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New article on nutrient concentrations in minke whale faeces
by Brandt, Carla Freitas 18 Dec '25

18 Dec '25

Dear Colleagues, On behalf of my co-authors I am pleased to present our recently published paper: Freitas, C., Gundersen, K., Lindblom, L., Biuw, M., Haug, T., 2023. Nutrient concentrations in minke whale faeces and the potential impact on dissolved nutrient pools off Svalbard, Norway. Progress in Oceanography, 210, 102927. Abstract: There is increasing interest in assessing the impact of whales on nutrient and carbon cycling in the ocean. By fertilising surface waters with nutrient-rich faeces, whales may stimulate primary production and thus carbon uptake, but robust assessments of such effects are lacking. Based on the analysis of faeces collected from minke whales (n = 31) off Svalbard, Norway, this study quantified the concentration of macro and micronutrients in whale faeces prior to their release in seawater. Concentrations of the macronutrients nitrogen (N) and phosphorous (P) in minke whale faeces were 50.1 ± 10.3 and 70.9 ± 12.1 g kg−1 dry weight, respectively, while the most important micronutrients were zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu). By combining measured faecal nutrient concentrations with estimated prey-consumption and prey-assimilation rates, we calculate that the current population of approximately 15, 000 individuals in the small management area (SMA) of Svalbard defecates daily 7 ± 1.4 tonnes (t) N and 10 ± 1.7 t P during summer. The molar ratio of N:P in minke whale faeces was 1.6:1, meaning that N was proportionally limiting, when compared to average elemental ratios of 16:1 in phytoplankton. In case of no N limitation in surface waters at that time, the release of elemental P through defecation in surface waters has the potential to stimulate 407 ± 70 t of carbon per day during summer as new or regenerated primary production in the SMA of Svalbard. This amounts to 0.2 to 4 % of daily net primary production in this region. This study provides the first assessment of nutrient concentration in whale faeces prior to their dissolution in sea water. Further research, namely on the amount of N released via urine and seasonal changes in excreted nutrients, is needed to better assess the full potential of whale nutrient additions to dissolved nutrient pools in surface waters at regional and global scales. The article is freely available at: https://www.sciencedirect.com/science/article/pii/S0079661122001860 Kind regards, Carla Carla Freitas Institute of Marine Research, Norway

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Sea Watch Foundation 2026 Anglesey Internships (North Wales)
by mel.mckenzie＠seawatchfoundation.org.uk 18 Dec '25

18 Dec '25

Dear MARMAM Community, The Sea Watch Foundation is pleased to announce the release of their 2026 internships in Anglesey, North Wales. APPLICATIONS FOR 2026 ARE NOW OPEN The Sea Watch Foundation is seeking Research Interns and a Research and Intern Assistant for the 2026 season at its field office in Anglesey, North Wales, to engage in an exciting citizen science initiative to engage local communities and visitors in observing and recording marine mammals and birds as part of a marine conservation project. These are 5-week internship periods throughout our field season from April-October. This position will suit volunteers who have a strong interest in marine conservation and recognise the importance of raising awareness of the marine environment by involving the public from all age groups. The interns will be responsible for the following duties: 1. Raising Sea Watch Foundation’s profile locally (taking part in events, talking to the public) 2. Carrying out surveys of marine mammals and seabirds in the area of SW Anglesey and Caernarfon Bay, undertaking watches from land and participating in boat-based surveys 3. Engaging with local communities, encouraging and training citizen scientists to collect data on marine mammals and seabirds 4. Promoting and organising the National Whale and Dolphin Watch education and outreach activities 5. Participating in presentations and creating activities to take to local schools/groups, as well as using our specialised talks at local events 6. Assisting in the creation of educational/promotional materials (posters, displays, flyers, social media posts) 7. Participating in training courses in Anglesey and Gwynedd 8. Representing Sea Watch at public events around Anglesey and Gwynedd 9. Training and supervision will be provided by the Project Manager and Research and Intern Assistant for the duration of the intern’s stay. The Research and Intern Assistant will ideally be available for the entire field season, with the option to split the role into two positions if they are unable to commit to the full season. They need to demonstrate their ability to deal with varied tasks from overseeing research interns, public outreach to boat based survey and scientific data collection. They will be encouraged to take initiatives and support the Project Lead and Project Officers in all aspects of their work, as well as with education & outreach activities in the region which due to its natural beauty receives large numbers of visitors during the summer. For more information and how to apply, please see the links to our website below. Research Intern: https://www.seawatchfoundation.org.uk/anglesey-research-intern/ Research and Intern Assistant: https://www.seawatchfoundation.org.uk/anglesey-internships/research-and-int… Mel McKenzie Volunteer Coordinator Cydgysylltwr Gwirfoddolwyr Sea Watch Foundation Ynys Môn e:mel.mckenzie@seawatchfoundation.org.uk This role is funded by the Welsh Council for Voluntary Action (WCVA) as part of the Sea Watchers Môn project, transforming the way we support communities. [image.png]

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New open access publication on proteomic characterization of bottlenose dolphin urine
by Cusick, Kelly Nicole (Student) 17 Dec '25

17 Dec '25

Dear MARMAM community, My co-authors and I are pleased to share our recent publication, “Proteomic Characterization of Bottlenose Dolphin (Tursiops truncatus) Urine,” in the Journal of Proteome Research, now available open access at Https://pubs.acs.org/doi/full/10.1021/acs.jproteome.5c00718<https://pubs.acs.org/doi/full/10.1021/acs.jproteome.5c00718> Abstract: Urinary proteins offer multifaceted insights into tissue repair, dysfunction, and renal health, with significant implications for both human and veterinary medicine. However, marine mammal medicine lacks comprehensive studies on urine protein composition. This study aimed to describe the urine proteome of wild common bottlenose dolphins (Tursiops truncatus) at two Gulf of Mexico sites (Sarasota Bay, FL, and Barataria Bay, LA) and to compare urine proteins by sex. Ten urine samples (Barataria Bay, LA: N = 6; Sarasota Bay, FL: N = 4) were analyzed by nano LC-MS/MS. Peptide spectral matching identified 1872 protein families across all individuals (FDR < 0.01). Cystatin 11 was notably present in males (median rank abundance: 8.1%) and absent in females (median: 0.0%), with semen contamination elevating protein diversity in male urine. Two putative antimicrobial proteins, cathelicidin and lysozyme, accounted for 2.66% of the urine proteome, suggesting an innate immune defense mechanism. In total, 27 proteins that are recognized as acute kidney injury markers in humans, and 12 putative stone formation proteins were detected in dolphin urine. This research provides a reference database of urinary proteins that can be used to develop advanced methods for investigating dolphin renal health. Data are available via ProteomeXchange with identifier PXD054283. Cusick, K. N., Bland, A., Stacy, N. I., McFee, W. E., Takeshita, R., Wells, R. S., Smith, C.R., Schwacke, L. & Janech, M. G. (2025). Proteomic Characterization of Bottlenose Dolphin (Tursiops truncatus) Urine. Journal of Proteome Research. Thanks, Kelly Cusick, M.S. College of Charleston

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Job Opportunity: Research Associate (North Atlantic Right Whales) at the Florida Fish and Wildlife Conservation Commission
by Rood, Kari 17 Dec '25

17 Dec '25

Please see below for information regarding a Research Associate position in St. Petersburg, FL. https://jobs.myflorida.com/job/ST-PETERSBURG-RESEARCH-ASSOCIATE-FWC-7707284… Florida Fish and Wildlife Conservation Commission (FWC) Wildlife Research-Marine Mammal Section Research Associate Salary: $45,000 annually Posting closes 1/4/2026 Position Overview and Responsibilities: The Florida Fish and Wildlife Conservation Commission (FWC), Fish and Wildlife Research Institute is seeking a Research Associate within the North Atlantic right whale research team. The successful candidate will be responsible for developing, maintaining, and analyzing right whale and vessel traffic spatial and relational databases to improve knowledge of the distribution of right whales and the threats they face in the Southeastern U.S. The successful candidate will also be responsible for developing and managing web mapping applications to serve relevant spatial data to collaborators and other stakeholders. Additionally, the successful candidate may have supervisory responsibilities. Applicants with any of the following demonstrated experiences are encouraged to apply and may be given preference: applying scientific programming languages, such as R and Python; processing, managing, and analyzing AIS vessel traffic data or other large geospatial databases; developing and managing web mapping and data visualization applications; and conducting ecological analyses using hierarchical models, such as distance sampling, mark-recapture, and spatial capture-recapture. Applicants must apply at the posting link to be considered. Knowledge, Skills and Abilities: Knowledge, skills, and abilities required for this position include knowledge of marine mammal ecology, GIS methods and programs (ArcGIS Pro), scientific programming, spatial analysis techniques, data management principles. Ability to maintain, process, analyze, and interpret spatial and relational data using GIS and scientific programming languages. Skill in the use of personal computers, low code tools, GIS technology, scientific programming, and databases. Knowledge of wildlife biology, terminology, principles and techniques used in conservation research on wildlife species. Ability to establish and maintain effective working relationships, plan and organize work assignments with minimal supervision, and communicate effectively with staff. Ability to effectively supervise others. Minimum Qualifications: 6 years professional experience in a closely related biological field or laboratory program is required. A bachelor's degree from an accredited college or university with major course of study in one of the physical or natural sciences or mathematics and two years of experience in one of the physical or natural sciences or mathematics; or two years of experience as a Research Assistant - FWC; or, A master's degree from an accredited college or university with major course of study in one of the educational areas listed above can substitute for one year of the required experience; or, A doctorate from an accredited college or university with major course of study in one of the educational areas listed above can substitute for the required experience. Preferred Qualifications: Preference may be given to candidates who possess a master's degree from an accredited college or university with major course of study in one of the physical or natural sciences or mathematics; Applicants with any of the following demonstrated experiences are encouraged to apply and may be given preference: applying scientific programming languages, such as R and Python; processing, managing, and analyzing AIS vessel traffic data or other large geospatial databases; developing and managing web mapping and data visualization applications; conducting ecological analyses using hierarchical models, such as distance sampling, mark-recapture, and spatial capture-recapture; and conducting spatial analysis using GIS software. Preference may also be given to candidates that have demonstrated experience with scientific project management, implementing wildlife conservation research and/or monitoring projects, candidates who have experience with fish and wildlife data collection and analysis, and natural resource and relational database management. Requirements: Employment in this position is contingent upon a satisfactory Level 1 background check at no cost to the candidate. Office hours are from 8:00 A.M. to 5:00 P.M. Eastern Standard Time, Monday through Friday. Not eligible for Telework. Responses to qualifying questions should be verifiable by skills and/or experience stated on the profile application/resume. Information should be provided regarding any gaps in employment. To view this posting and apply: https://jobs.myflorida.com/job/ST-PETERSBURG-RESEARCH-ASSOCIATE-FWC-7707284…

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New papers on long-term dynamics of the home range and trophic interactions of coastal bottlenose dolphins
by Jessica Carde 17 Dec '25

17 Dec '25

Dear MARMAM community, My coauthors and I are happy to share with you two papers recently published on the home range dynamics and trophic interactions of bottlenose dolphins exposed to long-term habitat degradation in the coastal waters of southern Florida (Biscayne Bay, in the Miami area): Cardé, J., Litz, J., Brossard, A., Wicker, J., Contillo, J. & Kiszka, J., 2025. Long-term dynamics of the home range and community structure of bottlenose dolphins in an estuarine ecosystem in southern Florida. Aquatic Conservation: Marine and Freshwater Ecosystems, 35: e70253. https://onlinelibrary.wiley.com/doi/full/10.1002/aqc.70253 Cardé, J., Caputo, M., Litz, J., Brossard, A., Wicker, J., Contillo, J. & Kiszka, J., 2026. Community-level variation in the trophic interactions of common bottlenose dolphins, Tursiops truncatus, experiencing a reduction of their foraging habitat. Marine Mammal Science, 42: e70090. https://onlinelibrary.wiley.com/doi/full/10.1111/mms.70090 Please don't hesitate to contact me (jecarde(a)fiu.edu) for a pdf copy or to ask any questions. Sincerely, Jessica Cardé Jessica Cardé, Ph.D. Principal Investigator, NSF CREST Postdoctoral Research Program Institute of Environment, Coastlines and Oceans Division Department of Biological Sciences Florida International University Marine Mammal Ecology Lab <https://marineconservationecologylab.com/> [cid:7c54c9ca-4a5c-4530-ae95-642b091742cd]

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Trophic redundancy within a community of small cetaceans from the Caribbean Sea
by Jeremy Kiszka 17 Dec '25

17 Dec '25

Dear MARMAM community, The following paper was recently published: Guillaume Chandelier and I are pleased to share the following paper published in Science of the Total Environment on the trophic relationships of small cetaceans in the Caribbean Sea: Chandelier, G. & Kiszka, J. 2025. Trophic redundancy within a diverse community of sympatric delphinids in the oligotrophic Caribbean Sea. Science of the Total Environment, 1009: 180994. Link to the paper: https://www.sciencedirect.com/science/article/pii/S0048969725026348 Abstract Understanding the trophic interactions of sympatric predators is essential to assess ecosystem structure, particularly in oligotrophic environments where resources are scarce. We examined the trophic structure of a diverse community of sympatric delphinids in the Lesser Antilles, in the eastern Caribbean Sea, using stable carbon (δ13C) and nitrogen (δ15N) isotope analysis. Isotope data suggest the existence of three distinct isotopic clusters. Killer whales (Orcinus orca) and false killer whales (Pseudorca crassidens) exhibited the highest δ15N and δ13C values, broad isotopic niches, and minimal overlap, indicating distinct apex predator roles. A cluster of mesopredators include short-finned pilot whales (Globicephala macrorhynchus), Risso's dolphins (Grampus griseus), melon-headed whales (Peponocephala electra), Fraser's dolphins (Lagenodelphis hosei), and Clymene dolphins (Stenella clymene) showed intermediate δ15N values and moderate to high isotopic overlap. In contrast, smaller delphinids (Stenella spp.) formed an isotopic cluster characterized by lower δ15N values, exhibited narrow isotopic niches, reflecting limited dietary variation and low trophic redundancy. Ontogenetic shifts and sex variation in isotopic niches were rarely detected. These findings provide novel insights into resource partitioning and ecological roles among a wide diversity of delphinids in a nutrient-poor tropical ecosystem. If you would like any additional information or a copy, please do not hesitate to contact gchandel(a)fiu.edu Sincerely, Jeremy Kiszka, Ph.D. Associate Professor Institute of Environment, Coastlines and Oceans Division Department of Biological Sciences Florida International University https://environment.fiu.edu<https://environment.fiu.edu/> - Principal Investigator, Marine Mammal Ecology Laboratory 3000 NE 151 St., FL-33181, North Miami, USA. Office (direct): (305)-919-5234 [File:ResearchGate icon SVG.svg - Wikimedia Commons] ResearchGate<https://www.researchgate.net/profile/Jeremy-Kiszka/research> (publications) - President, Society for Marine Mammalogy https://marinemammalscience.org<https://marinemammalscience.org/> [cid:6102cceb-6f03-4960-96d5-442043c46840]

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New paper on genetic population structure of Bottlenose Dolphin, Tursiops truncatus
by Moore, Daniel 17 Dec '25

17 Dec '25

Dear MARMAM community, My co-authors and I are pleased to share the following publication in Molecular Ecology on population structure of bottlenose dolphin, Tursiops truncatus, across the Mediterranean and eastern Atlantic: Moore, D.M., Moura, A.E., Natoli, A., Papale, E., Cunningham, E.G., Silva, M.A., Genov, T., Gaspari, S., Buscaino, G., Berggren, P. and Gröcke, D.R., 2025. Population Genomics and the Environmental Drivers of Population Structure in a Cosmopolitan Marine Predator, Tursiops truncatus. Molecular Ecology, p.e70182. https://onlinelibrary.wiley.com/doi/pdf/10.1111/mec.70182 The marine environment comprises vast regions without physical barriers to movement, making the understanding of population isolation and the evolution of diversity challenging. This is especially the case for highly mobile marine species. Here we investigate populations of the common bottlenose dolphin (Tursiops truncatus) across the Mediterranean Sea and adjacent North Atlantic using high-resolution genomic markers (RADseq) and stable isotope analyses to better understand the evolution of population structure in this system. High-resolution genomic data and broad geographic sampling revealed patterns of structure not previously identified, and integration with stable isotope data suggests that prey choice varies across this region. Unexpected patterns included genetic and isotopic similarity between the North Atlantic and the region around Sicily (but not including the medially located Gulf of Cádiz and surrounding regions). The regional habitat within and beyond the Mediterranean Sea is structured with ocean frontal systems including thermal and halocline transitions, several of which show alignment with genetic transitions within our data. Our data help to distinguish among possible drivers of population differentiation for a marine predator that has the potential for long-distance dispersion. If you would like any additional information then please do not hesitate to send me an email at d.moore4(a)exeter.ac.uk. All the best, Daniel Dr. Daniel Moore (He/Him) Lecturer in Marine Biology University of Exeter, Penryn Campus, Cornwall, TR10 9FE My working hours may not be your working hours. Please do not feel obliged to read, reply or act on this message outside of your normal schedule. ü Daniel Moore Profile | University of Exeter<https://experts.exeter.ac.uk/43311-daniel-moore> ü Dr Daniel Moore - Personal<https://danielmmoore.com/> ü Exeter Marine<https://www.exeter.ac.uk/research/marine/> Follow ExeterMarine on: Facebook<https://www.facebook.com/ExeterMarine/> / Twitter<https://twitter.com/ExeterMarine> / Instagram<https://www.instagram.com/exetermarine/> / LinkedIn<http://www.linkedin.com/company/exetermarine> [cid:160778ac-e1d1-4d45-aad9-06bd9e263cb9]

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New publication on weaving Māori knowledge and systematic surveys to characterise marine megafauna biodiversity
by Tom Brough 16 Dec '25

16 Dec '25

Kia ora MARMAM whānau, On behalf of our hononga (partnership) I am very pleased to announce a new publication that weaves Māori Indigenous knowledge (mātauranga Māori) and conventional systematic surveys to develop a baseline on marine megafauna in Te Akau, New Zealand. Our article is published in Ecology and Evolution’s special Issue – Indigenous Science and Practice, and we hope will be of interest to those interested in working across dual knowledge systems in marine mammal research. The open access article and pdf can be found at https://onlinelibrary.wiley.com/doi/10.1002/ece3.72558. Please reach out if you have any questions around the article. Full citation and abstract for the article is provided below. Meri Kirihimete, Tom Brough Brough, T., Kereopa, H., Shirkey, T., Zaeschmar, J., Leunissen, E., Milner, D., & Chetham, J. (2025). Tere Tohorā, karanga tāngata: Weaving Māori knowledge with conventional science to characterise a biodiversity hotspot for marine megafauna in an area facing multiple anthropogenic impacts. Ecology and Evolution, 15, e72558. https://doi.org/10.1002/ece3.72558 ABSTRACT Marine megafauna are important components of marine ecosystems and are of major significance to Indigenous communities, including Maori. Despite being recognised as a biodiversity hotspot for megafauna, most locations in Aotearoa New Zealand (NZ) do not have adequate information for the management of anthropogenic impacts on these taxa. Due to long-standing Relationships with Maori, there is a wealth of matauranga Maori (Maori knowledge) on megafauna that may help fill key gaps. This study, Tere Tohora Karanga Tangata, aims to address information gaps on marine megafauna within Te Akau/Bream Bay, on the north-east of NZ's North Island. We utilise a wananga (shared learning) approach alongside conventional visual and acoustic surveys to synthesise an accurate baseline of species occurrence, distribution, habitat use and site fidelity. Maori knowledge in a variety of forms was gathered and simultaneously integrated into the survey design across seven vessel-based field surveys. We calculate seasonal sighting rates and use species distribution models (SDM) to determine the distribution of commonly occurring species and use photo-identification to investigate site fidelity of marine mammals. Both knowledge systems confirmed the importance of Te Akau/Bream Bay for marine megafauna, reporting high diversity and abundance of marine mammal (8 species) and seabird species (24 species) and high sighting rates of threatened taxa. While most species were encountered year-round, sighting rates and predictions from SDMs highlight seasonal variability in the occurrence and distribution of most species. Maori knowledge aligned closely with results from conventional scientific approaches in confirming the most common species (common dolphin, Bryde's whale), seasonal habitat preferences, and, importantly, provided historical information on species that have been extirpated from the study area. Combined, the two knowledge systems have generated a robust baseline on marine megafauna that can be used to guide the management of these important species and showcase the advantages of utilising dual-knowledge systems for characterising marine biodiversity. Dr Tom Brough (he / him) Marine Ecologist - Quantitative Modeller +64-7-856-1735 +64-21-997-275 38 Harrow Street, Dunedin, New Zealand Earth Sciences New Zealand [Earth Sciences New Zealand]<https://earthsciences.nz> The Institute of Geological and Nuclear Sciences Limited and the National Institute of Water and Atmospheric Research Limited joined to become the New Zealand Institute for Earth Science Limited. We are known as Earth Sciences New Zealand. For more information on the Earth Sciences transition click here<https://niwa.co.nz/about-niwa/science-sector-reforms>. Notice: This email may contain information which is confidential and/or subject to copyright, and may not be used, published or redistributed without the prior written consent of Earth Sciences New Zealand. If you are not the intended recipient, please immediately notify the sender and delete the email and any attachments. Any opinion or views expressed in this email are those of the individual sender and may not represent those of Earth Sciences New Zealand. For information about how we process data and monitor communications please see our privacy policy<https://niwa.co.nz/about-niwa/privacy-policy>.

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New open access publication on fish-eating killer whale diet in the North Pacific
by Hannah Myers 16 Dec '25

16 Dec '25

Dear MARMAM community, On behalf of my co-authors, I'm pleased to share our new publication "The diverse diet of southern Alaska resident killer whales shifts across spatiotemporally distinct foraging hotspots" in the journal Ecosphere, available open access at https://doi.org/10.1002/ecs2.70509. Abstract: Top predators influence ecological communities in part through the prey they consume. Prey preferences often shift throughout the year, reflecting both seasonal and geographic patterns of habitat use and the relative abundance of preferred prey species. Killer whales (*Orcinus orca*) are top predators in the marine ecosystem, and understanding their diet is critical to assess their ecological impacts and role. In this study, we examine the diet of the southern Alaska resident killer whale population across three major foraging hotspots. We leverage two complementary sampling methods—morphological ID and genetic metabarcoding—to reveal strong spatiotemporal patterns in diet from May through September. Chinook, chum, and coho salmon were each important prey resources in different locations and times, with consistent dietary contributions from Pacific halibut, arrowtooth flounder, and sablefish. Our results reveal a diverse, location-specific, and strongly seasonal foraging strategy in this top predator and highlight the increased resolution provided by using ensemble techniques to characterize foraging behavior. Effective conservation and management of this population will depend on broad spatiotemporal sampling to accurately characterize foraging ecology. Myers, H.J., Olsen, D.W., Van Cise, A.M., Wells, A.H., Parsons, K.M., & Matkin, C.O. 2025. The diverse diet of southern Alaska resident killer whales shifts across spatiotemporally distinct foraging hotspots. Ecosphere 16(12), e70509. https://doi.org/10.1002/ecs2.70509. Thank you, Hannah -- *Hannah Myers, PhD* Assistant Professor, Department of Fisheries College of Fisheries and Ocean Sciences University of Alaska Fairbanks 2150 Koyukuk Drive Fairbanks, Alaska 99775 hannah.myers(a)alaska.edu <hmyers8(a)alaska.edu>

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New paper: Scaling of field metabolic rates in sympatric cetaceans
by Maria Glarou 16 Dec '25

16 Dec '25

Dear colleagues, My co-authors and I are happy to announce the open-access publication of the following article in the Journal of Comparative Physiology B: Glarou, M., Christiansen, F., Iwata, T., Basran, C.J., Ruppert, S.N.S., Sotiropoulou, D., Iversen, M.R., Akamatsu, T.,Schnitzler, J.G., Siebert, U., Rasmussen, M.H. (2025). Respiration rates and inferred mass-specific field metabolic rates decline with body size among five sympatric cetaceans. Journal of Comparative Physiology B. https://doi.org/10.1007/s00360-025-01640-1 Abstract: Metabolic rates in animals scale allometrically with body mass, a relationship well-established in terrestrial mammals. Whether these scaling laws apply to fully aquatic mammals remains uncertain, due to key physiological and ecological differences. We estimated field metabolic rates (FMRs) for five sympatric cetaceans of varying sizes, inhabiting sub-Arctic Icelandic waters: harbour porpoises (Phocoena phocoena; mean body length•s.d=1.35•0.19m), white-beaked dolphins (Lagenorhynchus albirostris; 2.42•0.17m), minke whales (Balaenoptera acutorostrata; 7.53•0.82m), humpback whales (Megaptera novaeangliae; 9.44•1.13m) and blue whales (Balaenoptera musculus; 21.97•0.96m). Unoccupied Aerial Vehicle (UAV) photogrammetry and published data were used to estimate body size, while respiration rates (breathes min-1) were obtained from UAV focal follows, biologging tags, and literature sources. From these data we predicted daily FMRs (MJ day-1) using existing bioenergetic models. As expected, mass-specific FMR declined with increasing body size among species, consistent with scaling laws. However, FMRs across all species were elevated relative to terrestrial predictions, likely reflecting the greater energetic demands of aquatic life. FMR also scaled positively with the surface-area-to-volume ratio (SVR) of each species, supporting the hypothesis that thermoregulatory costs are driven by body shape and size, and influence energy expenditure. This was further supported by the positive relationship between FMR and heat loss rates. Overall, our findings suggest that large mysticetes benefit from reduced mass-specific FMRs, enabling long migrations and extended fasting that broaden their habitat use. Smaller cetaceans face higher metabolic demands and may be more dependent on smaller, prey-rich habitats. These size-dependent energetic constraints may influence species plasticity and vulnerability to environmental changes. The PDF of the paper can be accessed from the following link: https://rdcu.be/eUoIG Best regards, Maria Glarou PhD Fellow Húsavík Research Centre University of Iceland Hafnarstétt 3, 640 Húsavík Email: mag133(a)hi.is<mailto:mag133@hi.is> / maria_glarou(a)outlook.com<mailto:maria_glarou@outlook.com> Instagram: @seagullseyeview<https://www.instagram.com/seagullseyeview/> Bluesky: @mglarou.bsky.social<https://bsky.app/profile/mglarou.bsky.social> ResearchGate<https://www.researchgate.net/profile/Maria-Glarou> / Google Scholar<https://scholar.google.com/citations?user=gVV1c04AAAAJ&hl=en>

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