North Atlantic Right Whale (Eubalaena glacialis) Welfare: Comparison
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Please note this is a comparison between Version 2 by Yvaine Wei and Version 1 by Katherine King.

Welfare assessments have been largely successful in improving management and quality of life for animals in human care. This has prompted an increased interest in their use for free-ranging wild animals to assess health, environment, and human-induced impacts that influence policy decisions. The North Atlantic Right Whale (NARW, Eubalaena glacialis) is one of the most endangered whale species. NARWs constantly face serious injuries and mortalities due to human activities, which poses both a species conservation and an individual welfare concern. Establishing a standardized welfare assessment for the NARW is a holistic way to understand the cumulative effects of anthropogenic activities at both the individual and population levels.

  • North Atlantic right whale
  • animal welfare
  • conservation
  • animal welfare assessments

1. The Plight of the North Atlantic Right Whale as a Welfare Concern

More than 75% of NARW deaths between 2003-208 have been attributed to human activities (entanglement in fishing gear and vessel strikes)[1]. Not only are these unintentional NARW deaths a substantial conservation concern for this declining population, but how entangled animals die is a significant animal welfare concern [2]. 

A slow death is common for entangled large whales. Moore et al. reported that an entangled NARW suffers for an average of 5.6 months from detection to death, an underestimation of total entanglement time because of delays in detection[2]. An estimated 83% of NARWs have been entangled at least once, and approximately 60% of individuals show evidence of multiple entanglements [3]. The methods by which NARWs can succumb to gear entanglement include drowning, starvation, increased energy expenditure,  and tissue damage and infection [4]. Entanglement in fishing gear is an inhumane way to die and causes a welfare concern in addition to the conservation threat for the NARWs [5].

Shipping traffic has increased steadily since 1950 and NARWs, due to their preferred habitat, are at two orders of magnitude more likely to be struck by vessels compared to other large whales [6]. Recently in 2020, half of the NARW deaths were due to vessel strikes which cause blunt trauma from the ship's hull, sharp trauma from the ship's propellors or a combination of both[7] . Unfortunately, not all NARWs struck by ships die immediately. 

Ocean noise pollution from human activities has also dramatically increased in recent decades with the greatest increases seen on the coastal and continental shelf regions that are core NARW habitat [8]. As NARWs are a highly social species and rely heavily on social communication, the increased ocean noise has forced NARWs to increase the amplitude of their calls to be heard by their conspecifics [9]. Increased ocean noise is also correlated with increased fecal cortisol levels, which are an indicator of stress[10]. 

The effects of global climate change also impact the survival of the NARWs. NARWs feed almost exclusively on Calanus finmarchicus, a sub-polar zooplankton species that has decreased in abundance and shifted its range northward in response to rapidly warming deep water along the Scotian Shelf [11][12]. The northward shift of this main prey source appears to have also driven NARWs northward [12][13]. This change in foraging habitat has been correlated with decreased reproduction and increased mortality from vessel strikes and gear entanglement [14].

Many tools have been developed to better understand the stressors of large whales [15]. These tools range from observational assessments of body condition, skin condition, and presence of scars to sampling and analyzing fecal material, respiratory vapor, or skin[15][16][17]. Fecal and respiratory vapor samples provide information on reproductive status, stress hormones, biotoxins, microbial communities, immunity, and nutritional status[16]. Biopsies of skin and blubber contribute additional information on endocrine status, microbiome, immune function, and toxin levels of large whales[15]. Observational analysis of growth, body condition, skin condition and wounds by aerial photogrammetry is useful in assessing individual and population health[16] and determining changes in whales’ growth rates over time[18]. Baleen has been used to gain a multi-year profile of cortisol levels in NARWs to evaluate stress and determine reproductive status[19]. Location and movement information are gained from passive acoustic data[20], mark-recapture using photo-identification data [21], or necropsies [16]. 

2. The History of and Relationship between Animal Welfare and Conservation Science

Animal welfare has been defined as everything about an animal's condition as it lives in its habitat [22]. It serves to answer question about an animal's consciousness, positive vs. negative welfare and how science can improve welfare [23]. 

In 1993, the Five Freedoms were established as freedom from thirst, hunger and malnutrition; the freedom from discomfort and exposure; the freedom from pain, injury and disease; the freedom from fear and distress; and the freedom to express normal behavior[24]. A year later in 1994, Mellor and Reid proposed the Five Domains Model (FDM) of animal welfare which includes four domains based on biological function (nutrition, environment, health and behavior) and a fifth domain which focuses on the mental of an animal[25].

Conservation science assesses the health of the population as a whole, while welfare science focuses on assessing individual animals to gauge the health of the entire population [25]. While it is difficult to apply both conservation science and animal welfare science to larger populations, it is more feasible to evaluate small populations, particularly threatened and endangered species, through both lenses [26][27].

Stress is an important concept that affects both conservation as well as animal welfare and as such should be a topic that is covered by both disciplines. Wild animals experience increased levels of stress due to negative human impacts on their environments, such as chemical and noise pollution, habitat degradation, or hunting/trapping [28], which are relevant to conservation science as well as animal welfare. Increased stress can decrease reproductive success, reduce immune function, and inhibit growth—all of which decrease the likelihood of survival of an individual and, ultimately, a population and species[29]. 

3. Welfare Assessments for Animals under Human Care

Historically, animal welfare assessments focused mainly on livestock and laboratory animals [22]. The positive effects of such assessments on animal management policies have driven the use of animal welfare tools in zoo and aquaria settings. In 2015, the World Association of Zoos and Aquariums (WAZA) called on zoos and aquaria to prioritize high animal welfare standards for animals in their care; to be leaders, advocates, and advisors in animal welfare; and to ensure that all zoo and aquaria-housed animals have environments that exceed their behaviorial and physical needs [30].
Since the animal welfare discussions within zoos and aquaria began, there have been challenges with how to adequately measure welfare in diverse species where biology and natural history differ greatly or are largely unknown [31]. An initial focus for animal welfare at zoos was on improving animal husbandry, including nutrition and enclosure design [32]. More recently, the welfare assessment strategies proposed for animals in zoos and aquaria not only focus on animal husbandry, but also apply both resource-based (what resources the animal has or is provided) and animal-based approaches (considers what the animal looks like physically, how it is behaving and its mental state)[33].

4. Welfare Assessment for Free-Ranging Wild Species

With the development of animal welfare assessments for species under human care, conservation and animal welfare scientists were interested in incorporating welfare assessments into the conservation of free-ranging wild species. Most of these are performed using the FDM [34][35]. A significant barrier to more widespread implementation is the lack of a standardized, systematic approach to developing welfare assessments for individual species. To aid expert wildlife biologists and conservation scientists to incorporate welfare assessments in their work, a ten-step method for building a welfare assessment for any free-ranging wild species has been developed [35]. It guides users through the necessary types of knowledge needed to create a welfare assessment, such as how to identify indicators of welfare, and how to incorporate those indicators into the FDM[35]. This protocol would be beneficial in the development of new welfare assessments for species that lack established tools, such as free-ranging wild cetaceans, including the NARW.

5. Welfare Assessments for Cetaceans

Two methods currently available are the Cetacean Welfare Assessment (C-Well) and the Welfare Assessment Tool for Wild Cetaceans (WATWC) [36][37].

5.1. C-Well

C-Well was the first welfare assessment tool used specifically for marine mammals. It was developed by Clegg et al. to explore the welfare of common bottlenose dolphins (Tursiops truncatus) under human care [36]. C-Well is based on Welfare Quality®, an animal welfare assessment tool for farm animals in the UK. Welfare Quality® evaluated welfare based on nutrition, housing, health, and appropriate behavior [36]. C-Well expanded upon the four categories of Welfare Quality®, creating a framework with 11 criteria based on these categories and 36 measures to evaluate the criteria [36]. 

5.2. The International Whaling Commission and the Welfare Assessment Tool for Wild Cetaceans (WATWC)

Considering the focus on animal welfare in zoos and aquaria, the International Whaling Commission (IWC) developed a working group focused on the welfare of cetaceans impacted by human activity in the ocean[37]. The issues of special concern were non-hunting activities, including entanglement, ship strikes, whale watching, marine debris/litter, and habitat degradation and related matters [38]. In 2016, the working group  concluded that the FDM is applicable to evaluate free-ranging wild cetacean welfare[38].  The recommendation by the IWC working group to use the FDM for assessing free-ranging wild cetacean welfare was further expanded by Nicol et al. (2020) with the Welfare Assessment Tool for Wild Cetaceans (WATWC) [37]. The WATWC focused on how a single event can affect free-ranging wild cetacean welfare. In comparison to the IWC model, the WATWC included all five domains, and added how long an event will affect the domains, event re-occurrence, and how the event will affect the lifespan of the animal [37]. The assessment also included a section where evaluators rated their confidence in their scoring. WATWC further supported the utility of the FDM for free-ranging cetaceans, such as the NARW, when the developers stated FDM is more useful for free-ranging animals than either Welfare Quality® or the Five Freedoms.

6. Introduction of the North Atlantic Right Whale Welfare Assessment Tool

With the increasing threats to NARWs, welfare assessments should be included as a tool to better understand the overall condition and stressors affecting individuals. As the abilities to detect steroid and thyroid hormones in fecal matter and baleen have developed, there is more evidence to demonstrate that individual NARWs are subjected to substantial stress [38]. A welfare assessment would help to quantify the welfare of NARW and could be combined with other objective data to provide a more complete indiction of the welfare status and overall health of the NARW individuals and population [15][17][19][39].

6.1 Development of a Prototypic NARW Welfare Assessment Tool

A welfare tool was designed using the FDM framework because it provides a structure that is easily transferrable to free-ranging wild species and has consistently proven to be a useful guide in measuring animal welfare [33].

The health section of the proposed NARW welfare assessment tool is based on the Visual Health Assessment developed by Pettis et al. (2004) [17]. This health assessment used photographs of NARWs taken by researchers to establish a health score based on skin condition (including the presence of wounds or scars), body condition, presence of rake marks, and presence of cyamids surrounding the blowholes [17]. The behavior section of the NARW welfare assessment was developed based on common behaviors, sighting observations, and environmental interactions defined in the North Atlantic Right Whale Consortium Photographic Database/Catalog Submission document[40].

Environment and mental state were not included in the assessment as specific data are not always easy to interpret and include in a welfare assessment due to the variability of the natural environment of the NARW. Environmental variables such as water and air temperature, weather, presence of pollutants, and boat traffic change throughout the course of the day, and the effects of changes in these parameters on NARWs are not established. Inference of mental state of the NARW is not currently possible, but with evolving research it may be possible to use cortisol, microbiota, or other physiologic measurements for this purpose. 

Nutrition was assessed with body condition score (BCS), feeding behaviors and prey data such as quality and abundance. A method of counting plankton using an optical plankton counter (OPC) has been validated and could be used to estimate prey abundance as part of this assessment[41]. Measuring the energy content of NARW prey provides a key indicator of feed quality and therefore nutritional welfare, so this parameter was included in the prototypic tool presented here[41]. Results of mathematical modeling suggest that for a region to be a suitable NARW feeding habitat the C. finmarchicus in the area need to provide a minimum energy density of 3 kJ/m3[42].

Table 1. Prototype of the NARW welfare assessment. Total health and behavior scores are determined by adding numeric values of the corresponding section. Total Welfare Score is the combined Total Health Score and the Total Behavior Score. A negative score means negative welfare, 0 means neutral welfare, and a positive score means positive welfare. For a detailed description of the parameters used in the health assessment, please refer to Pettis et al. 2004 [17].

* See Table 2 for list of behaviors comprising each of the following categories.

Table 2. List of behaviors under each category of the NARW welfare assessment tool (positive behaviors, neutral behaviors and negative behaviors). Each observed behavior is recorded under the associated behavior category and contributes its corresponding value to the overall behavior score.

6.2 The Importance of a Welfare Tool

The importance of this tool relies on its ability to compile and communicate data concerning the NARW population in a way that is easily understood by diverse audiences. This welfare tool will help collect that information to provide a more holistic view of how health, nutrition, and behavior interact to influence NARW welfare. Once the necessary data have been gathered and welfare scores calculated for NARW individuals, it will become easier to disseminate the findings to the public. The lack of action to conserve the NARWs is largely due to a complete lack of pressure from consumers. One of the main barriers to conservation of marine mammals, especially the NARW, is the lack of visibility. Moore and Van der Hoop (2012) summarize this issue well in the following quote: “Consider the likely difference in response if the results of long standing right whale entanglements (i.e., emaciation, starvation, chronic pain and infection) were observed on a daily basis by humans as they went about their lives in urban, suburban and rural communities rather than remaining out of sight at sea. If the equivalent fixed fishery traps and nets were to be set on land, with a comparably slow and painful death for wildlife, the responsible industry could be subject to consumer revolt, irrespective of whether there was an actual law concerning such an interaction” [4]. A welfare assessment specific for the NARW provides an enhanced ability to frame the plight of the NARW as a welfare concern. It also presents a different approach to conservation messaging and ultimately leads to greater public understanding and consumer pressure to take the necessary actions to save the NARWs from extinction. 

7. Conclusions

The increasing number of NARW serious injuries and deaths resulting from human-induced causes is both a conservation concern and an animal welfare concern [5]. This NARW welfare assessment tool can be used in conjunction with existing objective measures of health to integrate understanding of welfare and health in a critically endangered species.

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