals recorded this season, 56.8% (n=42) were recorded to be “skinny”, including 5.4% (n=4) with ribs clearly visible. The 2007 proportions of skinny whales are the highest documented to date. It is unknown if these skinny whales represents any potential threat to this population. Therefore, it is essential that longterm photo-identification research continue to monitor this condition.

Photo identification of individual blue whales during summer and autumn off the northwestern Isla de Chiloe, southern Chile, were collected from marine surveys conducted from 2004 to 2006. Re-sightings of individual whales both within and between years may provide evidence of residency and site fidelity by blue whales in the area. These records further document the importance of the northwestern Isla de Chiloe as a feeding area for blue whales. These records also highlight the necessity of further comparisons with photographic catalogues from other areas in southern Chile, off the northwestern coast of South America and the Pacific coast of Central America to better understand seasonal movements, distribution of individuals along the eastern South Pacific, and their wintering areas. INTRODUCTION Blue whales (Balaenoptera musculus) range from the tropics north and south into the pack ice of the Artic and Antarctic Ocean. In the southern hemisphere, two subspecies are currently accepted: B. m. brevicauda, the “pygmy” blue whale in the Subantartic zone and B. m. intermedia, for the whales that summer in the Antarctic Zone (Rice, 1998). During the 20th century, blue whales became a principal target of the whaling industry throughout the world, notably following the opening in 1904 of the rich whaling grounds in the Southern Ocean. Knowledge of blue whale populations is limited and few data are available to assess the status of the different populations, particularly in the Southern Hemisphere where blue whale numbers were dramatically reduced by decades of poor management and illegal whaling (Clapham et al., 1999). In Chile, catches of blue whales occurred in waters along the continent and in Antarctic waters. Approximately 2,982 individuals were taken in continental waters off Chile between 1929 and 1971, and at least 27,720 from 1911 to 1929 in the Chilean Antarctic Territory (Aguayo et al. 1998). Although the distribution and historical catches of each subspecies in Chile remains undetermined, new information is increasing our knowledge of blue whales in Chilean waters. We have assigned the blue whales off Isla de Chiloe to B. m. brevicauda. Here we report on results from photo-identification of blue whales off northwestern Isla de Chiloe from 2004 to 2006 and comment on residency by analyzing minimum residency times and re-sighting rates, including the first recapture between years of a photo-identified blue whale. MATERIAL AND METHODS Blue whales are individually identifiable from the unique pattern of mottling on both sides of the body near the dorsal fin, the size and shape of the dorsal fin and scars (Sears et al., 1990). Photo-identification has been shown to significantly contribute to identifying critical habitats in terms of minimum residency times, site fidelity, habitat use and seasonal variations in occupancy and movements patterns between areas (Clapham et al., 1995; Whitehead, 1995). Paper SC/58/SH18 presented to the International Whaling Commission Scientific Committee, June 2006, St Kitts and Nevis, WI.

A total of 150.7 h of land-based observations were collected in 24 days (x=6.3 h/d, SD=3.2 h). The number of groups of whales sighted daily ranged from 1 to 42, totaling 357 groups with an average of 14.9 groups per day (SD=11.2; CI95% =10.1 - 19.6). The number of individuals sighted daily ranged from 2 to 47, totaling 415 individuals with an average of 17.3 individuals per day (SD=13.1; CI95% =11.8 - 22.8). Species identification was possible on one occasion only, when a humpback whale (Megaptera novaeangliae) breached at a distance of 5nm from shore with its long pectoral flippers clearly visible. Marine surveys were conducted on good weather days within 12 nm from the coast of northwestern Isla de Chiloe, between Chacao Channel (41º45'S) and Metalqui Island (42º 12'S), on board Alfaguara's 7m research vessel. During marine surveys, photo-ID and, for the first year, biopsy samples were collected and correlated with data on group composition, behavior of whales, weather and sea conditions, associated fauna and sea surface temperatures. Position of a whale or group of whales was determined using a GPS device. Twelve photo-identification surveys totaling 68.9 hrs were conducted between 08 February and 19 April 2009. At total of 83 blue whale groups comprised of 126 individuals were encountered. The number of whales encountered does not include animals resighted on the same day. Photographs taken during 2009 are under analysis to determine if blue whales were new or known individuals and will be reported at a later date. Additionally, we recorded one sei whale (Balaenoptera borealis), two groups of two probable sei whales, three groups of at least nine peale's dolphins (Lagenorhynchus australis) and the Projects first sighting of a group of three fin whales (Balaenoptera physalus) and a group of two orcas (Orcinus orca). Thirteen skin biopsy samples for genetic analyses, obtained from blue whales and one sei whale were preserved in DMSO. Feeding behavior and defecation were recorded for blue whales and fin whales, further documenting the importance of the waters off north western coast of Isla de Chiloe as a feeding ground for blue whale and other baleen whales in the Eastern South Pacific. In comparison with the period 2004-2008, unfavorable weather conditions in 2009 were more frequent and limited the number of days spent on land-based observations and marine surveys. Additionally, the whales were the farthest from shore since 2004. During most marine surveys in 2009, whales were located at least 10nm from shore. However, on 7 th

Blue whales (Balaenoptera musculus) were heavily exploited in the southern Hemisphere during commercial whaling with about 3,000 blue whale catches reported off Chile. Although recent surveys have documented the presence of blue whales in waters off southern Chile, abundance estimates of blue whales in this feeding area, necessary to provide baseline information for the development and monitoring of future conservation measures, are lacking. Here we present the results of two aerial surveys using standard distance sampling techniques conducted in 2007 and 2009. Abundance estimates using uncorrected data were 44 (CV=0.62) individuals in 2007 and 50 (CV=0.32) individuals in 2009. An estimate for g(0) was made based on the proportion of time blue whales are at the surface. Abundance estimates with correction factor for g(0) increased to 96 (CV=0.65) individuals in 2007 and 110 (CV=0.38) individuals in 2009. The increase in abundance estimate from 2007 to 2009 does not reflect necessarily an increase on abundance but rather differences in the surveys coverage area. Blue whale abundance is considered to be low and therefore any lethal, anthropogenic impact needs to be avoided.