Marine Mammal Science Research Articles

This issue of Marine Mammal Science is dedicated to the memory of Dr. Michael F. Tillman

This issue of <i>Marine Mammal Science</i> is dedicated to the memory of Dr. Michael F. Tillman

Ethical standards for research on marine mammals

Conducting marine mammal research can raise several important ethical issues. For example, the continuation of whaling for commercial purposes despite the international moratorium provides opportunities for scientists to obtain data and tissue samples. In 2021 we analysed 35 peer-reviewed papers reporting research based on collaborations with Icelandic whalers. Results highlighted little consideration or understanding of the legal and ethical issues associated with the deliberate killing of whales amongst those researchers, funding bodies, universities and journals involved. Ethical statements were rarely provided. Those that were written were incomplete. Whilst research using whaling data may seem acceptable to some, it often becomes hard to justify when subject to scrutiny by the media and the public. Thus, there is a particular danger of reputational harm for early career researchers who may become unwittingly involved in such activities. Here we also consider the broader variety of ethical issues raised by non-lethal research (both historical and recent) on marine mammals including tagging and biopsy. We discuss instances where study animals were harmed or even killed and where the public mistook tags for harpoons. Without clear guidelines, reviewers and journal editors are put in an impossible position when considering whether to reject papers on ethical grounds. We propose that for such studies, universities, funders, journals, and permit issuers must require ethical assessments and that journals more effectively implement their existing policies on publishing ethical statements. The professional marine mammal societies need to work together to produce modern ethical guidance. Such guidance should require transparency in the provenance of data and samples while including advice on law, welfare issues, involvement of local scientists, and offshoring. Furthermore, it should require appraisal of and justification for the absolute necessity of invasive procedures. As is already the case in biomedical disciplines, ethical statements should be required in marine mammal science.

Yasunaga et al. (2022) meets the ethics code of Marine Mammal Science, and the journal's decision to publish the paper is correct

Yasunaga et al. (2022) meets the ethics code of <i>Marine Mammal Science</i>, and the journal's decision to publish the paper is correct

A legacy of excellence: SAY’s contributions to bioacoustics research at the Navy Marine Mammal Program

The dolphin SAY is considered a jack-of-all-trades in marine mammal science. This comes as no surprise as her mother was one of the five dolphins deployed to Cam Ranh Bay, Vietnam as part of the Navy’s first deployable marine mammal system. SAY was born in 1979 and began participating in research from birth; she was the first dolphin to have her caloric intake and weight tracked as a calf into adulthood, and while carrying her own calf in 1991. In her early years, she participated in cutting-edge studies using high-speed video endoscopy to better understand dolphin click production. She later participated in echolocation vigilance tasks that spearheaded our understanding of dolphin cognitive abilities focusing on duration and the effects of anthropogenic noise. During this same time, she diligently contributed to projects that revolutionized our understanding of dolphin biosonar and its relation to perception and auditory system neurophysiology. SAY will be remembered by her charismatic personality and her 38 years of service to science and the United States Navy. Her daughter continues to carry out her legacy working for the Navy’s fleet mine-hunting system.

“Nacho”—A willing and adventurous dolphin with diverse research accomplishments

The bottlenose dolphin, WEN (also known as “Nacho”), worked in the swimmer interdiction system of the United States Navy Marine Mammal Program (MMP) before being transferred to MMP research in the mid-2000s. During his time away from systems work, WEN participated in diverse research projects that benefited our understanding of dolphin hearing, bioacoustics, and auditory physiology. His contributions include several ground-breaking studies: (1) he demonstrated that dolphins could remain vigilant at an acoustic target detection task for days without rest or performance decrement, (2) participated in the first study matching dolphin structural (MRI) and functional imaging (SPECT, PET) with an emphasis on the anatomy of sound-reception and transmission, (3) performed open-ocean work to investigate the target strength of dolphins at depth and the potential for intravascular bubble formation during diving, (4) was instrumental in the development of auditory evoked potential (AEP) methods for use in MMP dolphins, and (5) performed the first direct comparison of AEP and behavioral thresholds to the same acoustic stimulus in a marine mammal. Not only have WEN’s contributions significantly advanced marine mammal science, but with his return to systems work, he continues to contribute to the national security of the United States.

Needles in an ocean haystack: using environmental DNA to study marine mammals in the North Atlantic

Marine mammals in the North Atlantic have experienced severe depletions due to overexploitation. While some species and populations have now recovered, there are numerous other anthropogenic activities impacting their North Atlantic ecosystem. Studying marine mammals is often associated with logistical challenges, and many species have an elusive nature, resulting in substantial knowledge gaps on the distribution, abundance and diversity of marine mammals in the North Atlantic. Environmental DNA (eDNA) is an emerging tool in biodiversity monitoring and has successfully been demonstrated to complement traditional monitoring methods for a wide range of marine taxonomic groups. The promising potential of seawater eDNA is owe to advances within an array of molecular methods used to extract, detect and/or sequence the genetic material of marine organisms from a single seawater sample. &#x0D; We present a literature review of eDNA studies of marine mammals and discuss the potential applications and practical challenges of eDNA in marine mammal research, management and conservation. &#x0D; Environmental DNA has already been introduced to a wide range of applications within marine mammal science, from detection of endangered species to population genetic assessments. Furthermore, eDNA has the power to capture other biologically important species in the marine ecosystem and food web, which could facilitate insight into the spatiotemporal variation of different marine communities in a changing environment. With methodological and technological standardization, eDNA based approaches have a promising potential to be integrated into regular monitoring practices and management strategies.

Probable signature whistle production in Atlantic white‐sided (Lagenorhynchus acutus) and short‐beaked common (Delphinus delphis) dolphins near Cape Cod, Massachusetts

Probable signature whistle production in Atlantic white‐sided (<i>Lagenorhynchus acutus</i>) and short‐beaked common (<i>Delphinus delphis</i>) dolphins near Cape Cod, Massachusetts

Sam Houston Ridgway 1936–2022

Sam Houston Ridgway 1936–2022

Determining marine mammal detection functions for a stationary land-based survey site

Abstract ContextThe shore-based survey is a common, non-invasive, and low-cost method in marine mammal science, but its scientific applications are currently limited. Such studies typically target populations whose distributions are not random with respect to nearshore sites and involve repeated scans of the same area from single, stationary platforms. These circumstances prohibit the use of classic distance sampling techniques for estimating animal densities or distributions, particularly the derivation of a detection function that describes the probability of detecting targets at various distances from the observer. AimsHere, we present a technique for estimating land-based detection functions, as well as quantifying uncertainty in their parameterisation, on the basis of the range-specific variability of observations from one scan to the next. MethodsThis Bayesian technique uses Monte Carlo simulation to determine the likelihood of thousands of candidate detection functions, then conducts weighted sampling to generate a posterior distribution estimate of the detection function parameterisation. We tested the approach with both archival and artificial datasets built from known detection functions that reflect whale and porpoise detectability. Key resultsWhen the base distribution of targets was random, the whale detection function was estimated without error (i.e. the difference of the median of the posterior and the true value was 0.00), and the porpoise detection function was estimated with an error equal to 4.23% of the true value. When the target base distribution was non-random, estimation error remained low (2.57% for targets concentrated offshore, 1.14% when associated with nearshore habitats). When applied to field observations of humpback whales and Dall’s porpoises from a land-based study in northern British Columbia, Canada, this technique yielded credible results for humpback whales, but appeared to underestimate the detectability of Dall’s porpoises. ConclusionThe findings presented here indicate that this approach to detection function estimation is appropriate for long-running surveys in which scan regularity is high and the focus is on large, slow-moving, low herd-size, and easily detectable species. ImplicationsThe derivation of a detection function is a critical step in density estimation. The methodology presented here empowers land-based studies to contribute to quantitative monitoring and assessment of marine mammal populations in coastal habitats.

Preface to Sea Mammal Research Unit 40th Anniversary Issue

Aquatic Conservation: Marine and Freshwater EcosystemsVolume 29, Issue S1 p. 5-5 SUPPLEMENT ARTICLE Preface to Sea Mammal Research Unit 40th Anniversary Issue First published: 06 September 2019 https://doi.org/10.1002/aqc.3138Read 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 No abstract is available for this article. Volume29, IssueS1Supplement: Sea Mammal Research Unit 40th Anniversary: Advances in Marine Mammal Science informing Policy. Guest Editors: Bennett, K., Hall, A., McConnell, B., Thompson, P., & Twiss, S.September 2019Pages 5-5 RelatedInformation

Marine mammal subspecies in the age of genetics: Introductory remarks from the Associate Editor and Editor‐in‐Chief of Marine Mammal Science

Marine mammal subspecies in the age of genetics: Introductory remarks from the Associate Editor and Editor‐in‐Chief of <i>Marine Mammal Science</i>

Equity and career‐life balance in marine mammal science?

AbstractIt is widely acknowledged that family and care‐giving responsibilities are driving women away from Science, Technology, Engineering, and Mathematics (STEM) fields. Marine mammal science often incurs heavy fieldwork and travel obligations, which make it a challenging career in which to find work‐life balance. This opinion piece explores gender equality, equity (the principles of fairness that lead to equality), and work‐life balance in science generally and in this field in particular. We aim to (1) raise awareness of these issues among members of the Society for Marine Mammalogy; (2) explore members’ attitudes and viewpoints collected from an online survey and further discussion at a biennial conference workshop in 2015; and (3) make suggestions for members to consider for action, or for the Board of Governors to consider in terms of changes to policy or procedures. Leaks in our pipeline—the attrition of women, and others with additional caring responsibilities—represent an intellectual and economic loss. By striving for equity and promoting work‐life balance, we will help to ensure a healthy and productive Society better able to succeed in its aims promoting education, high quality research, conservation, and management of marine mammals.

Evaluating morphometric and metabolic markers of body condition in a small cetacean, the harbor porpoise (Phocoena phocoena).

Mammalian body condition is an important individual fitness metric as it affects both survival and reproductive success. The ability to accurately measure condition has key implications for predicting individual and population health, and therefore monitoring the population‐level effects of changing environments. No consensus currently exists on the best measure to quantitatively estimate body condition in many species, including cetaceans. Here, two measures of body condition were investigated in the harbor porpoise (Phocoena phocoena). First, the most informative morphometric body condition index was identified. The mass/length2 ratio was the most appropriate morphometric index of 10 indices tested, explaining 50% of the variation in condition in stranded, male porpoises with different causes of death and across age classes (n = 291). Mass/length2 was then used to evaluate a second measure, blubber cortisol concentration, as a metabolic condition marker. Cortisol is the main glucocorticoid hormone involved in the regulation of lipolysis and overall energy balance in mammals, and concentrations could provide information on physiological state. Blubber cortisol concentrations did not significantly vary around the girth (n = 20), but there was significant vertical stratification through the blubber depth with highest concentrations in the innermost layer. Concentrations in the dorsal, outermost layer were representative of concentrations through the full blubber depth, showed variation by sex and age class, and were negatively correlated with mass/length2. Using this species as a model for live cetaceans from which standard morphometric measurements cannot be taken, but from which blubber biopsy samples are routinely collected, cortisol concentrations in the dorsal, outermost blubber layer could potentially be used as a biomarker of condition in free‐ranging animals.

Fractal analysis provides new insights into the complexity of marine mammal behavior: A review, two methods, their application to diving and surfacing patterns, and their relevance to marine mammal welfare assessment

AbstractFractals have been applied to describe the complexity of behavioral displays in a range of organisms. Recent work suggests that they may represent a promising tool in the quantification of subtle behavioral responses in marine mammals under chronic exposure to disturbance. This paper aims at introducing the still seldom used fractals to the broader community of marine mammal scientists. We first briefly rehearse some of the fundamental principles behind fractal theory and review the previous uses of fractals in marine mammal science. We subsequently introduce two methods that may be used to assess the complexity of marine mammal diving patterns, and we apply them to the temporal dynamics of the diving patterns of killer whales in the presence and absence of sea kayaks, the sequential behavior of harbor and gray seals in environments with distinct levels of anthropogenic influence, and southern right whales with and without calves. We discuss the ecological relevance of identifying fractal properties in marine mammal behavior, and the potential strength of the fractal behavioral parameters in comparison to more standard behavioral metrics. We finally briefly address the relevance fractal methods may have for the design and implementation of management and conservation strategies.

Photogrammetry of blue whales with an unmanned hexacopter

Author Posting. © Society for Marine Mammalogy, 2016. This article is posted here by permission of Society for Marine Mammalogy for personal use, not for redistribution. The definitive version was published in Marine Mammal Science 32 (2016):1510–1515, doi:10.1111/mms.12328.

Structure of intestinal helminth communities of the striped dolphin, Stenella coeruleoalba, in the western Mediterranean: a long-term analysis

Structure of intestinal helminth communities of the striped dolphin, Stenella coeruleoalba, in the western Mediterranean: a long-term analysis

Conservation benefits of an interdisciplinary approach to marine mammal science

Protected resource economists can greatly enhance the science and conservation of marine mammals, however such contributions are often hampered by a lack of understanding of the role of natural resource economics on behalf of more traditional marine mammal scientists. The three major threats to marine mammals - fishery bycatch, increasing underwater sound, and climate change could be more effectively addressed with an interdisciplinary approach that includes the full valuation of costs and benefits to society. Better management of these threats can be beneficial to humans as well as marine mammals.

North Pacific right whales (Eubalaena japonica) recorded in the northeastern Pacific Ocean in 2013

Notes MARINE MAMMAL SCIENCE, **(*): ***–*** (*** 2014) © 2014 The Authors. Marine Mammal Science published by Wiley Periodicals, Inc. on behalf of Society for Marine Mammalogy This is an open access article under the terms of the Creative Commons Attribution- NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. DOI: 10.1111/mms.12189 North Pacific right whales (Eubalaena japonica) recorded in the northeastern Pacific Ocean in 2013 A NA S IROVI C , 1 S ARAH C. J OHNSON , L AUREN K. R OCHE , L EAH M. V ARGA , S EAN M. W IGGINS and J OHN A. H ILDEBRAND , Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive MC 0205, La Jolla, California 92093-0205, U.S.A. The North Pacific right whale (Eubalaena japonica) is among the most critically endangered marine mammals in the world (Brownell et al. 2001). Its population was drastically reduced by 19th and 20th century whaling and its recovery was addition- ally slowed by illegal Soviet whaling that occurred during the 1960s (Clapham et al. 2004, Ivashchenko and Clapham 2012). With a severe decrease in the population also came a restriction in range, from extensive distribution across the North Pacific, to a constricted presence of two different populations, one in the Sea of Okhotsk and along the Western Pacific, and the other in the eastern Bering Sea (Scarff 1986, Clap- ham et al. 2004, Josephson et al. 2008). The abundance estimates for the eastern pop- ulation are around 30 animals (Wade et al. 2006, 2011b; Marques et al. 2011), while the western population is considered to be larger with current estimates of probably no more than 300 animals (Brownell et al. 2001). Most baleen whales undertake seasonal migrations, spending summers feeding in high latitude, productive areas and winters in warmer, lower latitude breeding grounds (Kellogg 1929). North Pacific right whales spend their summers in the Ber- ing Sea and, to a lesser extent, the Gulf of Alaska, the Aleutian archipelago, and off Kodiak (Scarff 1986, Brownell et al. 2001, Clapham et al. 2004, Mellinger et al. 2004, Shelden et al. 2005, Wade et al. 2011a). Most current research effort has been focused within the area in the Southeastern Bering Sea where North Pacific right whales have been sighted most frequently (Wade et al. 2006, Munger et al. 2008). Over the years, however, a small number of sightings of single right whales have been Corresponding author (e-mail: asirovic@ucsd.edu).

Berta, A.2012. Return to the Sea: the Life and Evolutionary Times of Marine Mammals. University of California Press, Berkeley, California, 205 pp. ISBN 978-0-520-27057-2, price (hardbound), $31.26

A. Berta 2012. Return to the Sea: the Life and Evolutionary Times of Marine Mammals. University of California Press, Berkeley, California, 205 pp. ISBN 978-0-520-27057-2, price (hardbound), $31.26. Annalisa Berta is probably best known for having written Marine Mammals: Evolutionary Biology , the leading textbook and reference for her field, now in its 3rd edition. That book treats its subject matter exhaustively and forms a prime reference for the serious professional and student of marine mammal science. Dr. Berta's new book, reviewed here, aims at a different audience. As stated in its preface, the need for it became clear while teaching nonbiology college majors. In order to appeal to that crowd, one needs to skip the jargon, emphasize concepts and major points, be well illustrated, and have clear examples. Berta is ideally qualified to write a book for undergraduates on this subject. Her research is carried out on the interface of the study of modern and fossil marine mammals, and she has taught undergraduate audiences for 30 years. …

A white humpback whale (Megaptera novaeangliae) in the Atlantic Ocean, Svalbard, Norway, August 2012

A white humpback whale ( Megaptera novaeangliae ) was observed on several occasions off Svalbard, Norway, during August 2012. The animal was completely white, except for a few small dark patches on the ventral side of its fluke. The baleen plates were light-coloured, but the animal’s eyes had normal (dark) colouration. This latter characteristic indicates that the animal was not an albino; it was a leucistic individual. The animal was a full-sized adult and was engaged in ‘‘bubble-feeding’’, together with 1520 other humpback whales, each time it was seen. Subsequent to these sightings, polling of the marine mammal science community has resulted in the discovery of two other observations of white humpback whales in the Barents Sea area, one in 2004 and another in 2006; in both cases the observed individuals were adult animals. It is likely that all of these sightings are of the same individual, but there is no genetic or photographic evidence to confirm this suggestion. The rarity of observations of such white individuals suggests that they are born at very low frequencies or that the ontogenetic survival rates of the colour morph are low. Keywords: White humpback whale; Megaptera novaeangliae ; Svalbard; leucism (Published: 26 April 2013) Citation: Polar Research 2013, 32 , 19739, http://dx.doi.org/10.3402/polar.v32i0.19739