Tursiops truncatus

Although bottlenose dolphins Tursiops truncatus are among the most common delphinid species, global population trends remain poorly understood. To improve the knowledge of the species in the Southwest Atlantic Ocean, thispaper reviews all available data related to the distribution and occurrence, abundance, residency and ranging patterns, group size and composition, survival and reproduction and population structure of the coastal bottlenose dolphin in Argentina. Most information proved to be scattered in time and space. Based on the available data, total abundance of coastal bottlenose dolphins in Argentina appears to be low. Data show sightings decreased notably since the 1990s in the northern province of Buenos Aires and the province of Chubut, with the species having disappeared completely from the former region. Data also indicated that two genetically and morphologically distinct coastal populations occur in Argentinean coastal waters, with a sympatric distribution in the prov...

We report on miscellaneous skin diseases or syndromes of unknown aetiology including whitish, velvety lesions (WVL, often associated with unrelated skin injuries, scars and tooth rakes), large, rounded lesions (LRL, large to very large lesions with an orange or dark outline and a light inner colour) and vesicular skin disease (VSD, small to medium vesicles) in Megaptera novaeangliae, Cephalorhynchus commersonii, C. eutropia, Pseudorca crassidens, Sotalia guianensis and Tursiops truncatus from marine waters of Argentina, Brazil, Chile, Ecuador, Peru and the Antarctic. No biopsy samples have been available yet for histopathology. WVL are now commonly recorded opportunistically through photo-identification studies in several coastal species and populations from South America. Mortality rates, if any, associated with these skin diseases is unknown. Though sometimes extensive and ulcerated WVL do not seem life-threatening and, at least in some individuals, may eventually heal. A calf C. eutropia with LRL died some weeks after being first sighted. While unknown bacteria or fungi superinfecting miscellaneous skin traumata and poxvirus tattoos are thought to cause WVL and LRL, vesiviruses are suspected as the aetiological agents of VSD. Importantly, all lesions were primarily seen in coastal cetaceans living in biologically or chemically contaminated waters. These various skin conditions may be indicative of a deteriorating coastal water environment and should be systematically monitored. Collection of biopsies or fresh samples for histopathology and microbiological analysis is urgently needed.

Recovery of cetacean carcasses provides data on levels of human-caused mortality, but represents only a minimum count of impacts. Counts of stranded carcasses are negatively biased by factors that include at-sea scavenging, sinking, drift away from land, stranding in locations where detection is unlikely, and natural removal from beaches due to wave and tidal action prior to detection. We estimate the fraction of carcasses recovered for a population of coastal bottlenose dolphins (Tursiops truncatus), using abundance and survival rate data to estimate annual deaths in the population. Observed stranding numbers are compared to expected deaths to estimate the fraction of carcasses recovered. For the California coastal population of bottlenose dolphins, we estimate the fraction of carcasses recovered to be 0.25 (95% CI = 0.20– 0.33). During a 12 yr period, 327 animals (95% CI = 253–413) were expected to have died and been available for recovery, but only 83 carcasses attributed to this...

Biological samples of free-ranging dolphins are increasingly used to gain information on population structure and ecology. In small cetaceans, the gender of individuals usually cannot be determined at sea, and population sex ratio has to be inferred indirectly. We used molecular sexing to determine the gender of 340 biopsy samples of bottlenose dolphins, Tursiops truncatus, spotted dolphins, Stenella frontalis, and common dolphins, Delphinus delphis, collected around the Azores and Madeira. Sex ratio was globally skewed in favor of males, and differed between species and archipelagos. Skew was probably influenced by the selectivity of biopsy collectors and seasonal or year-round predominance of males in natural populations. Skew was also influenced by sampling duration and intensity. In the Azores, when several samples were successively collected within the same group, the proportion of female samples decreased as a function of sample order. This trend indicated a tendency for females to increasingly avoid the boat while samples were being collected. It showed that males and females reacted differently to the perturbation caused by the biopsy sampling process (i.e. sample collection and driving style).

op ontdekking met ???, de bruinvis 2007 : Jaar van de Dolfijn educatief pakket Jaar van de Dolfijn 2007 is door de Verenigde naties uitgeroepen tot Jaar van de dolfijn. Op 17 september 2006 heeft Prins Albert II van Monaco (de peter van dit project) dit bekend gemaakt. Waarom een jaar van de dolfijn ? Omdat elke minuut wereldwijd nog één dolfijn sterft door vervuiling van de zee, jacht, verstrikking in visnetten, … en omdat 2007 wellicht ook het jaar wordt waarin een Chinese dolfijnensoort uitsterft. Maar ook dichterbij huis leven dolfijnen en ook hun verhaal is niet altijd even rooskleurig. Onbekend, en jammer genoeg ook bedreigd. Tijd voor verandering, vandaar dit educatief pakket. Waarin we kinderen warm willen maken voor de dolfijnen in onze Noordzee (en hun leefwereld). Opbouw van dit educatief pakket Dit pakket is gemaakt voor kinderen van kleuterschool tot middelbaar. Het bestaat uit verschillende hoofdstukken. Elk hoofdstuk is op de zelfde manier opgebouwd en u kan daar alles in vinden voor de diverse niveaus. A. Informatie : het eerste deel is informatie over het thema van de module. Dit kunnen teksten, tabellen of verhelderende schema's zijn. De uitleg kan soms heel volledig zijn, maar u moet niet alles vertellen. De bedoeling is eerder dat u aan (bijna) alle antwoorden van de kinderen kan antwoorden. B. Handleiding : hier leest u hoe u deze module aan bod kan brengen in klas. C. Activiteiten : deze formulieren beschrijven verschillende activiteiten die u kan doen met de kinderen om een beetje meer concreter (en leuker) te zijn. Het zijn vaak vakoverschrijdende activiteiten (o.a. gelinkt aan de vakken lichamelijke opvoeding). D. Bijlagen : deze bijlage bevat werkbladen (informatie, tekeningen, oefeningen, …) die u kan afdrukken voor uw leerlingen. Op elke bijlage is geschreven voor welke leeftijd het gemaakt is. De verschillende hoofdstukken zijn de volgende :  Introductie  Hoofdstuk 1 : Dolfijnen in de Noordzee ?  Hoofdstuk 2 : Dolfijnen zijn geen vissen  Hoofdstuk 3 : Dolfijnen, waterfans  Hoofdstuk 4 : Hoe planten de dolfijnen zich voort ?  Hoofdstuk 5 : Wat eten dolfijnen ?  Hoofdstuk 6 : Het sociale leven van dolfijnen  Hoofdstuk 7 : Wat bedreigt dolfijnen ?  Hoofdstuk 8 : de Noordzee, ons grootste natuur gebied Wilt u meer doen met uw leerlingen ? Dan kan uw school in dit speciale jaar mee helpen geld in te zamelen voor de dolfijnen, bijvoorbeeld door de organisatie een sponsorloop (Dolfijnenloop). Als veel scholen daaraan meedoen kunnen we aan het eind van dit jaar een mooi bedrag overhouden waarmee we veel dolfijnen kunnen redden (de opbrengst gaat immers naar een speciaal dolfijnenfonds). Alle scholen kunnen zelf een datum kiezen voor een activiteit maar het zou leuk zijn als er een heleboel activiteiten zijn tijdens Dolphin Week, van 10 t/m 17 oktober.

Biological samples of free-ranging dolphins are increasingly used to gain information on population structure and ecology. In small cetaceans, the gender of individuals usually cannot be determined at sea, and population sex ratio has to be inferred indirectly. We used molecular sexing to determine the gender of 340 biopsy samples of bottlenose dolphins, Tursiops truncatus, spotted dolphins, Stenella frontalis, and common dolphins, Delphinus delphis, collected around the Azores and Madeira. Sex ratio was globally skewed in favor of males, and differed between species and archipelagos. Skew was probably influenced by the selectivity of biopsy collectors and seasonal or year-round predominance of males in natural populations. Skew was also influenced by sampling duration and intensity. In the Azores, when several samples were successively collected within the same group, the proportion of female samples decreased as a function of sample order. This trend indicated a tendency for females to increasingly avoid the boat while samples were being collected. It showed that males and females reacted differently to the perturbation caused by the biopsy sampling process (i.e. sample collection and driving style).

Defining the age of attainment of physical maturity is important for many studies, including identification of stocks, populations or species. In order to identify the age when the skull of the bottlenose dolphin, Tursiops truncatus, reaches maturity, skulls of fifty-three specimens found stranded along the coasts of southern Brazil, Uruguay and northern Argentina (27o35’S, 48o34’W-36o49’S, 55o19’W) were analyzed. Sixty skull measurements were taken to compare the growth rate of the different functional apparatuses. Age was estimated by counts of growth layer groups in the dentine of decalcified, stained longitudinal sections of teeth. Von Bertalanffy’s equation was applied to assess the growth and determine the age at maturity of each apparatus. Generally the maturation of skull starts at age two and stabilizes at age five, and the age of reaching the mature size varies amongst different characters. The braincase is the most precocious apparatus, while the feeding is the one that l...

Se presenta una revision de las especies de mamiferos acuaticos para el Caribe Mexicano. Un gran numero de fuentes publicadas fueron consultadas para buscar informacion sobre mamiferos acuaticos reportados para el Caribe Mexicano. Ademas, se consultaron 29 colecciones y museos nacionales e internacionales. Basados en documentos, colecciones, registros directos y noticias locales, el presente trabajo reporta la presencia de 18 especies de mamiferos acuaticos en el area de estudio [Tursiops truncatus, Stenella clymene, S. frontalis, S. longirostris, Steno bredanensis, Grampus griseus, Globicephala macrorhynchus, Peponocephala electra; Pseudorca crassidens, Orcinus orca, Physeter macrocephalus, Kogia breviceps, K. sima, Ziphius cavirostris, Mesoplodon europaeus, Trichechus manatus manatus, Lontra longicaudis annectens and Monachus tropicalis (extincta)]. Para obtener informacion de linea de base que permita un manejo eficiente a largo plazo de este recurso, se recomienda realizar censo...

Boat-based photo-identification research has been carried out on bottlenose dolphins in eastern North Pacific coastal waters off northern Baja California, Mexico and southern and central California, USA from 1981 to 2001. Within these waters, bottlenose dolphins routinely travel back and forth between coastal locations while generally staying within a narrow corridor extending only 1-2 km from the shore. Inter-area match rates for 616 dolphins photo-identified between 1981-2000 in four California coastal study areas (CCSAs) of Ensenada, San Diego, Orange County and Santa Barbara averaged 76%. To explore possible southern range limits for these dolphins, photo-identification surveys were carried out in the

This study represents the first survey of the parasitic fauna of cetaceans off the northeastern coast of Brazil. Parasites were collected from 82 animals rescued from the states of Ceará to Bahia, including the archipelago of Fernando de Noronha. A total of 14 species of cetaceans were evaluated: Sotalia guianensis, Stenella sp., Stenella clymene, Stenella longirostris, Stenella coeruleoalba, Stenella frontalis, Megaptera novaeangliae, Peponocephala electra, Steno bredanensis, Kogia breviceps, Kogia sima, Globicephala macrorhynchus, Tursiops truncatus, Physeter macrocephalus and Lagenodelphis hosei. The parasites were fixed and preserved in 70% ethanol or alcohol-formalin-acetic acid solution (AFA), clarified in phenol and mounted on slides for morphological identification. In total, 11 species and 8 genera of endo-and ectoparasites were identified:

Examination of mucus discharged from the blowhole of Atlantic bottlenose dolphin (Tursiops truncatus) at Marine Life Oceanarium, Gulfport, Mississippi, and false killer whale (Pseudorca crassidens) and Atlantic bottlenose dolphin at SeaWorld Orlando, Orlando, Florida, using live observations and protargol impregnation revealed mixed infections of Kyaroikeus cetarius and two new species. Planilamina n. gen. is characterized by a C-shaped argentophilic band located along the laterally flattened margin of cell and extending from the cell apex to subposterior cone-shaped podite; a deep oral cavity containing one short preoral kinety, two circumoral kineties, seven to 13 infundibular kinetics, and a cytostome; a broadly funnel-shaped cytopharynx reinforced by argentophilic fibers but without nematodesmata; closely packed postoral kinetofragments set in a pocket located anterior left of the podite; and somatic kineties as a right field closely situated at the right surface and a left field bordering the anterior left margin of the oral cavity. The type species for the genus, Planilamina ovata n. sp., is distinguished from its sister species Planilamina magna n. sp. by the following characteristics: body size (28-65 x 20-43 (xm vs. 57-90 x 40-63 um), number of right field kineties (38-55 vs. 79-99), and position of the anterior end of the leftmost kinety in the right somatic field (anterior one-third vs. mid-body). The morphogenesis of Planilamina ovata is similar to that of K. cetarius. The diagnosis of Kyaroikeidae is emended to accommodate the new genus.

ABSTRACT. Examination of mucus discharged from the blowhole of Atlantic bottlenose dolphin (Tursiops truncatus) at Marine Life Oceanarium, Gulfport, Mississippi, and false killer whale (Pseudorca crassidens) and Atlantic bottlenose dolphin at SeaWorld Orlando, Orlando, Florida, using live observations and protargol impregnation revealed mixed infections of Kyaroikeus cetarius and two new species. Planilamina n. gen. is characterized by a C‐shaped argentophilic band located along the laterally flattened margin of cell and extending from the cell apex to subposterior cone‐shaped podite; a deep oral cavity containing one short preoral kinety, two circumoral kineties, seven to 13 infundibular kineties, and a cytostome; a broadly funnel‐shaped cytopharynx reinforced by argentophilic fibers but without nematodesmata; closely packed postoral kinetofragments set in a pocket located anterior left of the podite; and somatic kineties as a right field closely situated at the right surface and a...

Resumen. En México no se conoce el tamaño de las poblaciones de la tonina (Tursiops truncatus) debido a su gran movilidad y al ocasional intercambio de individuos entre poblaciones. El objetivo de este estudio fue determinar la abundancia de toninas en la zona norte de Veracruz. De marzo de 2005 a diciembre de 2007 se realizaron 50 navegaciones con un esfuerzo total de 236.7 horas. Los resultados obtenidos de la foto-identificación de toninas, se emplearon en el modelo Jolly-Seber y se estimó con este modelo un total de N=302 ±113 organismos para toda el área de estudio. Para Tamiahua, se estimó una población de N=177 ± 10 delfines y para Tuxpan N=161 ± 68 delfines. Estos resultados sugieren que existe un mínimo intercambio de delfines entre zonas y por tanto, las poblaciones no están aisladas; sin embargo, los organismos tienen preferencia por ciertas áreas. La foto-recaptura de algunos individuos en la zona de Tamiahua confirma que la fidelidad al sitio se ha mantenido por 13 años. Es probable que esto se deba a que cada una de las zonas presenta estuarios con alta productividad que son ideales para refugio y crianza de las toninas. Palabras clave: foto-identificación, golfo de México, Jolly-Seber , esfuerzo, fidelidad al sitio, intercambio de individuos.

With the goal of gathering ecological data to develop future cetacean management and conservation plans, the distribution, home range, and residency of bottlenose dolphins (Tursiops truncatus) were studied in the central-north Mexican Gulf of Mexico. Between July 2005 and June 2008, 59 boat surveys were carried out for a total of 313 h of effort at sea. During these surveys, 471 individuals were observed in 88 different groups. Photographs of naturally marked animals resulted in 275 different individuals photo-identified. Their distribution was homogeneous throughout the study area at a mean distance from the coast of 2.5 km (SD = 2.9, n = 471) and depths less than 20 m. Of the total of dolphins identified, 202 (73%) had a low sighting rate and were considered transients, whereas 34 individuals (12%) had medium and high sighting rates and were considered resident animals. At the population level, home range estimates calculated using the minimum convex polygon method showed a mean o...

Marine mammals use vocalisations for a number of purposes: in locating food and underwater obstacles, and to maintain contact with members of their family group. These sounds are loud in comparison with the ambient background, but are subject to masking due to underwater noise sources such as tidal turbines. We developed a model of animal movement which implements simple behavioural rules to allow group cohesion. We discuss some general features of group behaviour, and approaches to validation of the model using empirical data. Including external sources of noise can lead to loss of contact between group members. However, animals can take various measures to deal with these effects, such as more frequent vocalisation or "panic" swimming in response to sounds.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires 11) GLOSSARY OF TERMS REFERENCES Appendix 1 Existing knowledge on population genetics of cetaceans in the ACCOBAMS area [September 2022] 1) Summary for each species 2) Summary table of scientific literature 3) Full reference list for species summaries Appendix 2 Suitable genetics labs in the ACCOBAMS area [October 2022] Appendix 3 Example laboratory protocols for DNA extraction from tissue A) The Ammonium acetate precipitation method B) The Phenol/Chloroform method Appendix 4 Example of Biological Material Transfer Agreement ACCOBAMS-MOP8/2022/Inf54

Variation in dorsal fin morphology was assessed in five bottlenose dolphin (Tursiops truncatus) populations from the Southeast Pacific. We hypothesized that habitat specialization between coastal and offshore ecotypes led to differences in dorsal fin morphology. Photographs and direct measurements of dorsal fins were used to calculate three indexes: height/length base (h/b), width at half height/length base (a/b) and overhang of the dorsal fin tip/length base (falcateness) (s/b). The sample included 163 individuals (129 coastal and 34 offshore) from Ecuador, 60 individuals (9 coastal and 51 offshore) from Peru and 25 individuals of an inshore form from northcentral Chile (Pod-R). Values were logarithmically transformed to allow one-way ANOVAs and t-tests. Ontogenetic variation was found in coastal dolphins from Ecuador, with indices significantly different among age/classes. All indices were higher in juveniles and calves, suggesting a stronger (allometric) growth of the dorsal fin base (b) than in the upper parts of the fin. Hence only adults and subadults were considered in further analysis. Statistically significant differences were found in h/b and a/b indices between coastal specimens from Ecuador and Peru, and between offshore specimens from Ecuador and Peru, and Pod-R. Offshore and Pod-R data were pooled and compared with coastal specimens from Ecuador and Peru; significant differences were found in indices h/b and s/b. Offshore dorsal fins are relatively higher than coastal fins. However the most consistent and visible difference between ecotypes was the strong falcateness (high s/b) in the offshore forms vs. a more triangular shape (low s/b) in coastal forms. Except one outlier, all other cases could be correctly classified through ocular inspection by experienced observers. Chile's Pod-R represents a unique case of an inshore form with strong falcateness, a typical offshore trait. Ecuadorian offshore form showed highest relative dorsal fin height (h/b), followed by Peruvian coastal form, Pod-R, Peruvian offshore and, lowest, Ecuadorian coastal. Relative fin width at mid-height (a/b) was widest in Peruvian coastal stock, followed by Ecuadorian offshore, Peruvian offshore, Ecuadorian coastal and narrowest in Chilean Pod-R. The latter had also the highest falcateness index of all groups, consistent with their extremely falcate dorsal fins. Extreme values for two of three indices agree with marked molecular differences between Pod-R dolphins and Peruvian dolphins and, to a lesser degree, Chilean offshore. Pod-R may represent a recent radiation into the coastal environment from offshore ancestors, a sort of 'transitional form'. High falcateness may be retained due to particularities of the local environment, e.g. fairly deep water.

Previous studies of eastern South Pacific bottlenose dolphins Tursiops truncatus, defined offshore and inshore ecotypes based on cranial and tooth morphology in Pera, documented the presence of a single resident coastal community ('pod-R ') in central north Chile and confirmed the presence of offshore bottlenose dolphins off Chile. Morphological and behavioural differences between pod-R and the transient offshore animals suggested a reproductive isolation. To test this hypothesis and determine the pod-R probable origin, 33 lbp of mtDNA control region were analysed from the pod-R (n=8), Chilean offshore population (n=8), and inshore (n=3) and offshore (n=12) Peruvian ecotypes, as the first genetic analysis in T. truncatus of the eastern South Pacific. Levels of mtDNA diversity and phylogenetic relationships among haplotypes were determined. Three bottlenose dolphin specimens, morphologically identified as Peruvian inshore, grouped in an independent cluster supported by a bootstrap value of 100%. The net genetic distance between Peruvian inshore and Peruvian offshore was estimated at 2.9% and even higher when compared with the Chilean groups. The combination of morphological and mtDNA evidence conclusively argues for a reconsideration of the taxonomic status of the inshore ecotype. Further studies are required to determine boundaries of its distribution range and to estimate its population size and trend. Despite its inshore behavioural ecology, 'pod-R', which is the only resident bottlenose dolphin community recorded in Chile, presented a very high divergence from Peruvian inshore form (3.41% net interpopulational distance) and a relatively closer affinity with the Chilean offshore stock (0.87% net interpopulational distance). However, homogeneity tests showed significant genetic differences of pod-R with all other groups, including Chilean offshore. This, combined with a low nucleotide diversity of 0.0069 strongly suggests that 'pod-R' may be reproductively isolated and active protection measures and continuous monitoring of its status are recommended. Only one haplotype (from a total of 21) was shared by Pera and Chile offshore animals. The net genetic distance between them was estimated at 0.024% and no significant differences were found in haplotype frequencies, suggesting they form a single, wide-ranging offshore stock of unknown abundance.

This work provides the first direct, at-sea monitoring of small cetacean interactions with Peruvian artisanal drift gillnet and longline vessels. A total of 253 small cetaceans were observed captured during 66 fishing trips (480 sets) monitored from March 2005-July 2007 in the port of Salaverry, northern Peru. Interactions consisted of 231 animals caught in gillnets, 1 in a longline and 21 direct takes by harpooning for use as bait. The most commonly captured species were long-beaked common dolphins Delphinus capensis, dusky dolphins Lagenorhynchus obscurus, common bottlenose dolphins Tursiops truncatus (offshore stock) and Burmeister's porpoises Phocoena spinipinnis. Overall bycatch CPUE (catch per unit effort) was estimated to be 0.677 animals/set and 0.007 animals/set for gillnet and longline vessels, respectively. Based upon total fishing effort for the port, we estimated the average of small cetacean bycatch at 2,623 animals/year (CI 2,061-3,185) for 2002-2007. This work i...

In the last 60 years, incidental entanglement in fishing gears (so called by-catch) became the main cause of mortality worldwide for small cetaceans and is pushing several populations and species to the verge of extinction. Thus, monitoring and quantifying by-catches is an important step towards proper and sustainable management of cetacean populations. Continuous studies indicated that by-catches and directed takes of small cetaceans in Peru greatly increased since 1985. Legal measures banning cetacean takes, enforced in 1994 and 1996, ironically made monitoring highly problematic as fishers continue catching these animals but utilize or dispose of carcasses clandestinely. Hence, in locations where cetaceans are landed covertly or already butchered, molecular genetic methods can provide the only means of identification of the species, sex, and sometimes the population of each sample. Here, we generate and analyse a fragment of the mitochondrial DNA cytochrome b gene and 5 nuclear microsatellite markers from 182 meat and skin samples of unidentified small cetaceans collected at three Peruvian markets between July 2006 and April 2007. Our results, compared to past surveys, indicate that Lagenorhynchus obscurus, Phocoena spinipinnis, Tursiops truncatus, Delphinus capensis, and D. delphis continue to be caught and marketed, but that the relative incidence of P. spinipinnis is highly reduced, possibly because of population depletion. The small number of possible sampling duplicates demonstrates that a high monitoring frequency is required for a thorough evaluation of incidental catches in the area. A wide public debate on by-catch mitigation measures is greatly warranted in Peru.

Of 722 cetaceans captured mostly & multi-filament gillnets and landed at Cerro Azul, central Peru, in 87 days during January-August 1994, 82.7% were dusky dolphin Lagenorhynchus obscurus, 12.6% Burmeister's porpoise Phocoena spinipinnis, 2.4% long-beaked common dolphin Delphinus capensis and 2.4% bottlenose dolphin Tursiops truncatus. The total kill estimate for a sevenmonth period, stratified by month, was 1567+ 237 (SE) cetaceans. Data collected at 16 other ports showed that high levels of dolphin and porpoise mortality persisted in coastal Peru at least until August 1994 when an unimplernented 1990 ban on small cetacean exploitation was renewed. Circumstantial evidence suggests that, thereafter, increasing enforcement reduced direct takes and illegal trade in meat but also hampered monitoring. The absence of abundance data precludes any assessment of impact on populations. An interview study in October-December 1994 of the extensive multi-filament gillnet fishery from Puerto Bolivar in southern Ecuador indicated, despite a low catch rate per boat, an estimated annual take of 227 bottlenose dolphins in the inner estuary of the Gulf of Guayaquil. This represents some 9% of the resident bottlenose dolphin population, or more than twice its estimated birth rate. Two mono-filament gillnet boats did not report any entangled cetaceans.

We report on miscellaneous skin diseases or syndromes of unknown aetiology including whitish, velvety lesions (WVL, often associated with unrelated skin injuries, scars and tooth rakes), large, rounded lesions (LRL, large to very large lesions with an orange or dark outline and a light inner colour) and vesicular skin disease (VSD, small to medium vesicles) in Megaptera novaeangliae, Cephalorhynchus commersonii, C. eutropia, Pseudorca crassidens, Sotalia guianensis and Tursiops truncatus from marine waters of Argentina, Brazil, Chile, Ecuador, Peru and the Antarctic. No biopsy samples have been available yet for histopathology. WVL are now commonly recorded opportunistically through photo-identification studies in several coastal species and populations from South America. Mortality rates, if any, associated with these skin diseases is unknown. Though sometimes extensive and ulcerated WVL do not seem life-threatening and, at least in some individuals, may eventually heal. A calf C. eutropia with LRL died some weeks after being first sighted. While unknown bacteria or fungi superinfecting miscellaneous skin traumata and poxvirus tattoos are thought to cause WVL and LRL, vesiviruses are suspected as the aetiological agents of VSD. Importantly, all lesions were primarily seen in coastal cetaceans living in biologically or chemically contaminated waters. These various skin conditions may be indicative of a deteriorating coastal water environment and should be systematically monitored. Collection of biopsies or fresh samples for histopathology and microbiological analysis is urgently needed. Skin lesions of unknown aetiology in South American cetaceans SC/60/DW4 MATERIAL AND METHODS Free-ranging cetaceans The presence and evolution of WVL and LRL was studied in a minimum of 926 free-ranging Delphinidae belonging to five species (Table) mostly from photo-identification images taken during surveys from small boats or from shore in the

The function of the hyolingual complex in three odontocete species was investigated to compare adaptations of divergent feeding strategies, suction and ram feeding. Pygmy and dwarf sperm whales, members of the genus Kogia (or kogiids), are known to be strong suction feeders. We tested the hypotheses that kogiids would have a larger, more robust hyolingual complex, and that hyolingual muscles would have a greater maximum theoretical muscle tension compared with ram‐based feeders such as bottlenose dolphins (Tursiops truncatus). A robustness index and surface area was calculated for bony hyoid elements in kogiids and bottlenose dolphins. The anatomy, muscle architecture, pinnation, two‐dimensional angle of attachment and maximum theoretical muscle tension were measured in each hyolingual muscle. A functional model incorporating vector analyses of hyolingual musculature was created for kogiids and bottlenose dolphins to assess differences in function of their hyolingual complexes. Kogi...

The common bottlenose dolphin (Tursiops truncatus) subpopulation in the Mediterranean is listed as vulnerable by the International Union for Conservation of Nature. This species is strictly protected in France and the designation of Special Areas of Conservation (SAC) is required under the EU Habitats Directive (92/43/EEC). However, little information is available about the structure and dynamics of bottlenose dolphins in French Mediterranean waters. We collected photo‐identification data over the whole French Mediterranean continental shelf year‐round between 2013 and 2015. We sighted 151 groups of bottlenose dolphins allowing the individual photo‐identification of 766 animals. The encounter rate distribution showed the presence of bottlenose dolphins over the whole continental shelf year‐round. We estimated for the first time, using capture‐recapture methods, the size of this bottlenose dolphin population at 2,350 individuals, 95% credible interval [1,827, 3,135]. Our results were...

Cetacean interactions with fishing gear are reported regularly and most frequently involve incidental capture. However, limited records exist related to depredation resulting in fishing gear ingestion. Here, we present cases of depredation resulting from ingestion of gill-net parts and larynx strangulation documented for the first time in a cetacean species. The bottlenose dolphin (Tursiops truncatus) is the only-DURAS GOMERČIĆ ET AL.: LARYNX STRANGULATION IN TURSIOPS 393 resident species in the Adriatic Sea, where small-scale commercial and private fisheries use gill nets throughout the year. A total of 120 dead-stranded bottlenose dolphins found along the Croatian coast of the Adriatic Sea were examined from 1990 to March 2008; 12 of them (10%) were affected by larynx strangulation with gill-net parts. The larynx of all affected animals showed at least one of the following pathological changes: edema, mucosal injury, and hypergranulation. In the majority of cases, it was a chronic condition. Larynx strangulations were found only in adult animals and appeared more often in animals with reduced ability to catch free-swimming prey.

Enhanced oxygen reserves in the blood facilitate diving in marine mammals. For pinnipeds (seals and sea lions), a developmental period of 4 to 24 months is required for blood oxygen stores to reach adult capacities. We investigated whether a similar developmental period for the blood occurs in cetaceans (dolphins and whales), a group of mammals that are exposed to diving immediately after birth. Blood samples were collected from wild and zoological park bottlenose dolphins Tursiops truncatus aged 0±12 years. Red blood cell number (RBC), haemoglobin content (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean cell haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) were determined for each sample. We found that during postnatal development, RBC, Hb and Hct decreased from 0 to 1.5 months and then increased from 1.5 to 6 months, reaching adult levels by 3 years. MCV and MCH both increased from birth. MCHC decreased from 0 to 3.2 months and then increased. Adult levels for MCV were attained as early as 2 months of age while adult levels for MCH and MCHC were attained by 6 months of age. These results indicate that, for bottlenose dolphins, the development of the blood and its capacity to store oxygen is not complete with weaning, which generally occurs at 1.5 years old. The lower oxygen storage capacity of immature dolphins is likely to limit dive capabilities. Calculated aerobic dive limits (cADLs) for 0-to 2-year-old dolphin calves are 1.9±3.6 min, compared to 4.8±5.4 min for 3-to 12-year-old dolphins. Increases in cADLs from 0 to 3 years are attributed to increases in both body mass and mass speci®c oxygen stores while body mass alone explains the increases in cADLs from 3 to 9 years. The limited diving capacity of young dolphins may in¯uence the foraging behaviours of newly weaned juveniles and females accompanied by calves.

Photo-identification technique of Bryde’s whales was carried out off the coast of Cabo Frio region, south-eastern Brazil between December 2010 and November 2012. Twenty-five individuals were sighted on nineteen different days, and of these, nine were individually identified using natural marks on the dorsal fin. Of these, two individuals were seen in four different days, and one was seen in two different days. The mean interval between re-sighting was 133 days (minimum: one day, maximum: 431 days). Two different adult individuals that were previously identified were seen again accompanied by calves and one of these was also seen next to the Rio de Janeiro city coast (126 km apart). Most of the observations consisted of lone individuals (58.8% of sightings). The data reported here indicate that the Cabo Frio coast may be important for the studied species in Brazilian waters and indicated the possible habitat fidelity of Bryde’s whales to this area. 

Although Indo-Pacific bottlenose dolphins (Tursiops aduncus) are a valued component of the Swan-Canning Estuary and the Swan Canning Riverpark, little is known about the health and ecology of the small community of dolphins inhabiting the estuary. To improve the scientific basis for management, we examined the population genetics, trophic associations, and contaminant exposure of dolphins within the estuary. This Swan Canning Research Innovation Program (SCRIP) study had the following objectives: (1) detail contaminant concentrations in dolphins (as a baseline for future monitoring); (2) provide a preliminary assessment of health risk posed by contaminants to dolphins; (3) examine trophic pathway associations for Swan River bottlenose dolphin community; (4) use genetic information to examine whether bottlenose dolphins from the Swan-Canning Estuary and adjacent waters (Cockburn Sound) represent one homogenous population or (alternatively) if fine-scale population structuring occurs; and (5) put project findings into the perspective of system ecology and management implications. Tissue samples for this study were obtained through remote biopsy sampling of free-ranging dolphins and the collection of tissues during post-mortem examinations under permits and licences from the WA

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have wellestablished dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n = 929) or biopsied (n = 152) cetaceans, three out of four species:-striped dolphins (SDs), bottlenose dolphins (BNDs) and killer whales (KWs) had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds. Some locations (e.g. western Mediterranean Sea, southwest Iberian Peninsula) are global PCB "hotspots" for marine mammals. Blubber PCB concentrations initially declined following a mid-1980s EU ban, but have since stabilised in UK harbour porpoises and SDs in the western Mediterranean Sea. Some small or declining populations of BNDs and KWs in the NE Atlantic were associated with low recruitment, consistent with PCB-induced reproductive toxicity. Despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas. The severe impact on top predators of the bioaccumulation of DDT and other organochlorine (OC) pesticides in food webs was first identified in the early 1960s 1. Most OC pollutants were banned in developed countries in

Although bottlenose dolphins Tursiops truncatus are among the most common delphinid species, global population trends remain poorly understood. To improve the knowledge of the species in the Southwest Atlantic Ocean, thispaper reviews all available data related to the distribution and occurrence, abundance, residency and ranging patterns, group size and composition, survival and reproduction and population structure of the coastal bottlenose dolphin in Argentina. Most information proved to be scattered in time and space. Based on the available data, total abundance of coastal bottlenose dolphins in Argentina appears to be low. Data show sightings decreased notably since the 1990s in the northern province of Buenos Aires and the province of Chubut, with the species having disappeared completely from the former region. Data also indicated that two genetically and morphologically distinct coastal populations occur in Argentinean coastal waters, with a sympatric distribution in the prov...

where he has worked since earning his Ph.D. there in 1984. He has over 20 years of experience in marine mammal and sea turtle research, with a primary focus on right whales. He sits on the board of the North Atlantic Right Whale Consortium and is a member of the Atlantic Scientific Review Group,

From 1991-2002 data on the presence and distribution of cetaceans in the Greek Seas have been systematically collated in a database (821 sightings and 715 strandings). Data originated from dedicated surveys, stranding reports, opportunistic sightings and published or unpublished photographic and video documents. Twelve cetacean species have been recorded. Seven of them are permanently present and commonly observed in one or more of the Greek Seas: striped dolphin, common bottlenose dolphin, short-beaked common dolphin, Cuvier's beaked whale, sperm whale, Risso's dolphin and fin whale. In addition, the harbour porpoise is present locally in the Thracian and northern Aegean Seas. The humpback whale, false killer whale and common minke whale are occasional Mediterranean species that were sighted or stranded infrequently; the Sowerby's beaked whale is an accidental species that was found floating dead only once. Five other species (white whale, Blainville's beaked whale, long-finned pilot whale, killer whale, blue whale) have been erroneously included in the Greek cetacean fauna in the past due to wrong assumptions, false identifications or lack of supporting evidence. The occasional occurrence of pilot and killer whales in the Greek Seas should still be regarded as unconfirmed. The distributional range, stranding numbers and sighting frequencies of sperm whales, Cuvier's beaked whales and short-beaked common dolphins in the Greek Seas indicate that their local 'sub-populations' are among the most important in the entire Mediterranean Sea. Harbour porpoises in the Thracian and northern Aegean Seas are important from a conservation perspective since this species does not inhabit any other part of the Mediterranean Sea.

The head of a newborn dolphin (Tursiops truncatus), that died shortly after birth was imaged using computed tomography (CT). Gross cross-sectional slices of the head were compared with the CT images to identify normal structures of the cranium, brain, and respiratory and digestive pathways. Labelled transverse CT images of the dolphin head are presented sequentially as a reference for normal anatomy.

The genus Sotalia was recently separated in two species: the estuarine dolphin (Sotalia guianensis) and the tucuxi dolphin (Sotalia fluviatilis) based on cranial characteristics (Monteiro Filho et al., 2002) and genetic divergence (Cunha et al., 2005; Caballero et al., in press). The name estuarine dolphin has been recognized and proposed for marine Sotalia (Reeves et al., 2003).

We report here the first documented case of a cetacean fatality from entanglement in recreational Spectra ® fishing twine. Spectra ® twine is a relatively new microfilament braided twine that is marketed to replace nylon monofilament twine in rod and reel fisheries. Following the case of this entangled bottlenose dolphin (Tursiops truncatus), we conducted tests with Spectra ® and comparable monofilament twines on Tursiops tissue from stranded animals to compare the abrasion properties of the twines. We found that Spectra ® twine was significantly more abrasive on bottlenose dolphin fluke tissue than a sim ilar strength and diameter monofilament. With the same forces applied, the Spectra ® twine cut deeper than the monofilament, exhibiting a linear relationship with force applied where the monofilament appeared to reach a maximum depth of penetration of approximately 2 mm. These tests may explain why this bottlenose dolphin was so severely debilitated from carrying a relatively light load of twine over a short period of time (20 days). Future public and corporate outreach will be essential to minimize the effect that this increasingly popular fishing twine will have on non-target species.

The coastal waters of the southwest Indian Ocean (including Mozambique, Tanzania, Kenya, the Seychelles, Comoros, Mayotte, Madagascar and the Mascarenes and their EEZ) countries are characterized by a high marine biodiversity. This paper review information on the diversity, distribution and conservation issues to cetaceans in this region. To date, up to 33 species of cetaceans have been recorded in the southwest Indian Ocean: 16 delphinids (Stenella longirostris, Stenella attenuata, Stenella coeruleoalba, Delphinus spp., Steno bredanensis, Grampus griseus, Sousa chinensis, Tursiops truncatus, Tursiops aduncus, Globicephala melas, Globicephala macrorhynchus, Pseudorca crassidens, Orcinus orca, Lagenodelphis hosei, Feresa attenuata, Peponocephala electra), 8 large toothed whales (Physeter macrocephalus, Kogia sima, Kogia breviceps, Mesoplodon pacificus, Mesoplodon densirostris, Mesoplodon mirus, Ziphius cavirostris, Mesoplodon gingkodens) and 7 baleen whales (Megaptera novaeangliae, B...

This article explores the legal regime of the protection of marine species and habitats within European waters by taking the protection of harbour porpoises in the German territorial sea and exclusive economic zone as an example. The analysis is based on a scientific assessment of the occurrence of and the anthropogenic impacts on harbour porpoises in the North Sea. The relationship between the protection of marine species within the European Union (EU) on the one hand and the Common Fisheries Policy of the EU on the other constitutes a classic example of a user-environment conflict. The article explores how such conflicts ought to be solved under the pertinent legal rules.

The use of aquatic mammals as bait to enhance the harvest of fisheries species has garnered little attention by the scientific and conservation communities, often receiving only brief mention in reports focused on the human consumption or bycatch of aquatic mammals. A number of studies, however, highlight the negative impact of this practice on affected mammal populations. A systematic review of relevant literature published since 1970 yields new insight into the scope of the issue. Findings indicate that the practice of using aquatic mammals for bait has been and continues to be geographically widespread, has affected at least 42 species, and often involves deliberate killing for the express purpose of securing bait. The nature of the fisheries involved is diverse, encompassing a wide range of target species and gear types; however, shark fisheries that employ longlines appear to be the most widely engaged in using aquatic mammals as bait. This practice appears to be most common in Latin America and Asia. It is evident, based on our review, that there is little information on the impact of the direct take on most targeted mammal populations, commonly small cetaceans, and increased monitoring efforts are needed in many locales. In most instances, the ecology and population dynamics of the targeted fishery species is poorly understood and in some cases the species is classified as threatened, suggesting a fishery sustainability issue that cannot be fully addressed with a substitute for the aquatic mammal bait. It is essential that natural resource managers implement mitigation approaches that consider the socioeconomic , cultural, political, and ecological circumstances leading to the use of aquatic mammal bait in each fishery.

The pygmy killer whale (Feresa attenuata) is one of the least studied cetacean species. It is a pantropical toothed whale not previously reported in the Gulf of California (GC). The aim of this study is to analyze the first sighting for this region in environmental and dietary terms. In October 2014, three pygmy killer whales were stranded and three others were sighted at sea in the Bay of La Paz, Baja California Sur, Mexico. We analyzed stomach contents and used skin samples from the dead individuals to evaluate stable isotopes of N and C. We found high δ15N (19.2 ± 0.2‰) and low δ13C (-16.5 ± 0.1‰) values, similar to those reported for other teuthophagous cetaceans in the GC. We also identified the remains of purpleback flying squids (Sthenoteuthis oualaniensis) in the stomach of the stranded individuals. The presence of tropical species, like the pygmy killer whale and probably the purpleback flying squid, appeared to be related to the anomalous SST in the GC in 2014, which was 1 to 1.5° C warmer than the same period during 2013. This highlights the importance of monitoring how environmental changes alter the composition and distribution of cetacean species and their prey.

We report on the investigation of a mass stranding of 68 short-beaked common dolphins (Delphinus delphis) that occurred in Golfo Nuevo, Peninsula Valdes, Argentina in March 2018. Twenty-one of the stranded dolphins were returned alive to the sea, while 47 animals died. Dead dolphins included all ages, with more males than females (29 males and 18 females). The cause of death investigation reported here is restricted to 15 adult individuals and one fetus on which a full set of diagnostics was prioritized due to limited funding. Our results demonstrate that the death of 16 dolphins assessed in this study was not due to obvious human effects (e.g. bycatch) or underlying pathologies, as all animals were in good body condition and had no external evidence of injuries. Infections by Morbillivirus, Influenza A virus, Sarcocystis spp., Toxoplasma gondii, or Neospora caninum, as well domoic acid (DA) toxicity were ruled out as ethiologies in this event. Notably, results on exposure to paraly...

The cetaceans of Ghana and the Gulf of Guinea have, until recently, remained unstudied. Periodical monitoring of artisanal fisheries for bycatches in seven Ghanaian artisanal fishing ports and landing sites over 1996-2004 has provided photographic and specimen evidence to validate occurrence of 18 species (17 odontocetes, 1 mysticete) in a tropical, predominantly pelagic cetacean fauna. At least nine species and subspecies had not previously been documented for Ghana (with asterisk), and four species are authenticated for the first time in the Gulf of Guinea (double asterisk), i.e.

Stranded large whales represent an opportunity to learn about the anatomy and health of these cryptic free-ranging animals. However, where time and access is frequently limited, law enforcement and management priorities often take precedence over research, outreach, and educational uses. On 14 March 2021, a dead female adult humpback whale was reported stranded on an uninhabited island 15 miles west of Sitka, Alaska. The whale was three-dimensionally scanned using light detection and ranging (LiDAR) and photogrammetry before, during, and at multiple time points after a necropsy, including full decomposition 17 days later (NOAA Fisheries permit 18786-01). These scans were organized and displayed on the site Sketchfab with annotations and made publically available as a “4D virtual necropsy” (the fourth dimension is time). After one month, our user survey indicated widespread interest in the platform by both the local community and worldwide by stranding professionals, researchers, and...