Entanglement in static fishing gear is the largest cause of non-natural mortality for minke whales (Balaenoptera acutorostrata) in Scottish waters. To mitigate whale entanglement, one priority is to identify areas where the risk of entanglement is consistently high. Sightings data for minke whales and creel fleets were collected by the Hebridean Whale and Dolphin Trust, during vessel line transect surveys conducted between 2008 and 2014. Habitat modelling was used to relate survey, environmental, and temporal variables to the co-occurrence of minke whales and creels in coastal waters of western Scotland. This revealed that minke whale occurrence was related to depth, peaking around 70 m. Using predictive habitat modelling, the overlap between minke whale habitat and the creel fishery was measured as risk of entanglement. A method was developed to quantify the consistency of risk over the seven-year time period. This allowed for the identification of areas where there had been a consistently low, medium, or high risk of entanglement from 2008 to 2014. The three areas with a consistent high risk of entanglement were identified: Inner Sound and Sound of Raasay, east of North and South Uist, and north of The Small Isles. The method presented here could be used to guide management to areas where mitigation efforts will be the most consistently effective over time.

The goals of this paper are to: define terms relevant to industrially induced, but unintentional, trauma to whales; place the issue in a context of the prevalence of such mortalities in North American east coast waters; examine pertinent case studies; summarise the resultant pathobiology; and from this infer likely welfare concerns.

Subsistence whale hunting dates back to 400AD (Perrin et al 2009). Large-scale industrialised whaling to provide whale oil commenced in the late nineteenth century. Hunts escalated in the early 20th century and reports to the International Whaling Commission (IWC) show that over two million great whales were killed in hunts in the Southern Ocean between 1925 and 1985 and that unreported ‘pirate’ whaling was also widespread (Clapham & Ivashenko 2009). In 1982, as several whale species neared extinction, the IWC agreed an international moratorium on commercial whaling, which took effect in 1986.

The stranding of cetaceans raises significant welfare and associated logistical issues. A survey of opinions on euthanasia methods based on the recommendations of an International Whaling Commission (IWC) workshop was conducted. Descriptive statistics showed that the workshop recommendations were generally supported and understood, and these included the use of specific euthanasia techniques, but important barriers to adherence were identified, including lack of governmental support, lack of resources, and lack of experienced or trained personnel. Conjoint analysis of factors identified that ‘time to death’ was considered the most important determinant of welfare outcome. In view of the findings of this study, it is recommended that the IWC should consider creating a training programme for responders (both veterinary and non-veterinary) to ensure that trained personnel are available who can implement timely and tailored euthanasia techniques, if required, when strandings occur. Further research on this topic is also advocated to ensure a better understanding of what is being applied in different nations.

The welfare of animals is a major factor affecting the acceptability of human activities, and hence their sustainability, and whales are the subject of much concern because they are considered to be sentient animals. The scientific study of animal welfare has developed rapidly and now allows evaluation of the effects on whale welfare of disturbance by boats, harpoon entry, pulling whales to a boat, capture procedures, the point of unconsciousness and consequences for animals that escape. Useful data are now being collected on some aspects but recent evidence shows that, on average, during the capture and killing of whales, there is a high magnitude of poor welfare and the procedure is not humane.

Despite a general paucity of archaeological, archaeozoological and iconographic evidence from the Upper Palaeolithic through to Late Antiquity, the corpus of whalebone finds in the Mediterranean region indicates that some level of interaction between humans and whales did indeed occur. A concentration of finds from Roman contexts suggests more active interventions in this period, especially around the Western Mediterranean and the Strait of Gibraltar—a ‘cetacean hotspot’. Whale vertebrae or scapulae were sometimes fashioned into portable chopping boards, identified from cut-marks made by fishermen or craftsmen, but whale meat and blubber may have been less important owing to abundant alternative food and fuel sources.

Whale oocytes recovered from follicles can be matured in vitro. Whale sperm and mature oocytes can be used for in vitro fertilization (IVF), and IVF embryos have the ability to develop to morula stage. Whale sperm injected into bovine or mouse oocytes can activate the oocytes and form pronucleus. Interspecies somatic cell nuclear transfer embryos have been reconstructed with whale somatic cell nucleus and enucleated bovine or porcine oocytes, and interspecies cloned embryos can develop in vitro. This paper reviews recent progress in maturation, fertilization and development of whale oocytes.

The cumulus–oocyte–complexes (COCs) recovery rates with respect to reproductive status per sei (Balaenoptera borealis) and Bryde's (B. edeni) whales were determined in Experiment 1. The number of COCs recovered ranged from 16.0 to 30.6 and from 6.7 to 26.8 per sei and Bryde's whales, respectively. The effects of COCs grades and protein supplementation in embryo culture medium on development of in vitro fertilized (IVF) embryos were evaluated in sei and Bryde's whales in Experiment 2. The COCs were classified into either Grade A (COCs with five or more layers of compact cumulus cells) or Grade B (COCs with less than five layers of compact or expanded cumulus cells) before being cultured for IVM. The cleavage (12.0 to 19.5%), 4-cell (8.0 to 12.0%) and 8-cell (4.0 to 8.0%) formation rates in sei whales did not vary significantly between embryos derived from either grade A or B oocytes and between embryos cultured in either fetal whale serum (FWS)- or bovine serum albumin (BSA)-supplemented medium. The cleavage (4.0 to 14.8%), 4-cell (0.0 to 7.5%) and 8-cell (0.0 to 2.6%) formation rates in Bryde's whales did not vary significantly between embryos derived from either grade A or B oocytes and between embryos cultured in either FWS- or BSA-supplemented medium. The grade B oocytes cultured in FWS-supplemented medium developed to morula stage (1.1%) in sei whales. In conclusion, the present study indicates that IVF in sei whales is possible to achieve cleaved embryos developing to morula stage. This is the first in vitro embryo production attempt in sei and Bryde's whales.

Johnstone Strait provides important summer habitat for the northern resident killer whales Orcinus orca of British Columbia. The site is also an active whale-watching area. A voluntary code of conduct requests that boats do not approach whales closer than 100 m to address perceived, rather than demonstrated, effects of boat traffic on killer whales. The purpose of the study was to test the relevance of this distance guideline. Relationships between boat traffic and whale behaviour were studied in 1995 and 1996 by shore-based theodolite tracking of 25 identifiable focal animals from the population of 209 whales. Individual killer whales were repeatedly tracked in the absence of boats and during approaches by a 5.2 m motorboat that paralleled each whale at 100 m. In addition, whales were tracked opportunistically, when no effort was made to manipulate boat traffic. Dive times, swim speeds, and surface-active behaviours such as breaching and spy-hopping were recorded. On average, male killer whales swam significantly faster than females. Whales responded to experimental approaches by adopting a less predictable path than observed during the preceding, no-boat period, although males and females used subtly different avoidance tactics. Females responded by swimming faster and increasing the angle between successive dives, whereas males maintained their speed and chose a smooth, but less direct, path. Canonical correlations between whale behaviour and vessel proximity are consistent with these conclusions, which suggest that weakening whale-watching guidelines, or not enforcing them, would result in higher levels of disturbance. High variability in whale behaviour underscores the importance of large sample size and extensive experimentation when assessing the impacts of human activity on killer whales.

A comparative study was made on one Mysticete (the fin whale, Balaenoptera physalus) and one Odontocete species (the striped dolphin, Stenella coeruleoalba) by measuring several morphological characteristics seen in cross sections of the optic nerve. We found that the two cetacean nerves share a number of specializations that distinguish them from the optic nerve of terrestrial mammals. Fiber density is approximately two-fold lower than in land mammals. A corresponding increase in the cross-sectional area occupied by astrocytes is observed. A population of “giant” (up to 15 μm in diameter) optic axons is present in both the B. physalus and the S. coeruleoalba nerve. It is argued that these features probably reflect common adaptations to the constraints imposed by the aquatic environment. “Giant” optic axons might ensure short-latency detection of preys and other targets during navigation while the increased astroglial content might be related to the maintenance of neuronal function during periods of anaerobic metabolism under water.

The helminth parasites from more than 300 cetaceans stranded on the coast of England and Wales during the period 1990-1994 were identified, this being the largest organized survey of cetacean parasites yet undertaken. Thirteen species of cetaceans were examined, although the majority were common (harbour) porpoises Phocoena phocoena (n=173) and common dolphins Delphinus delphis (n=101). The parasites found included 11 species of nematode (Anisakis simplex, Pseudalius inflexus, Torynurus convolutus, Stenurus globicephalae, S. minor, Halocercus delphini, H. invaginatus, H. lagenorhynchi, H. taurica, Crassicauda boopis, Crassicauda sp.), five cestodes (Diphyllobothrium polyrugosum, D. stemmacephalum, Phyllobothrium delphini, Monorygma grimaldii, Tetrabothrius sp.), five digeneans (Campula oblonga, Oschmarinella albamarina, O. rochebruni, Lecithodesmus palliatus, Pholeter gastrophilus) and two acanthocephalans (Bolbosoma capitatum, B. physeteris). The results of this survey are tabulated and each helminth species is discussed in terms of its biology and pathogenicity.