June 2026 - MARMAM - devlists.uvic.ca

Mailing list submission - New publication: Comparative non-targeted lipidomic profiles in blubber of endangered St. Lawrence Estuary belugas and their potential prey (Zeppetelli-Bedard et al., 2026)
by Laura Zeppetelli-Bedard 12 Jun '26

12 Jun '26

Dear MARMAM community, On behalf of my co-authors and me, I am very pleased to share our latest publication in *Endangered Species Research*: Zeppetelli-Bedard L, Sherrill M, Ewald J, Pang Z, Cabrol J, Lesage V, Michaud R, Verreault J (2026) Comparative non-targeted lipidomic profiles in blubber of endangered St. Lawrence Estuary belugas and their potential prey. Endang Species Res 60:esr01501 https://doi.org/10.3354/esr01501 ABSTRACT: The St. Lawrence Estuary (SLE) belugas *Delphinapterus leucas* are a small and isolated population listed as endangered in Canada. Profound changes in the SLE ecosystem and a parallel deterioration in SLE beluga body condition suggest a potential decline in the quality and/or quantity of their prey. Using a non-targeted screening approach, this study aimed to gain insights into the blubber lipid profiles of SLE belugas and their potential prey, and to examine variations among beluga males and females and age classes, as well as among prey taxa and sampling seasons. Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was used to analyze 71 SLE beluga blubber biopsies (outer blubber layer) and 126 prey homogenates from 10 fish and 2 invertebrate species. Over 10383 features were detected across SLE beluga and prey samples, highlighting structural lipids such as glycerolipids, sphingolipids, and glycerophospholipids as the predominant components. Distinct lipid profiles were found between SLE beluga males and females, suggesting potential differences in diet and lipid metabolism, thus underscoring the importance of considering sex-specific lipid variations in beluga blubber. Prey species displayed unique lipid fingerprints, clustering according to phylogeny, diet, and trophic guilds. Significant seasonal variations in lipid composition were also observed in prey sampled across seasons. This study constitutes a critical first step toward assessing beluga–prey ecological interactions and lipid composition in the SLE food web, as well as how lipid composition influences energy allocation and storage. Cheers, Laura Zeppetelli-Bédard, MSc., University of Quebec in Montreal, Canada Aquatic science technician at Fisheries and Oceans Canada Laura.zeppbed(a)gmail.com or laura.zeppetelli-bedard(a)dfo-mpo.gc.ca Tel.: (514)-691-9712

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Consequences of culturally-driven ecological specialization: Killer whales and beyond
by Hal Whitehead 12 Jun '26

12 Jun '26

The following paper has just been published: Consequences of culturally-driven ecological specialization: Killer whales and beyond. by: Hal Whitehead and John K.B. Ford Journal of Theoretical Biology 456: 279-294 Abstract: Culturally-transmitted ecological specialization occurs in killer whales, as well as other species. We hypothesize that some of the remarkable demographic and ecological attributes of killer whales result from this process. We formalize and model (using agent-based stochastic models parametrized using killer whale life history) the cultural evolution of specialization by social groups, in which a narrowing of niche breadth is spread and maintained in a group through social learning. We compare the demographic and ecological results of cultural specialization to those of a similar model of specialization through natural selection. We found that specialization, through either the cultural or natural selection routes, is adaptive in the short term with specialization often increasing fitness. Generalization, in contrast, is rarely adaptive. The cultural evolution of specialization can lead to increased rates of group extirpation. Specialization has little effect on group size but tends to reduce population size and resource abundance. While the two specialization processes produce similar results, cultural specialization can be very much faster. The results are generally consistent with what we know of the formation and maintenance of specialist ecotypes in killer whales, and have implications for the persistence, nature and ecological effects of these apex predators. You can read a .pdf at: http://whitelab.biology.dal.ca/labpub.htm Hal Whitehead Dalhousie University hwhitehe(a)dal.ca

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LAMLA V – Second Circular
by Gisela Giardino 11 Jun '26

11 Jun '26

Dear colleagues, We are pleased to share the Second Circular of LAMLA V – Listening for Aquatic Mammals in Latin America, which will be held in Mar del Plata, Argentina, within the framework of the XX Argentine Congress on Acoustics (AdAA2026). LAMLA brings together researchers, professionals, and students interested in aquatic mammal bioacoustics, passive acoustic monitoring, animal behavior, conservation, and related fields. 📅 Important reminder: Abstract submission deadline: June 15, 2026. We encourage you to submit your work and to share this announcement with colleagues and students who may be interested. The circular includes information about: • Abstract submission • Mel Cosentino Fellowships • Workshop activities • Important dates • Registration details We look forward to welcoming you to Mar del Plata in November 2026. Best regards, The LAMLA V Organizing Committee More information: https://congresoadaa2026.web.app/lamla -- Dra. Gisela Giardino Grupo de Investigacion Biol., Ecología y Conserv. de Mamíferos Marinos Universidad Nacional de Mar del Plata (UNMdP) -IIMyC (CONICET) Deán Funes 3350, (7600) Mar del Plata, Argentina. Tel: +54 223 4752426 (int. 244) Casilla de Correo 1260-Correo Central-MdP https://linktr.ee/becmm

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New publication: Changes in sea ice influence bowhead whale distribution and overlap with vessel transits in the Pacific Arctic
by Angela Szesciorka 11 Jun '26

11 Jun '26

Dear MARMAM community, My co-authors and I are pleased to share our new publication in Frontiers in Marine Science: https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.… Szesciorka, A.R., Crawford, J.A., Ferloni G., Hauser, D.D.W., Quakenbush, L., Stafford, K.M. (2026). Changes in sea ice influence bowhead whale distribution and overlap with vessel transits in the Pacific Arctic. Frontiers in Marine Science, 13:1818623e. https://doi.org/10.3389/fmars.2026.1818623 Abstract: Arctic warming has resulted in substantial decreases in sea ice and a longer open-water season. This is occurring concurrently with changes in Bering-Chukchi-Beaufort bowhead whale seasonal movements and increasing vessel traffic through Bering Strait, which may increase strike risk. To assess vessel traffic relative to bowhead whale distributions before (2013/14–2016/17), during (2017/18), and after (2018/19) a significantly low winter sea ice event in the Pacific Arctic, we combined vessel location data for eight vessel types during six seasons (September–March 2013–2019) transiting through whale utilization distributions (UDs) developed from satellite-linked telemetry from whales tagged during 2008–2019. Before the low ice event, the home range (95% UD) and core use area (50% UD) followed a consistent seasonal pattern of bowhead whales migrating south through the Chukchi Sea to wintering areas in the western Bering Sea. The UDs shifted northward during the low ice event, resulting in a decline in annual vessel transits through UDs, from an average of 234 transits in the 95% UD and 139 in the 50% UD during the four seasons before the event to 62 and 45 transits, respectively during the low ice event. Mean vessel speeds, however, increased from 7.2 to 8.7 kt in the 95% UD. After the event, UDs shifted southward, although not as far as before, and transits through UDs remained low (81 and 34) and at similar mean speeds (8.9 and 8.7 kt) than during the event. Regardless of period, vessels spent the most time along the northern coast of Chukotka and western Bering Sea resulting in the highest vessel densities and fastest mean vessel speeds. While it appears bowhead whales can adjust their distributions to rapidly changing ice conditions consequently overlapping with fewer vessels, faster transits through their UDs could put whales at increased risk of lethal strikes in the future. Please reach out if you have any questions. Best regards, Angela Szesciorka, Ph.D. Bioacoustician, Greenland Institute of Natural Resources Faculty Affiliate, Marine Mammal Institute, Oregon State University

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Full-Time Marine Mammal Rehabber Position
by Savannah Costner 10 Jun '26

10 Jun '26

Hi Marmam! We are looking to add one member to our small rehabilitation team at the Alaska SeaLife Center. Our main focus is harbor seals and sea otters with the occasional ice seal or walrus calf! Please see the posting below for details and apply at this link https://workforcenow.cloud.adp.com/mascsr/default/mdf/recruitment/recruitme… Summary: This position is responsible for the routine handling and care of animals being housed in the rehabilitation and quarantine areas under the supervision of the Wildlife Response Curator at the Alaska Sealife Center. The primary focus of this position is marine mammals, though there are occasional responses to birds and other wildlife in the Seward area. Education/Training Requirements: Bachelor's degree in biology, animal science, zoology, veterinary science, or related profession preferred. Computer skills including Google mail, spreadsheets, word processing, and database programs. Must possess a valid driver’s license and be comfortable driving in rain and snow conditions. SCUBA certification preferred. Specialist 1 In addition to the above, Experience in animal husbandry and wildlife rehabilitation is required; experience with marine mammals is preferred. For Specialist 2 In addition to the above, Experience in animal husbandry and wildlife rehabilitation is required with at least two years of experience in marine mammal rehabilitation preferred. Experience with operant conditioning is also preferred. Essential Duties: Specialist 1 Under the supervision of the Wildlife Response Curator, provides care for animals admitted into rehabilitation. Assists with the care and husbandry of animals housed in the rehabilitation area, quarantine area, and other animal care areas at ASLC. Coordinates with the Wildlife Response Curator and veterinary staff to ensure consistency in animal care. Performs routine animal husbandry duties, including diet preparation, feeding animals, cleaning animal enclosures, disinfecting preparation areas and equipment, and maintaining animal records. Under the supervision of a veterinarian or a veterinary technician, performs basic medical treatments such as administering oral medications and cleaning wounds, and assists in basic medical procedures including animal restraint for physical exams. Under the direction of the Wildlife Response Curator, supports research and data collection within accepted research and husbandry protocols and assists with data collection and sampling procedures. Maintains accurate records in accordance with ASLC and permit requirements. Serves as a team leader for interns and volunteers to ensure animals are appropriately monitored and daily tasks are completed in a timely manner. Monitors animal behavior, health, and progress, and reports updates or concerns to senior staff and veterinary personnel. Participates, as needed, in presentations for visitors and the public on topics related to marine science and ASLC operations. Learns to appropriately lead VIP tours through quarantine spaces while respecting the needs of animals in care. Answers the ASLC stranding hotline and may be scheduled for on-call coverage outside regular working hours. Employees are compensated for on-call duties. Maintains HAZWOPER 24 certification (training provided) and serves as member of the Oil Spill Response Team. If certified in SCUBA, maintains active SCUBA diver status and is comfortable diving in cold water environments. Functions as a diver/dive tender during underwater activities carried out at the ASLC. Fosters positive relationships with the public, ASLC visitors, volunteers, community leaders, contractors, and fellow staff members by promoting cooperation, professionalism, goodwill, and high standards of service. Becomes familiar with the fundamentals of operant conditioning for animals housed at ASLC and for animals that may remain in permanent human care following rehabilitation. Cross-trains with other husbandry departments to support efficient use of staff resources when appropriate. Complies with all Alaska Sealife Center policies, procedures, and programs. Performs other duties as assigned. Specialist 2 In addition to the above duties, 1. Under the supervision of a veterinarian or a veterinary technician, assist with medical procedures such as blood collection, anesthesia preparation and monitoring, and animal restraint for advanced physical exams and radiographs. 2. Under supervision of senior staff, assist in developing animal care and treatment plans. 3. Develop supervisory skills by mentoring interns and supporting their progression through the program. 4. Leads animal pickups and releases in the field. 5. Assist with the preparation and transport of non-releasable animals to permanent placement in zoos and aquariums. 6. Use principles of operant conditioning to shape and maintain husbandry behaviors of non-releasable animals. Other Skills and Abilities: Ability to remain organized, self-motivated, independent, and attentive to cleanliness and wildlife safety awareness. Willingness to work holidays, weekends, and overnights as needed to accommodate animal requirements. Comfortable with social media and with potentially being filmed and interviewed while working. Physical Requirements: The physical demands described here are representative of those that must be met to successfully perform the essential functions of this position. Reasonable accommodations may be made to enable individuals with disabilities. This role includes a range of physical activities, such as standing or moving for extended periods, bending, kneeling, crouching, and occasional climbing, as well as handling tools, equipment, and materials. The ability to lift and move up to 50 pounds may be needed depending on the assignment. Salary Range: $20.35-$25.03(1), $23.65-$29.15(2) Full Time with Benefits Please submit a resume, cover letter and letter of recommendation with your application. Must be able to pass a background check. --

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New publication - Far from the coast: organohalogen bioaccumulation in spinner dolphins from the Southwestern Atlantic
by Caroline Castro 10 Jun '26

10 Jun '26

Dear MARMAM community, My co-authors and I are pleased to share our new publication in Marine Pollution Bulletin, available in: https://www.sciencedirect.com/science/article/pii/S0025326X26005850 Caroline A.C. Corrêa, Bárbara M.R. Manhães, Nara Oliveira-Ferreira, Elitieri B. Santos-Neto, Eduardo R. Secchi, Juliana C. Di Tullio, Rodrigo C. Genoves, Haydée A. Cunha, Tatiana L. Bisi, Alexandre F. Azevedo, José Lailson-Brito. Far from the coast: organohalogen bioaccumulation in spinner dolphins from the Southwestern Atlantic, Marine Pollution Bulletin, Volume 230, 2026, 119798. https://doi.org/10.1016/j.marpolbul.2026.119798. Abstract: Organohalogenated compounds (OCs) are persistent, toxic, and easily transported in the environment. They bioaccumulate in biota and biomagnify along trophic webs, reaching high concentrations in top predators, such as odontocetes. Although data on OCs in South Atlantic oceanic species are limited, these compounds have been detected in dolphins far from pollution sources. This study evaluated the levels and contamination profile of organochlorine (PCBs, DDTs, HCHs, HCB, and mirex) and organobromine compounds (PBDEs, MeO-BDEs, HBB, and PBEB) in spinner dolphins (Stenella longirostris) from the outer continental shelf and slope of southeastern and southern Brazil. Remote biopsies of subcutaneous adipose tissue were collected (n = 42) and grouped by region (southeastern: n = 33; southern: n = 9). Discriminant analysis was conducted to assess differences in the contamination profile; five subgroups were found and defined by oceanographic features. PCBs were predominant in the Southeast (Sub-areas 1 and 2) while DDTs in the South (Sub-areas 3, 4 and 5). Concentrations (in ng/g lw) ranged from <11.90 to 15,344 for ΣDDT; <10.70 to 13,267 for ΣPCB; 1521.4 to 12,152 for ΣMeO-BDE; <18.30 to 3139.7 for Mirex; and <1.00 to 324.7 for ΣPBDE. HCHs, HCB, HBB, and PBEB were below the quantification limits. Mirex concentrations were among the highest reported in South Atlantic delphinids. Three assemblages (Sub-areas 1, 2 and 3 + 4 + 5) were identified, suggesting different foraging areas related to oceanographic processes. These results reveal cross-regional environmental dispersion and bioaccumulation in oceanic top predators of organohalogenated compounds, suggesting that coastal pollution can significantly impact the conservation of oceanic species. Thank you and all the best, -- *Caroline de Araujo Castro Corrêa* *B.S. and M.Sc. in Oceanography - UERJ*

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New publication: Trophic Transfer of Paralytic Shellfish Toxins to Common Dolphins (Delphinus delphis) in a North Patagonian Coastal Ecosystem
by Valeria D'Agostino 10 Jun '26

10 Jun '26

Dear MARMAM community, My co-authors and I are pleased to announce the publication of the following paper in Marine Mammal Science: D'Agostino, V. C., M. Degrati, M. Uhart, E. A. Crespo, and B. Krock. 2026. “Trophic Transfer of Paralytic Shellfish Toxins to Common Dolphins (Delphinus delphis) in a North Patagonian Coastal Ecosystem.” Marine Mammal Science 42, no. 3: e70204. https://doi.org/10.1111/mms.70204. Abstract: Harmful algal blooms represent an emerging risk for marine mammals through the trophic transfer of phycotoxins. This study assessed exposure to domoic acid and paralytic shellfish toxins (PSTs) in short-beaked common dolphins (Delphinus delphis) involved in a mass stranding event in Golfo Nuevo, northern Patagonia, Argentina, in March 2018. Samples from 47 dead dolphins, together with phytoplankton, mesozooplankton and Argentine anchovies (Engraulis anchoita), were analyzed by LC–MS/MS. Domoic acid was not detected in any sample. PSTs were absent from phytoplankton and mesozooplankton, but C1/C2 analogs were detected in anchovies, suggesting a potential trophic pathway. PSTs were detected in blood and kidney samples from 32 dolphins, including adults, juveniles, calves and one fetus. Although a direct causal link with the stranding could not be established, the results provide the first evidence of PST exposure in common dolphins from the Argentine Sea and highlight the potential health risks associated with sublethal phycotoxin exposure in coastal marine predators. Regards Dra. Valeria C. D'Agostino Investigadora - Laboratorio de Mamíferos Marinos Centro para el Estudio de Sistemas Marinos (CESIMAR-CONICET) Abuelas de Plaza de Mayo 2915, U9120ACD Puerto Madryn, Chubut, Argentina. Tel: (54-280) 4883184 - int. 1247 www.lamama.com.ar *CONICET* <https://www.conicet.gov.ar/new_scp/detalle.php?id=46111&keywords=Valeria%2B…> // *Google* <https://scholar.google.com/citations?user=7l-3q_8AAAAJ&hl=es> *Scholar* <https://scholar.google.com/citations?user=7l-3q_8AAAAJ&hl=es> "Lo que sabemos es una gota de agua; lo que ignoramos es el océano" - *Isaac Newton*

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A few new killer whale focused publications
by Jared Towers 10 Jun '26

10 Jun '26

Hello colleagues, Co-authors and I have recently had a few papers published open access in Marine Mammal Science. References and links are pasted below. best regards, Jared Executive Director Bay Cetology www.baycetology.org Barnhill, A., Towers, J.R., van Weelden, C., Rörup, T., Nöth, E., Maier, A., Bergler, C. (2026). Machine learning detection of scarring events in killer whales. Marine Mammal Science, 42:e70207. https://doi.org/10.1111/mms.70207 Abstract: Detection and analysis of body scars using photo-identification data of cetaceans can provide insights into life history, behavior, and exposure to threats, but such analyses typically require manual examination of large image datasets. To explore whether machine learning can assist this process, we developed a pipeline for automatically detecting and counting conspecific scarring events on killer whales. The approach combines an nnU-Net segmentation model, which generates binary masks containing individual scar lines, with hand-crafted feature representations and HDBSCAN clustering to group scars into events and estimate the number of events per image. Across a dataset in which images contained between 1 and 10 annotated scarring events (median = 2), the best-performing configuration produced a conservative estimator with a mean absolute error (MAE) of 0.82 events per image and exactly recovered the annotated number of events in just over 50% of cases. These results demonstrate that machine learning-assisted analysis can extract biologically meaningful information on scarring burden from standard photo-identification images of killer whales. While accurate recovery of absolute scarring burden from single images is achievable with useful reliability, detecting small inter-annual changes remains more challenging under heterogeneous field conditions. Rather than replacing expert annotation, the present system is best viewed as a semiautomated framework that can extend existing photo-identification workflows toward longitudinal scarring analysis and broader population-level assessment. It therefore provides a practical foundation on which more comprehensive detectors of cetacean scarring events can be built. Towers, J.R., Tixier, P., Guinet, C., Gasco, N., Arnould, J.P.Y., Cheeseman, T., Pitman, R.L. (2026). Total numbers and movements of photo-identified subantarctic (type D) killer whales. Marine Mammal Science, 42:e70192. https://doi.org/10.1111/mms.70192 Abstract: The distinctive Subantarctic (Type D) killer whale (DKW) (Orcinus orca) is a highly divergent and apparently inbred form previously known only from three mass strandings and several dozen at-sea sightings, primarily from Patagonian toothfish (Dissostichus eleginoides) longline vessels in the southern Indian Ocean and from tourism vessels in the Scotia Sea. Its range appears to be circumpolar throughout the Subantarctic, but very little is known about total numbers and overall movements. We summarize photo-identification data from 352 of 406 sightings collected between 44° S and 62° S from 2003 to 2024. Among 207 photo-identified individuals there were two distinct clusters of 78 and 29 toothfish depredators, one in the southern Indian Ocean and the other off southern Chile, respectively. An additional 100 DKW were photo-identified throughout the wider Subantarctic. Discovery curves indicate that DKW may be more abundant than some less divergent or inbred killer whale populations. Depredating DKW showed seasonal and interannual site fidelity, but 10 depredating individuals identified in the southern Indian Ocean were also resighted in the southern South Atlantic, 4428 km away. Probable re-sightings of two other DKW occurred in the Scotia Sea over distances of 1070 and 41 km, respectively. These latitudinally narrow, long-distance inter-ocean movements are unique among killer whales. During the study period, the entirely pelagic distribution of encounters appears to have shifted significantly southward. Scarff, T.M., Towers, J.R., Trites, A.W. (2026). The inside waters of Vancouver Island are critical foraging habitat for west coast transient killer whales. Marine Mammal Science, 42:e70205. https://doi.org/10.1111/mms.70205 Abstract: West Coast Transient (WCT) killer whales (Orcinus orca rectipinnus) hunt marine mammals along the west coast of North America from California to southeastern Alaska. However, little information is available on their seasonal use of nearshore areas and the relative importance of different parts of their range. Using sighting data from 2016 to 2023, we assessed their seasonal distribution and abundance in the inside waters of Vancouver Island (the Salish Sea and North Island Waters). WCT killer whales were seen an average of 250 days throughout each year. They were most frequently observed in the Salish Sea from March to September but had fewer sightings in July of even years when pink salmon returns were low. In contrast, occurrences of WCT killer whales in the North Island Waters peaked in September but were significantly lower overall. Peak occurrences in both areas corresponded with the seasonal presence of seals and sea lions, their primary prey. Overall, ~70% of the coastal subset of the WCT population occurred annually in a region that accounts for a relatively small portion of their range. This high concentration highlights the importance of the inside waters for their survival and emphasizes the need to assess other key areas within their range.

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Harassment Conversation
by Jeremy Kiszka 09 Jun '26

09 Jun '26

Dear MARMAM, Please join the Society for Marine Mammalogy for a conversation about harassment within the field of marine mammal science. This 6-part event, which began in 2025, provides an opportunity for our community members across all career stages to share their experiences with discrimination, harassment, solidarity or allyship; brainstorm resources or actions to mitigate harassment and create solidarity or allyship; and build a network dedicated to creating positive change. All are welcome and encouraged to join regardless of SMM membership, or career stage. These meetings, moderated by the DEI Committee, are offered in alternating months and across various time zones to provide the greatest flexibility for the global marine mammal research community. Each meeting will be limited to 25 participants; three meetings will be open only to female-identifying individuals, and three will be open to all regardless of gender identity. We are nearing the end of the series, with only two sessions remaining (see below). The conversations will focus on four topics: experiences with harassment, experiences with power dynamics, experiences with solidarity or allyship, and suggestions to create or improve resources and infrastructure in our community. Participants will have the option to join the conversation verbally or using an online whiteboard tool to type your responses if you do not feel comfortable sharing them verbally. Register here <https://forms.gle/72z78i7z2QBMAdQZA> (https://forms.gle/72z78i7z2QBMAdQZA) for the meeting time that works best for you (remaining sessions listed below) - because space is limited, please commit to attending for the meeting that you register for. If you register and are unable to attend, please let us know as soon as possible so that we can offer the spot to someone on the waitlist. Remaining Meeting Times: June 24, 2026 @ 2PM PST August 26, 2026 @ 5PM PST Dr. Jeremy J. Kiszka Society for Marine Mammalogy, President president(a)marinemammalscience.org

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New Publication: Ocean to Ocean: First Documented Migration of a Southern Right Whale From the Southwest Atlantic to the Southeast Pacific Ocean
by Santiago José Fernández 09 Jun '26

09 Jun '26

Dear MARMAM community, My co-authors and I are pleased to announce the publication of the following paper in Marine Mammal Science: Fernández, S. J., M. M.Uhart, A. M.García-Cegarra, V. Falabella, M. P. Heide- Jørgensen, M. Holland, A. Orce, M. Pujana, M. Sironi, F. Sucunza, M. Coscarella, A. N. Zerbini . 2026. “Ocean to Ocean: First Documented Migration of a Southern Right Whale From the Southwest Atlantic to the Southeast Pacific Ocean.” Marine Mammal Science42, no. 3: e70211. [ https://doi.org/10.1111/mms.70211 | https://doi.org/10.1111/mms.70211 ] . ABSTRACT: This study documents the first recorded migration of a southern right whale (Eubalaena australis) from the southwestern South Atlantic to the southeastern South Pacific. On October 25, 2023, an adult female with calf, named “Atenea,” was tagged with a satellite transmitter in Península Valdés, Argentina. During a 24.5-day journey, Atenea traveled 2,767 km, moving southward along the Argentine continental shelf, rounding Cape Horn, and then heading north along the Chilean coast. Mitochondrial DNA and photo-identification analyses revealed no significant genetic differentiation and no previous matches in regional catalogs. The results showed that haplotypes from whales sampled in the Pacific were interspersed among those from the Atlantic, suggesting contemporary or recent genetic and demographic connectivity between populations from both ocean basins. This unprecedented interoceanic movement challenges the notion of strictly segregated populations and provides a new perspective on the migratory plasticity of the species. The findings highlight the importance of continued satellite tracking and genomic studies to improve our understanding of habitat use and to inform conservation strategies for the critically endangered southeastern South Pacific population. Regards Santiago Fernández Laboratorio de Mamíferos Marinos (LAMAMA). Centro para el Estudio de Sistemas Marinos (CESIMAR) Centro Nacional Patagónico, CONICET Blvd. Brown 2915, 9120 Puerto Madryn Chubut, Argentina [ mailto:sfernandez@cenpat-conicet.gob.ar | sfernandez(a)cenpat-conicet.gob.ar ] / +54 (03401) 15434922

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