Live cetacean stranding response can include euthanasia decisions, which are influenced by multiple complex factors, such as interacting welfare, governance, logistical and sociocultural considerations. This study aimed to examine how euthanasia is conducted during cetacean strandings, identify barriers to its implementation, and explore potential improvements. To do this, we applied two methods: (1) an online survey (n = 48; 22 countries) and (2) an in‐person workshop (n = 30; 15 countries) to gain insight from stranding responders on how euthanasia is conducted at live stranding events. We used thematic analyses to investigate participant responses. Our findings indicate that effective euthanasia decision‐making during cetacean strandings depends fundamentally on national law, the availability of appropriately trained personnel, and suitable logistical resources (e.g., appropriate equipment and chemical agents), yet is frequently constrained by systemic governance fragmentation, uneven regional capacity, and inconsistent resource allocation. These structural and operational limitations can delay or complicate time‐sensitive animal welfare decisions. Strengthening national and regional stranding networks through sustained investment in training, resource provision, clear governance pathways, and coordinated information‐sharing is therefore essential to enable timely, consistent, transparent, and animal welfare‐centred outcomes, while also enhancing operational effectiveness and maintaining public confidence in live stranding response.

This paper describes the history of solitary dolphins in Spain since 1970 and reviews the challenges they present for both their own survival and welfare, and the safety of humans that interact with them. Seventeen solitary common bottlenose dolphins, Tursiops truncatus, have been recognized in Spanish waters, with the majority of these (N=14) in the waters of Galicia (northwest Iberian Peninsula). Some of these solitary dolphins have come to interact with humans, leading to them being referred to as solitary-sociable dolphins, which present particular problems in terms of their management. The different stages of sociability of solitary dolphins are presented and discussed. Two cases from Galicia, the dolphins known as Gaspar and Confi, are presented in detail. The legal frameworks in place to protect cetaceans in Spain are outlined and how these could be used to help protect solitary dolphin welfare is discussed. Human safety also needs to be considered, particularly when people come into close contact with a solitary dolphin either when seeking to interact with the animal or if the dolphin approaches them, for example professional divers working in Galicia. Recommendations are provided for how management plans can be developed for use when a solitary dolphin is present in Spanish waters. These plans could include restricting access by the public to certain areas and implementing flexibility in local fishing practices to help avoid conflict. Education is key to ensure that the public is aware of how to behave appropriately around a solitary dolphin (and cetaceans in general) and to ensure that relevant laws are followed. It is imperative to avoid allowing a solitary dolphin to develop into a solitary-sociable dolphin whenever possible. (c) 2026 The Authors. Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Marine mammals may be particularly vulnerable to climate change. While some climate-change-induced impacts on these species have been recognised, the potential consequences of storminess have been less well-defined, and understanding of its significance largely relies on anecdotal evidence. To quantify the relationship between storminess and its possible impacts on grey seal pups (Halichoerus grypus), data from marine wildlife rescue databases and hospitalisation records (2015–2024) within the British Isles were examined (n = 20,686). Daily mean windspeed was used as a proxy for storminess. Significant relationships were found between storminess and pups presenting with malnourishment, head trauma, flipper injury, other wounds, and infections. This study provides the first empirical evidence of the explicit impacts of storminess on seal pup health, with all the presenting conditions increasing and higher rates of call-outs and pup admissions to rescue centres following stormy weather also recorded. Given the predicted increase in storm severity, these findings will aid rescue and rehabilitation planning by helping to predict when rescuers can anticipate increased admissions and the potential injuries that pups may experience following storms. The potential significance to the long-term conservation of the species is also highlighted.

Drive hunts in the Faroes and Japan typically involve prolonged herding of cetaceans (over hours or even days) into shallow water, forced stranding, restraint and killing using a spinal lance and exsanguination. These methods raise significant animal welfare concerns. This study applies the Five Domains Model to the Faroe Islands' grindadráp hunt to consider potential welfare implications and associated affective states. We examined published hunting guidelines and divided the hunt into six stages. Each author independently summarized potential impacts within the Five Domains Model; subsequent group consensus via online meetings assigned likely welfare impacts and affective states. Demonstrable welfare impacts and negative affective states were identified for each grindadráp stage. The prolonged chase, forced stranding, capture and restraint probably cause chronic and acute physiological stress. The spinal lance may not render animals instantaneously unconscious, raising substantial concerns that some animals may remain aware during exsanguination. Commonly inferred affective states for each domain included: pain, anxiety, disorientation, fear and panic. Given the inherent constraints of the hunt, it is unlikely that grindadráp can be undertaken humanely. If the hunt is to continue, substantial reform would be necessary to minimize animal suffering and align with welfare standards applicable to mammals in food production or research.

An out of habitat (OOH) marine mammal is an individual found outside of their natural range, e.g., an Atlantic walrus (Odobenus rosmarus rosmarus) along the coastline of mainland Europe, or an individual within their natural range in habitat that is not optimal for their health or survival due to a lack of suitable conditions and/or because of potential conflict with humans. As the number of OOH marine mammals appears to be increasing, and following on from two international workshops, here we define what constitutes an OOH marine mammal and provide a detailed assessment of potential drivers. Climate change, habitat loss and/or degradation, disturbance, changes in prey distribution, and morbidity may all be reasons for a marine mammal being OOH. Appropriate management of OOH marine mammals is considered. This may simply involve monitoring to better understand the situation, to protect the welfare of the animal(s) and to ensure that members of the public are kept safe. However, on occasion, further intervention may be required, such as providing safe areas for the OOH marine mammal(s), encouraging the animal(s) to move, capture and translocation, or euthanasia. Regardless of the action taken, educating and communicating with the public are key elements of OOH marine mammal management. Lessons can be learned from human-wildlife conflict and rewilding scenarios. The potential for OOH marine mammals to be pioneers seeking new habitat, contributing to species resilience in the face of rapidly changing environments, and how to include them in conservation legislation and management planning are considered.

Climate change is predicted to impact the distribution of many marine species. In the North-East Atlantic and elsewhere in the world, studies indicate that climate change is leading to poleward shifts in cetacean distribution. Here, strandings data collected in the British Isles from 1990 to 2020 were used to assess whether there is evidence of a shift in baleen whale distribution. Linear regression models were used to compare the number of strandings over time between six regions of the British Isles and, whilst the results indicate no significant change in the number of strandings in the most southerly region of the British Isles, there have been significant increases in more northern regions. Data related to stranded minke whales is the primary driver of these increases, with a number of potential variables affecting this trend, including observer effort. These variables are discussed and further research to explore this potential association is suggested.

Human activities are increasingly impacting our oceans and the focus tends to be on their environmental impacts, rather than consequences for animal welfare. Global shipping density has quadrupled since 1992. Unsurprisingly, increased levels of vessel collisions with cetaceans have followed this global expansion of shipping. This paper is the first to attempt to consider the severity of ship-strike on individual whale welfare. The methodology of the 'Welfare Assessment Tool for Wild Cetaceans' (WATWC) was used, which is itself based upon the Five Domains model. Expert opinion was sought on six hypothetical but realistic case studies involving humpback whales (Megaptera novaeangliae) struck by ships. Twenty-nine experts in the cetacean and welfare sector took part. They were split into two groups; Group 1 first assessed a case we judged to be the least severe and Group 2 first assessed the most severe. Both groups then additionally assessed the same four further cases. This was to investigate whether the severity of the first case influenced judgements regarding subsequent cases (i.e. expert judgements were relative) or not (i.e. judgements were absolute). No significant difference between the two groups of assessors was found; therefore, the hypothesis of relative scoring was rejected. Experts judged whales may suffer some level (>1) of overall (Domain 5) harm for the rest of their lives following a ship-strike incident. Health, closely followed by Behaviour were found to be the welfare aspects most affected by ship-strikes. Overall, the WATWC shows a robust potential to aid decision-making on wild cetacean welfare.

The accumulation of human-derived debris in the oceans is a global concern and a serious threat to marine wildlife. There is a volume of evidence that points to deleterious effects of marine debris (MD) on cetaceans in terms of both entanglement and ingestion. This review suggests that about 68% of cetacean species are affected by interacting with MD with an increase in the number of species reported to have interacted with it over the past decades. Despite the growing body of evidence, there is an ongoing debate on the actual effects of plastics on cetaceans and, in particular, with reference to the ingestion of microplastics and their potential toxicological and pathogenic effects. Current knowledge suggests that the observed differences in the rate and nature of interactions with plastics are the result of substantial differences in species-specific diving and feeding strategies. Existing projections on the production, use and disposal of plastics suggest a further increase of marine plastic pollution. In this context, the contribution of the ongoing COVID-19 pandemic to marine plastic pollution appears to be substantial, with potentially serious consequences for marine life including cetaceans. Additionally, the COVID-19 pandemic offers an opportunity to investigate the direct links between industry, human behaviours and the effects of MD on cetaceans. This could help inform management, prevention efforts, describe knowledge gaps and guide advancements in research efforts. This review highlights the lack of assessments of population-level effects related to MD and suggests that these could be rather immediate for small populations already under pressure from other anthropogenic activities. Finally, we suggest that MD is not only a pollution, economic and social issue, but also a welfare concern for the species and populations involved.

Wild animal welfare may be compromised in many different ways during hunting, trapping, fishing and whaling activities. Some key hunting methods and their welfare implications for both target and non-target animals are discussed highlighting the issues that impact on animal welfare, including the equipment used in hunting, the skill of the hunter and the duration of the hunt. The impacts on fish welfare of catch and release recreational fishing, subsistence fishing, bycatch in artisanal fisheries and killing methods are also presented. The hunting of whales and other cetaceans is considered, focused on Japanese dolphin drive hunts and the commercial hunting of large whales and how these activities impact cetacean welfare.

A key goal of conservation is to protect biodiversity by supporting the long-term persistence of viable, natural populations of wild species. Conservation practice has long been guided by genetic, ecological and demographic indicators of risk. Emerging evidence of animal culture across diverse taxa and its role as a driver of evolutionary diversification, population structure and demographic processes may be essential for augmenting these conventional conservation approaches and decision-making. Animal culture was the focus of a ground-breaking resolution under the Convention on the Conservation of Migratory Species of Wild Animals (CMS), an international treaty operating under the UN Environment Programme. Here, we synthesize existing evidence to demonstrate how social learning and animal culture interact with processes important to conservation management. Specifically, we explore how social learning might influence population viability and be an important resource in response to anthropogenic change, and provide examples of how it can result in phenotypically distinct units with different, socially learnt behavioural strategies. While identifying culture and social learning can be challenging, indirect identification and parsimonious inferences may be informative. Finally, we identify relevant methodologies and provide a framework for viewing behavioural data through a cultural lens which might provide new insights for conservation management.

The conservation of harbor porpoises (Phocoena phocoena) appears to be failing in Europe. There are particular concerns about this species in the Baltic Proper, Black, and Mediterranean Seas, as well as in the Northeast Atlantic, including the Iberian population, off the Spanish and Portuguese coasts. The Baltic Proper porpoise is “critically endangered,” with a population only in the low hundreds, and the Scientific Committee of the International Whaling Commission has repeatedly called for action to ensure its survival. In 2020, the Committee issued a series of recommendations relating to it and the Iberian population. Similarly, the Black Sea harbor porpoise, Phocoena phocoena ssp. relicta, is classified by the IUCN as endangered. Another population which may be genetically distinct is the West Greenland harbor porpoise, which is hunted without quotas or close seasons. European cetaceans and their habitats are covered by a number of international and regional conventions and agreements and, under European Union law, are “highly protected.” In practice, however, these legal protections have failed to generate effective conservation. For example, Special Areas of Conservation (SACs) are required for them and, although sites have been designated in some marine areas/countries, in the absence of appropriate management plans, SACs cannot be expected to help improve the harbor porpoise's conservation status. Compared to many other species, porpoises are relatively long-lived with low reproductive capacity and only poor public recognition. Conservation and management efforts are caught up in a complicated nexus of interactions involving a web of commitments under international conventions and agreements, European environmental laws, and European fisheries policy. However, public disinterest, lack of political will to implement conservation measures, and complicated fishing-related issues hinder any real progress. More positively, recent advice from the International Council for the Exploration of the Seas (ICES) provides a new scientific foundation for conservation action to address fisheries bycatch in the Baltic Proper harbor porpoise population. Populations of other porpoise species (family Phocoenidae) are also threatened, most notably the global population of the critically endangered vaquita, or Gulf of California porpoise (Phocoena sinus). The common threats and factors affecting porpoise populations are discussed and recommendations offered.

Marine litter is a growing concern for marine animals, including cetaceans for which there is a developing body of evidence showing impacts of both entanglement and ingestion. Better understanding is needed of the current and predicted scales of impacts on cetacean species of both macro- and micro-litter. Some emerging methodological approaches, such as the "threefold approach," will help address data gaps. The relationship between this form of pollution and some cetaceans is strong and the particular feeding habits, and widespread distribution of two whale species means that they can be proposed as ocean health indicators for macro- and micro-litter impacts at global scales, helping steer research. The species concerned are sperm whales (Physeter macrocephalus), for macro-litter at depth, and fin whales (Balaenoptera physalus), for micro-debris. Once appropriate techniques have been fully developed for non-lethal assessment, other whale species might also be used as indicators of litter pollution in their specific feeding zones.

Recent years have seen rapid development of tools and approaches to model population consequences of disturbance in several marine mammal populations from high-amplitude, acute sound sources. Ocean noise from shipping and other maritime activities is now recognized as a chronic, habitat-level stressor. In order to understand population consequences of chronic ocean noise to whales and their populations, advances are needed in several key areas, which are explored in this review. One tractable way to predict population-level consequences of noise-mediated disruption of feeding, which can include both behavioural responses and foraging opportunities lost due to acoustic masking. Masking may be defined as both the process and the amount by which the threshold of hearing of one sound is raised by the presence of another. Parameterising any such model requires information on sensitivity and vulnerability of large whales to ocean noise, in which sensitivity is the degree to which marine features respond to a stressor (e.g., behavioural responses to noise or proportional reduction in foraging efficiency due to masking), and vulnerability is the probability that whales are exposed noise to which they are sensitive. Efforts are underway to provide much-needed information on hearing sensitivity in baleen whales, the role of acoustic cues in foraging, and deriving links between long-term variability in prey availability and whale demography. As this information becomes available, we expect rapid advancement on modelling population consequences of acoustic masking in baleen whales, because those efforts can leverage substantial investments in statistical methodological approaches to model population consequences of disturbance. Pathways of effects other than via foraging disruption (e.g., stress hormones affecting reproduction or disease) are possible, but we illustrate potential ways to proceed based on this tractable approach, namely noise-mediated impacts on foraging. This report highlights case studies of local, national, international, and inter-governmental efforts to monitor and reduce the contribution of global shipping to ocean ambient noise. The following outlines approaches that can be used to assess the risk to baleen whale recovery of existing levels of ocean noise, and consequently, predict the benefits likely to arise from reducing chronic ocean noise.

Human activities and anthropogenic environmental changes are having a profound effect on biodiversity and the sustainability and health of many populations and species of wild mammals. There has been less attention devoted to the impact of human activities on the welfare of individual wild mammals, although ethical reasoning suggests that the welfare of an individual is important regardless of species abundance or population health. There is growing interest in developing methodologies and frameworks that could be used to obtain an overview of anthropogenic threats to animal welfare. This paper shows the steps taken to develop a functional welfare assessment tool for wild cetaceans (WATWC) via an iterative process involving input from a wide range of experts and stakeholders. Animal welfare is a multidimensional concept, and the WATWC presented made use of the Five Domains model of animal welfare to ensure that all areas of potential welfare impact were considered. A pilot version of the tool was tested and then refined to improve functionality. We demonstrated that the refined version of the WATWC was useful to assess real-world impacts of human activity on Southern Resident killer whales. There was close within-scenario agreement between assessors as well as between-scenario differentiation of overall welfare impact. The current article discusses the challenges raised by assessing welfare in scenarios where objective data on cetacean behavioral and physiological responses are sparse and proposes that the WATWC approach has value in identifying important information gaps and in contributing to policy decisions relating to human impacts on whales, dolphins, and porpoises.

Laetitia Nunny1, Carlos Bautista2, Santiago Palazón3, Andrew W. Trites4, Diederik van Liere5, Mark P. Simmonds6 1 Wild Animal Welfare, La Garriga, Barcelona, Spain. Contact: laetitia.nunny@me.com 2 Institute of Nature Conservation, Polish Academy of Sciences – IOP PAN, Kraków, Poland 3 Fauna and Flora Service, Generalitat de Catalunya, Barcelona, Spain 4 Marine Mammal Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, Canada 5 Institute for Coexistence with Wildlife, Almen, Netherlands 6 Humane Society International, London, UK, and School of Veterinary Sciences, University of Bristol, UK

Marine litter is a pollution problem affecting thousands of marine species in all the world's seas and oceans. Marine litter, in particular plastic, has negative impacts on marine wildlife primarily due to ingestion and entanglement. Since most marine mammal species negatively interact with marine litter, a first workshop under the framework of the European Cetacean Society Conference, was held in 2017 to bring together the main experts on the topic of marine mammals and marine litter from academic and research institutes, non-governmental organisations, foundations and International Agreements. The workshop was devoted to defining the impact of marine litter on marine mammals by reviewing current knowledge, methodological advances and new data available on this emerging issue. Some case studies were also presented from European waters, such as seals and cetaceans in the North, Baltic, and Mediterranean Seas. Here, we report the main findings of the workshop, including a discussion on the research needs, the main methodological gaps, an overview of new techniques for detecting the effects of marine litter (including microplastics) on marine mammals and, also, the use of citizen science to drive awareness. The final recommendations aim to establish priority research, to define harmonised methods to detect marine litter and microplastics, enforce networking among institutions and support data sharing. The information gathered will enhance awareness and communication between scientists, young people, citizens, other stakeholders and policy makers, and thereby facilitate better implementation of international directives (e.g., the Marine Strategy Framework Directive) in order to answer the question about the actual status of our oceans and finding solutions.

Philippa Brakes, Sasha R. X. Dall, Lucy M. Aplin, Stuart Bearhop, Emma L. Carroll, Paolo Ciucci, Vicki Fishlock, John K. B. Ford, Ellen C. Garland, Sally A. Keith, Peter K. McGregor, Sarah L. Mesnick, Michael J. Noad, Giuseppe Notarbartolo di Sciara, Martha M. Robbins, Mark P. Simmonds, Fernando Spina, Alex Thornton, Paul R. Wade, Martin J. Whiting, James Williams, Luke Rendell, Hal Whitehead, Andrew Whiten, and Christian Rutz

Dolphins are typically regarded as highly social animals. However, some individuals live apart from their own species and may come to socialize with people through a recognized series of stages which are presented and expanded on in this paper. The term "solitary-sociable dolphins" has been used to describe these animals and such individuals have been identified from several different species and reported in many parts of the world. In many instances, the interactions with people that may follow their original isolation, and which typically become more intense over time, have created situations where the welfare of the animal has been compromised by disturbance, injury, the feeding of inappropriate items and aggressive human behavior. Several solitary-sociable dolphins have also been deliberately injured and killed by humans. People who interact with these dolphins may also put themselves at risk of injury. This paper reports on recent cases drawing on published and unpublished sources. Since 2008, 32 solitary dolphins have been recorded including 27 bottlenose dolphins (25 Tursiops truncatus and two Tursiops aduncus), two striped dolphins and three common dolphins. Four solitary belugas have also been recorded. There are some ten solitary dolphins and one beluga known at the present time. Laws and guidelines currently in place to protect solitary-sociable dolphins need to be strengthened and interactions with people should be avoided or, at the least, carefully managed to protect both the dolphin and the humans involved in the interaction. Terms, such as disturbance and harassment which are included in laws need to be clearly defined. Additionally, management plans for solitary-sociable dolphins need to be developed and adapted on a case by case basis taking into account the individual dolphin's sex, age, personality, stage of sociability and home range. It is also important that government officials and local stakeholders work together to implement guidelines which set out how the public can observe or interact with the dolphin safely.