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Most cetaceans are born with vibrissae but they can be lost or reduced in adulthood, especially in odontocetes. Despite this, some species of odontocetes have been found to have functioning vibrissal follicles (including the follicle itself and any remaining vibrissal hair shaft) that play a role in mechanoreception, proprioception and electroreception. This reveals a greater diversity of vibrissal function in odontocetes than in any other mammalian group. However, we know very little about vibrissal follicle form and function across the Cetacea. Here, we qualitatively describe the gross vibrissal follicle anatomy of fetuses of three species of cetaceans, including two odontocetes: Atlantic white-sided dolphin (Lagenorhynchus acutus), harbour porpoise (Phocoena phocoena), and one mysticete: minke whale (Balaenoptera acutorostrata), and compared our findings to previous anatomical descriptions. All three species had few, short vibrissae contained within a relatively simple, single-part follicle, lacking in muscles. However, we observed differences in vibrissal number, follicle size and shape, and innervation distribution between the species. While all three species had nerve fibers around the follicles, the vibrissal follicles of Balaenoptera acutorostrata were innervated by a deep vibrissal nerve, and the nerve fibers of the odontocetes studied were looser and more branched. For example, in Lagenorhynchus acutus, branches of nerve fibers travelled parallel to the follicle, and innervated more superficial areas, rather than just the base. Our anatomical descriptions lend support to the observation that vibrissal morphology is diverse in cetaceans, and is worth further investigation to fully explore links between form and function.

Summary Fatal meningoencephalitis due to Brucella ceti infection has been described in striped dolphins (Stenella coeruleoalba), Atlantic white-sided dolphins (Lagenorhynchus acutus), short-beaked common dolphins (Delphinus delphis) and long-finned pilot whales (Globicephala melas), which are all within the family Delphinidae. We report B. ceti-associated neurobrucellosis in three juvenile male Sowerby's beaked whales (Mesoplodon bidens) that all had typical lesions of lymphocytic meningoencephalitis, which increased in severity from rostral to caudal regions of the brain. In two cases there was loss of ependymal cells lining the cerebral ventricular system, with large numbers of lymphocytes in the underlying neuropil. This finding suggests that B. ceti gains access to, and multiplies in, the cerebrospinal fluid, and confirms that this is the sample of choice for bacteriological recovery of the causative organism. These findings expand the increasing range of cetaceans susceptible to neurobrucellosis to members of the family Ziphiidae.

The North Atlantic Oscillation (NAO) is a dominant climatic driver that influences hydrographic and ecological parameters at multiple spatial scales and several trophic levels. To date, linkages between NAO variability and dolphin strandings on a regional scale have not been investigated. Stranding records of short-beaked common dolphins (Delphinus delphis) and Atlantic white-sided dolphins (Lagenorhynchus acutus) during 1990–2014 between Maine and New York were correlated against the winter NAO index at several time lags in order to explore the link between stranding variability and NAO. The stranding frequencies of the two species were positively correlated to one another. When analyzed against the winter NAO index, the stranding time-series for both species yielded statistically significant inverse correlations at time lags of one and/or two years. Dolphin strandings were lower during the two years after winters when the NAO was positive and were higher during the two years after a negative NAO. Linear regression modeling confirmed a significant relationship between strandings and winter NAO at both 1and 2-year lags for common dolphins, but not for white-sided dolphins. The hypothesized mechanism underlying the relationship is that NAOlinked hydrographic changes during winter in outer shelf and slope waters affect the abundance and/or availability of prey, leading to changes in the inshoreoffshore distribution patterns of the dolphins. Increased occurrence and foraging closer to shore increases the dolphin’s susceptibility to stranding caused by other localized or short-term factors. This study represents the first attempt at linking NAO variability to dolphin mortality within New England waters.

The basal forebrain (BFB) cholinergic neurotransmitter system is important in a number of brain functions including attention, memory, and the sleep-wake cycle. The size of this region has been linked to the increase in encephalization of the brain in a number of species. Cetaceans, particularly those belonging to the family Delphinidae, have a relatively large brain compared to its body size and it is expected that the cholinergic BFB in the dolphin would be a prominent feature. However, this has not yet been explored in detail. This study examines and maps the neuroanatomy and cholinergic chemoarchitecture of the BFB in the Atlantic white-sided dolphin (Lagenorhynchus acutus). As in some other mammals, the BFB in this species is a prominent structure along the medioventral surface of the brain. The parcellation and distribution of cholinergic neural elements of the dolphin BFB was comparable to that observed in other mammals in that it has a medial septal nucleus, a nucleus of the vertical limb of the diagonal band of Broca, a nucleus of the horizontal limb of the diagonal band of Broca, and a nucleus basalis of Meynert. The observed BFB cholinergic system of this dolphin is consistent with evolutionarily conserved and important functions for survival.

Úrtak: Síðan 1872 siga veiðihagtølini frá, at uml. 9.435 skjórutir springarar hava lagt beinini í 158 grindum, og tað gevur eitt árligt miðaltal á 68.4 hvalir og 1.1 flokkur. Fyri tey árini, har ið dráp var, er talið 168 hvalir og 2.8 flokkar. Tað, ið árliga hevur verið dripið, hevur ligið um 0-774 hvalir á 1-10 flokkar. Støddin á flokkunum hevur ligið um 1-544 (í miðal 60 hvalir) við 74% < 50 hvalir/flokk. Flestir skjórutir springarar vórðu sæddir sunnan fyri Suðuroynna, og 37% av springarunum úr 20 flokkum eru hildnir til í Vági og Hvalba. Raksturin er í hæddini í september, og eingin hevur verið í mars og desember. Úti á havinum hava hvalir verið sæddir alt árið. Ein mislittur hvalur kom fyri í tveimum drápum.Abstract: Since 1872, the catch data informs about 9,435 white- sided dolphins taken in 158 drives, an annual average of 68.4 whales and 1.1 pod, and 168 whales and 2.8 pods for only the years containing a catch. The annual catch has ranged 0-774 whales in 1-10 pods. The pod size has ranged 1-544 (avg. 60 whales) with 74% < 50 whales/pod. Most white-sided dolphins were observed south off Suðuroy and 37% dolphins from 20 pods has been killed in Vágur and Hvalba. The drives peak in September and none has occurred in March and December. Offshore the whale has been reported all year round. A discoloured whale occurred in two catches.

The present study is the first record of twinning inLagenorhynchus acutusand indeed anyLagenorhynchussp. Both foetuses were male and located in the left uterine horn, had distinct grossly normal placentas and amniotic sacs, and were therefore likely dizygotic twins. The twins were an incidental finding in an animal that died of a systemicBrucella cetiinfection.

Fatal Brucella ceti infection with histological lesions specific to the central nervous system has been described in only 3 species of cetaceans: striped dolphins Stenella coeruleoalba, Atlantic white-sided dolphins Lagenorhynchus acutus and short-beaked common dolphins Delphinus delphis. This paper describes the first report of a B. ceti-associated meningoencephalitis in a long-finned pilot whale Globicephala melas, showing the increasing range of species susceptibility. Brucella was recovered in larger numbers from cerebrospinal fluid than from brain tissue and is the sample of choice for isolation.

Cobbold (1858) established Diphyllobothrium Cobbold, 1858 with the description of Diphyllobothrium stemmacephalum Cobbold, 1858 from the common harbor porpoise, Phocoena phocoena (Linnaeus) (Phocoenidae), from the North Sea off Scotland. Diphyllobothrium stemmacephalum typically has been reported from a number of Phocoenidae and Delphinidae hosts from a variety of localities: common harbor porpoise from the northern Atlantic Ocean, Baltic Sea and Black sea (e.g. Cobbold, 1858; Delyamure 1955; Delyamure 1968; Delyamure 1971; Delyamure et al. 1985; Anderson, 1987); bottlenose dolphin, Tursiops truncatus (Montagu), from the Gulf of Mexico (Ward & Collins 1959), the Black sea (Delyamure et al. 1985); common harbor porpoise off Newfoundland (Brattey & Stenson 1995), the Black Sea (Krivokhizin & Birkun 1994 [see Yera et al. 2008]), off Denmark (Herreras et al. 1997); long-finned pilot whale, Globicephala melas [Traill], North Atlantic off Faroe Island (Balbuena & Raga 1993); Atlantic white-sided dolphin, Lagenorhynchus acutus [Gray], off Massachusetts (Olson & Caira 1999).

Publisher Summary This chapter describes the Atlantic white-sided dolphins that are robust and powerful, impressively patterned, and more colorful than most dolphins. A narrow, bright white patch on the side extends back from below the dorsal fin and continues toward the flukes as a yellow brown blaze above a thin dark stripe. The back and dorsal fin are black or very dark gray, as are the flippers and flukes, while the belly and lower jaw are white, and the sides of the body a lighter gray. A black eye ring extends in a thin line to the upper jaw, and a very thin stripe extends backward from the eye ring to the external ear. A faint gray stripe may connect the leading edge of the flipper with the rear margin of the lower jaw. The beak is short and grades smoothly into the “melon” (forehead). The upper jaw contains 29–40 and the lower jaw 31–38 small, conical teeth. Molecular analysis has recently been used to examine the evolutionary relationships of Lagenorhynchus acutus and the five other currently recognized members of the genus Lagenorhynchus. Although formal taxonomic revision awaits a comprehensive review of morphological and molecular characters, the molecular evidence suggests that some of the five are actually more closely related to the right whale dolphins (genus Lissodelphis) and some Southern Hemisphere dolphins (genus Cephalorhynchus) than they are to L. acutus.

Perfluorinated alkyl acids (PFAAs) have been used for 50 + years in materials such as stain-resistant treatments for paper and clothing, lubricants, and foam fire extinguishers. PFAAs are characterized by a fully fluorinated alkyl chain with a terminal acid group. Their long half-lives and ubiquitous environmental distribution create considerable concern for wildlife and human exposure. There is interest in examining temporal trends of PFAAs using the National Marine Mammal Tissue Bank (NMMTB), but NMMTB tissues are frozen and cryohomogenized in polytetrafluoroethylene (PTFE)-based materials. Because PTFE supplies may leach PFAAs into samples, this study mimicked collection, processing and storage steps of NMMTB samples and measured PFAA leaching to determine the feasibility of using this sample archive for PFAA temporal trends. We also explored concentrations in Atlantic white-sided dolphin (Lagenorhynchus acutus, WSDs) and rough-toothed dolphin (Steno bredanensis, RTDs) blubber (n = 3 and 0) and liver (n = 48 and 12, respectively). The materials used in NMMTB protocols may add up to 0.968 ng/g perfluorooctanoic acid (PFOA), 0.090 ng/g perfluorononanoic acid (PNFA), and 0.221 ng/g perfluorooctane sulfonate (PFOS) to each archived sample. Leaching of PFNA and PFOS from supplies compared to dolphin levels was negligible, but PFOA contributions were substantially higher than levels found in most dolphin liver samples. Therefore, monitoring PFOA temporal trends from the NMMTB would require careful consideration. RTDs had significantly higher levels of PFOS and PFNA than WSDs. Both species have similar life history, trophic status, and foraging behaviors in deep pelagic waters, so differences could be from latitudinal variation in contamination. RTDs stranded in Florida; WSDs stranded farther north mostly in Massachusetts. Juveniles had significantly higher levels of PFOS and PFNA than adults in both species, suggesting growth dilution as they approach maturity. PFOS significantly decreased after 2001 in both species as expected based on changes in production.

Helicobacter infection in cetaceans was first reported from the US in 2000 when the isolation of a novel Helicobacter species was described from two Atlantic white-sided dolphins (Lagenorhynchus acutus). Since then, Helicobacter species have been demonstrated in cetaceans and pinnipeds from around the world. Since 1990, the Animal Health and Veterinary Laboratories Agency Polwhele, Truro, has been involved in the UK Cetacean Strandings Investigation Programme to establish the cause of death of cetacean species stranded along the coast of Cornwall, England. We describe the isolation of Helicobacter cetorum in a striped dolphin (Stenella coeruleoalba) and evidence of H. cetorum infection in cetaceans from European waters.

Apex predators such as Pacific white-sided dolphins (Lagenorhynchus obliquidens) have the potential to impact prey populations and to be affected by changes in prey abundance. As abundant predators that range widely across the North Pacific Ocean, their interactions with prey populations may have conservation implications. The energy required by individual Pacific white-sided dolphins was estimated using a bioenergetic model that accounted for different age classes and reproductive stages (calf, juvenile, adult, pregnant, and lactating). Monte Carlo simulations incorporating variability in model parameters (i.e., body mass, growth rate, costs of gestation and lactation, metabolic rate, cost of activity, and assimilation efficiencies) were used to predict ranges in energetic requirements of this species. Mean (± SD) total energy requirements in MJ/day were 40.3 ± 6.2 for calves, 70.8 ± 8.2 for juveniles, 69.0 ± 3.6 for adults, 70.3 ± 3.6 for pregnant females, and 98.4 ± 20.0 for lactating females....

The health, postrelease movements, and behavior of mass stranded Atlantic white-sided dolphins (Lagenorhynchus acutus) and short-beaked common dolphins (Delphinus delphis) from Cape Cod, Massachusetts, were evaluated. Health was assessed through physical examination and blood analysis. Eleven dolphins (eight white-sided dolphins and three common dolphins) were relocated, outfitted with satellite transmitters, and released during seven mass stranding events. Five transmitters recorded only location, and six also included a time-depth recorder. Transmission duration ranged from 8 h to 218 d, with a mean of 117 d (median = 118 d, SD = 82 d), after release. All dolphins demonstrated extensive movement throughout the Gulf of Maine. The distribution of tagged dolphins was considered normal based on comparisons with published data for these species. Excluding the dolphin that transmitted for only 8 h, mean minimum speeds for individual dolphins ranged from 3.4 to 6.6 km/h; overall mean for all dolphins was 5.4 km/h (SD = 0.9 km/h). The five dolphins with time-depth recorders had mean dive depths of 8.6–40.3 m and mean dive durations of 46–296 s. Hematologic and biochemical data revealed only minor abnormalities. Data suggest that at least 10 of the 11 dolphins were likely successfully reintroduced into the wild.

Stenson, G. B., Benjamins, S., and Reddin, D. G. 2011. Using bycatch data to understand habitat use of small cetaceans: lessons from an experimental driftnet fishery. – ICES Journal of Marine Science, 68: 937–946. Many marine mammals inhabit offshore areas where it is difficult to determine distribution and abundance. Historical bycatch data of marine mammals in the Northwest Atlantic obtained from the Canadian experimental Atlantic salmon (Salmo salar) driftnet fishery were examined to obtain information on seasonal distribution and relative abundance. From 1965 to 2001, 47 cruises were undertaken totalling 12 566.5 km-h of fishing effort; four species of small cetacean and two species of pinniped were caught. Harbour porpoises (Phocoena phocoena) were the most frequently caught species in all areas except the Labrador Sea, where Atlantic white-sided dolphins (Lagenorhynchus acutus) were more common. Long-finned pilot whales (Globicephala melas), common dolphins (Delphinus delphis), harp seals (Pagophilus groenlandicus), and harbour seals (Phoca vitulina) were also taken occasionally. Although typically considered an inshore species, harbour porpoises were regularly reported in deep water (>2000 m), in the Newfoundland Basin and Labrador Sea. Atlantic white-sided dolphins were often caught along the edge of the continental shelf and appeared to prefer relatively warm water. Finally, catch records indicate that waters of the Newfoundland Basin and Southern Grand Banks may contain important winter habitat for several small species of cetacean.

The analysis of stranding events and the application of molecular markers can be powerful tools to study cryptic biological aspects of delphinid species that occur mainly in open ocean habitat. In the present study, we investigated nuclear and mitochondrial genetic variability of Atlantic white-sided dolphins that stranded from 1990 to 2006 (n = 42) along the west coast of Ireland, using 8 microsatellite loci and 599 bp of the mitochondrial DNA control region. Results from both classes of markers are concordant with the hypothesis of a large random-mating population of white-sided dolphins along the west coast of Ireland. In addition, the analyses of 2 live mass stranding events (19 and 5 individuals, respectively) revealed that dolphins within each group were mainly unrelated to each other, suggesting dispersal of both sexes from the natal group (i.e., no natal phylopatry). Parentage analyses allowed the identification of mother-offspring pairs but ruled out all adult males as possible fathers. In combination with data on age of individuals, these results confirmed previous knowledge on life-history parameters, with sexually mature females ranging between 11 and 15 years of age and an interbirth interval of at least 2 years. The present study provides novel information on population and group composition of Atlantic white-sided dolphins along the west coast of Ireland, where population and social structure of the species are still poorly understood.

Hexabromocyclododecane (HBCD) is a brominated flame retardant used primarily in expanded polystyrene foams and other styrene resins. Samples of blubber (n = 57) and liver (n = 16) from Atlantic white-sided dolphins, Lagenorhynchus acutus, that stranded on the eastern coast of United States between 1993 and 2004 were obtained from the National Marine Mammal Tissue Bank (NMMTB). Blubber samples from most of these animals (n = 47) were previously analyzed for polybrominated diphenyl ethers (PBDE), polychlorinated biphenyls (PCB), and several toxaphene congeners. The three most abundant diastereomers in the technical HBCD mixture (alpha-HBCD, beta-HBCD, and gamma-HBCD) and their enantiomers were determined using liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS). alpha-HBCD was found in all blubber and liver samples while beta-HBCD and gamma-HBCD were not detected in any samples. The alpha-HBCD concentration in blubber and liver ranged from 14 ng/g wet mass (19 ng/g lipid) to 280 ng/g wet mass (380 ng/g lipid) and 0.051 ng/g wet mass (2.9 ng/g lipid) to 3.6 ng/g wet mass (140 ng/g lipid), respectively. Concentrations of alpha-HBCD were 2 to 3 orders of magnitude lower than previously reported PBDE, PCB, and toxaphene concentrations in these same animals. There was not a significant temporal trend for these compounds in white-sided dolphin blubber. The enantiomeric fractions (EF) measured in blubber and liver were not statistically different and ranged from 0.34 to 0.53. Blubber EFs were significantly correlated with both alpha-HBCD concentrations and white-sided dolphin body length. In general, concentrations of HBCDs were lower in these white-sided dolphins than in cetaceans from Western Europe.

During Leg 1 of the MAR-ECO expedition on the R.V. G.O. Sars in June 2004 four main species of dolphins were observed along the Mid-Atlantic Ridge from Iceland to the Azores: pilot whale ( Globicephala melas ) ( n =326), short-beaked common dolphin ( Delphinus delphis ) ( n =273), white-sided dolphin ( Lagenorhynchus acutus ) ( n =103), and striped dolphin ( Stenella coeruleoalba ) ( n =86). Pilot whales and white-sided dolphins were found in cold (5–16 °C) and less-saline (34.6–35.8‰) water masses in the northern part of the study area, whereas common and striped dolphins inhabited warmer (12–22 °C) and more-saline (34.8–36.7‰) waters in the south. Dolphins tended to aggregate in areas of steep slopes, but actual bottom depth appeared to be less important. Based on spatial correlations between dolphin occurrence and candidate prey organisms recorded acoustically and by midwater trawling, mesopelagic fishes and squids were assumed to be important prey items, with Benthosema glaciale probably being the most important prey for pilot whales and white-sided dolphins, while Lampanyctus macdonaldi , Stomias boa ferox and Chauliodus sloani were probably of particular importance for common dolphins. Cephalopods, especially Gonatus sp. and Teuthowenia megalops were the most likely prey species of pilot whales and striped dolphins, respectively. The difference in physical habitat north and south of the Sub-polar Frontal Zone seemed to have important effects on prey distribution, in turn influencing dolphin distribution.

The structure and development of the brain are extremely difficult to study in free-ranging marine mammals. Here, we report measurements of total white matter (WM), total gray matter (GM), cerebellum (WM and GM), hippocampus, and corpus callosum made from magnetic resonance (MR) images of fresh, postmortem brains of the Atlantic white-sided dolphin (Lagenorhynchus acutus) imaged in situ (i.e., the brain intact within the skull, with the head still attached to the body). WM:GM volume ratios of the entire brain increased from fetus to adult, illustrating the increase in myelination during ontogeny. The cerebellum (WM and GM combined) of subadult and adult dolphins ranged from 13.8 to 15.0% of total brain size, much larger than that of primates. The corpus callosum mid-sagittal area to brain mass ratios (CCA/BM) ranged from 0.088 to 0.137, smaller than in most mammals. Dolphin hippocampal volumes were smaller than those of carnivores, ungulates, and humans, consistent with previous qualitative results assessed from histological studies of the bottlenose dolphin brain. These quantitative measurements of white matter, gray matter, corpus callosum, and hippocampus are the first to be determined from MR images for any cetacean species. We establish here an approach for accurately determining the size of brain structures from in situ MR images of stranded, dead dolphins. This approach can be used not only for comparative and developmental studies of marine mammal brains but also for investigation of the potential impacts of natural and anthropogenic chemicals on neurodevelopment and neuroanatomy in exposed marine mammal populations. Anat Rec, 291:263–282, 2008. 2008 Wiley-Liss, Inc.

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The testes of 31 Atlantic white-sided dolphins, Lagenorhynchus acutus bycaught in the northeastern Atlantic were studied by histological and morphometric techniques. Twenty specimens were classified as mature, nine as immature and two as pubescent. Between immature and mature specimens there were overlappings in body length and body weight, but clear differences in the diameter of seminiferous tubules ( 480 μm) and the proportion of seminiferous tubules to interstitial tissue (ST:INT-ratio). Also relative testes weight differed clearly. The pubescent specimens showed intermediate characteristics. Spermatogenetic activity of mature dolphins ranged from quiescent to different degrees of activity and varied even in animals from the same site and capture date. The fact that we found mature males with quiescent testes suggests a seasonal rather than a continuous spermatogenesis. We assume that sexual activity in L. acutus begins at an age of 7-8 GLGs and that the reproductive season of this species in the northeastern Atlantic starts in February. Further, the ultrastructure of the spermatozoon is similar to that of the related Lagenorhynchus obliquidens.

Using a large passenger cruise-ship (MV ‘Discovery’) as a platform, a cetacean survey was conducted between 1 August and 3 September 2005 across the northern North Atlantic Ocean and back, covering waters between the UK, Iceland, Greenland and Canada. The objective was to collect sightings data for all cetacean species encountered to begin to collate information for a large-scale sightings database. Two observers employed standard-distance sampling techniques and visual observations (naked eye) to scan for cetaceans during daylight hours and favourable weather conditions. Approximately 112 h were spent surveying over 23 d. A total of 13 cetacean species were encountered, with 173 separate sightings recorded, totalling over 2000 animals. The most commonly sighted species were minke whales (Balaenoptera acutorostrata: N=44), Atlantic white-sided dolphins (Lagenorhynchus acutus: N=34, with group sizes of up to 600), and humpback whales (Megaptera novaeangliae: N=31). The distribution of minke whales, Atlantic white-sided dolphins and fin whales was linked to underlying oceanographic variables. Overall patterns of distribution were consistent with our understanding of the summer distributions for the species encountered. The survey highlighted the cetacean diversity of the northern North Atlantic region. Repeat work using this methodology will allow an examination of species' distributions and estimation of their relative abundance.

Three novel halogenated organic compounds (HOCs) have been identified in the blubber of marine mammals from coastal New England with the molecular formulae C 9 H 3 N 2 Br 6 Cl, C 9 H 3 N 2 Br 7 , and C 9 H 4 N 2 Br 5 Cl. They were identified using high and low resolution gas chromatography mass spectrometry (GCMS) and appear to be highly brominated analogues of Q1, a heptachlorinated HOC suspected to be naturally produced. These compounds were found in Atlantic white sided dolphin ( Lagenorhynchus acutus ), bottlenose dolphin ( Tursiops truncatus ), common dolphin ( Delphinus delphis ), Risso's dolphin ( Grampus griseus ), harbor porpoise ( Phocoena phocoena ), beluga whale ( Delphinapterus leucas ), fin whale ( Balaenoptera physalus ), grey seal ( Halichoerus grypus ), harp seal ( Phoca groenlandica ) and a potential food source ( Loligo pealei ) with concentrations as high as 2.7 μg/g (lipid weight). The regiospecificity of C 9 H 3 N 2 Br 6 Cl is suggestive of a biogenic origin. Debromination of C 9 H 3 N 2 Br 6 Cl may be significant in the formation of C 9 H 4 N 2 Br 5 Cl.

From May to September 2004 a survey of cetacean distribution and relative abundance was conducted on board a ‘ship of opportunity’ * a vessel used as a survey platform but not chartered for this purpose * off the west coast of Ireland. In total, 508 hours of survey effort were completed, with 304.2 hours in Beaufort sea-state 3 or less. Two hundred and thirty one sightings of eight species* common dolphin Delphinus delphis (L.), Atlantic white-sided dolphin Lagenorhynchus acutus (Gray), bottlenose dolphin Tursiops truncatus (Montagu), harbour porpoise Phocoena phocoena (L.), Risso’s dolphin Grampus griseus (Cuvier), pilot whale Globicephala melas (Traill), minke whale Balaenoptera acutorostrata (Lacepede) and fin whale Balaenoptera physalus (L.) * were recorded, totalling 2,933 individuals. The greatest diversity and relative abundance were recorded on the Rockall Bank where Atlantic white-sided dolphin was the most abundant species. The common dolphin was the most abundant species recorded on the continental shelf to the south-west of Ireland, while the relative abundance of cetaceans off the north coast was very low. The data suggest that cetacean species composition and relative abundance can vary greatly between adjacent marine habitat types and over relatively small geographical distances.

The vertebral column of the Atlantic white-sided dolphin, Lagenorhynchus acutus, reflects the radical reorganization of the cetacean column for locomotion in water. Both posterior thoracic and anterior caudal vertebrae have been ‘‘lumbarized,’’ and discontinuities occur within the caudal series at the synclinal point and fluke base. Morphology changes subtly as body size increases. Neural process height increases more rapidly, and centrum length more variably, than other vertebral parameters. As a result, large animals have disproportionately tall neural processes, short necks, long mid-body regions, and short flukes. Vertebral columns of large animals also show greater complexity (range, irregularity, and polarization) of centrum length than do those of smaller animals. Comparisons among dolphins reveal that complexity trends with respect to differentiation of parts run counter to the trend with respect to number of parts, a relationship predicted by Williston in 1914.

Assessing trends of persistent organic pollutants (POPs) in marine mammals is difficult due to age, gender, and metabolism influences on accumulation. To help elucidate these effects in dolphins, POP concentrations were determined in the Atlantic white-sided dolphin, Lagenorhynchus acutus, a pelagic delphinid inhabiting North Atlantic waters, and in the rough-toothed dolphin, Steno bredanensis, a pelagic delphinid inhabiting tropical and subtropical waters. The specific objectives of this study were to determine baseline POP concentrations in L. acutus and S. bredanensis blubber samples and to examine the effects of age, gender, and metabolism on POP concentrations in dolphin blubber. Focus was aimed at contaminants of emerging concern, specifically, toxaphene and polybrominated diphenyl ethers (PBDEs). Samples collected from L. acutus (n = 47) stranding events in Massachusetts (1993--2000) and S. bredanensis samples (n = 15) were analyzed for PCBs, toxaphene, and other organic pesticides by gas chromatography/mass spectrometry (GC/MS). Age and gender influences were similar between the two species, with adult females having significantly lower POP concentrations as compared to adult males and juveniles. Mean sigma toxaphene concentrations were highest in juvenile L. acutus, 13.0 (6.7) microg/g wet mass (1 SD), and lowest in adult female S. bredanensis, 1.49 (1.4) microg/g wet mass. sigma PBDE (sum of congeners 47, 99, 100, 153, and 154) concentrations were highest in juvenile L. acutus, 2.41 (1.2) microg/g wet mass, and lowest in adult female S. bredanensis, 0.51 (0.6) microg/g wet mass. POP concentrations did not significantly differ between adult males and juveniles, suggesting metabolism of congeners and/or dilution with growth. PBDE concentrations in juvenile white-sided dolphins were not significantly related to collection year, suggesting that there may be a lag period for higher concentrations to be detected in pelagic marine mammals such as L. acutus or that concentrations have already peaked in this species prior to the first collection in 1993.

Cetacean calves routinely swim in echelon position with their mothers and occasionally with other individuals. In August 2002, we observed an adult Atlantic white-sided dolphin (Lagenorhynchus acutus) swimming with two calves in echelon position, one on each side, three times over a 90min period. Four possible explanations for this behaviour are considered: (1) twins, (2) chance association, (3) alloparental association in the form of “babysitting,” or (4) adoption. We believe that it is unlikely that this behaviour can be explained by chance or twins; therefore, we believe it represents alloparental association. The presence of a dead lactating female in the area five days before the observation lends support for the adoption hypothesis to explain this unusual observation.

Vertebral anatomy in delphinid cetaceans exhibits marked heterogeneity. Description and functional interpretation of this variability is facilitated by the recognition of structural units along the column whose boundaries transgress those of the classical mammalian series. Vertebral anatomy of the killer whale (Orcinus orca) and the Atlantic whitesided dolphin (Lagenorhynchus acutus) lie near the ends of an anatomical continuum. Primitive columns resemble those of living delphinapterid delphinoids in exhibiting minimal intervertebral variation, low counts and spoolshaped vertebrae. Derived columns are more regionalized, displaying traits that limit mobility in the anterior torso, enhance flexibility at the point of neural spine syncliny and increase dorsoventral displacement of prefluke vertebrae. Reconstruction of the historical sequence of anatomical innovations identifies syncliny as an early and critical step in delphinid column evolution. Trait distribution supports evolutionary isolation of Pseudorca and Orcinus from remaining delphinids, inclusion of Feresa and Peponocephala among delphinine delphinids, and subdivision of delphinines on the basis of centrum dimensions, neural spine inclination and count. Details of vertebral anatomy can also be used to place fragmentary postcranial material, particularly that of fossils, in functional and evolutionary context. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 140, 383‐401.

A line transect survey was conducted in July/August 1998 to investigate the distribution and abundance of cetaceans off north-west Scotland. Over 2156.5 km of survey effort, 304 sightings were recorded of which 184 were identified to species. Nine species were identified: Atlantic white-sided dolphin Lagenorhynchus acutus, fin whale Balaenoptera physalus, sei whale Balaenoptera borealis, long-finned pilot whale Globicephala melas, sperm whale Physeter macrocephalus, common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, white beaked dolphin Lagenorhynchus albirostris and Risso's dolphin Grampus griseus. The Atlantic white-sided dolphin was the most relatively abundant species. The relative abundance of large whales and dolphins was greatest in the Faroe–Shetland Channel. The continental slopes of this area are undergoing development by oil industries and concerns have been raised about the potential impacts of these activities on cetaceans. These waters are used year-round by cetaceans and provide feeding and breeding grounds and are a migration route for large whales.

The relationship between trophic position through delta13C and delta15N and trace metal concentrations (Zn, Cd, Cu and Hg) was investigated in the tissues of six marine mammal species from the Northeast Atlantic: striped dolphin Stenella coeruleoalba, common dolphin, Delphinus delphis, Atlantic white-sided dolphin Lagenorhynchus acutus, harbour porpoise Phocoena phocoena, white beaked-dolphin Lagenorhynchus albirostris, grey seal Halichoerus grypus stranded on French Channel and Irish coasts. White-beaked dolphins, harbour porpoises, white-sided dolphins, common and striped dolphins display the same relative and decreasing trophic position, as measured by delta15N values, along both the Irish and French channel coasts, reflecting conservative trophic habits between these two places. Hepatic and renal Cd concentrations were significantly correlated to muscle delta13C and delta15N values while Hg, Zn and Cu did not. These results suggest that Cd accumulation is partly linked to the diet while other factors such as age or body condition might explain Hg, Zn or Cu variability in marine mammals. Combined stable isotope and trace metal analyses appear to be useful tools for the study of marine mammal ecology.

1. The status of small cetaceans in the North Sea and adjacent waters has been of concern for many years. Shipboard and aerial line transect surveys were conducted to provide accurate and precise estimates of abundance as a basis for conservation strategy in European waters. 2. The survey, known as SCANS (Small Cetacean Abundance in the North Sea), was conducted in summer 1994 and designed to generate precise and unbiased abundance estimates. Thus the intensity of survey was high, and data collection and analysis methods allowed for the probability of detection of animals on the transect line being less than unity and, for shipboard surveys, also allowed for animal movement in response to the survey platform. 3. Shipboard transects covered 20 000 km in an area of 890 000 km2. Aerial transects covered 7000 km in an area of 150 000 km2. 4. Three species dominated the data. Harbour porpoise Phocoena phocoena were encountered throughout the survey area except in the Channel and the southern North Sea. Whitebeaked dolphin Lagenorhynchus albirostris and minke whale Balaenoptera acutorostrata were found mainly in the north-western North Sea. 5. Phocoena phocoena abundance for the entire survey area was estimated as 341 366 [coefficient of variation (CV) = 0.14; 95% confidence interval (CI) = 260 000-449 000]. The estimated number of B. acutorostrata was 8445 (CV = 0.24; 95% CI 5000-13 500). The estimate for L. albirostris based on confirmed sightings of this species was 7856 (CV = 0.30; 95% CI = 4000-13 000). When Atlantic whitesided dolphin Lagenorhynchus acutus and Lagenorhynchus spp. sightings were included, this estimate increased to 11 760 (CV = 0.26; 95% CI 5900-18 500). 6. Shortbeaked common dolphin Delphinus delphis were found almost exclusively in the Celtic Sea. Abundance was estimated as 75 450 (CV = 0.67; 95% CI = 23 000-149 000). 7. Current assessments and recommendations by international fora concerning the impact on P. phocoena of bycatch in gillnet fisheries in the North Sea and adjacent waters are based on these estimates.

In January 1998 and 1999, two mass strandings of dolphins occurred in Wellfleet, Massachusetts. The strandings were composed of 97 and 53 animals, respectively. Tissues from 35 Atlantic white-sided dolphins (Lagenorhynchus acutus) from the 1998 stranding and 52 from the 1999 stranding were examined histologically. In the 1998 stranding, unidentified protozoal tissue cysts were seen in skeletal muscle from 11 of 28 (39%) dolphins. In addition, two dolphins had a protozoal tissue cyst in cardiac muscle. In the 1999 stranding, nine of 23 (39%) dolphins had the same protozoal tissue cysts in skeletal muscle. The identification of these protozoal tissue cysts as Sarcocystis sp. was confirmed by light and transmission electron microscopy. The high prevalence of sarcocysts in these dolphins suggests that they are likely intermediate hosts for previously undescribed Sarcocystis spp. The ultrastructure of the sarcocyst walls suggests that more than one species of Sarcocystis are present in dolphins.

We present the first acoustic observations of predator-prey interactions between fin whales and herring. The school dynamics and predation events of Norwegian spring-spawning herring (Clupea harengus) in a cold front area (about 125 km 2 ) in the Norwegian Sea in April were quantified. Data from high-resolution sonar tracking of herring schools combined with echosounder data were integrated with pelagic-trawl samples. A total of 44 herring schools were each observed for an average of 34.8 min. Altogether, 184 behavioural events were recorded, with an event occurring every 8.3 min on average. Intra-school events (compression, reorganization, ring, pseudopodium, elongate, diving, surfacing) were observed every 15.3 min and inter-school events (approach, join, leave, split) every 22.9 min. We observed 17 fin whales (Balaenoptera physalus), six Atlantic white-sided dolphins (Lagenorhynchus acutus) and five killer whales (Orcinus orca) within the experimental area. Predator events occurred every 91 min on average. Of these marine mammals only fin whales swimming alone or in small groups (2-5 ind.) were observed to attack herring. Attacks from fin whales were observed every 170 min. They strongly influenced the density, shape and structure of the herring schools. Large fish such as cod (Gadus morhua) and saithe (Pollachius virens) preying on herring in coastal areas were not caught in the pelagic trawl or detected by acoustics. Herring schools were on average large (987 m 2 ), dense, swam at depth (148 m) and had a moderate swimming speed (1.1 body lengths per second), reflecting a risk-averse, anti-predator behaviour to marine mammals. We discuss differences in schooling dynamics, anti-predator behaviour, attack frequency and predation risk between herring attacked by fin whales in an offshore area and herring attacked by gadoid predators closer to the coast in a similar study in May.

Metallothioneins (MTs) were characterised in the kidneys of a white-sided dolphin Lagenorhynchus acutus stranded along the Belgian coast, displaying high levels of cadmium (Cd) and mercury (Hg) in liver and kidney. The protein has two isoforms: MT-1 and MT-2. MT-1 binds Cu, Zn, Hg and Cd, while MT-2 only binds Zn, Hg and Cd. This suggests different metabolic functions for the two isoforms: MT-1 is mainly involved in Cu homeostasis; MT-2, which was four-fold more abundant than MT-1, detoxifies most of the accumulated cadmium.

Atlantic white-sided dolphins (Lagenorhynchus acutus) are among the most abundant, and least studied, cetaceans in coastal New England. Between April and October 1984 through 1997 we sighted 1,231 groups of Atlantic white-sided dolphins, primarily on Stellwagen Bank and Jeffreys Ledge (two shallow glacial deposits along the coasts of Massachusetts, New Hampshire, and Maine). Mean group size was 52 (±90.9), and was significantly larger from August through October (71.9 ± 111.4) than April through June (35.0 ± ± 45.4). Calf sightings were uncommon until June and July, after which they were present in over 50% of groups. Combined with observations of apparent newborn calves, this confirms that early summer is an important calving period. The presence of calves did not, however, solely account for the increase in group size. Boat interaction (bow- and stern-wake riding) was the most commonly recorded behavior (47.4% of sightings), followed by traveling (31.4%), interactions with other cetacean species (27.6%), social interaction (15.5%), and feeding (9.5%). While feeding was uncommon, one observation of apparently coordinated ball feeding was seen with sand lance (Ammodytes spp.) as the visible prey. Aerial behavior showed a positive correlation with group size, although it was often impossible to tell whether the same dolphins were leaping repeatedly. Eighty-eight dolphins were photo-identified using either unusual body pigment or a distinctive dorsal fin. While several individuals were reidentified between years and between areas, no reidentifications were made within a year in the same area. Unusually pigmented individuals were much more likely to be reidentified than those with distinctive dorsal fins, most likely due to higher visibility. We suggest that Atlantic white-sided dolphins are generally using the study area as transients in what appears to be a large home range.

The stomachs and intestines of 23 dusky dolphins incidentally caught in a trawl fishery off Patagonia were surveyed for helminths. All the dolphins were parasitized, with a total of 3,936 helminth individuals. Only five species occurred, of which three were common (prevalence ± 10%): Anisakis simplex, Braunina cordiformis and Hadwenius sp. A. simplex was present in all the dolphins and showed the highest abundance and mean intensity (104.9 individuals/infected host). B. cordiformis was next most common (87%), and Hadwenius sp. third (52.2%). A. simplex was found mostly in the stomach (94.8%), B. cordiformis in the duodenal ampulla (51.4%), and Hadwenius sp. in the stomach (64.5%). The rare species Corynosoma australe (immature specimens) and Pholeter gastrophilus occurred in the stomach. A. simplex and B. cordiformis showed a clumped distribution along the intestine. Brillouin's diversity and evenness indices for the intestinal helminth community were 0.329 and 0.393, respectively. The diversity values and the number of parasite species were within the range for other small cetaceans.

Marine mammal by-catch in 11 pelagic trawl fisheries operated by four different countries in the northeast Atlantic was studied. Observers accompanied commercial fishing vessels and monitored 374 tows totalling 1771 h of towing during 377 days fishing. Three species of marine mammal were identified in by-catches (white-sided dolphin, Lagenorhynchus acutus, common dolphin, Delphinus delphis and grey seal Halichoerus grypus) and a fourth, bottlenose dolphin Tursiops truncatus, was probably present. Dolphins were caught in four of the 11 fisheries and seal in one. In those fisheries with cetacean bycatch, rates varied from 0.0606 to 0.1000 per tow and 0.0107 to 0.0137 per hour of towing and were highest in the French sea bass fishery and lowest in the French tuna fishery. Grey seals were caught in the Irish Celtic Sea herring fishery at a rate of 0.0513 per tow or 0.0396 per hour of towing. The meanSD dolphin catch rate for all fisheries combined was 0.0480.013 per tow (one dolphin per 20.7 tows), or 0.01850.0019 per hour of towing (one dolphin per 98 h of towing) and, for all marine mammals, 0.0590.019 (1 per 17.0 tows) or 0.01240.0121 (1 per 80.6 h of towing). 95% confidence intervals, calculated on untransformed data, for all fisheries combined were 0.4‐1.6 dolphins per 100 h of towing. No operational factors were correlated with by-catch rates but the haul-back procedure was identified as a potentially important factor. All dolphin by-catches occurred during the night which may be a due to an association between cetaceans and trawlers at night. White-sided dolphins and grey seals were observed feeding around the net during towing and this behaviour may make them more vulnerable to capture. Operational difficulties in observing by-catch and potentially significant annual fluctuation in catch rates warrant further observer studies of these and other trawl fisheries. # 1999 Elsevier Science B.V. All rights reserved.

Clinical hematology values were determined for 29 harbor porpoises (Phocoena phocoena) released from herring weirs in the Bay of Fundy, Canada. Erythrocyte values exhibited narrow ranges, but there was a high degree of individual variability in counts of white blood cells. Total white cell counts ranged from 2.6 to 15.5 ± 109/liter, with an overall mean of 6.5 ± 2.7 ± 10±/liter. There were significant differences among reproductive classes in mean values of total red blood cells, hematocrit (HCT), mean cell volume (MCV), mean cell hemoglobin (MCHC) and total monocyte count. Wild harbor porpoises had fewer white blood cells, lower relative total number of neutrophils and lymphocytes, and higher percentages of monocytes and eosinophils than reported in the literature for captive porpoises. Compared to published values for other odontocetes, the hemograms of harbor porpoises were most similar to those of Pacific white-sided dolphins (Lagenorhynchus acutus). These hematology data represent a baseline from free-ranging harbor porpoises that can be used as a reference for long-term monitoring of the health of this population and as a tool for rehabilitation facilities.

Aerial line-transect surveys of cetaceans were flown in the Gulf of St. Lawrence in late August and early September of 1995 and in late July and early August of 1996. Systematic north-south transects were spaced 15' of longitude apart. In 1995, the study area comprised the entire Gulf, divided into three strata for analysis; 69% was flown. In 1996, a single stratum covered only the north shore shelf; 75% of the design was flown. The survey platform was a light high-winged aircraft with bubble windows flown at 213 m (700 ft). Ten species were seen. Minke whales (Balaenoptera acutorostrata), Atlantic white-sided dolphins (Lagenorhynchus acutus), and harbour porpoises (Phocoena phocoena) yielded enough sightings to support good estimates, while fin whales (Balaenoptera physalus), humpback whales (Megaptera novaeangliae), white-beaked dolphins (Lagenorhynchus albirostris), and long-finned pilot whales (Globicephala melas) yielded few sightings and unreliable estimates. Blue whales (Balaenoptera musculus) and belugas (Delphinapterus leucas) were seen too rarely to support any analysis. The tenth species was a small delphinid, not positively identified. Minke whales were ubiquitous, but more common in the northern strata. We estimated about 1000 in the whole Gulf in 1995 and about 600 in the northernmost stratum in 1996 (these numbers, and those following, are uncorrected for visibility bias). We estimated about 12 000 Atlantic white-sided dolphins in the Gulf in 1995, but in 1996 saw hardly any, perhaps because we flew the survey earlier. Harbour porpoises (12 000 in 1995 and 21 000 in 1996) were most numerous in the northern stratum, but were also widely distributed at lower densities in the central and southern Gulf. White-beaked dolphins (2500 in 1995 and 2500 in 1996) occurred only in the Strait of Belle Isle and the extreme northeastern Gulf. We estimated a few hundred fin whales in the northern and central strata and about 100 humpbacks, mostly in the northeast. Long-finned pilot whales were only seen in the southeastern Gulf, surveyed only in 1995 (about 1500). Resume : Des inventaires aeriens le long de transects ont ete effectues au-dessus du golfe du Saint-Laurent a la fin d'aout et au debut de septembre en 1995 et a la fin de juillet et au debut d'aout en 1996. Les transects nord-sud etaient systematiquement espaces par 15 minutes de longitude. En 1995, tout le golfe a ete inventorie, divise en 3 strates pour fins d'analyse; 69% a ete survole. En 1996, une seule strate ne couvrait que la plate-forme le long de la rive nord; 75% a ete survole. Le vehicule utilise etait un petit avion leger a ailes hautes et a fenetres en bulles volant a 213,4 m (700 pieds) d'altitude. Dix especes ont ete reperees. Nous avons vu suffisamment de Petits Rorquals (Balaenoptera acutorostrata), de Dauphins a flancs blancs (Lagenorhynchus acutus) et de Marsouins communs (Phocoena phocoena) pour faire une bonne estimation des populations, mais le nombre restreint de Rorquals communs (Balaenoptera physalus), de Rorquals a bosse (Megaptera novaeangliae), de Dauphins a nez blanc (L. albirostris )e t de Globicephales noirs (Globicephala melas) observes ne permettait de faire que des estimations approximatives des populations. Les Rorquals bleus (Balaenoptera musculus) et les Belugas (Delphinapterus leucas) ont egalement ete vus trop rarement pour permettre toute analyse. La dixieme espece etait un petit delphinide qu'il a ete impossible d'identifier. Les Petits Rorquals ont ete vus partout, mais ils abondaient surtout dans la strate nord. Nous avons estime leur nombre a environ 1 000 dans tout le golfe en 1995 et a environ 600 dans la strate nord en 1996 (ces nombres et

Highly mobile species in the marine environment may be expected to show little differentiation at the population level, but this is often not the case. Instead cryptic population structure is common, and effective conservation will require an understanding of how these patterns evolve. Here we present an assessment from both sides of the North Atlantic of differentiation among populations of a dolphin species that inhabits mainly pelagic waters, the Atlantic white-sided dolphin. We compare eleven putative populations in the western and eastern North Atlantic at mtDNA and microsatellite DNA loci and find reduced nucleotide diversity and signals for historical bottlenecks and post-bottleneck expansions in all regions. We calculate expansion times to have occurred during the early Holocene, following the last glacial maximum (LGM). We find evidence for connectivity among populations from either side of the North Atlantic, and differentiation between putative populations in the far northeast compared with all other areas sampled. Some data suggest the possibility of separate refugia during the LGM explaining this pattern, although ongoing ecological processes may also be a factor. We discuss the implications for developing effective programs of conservation and management in the context of ongoing anthropogenic impact.

Incidental catches of cetaceans in the Dutch pelagic trawl fishery are largely restricted to late-winter early-spring in an area along the continental slope southwest of Ireland. Available evidence indicates that annual variations in such incidents are large. Using combined mid-water trawl by-catch and dolphin stomach content data, the hypothesis is put forward that Atlantic white-sided dolphin (Lagenorhynchus acutus), normally a more oceanic species, may actively search for mackerel (Scomber scombrus) closer to shore in early-spring, at least in some years. Supporting data were from an observer program during 1992–94, which covered seven trips representing 5% of the annual effort in the fishery. Also over the period 1989–94, a total of 71 records of by-catch incidents were collected (involving a minimum of 312 individuals), of which 41 occured in 1994 (172 individuals). Approximately 90% of the incidents occurred late-winter early-spring, when both the mackerel and horse mackerel (Trachurus trachurus) pelagic fisheries were operating in the same area, southwest of Ireland. Incidence frequency peaked by late February and March, when mackerel is known to move into the area during its southward migration. The Atlantic white-sided dolphin was the main cetacean species in the by-catch (83% of all identified individuals). Other species recorded included long-finned pilot whale (Globicephala melas), short-beaked common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus) and the white-beaked dolphin (Lagenorhynchus albirostris). The stomachs of 47 Atlantic white-sided dolphins, 11 common dolphins, two bottlenose dolphins and one white-beaked dolphin were examined. Fresh mackerel remains were found in nearly all white-sided dolphin stomachs, whereas fresh horse mackerel remains occured only in stomachs of bottlenose and common dolphins. Deep-water fish otolith incidents suggested that white-sided, common and bottlenose dolphin had completely different diets before moving to the southwest of Ireland.

We give details of the biological and pathological findings in a mass stranding of 19 white-sided dolphins on the west coast of Ireland. The pod consisted of adults and calves; no juveniles were present. The calf of a recently parturient female was not found. The presence of small foetuses suggested that mating took place in late August or early September. The largest and oldest male was severely diseased but the remainder of the pod were in good health although some minor lesions were found. The site where the animals came ashore was compatible with the geomagnetic theory of mass strandings.

Chlorobiphenyls (CBs) and organochlorine pesticides (OCPs) have been determined in the blubber of 17 Atlantic white-sided dolphins stranded at Killala Bay, Co Mayo, Ireland and five from the Scottish coast. The concentrations of the contaminants measured range from 773 to 63,400 microg kg(-1) for sigmaCB and from 160 to 54,600 microg kg(-1) for sigmaDDT. The concentrations of the CBs and OCPs is highly dependent on the age, sex, reproductive state and nutritional condition of the animals in addition to the intake via the food web. Principal Components Analysis (PCA) has been used to study the variation of chemical patterns (data ratioed to CB 153). Immature animals (6 years), mature males and primogravid females, and lactating females could be distinguished on the basis of their contaminant patterns. This paper describes the different processes of bioaccumulation and metabolism of organochlorine contaminants (OCs) in this species.

Brucella species infection in marine mammal species has been reported to have a global distribution. In 2007, the description of Brucella ceti was published and formally adopted for those isolates originating from cetaceans and pathologic lesions similar to those seen in terrestrial mammals infected with Brucella spp. have been associated with its isolation. Brucella ceti infection specific to the central nervous system has been described in two species of cetacean: striped dolphins (Stenella coeruleoalba) in Europe and Costa Rica and an Atlantic white-sided dolphin (Lagenorhynchus acutus) in the UK. We describe the first report, to our knowledge, of B. ceti–associated meningitis and arthritis in a third species, the short-beaked common dolphin (Delphinus delphis), in an animal that stranded in the UK.

Brucella organisms which differed from the recognised species of the genus, were isolated from nine seals, eight cetaceans and one otter. A method is described for the isolation of Brucella species from sea mammals and the first isolations of Brucella species are recorded from an Atlantic white-sided dolphin ( Lagenorhynchus acutus ), two striped dolphins ( Stenella coeuleoalba ), a hooded seal ( Cystophora cristata ), a grey seal ( Halichoerus grypus ) and a European otter ( Lutra lutra ). There were differences in the culture media required for the primary isolation of the organisms and in their dependency on carbon dioxide. Subcutaneous lesions, when present, always yielded a confluent growth. The organisms were isolated from seven of 14 spleen samples and also from the mammary glands, uterus, testes and blood and the mandibular, gastric, iliac, sub-lumbar and colorectal lymph nodes.