Mediterranean Dolphins Research Articles

Mediterranean Dolphins from Miami: Knowledge and Practices in Barcelona Zoo's Aquarama (1962–1970)

In May 1965, in the midst of Franco's dictatorship in Spain, four bottlenose dolphins travelled from Miami to Barcelona Zoo. These became the inhabitants of one of the first dolphinariums in Europe. The arrival of the dolphins was preceded by two trips of the zoo's director, accompanied by an architect and a politician, to visit the installations at the Miami Seaquarium, Sea World San Diego, and Marineland of the Pacific in California. In this paper, I reflect on how knowledge and practices about a completely new animal and its keeping were acquired in the Barcelona Zoo. This was a time when exhibitions, popular perception, and scientific research regarding marine mammals were being developed. The training and exhibition of dolphins was shaped by a mixture of circus-like practices and scientific knowledge. Dolphins arrived in Europe with “knowledges” and practices attached, but also with a lot of uncertainty. However, circumstances like geography, logistics, and the corporate character of American aquaria prevented a straightforward flow of information from the United States to Europe. How did Barcelona Zoo keepers manage to gather information on the building and maintenance of a dolphinarium? And how did they gather information on how to feed, care, train, and exhibit the dolphins? This paper seeks to understand how the particular setting of Barcelona Zoo, as well as its social, scientific, and political context shaped the exhibition of and creation of knowledge about animals at the zoo.

Brucella ceti infection in dolphins from the Western Mediterranean sea.

BackgroundBrucella ceti infections have been increasingly reported in cetaceans. Brucellosis in these animals is associated with meningoencephalitis, abortion, discospondylitis’, subcutaneous abscesses, endometritis and other pathological conditions B. ceti infections have been frequently described in dolphins from both, the Atlantic and Pacific Oceans. In the Mediterranean Sea, only two reports have been made: one from the Italian Tyrrhenian Sea and the other from the Adriatic Sea.ResultsWe describe the clinical and pathological features of three cases of B. ceti infections in three dolphins stranded in the Mediterranean Catalonian coast. One striped dolphin had neurobrucellosis, showing lethargy, incoordination and lateral swimming due to meningoencephalitis, A B. ceti infected bottlenose dolphin had discospondylitis, and another striped dolphin did not show clinical signs or lesions related to Brucella infection. A detailed characterization of the three B. ceti isolates was performed by bacteriological, molecular, protein and fatty acid analyses.ConclusionsAll the B. ceti strains originating from Mediterranean dolphins cluster together in a distinct phylogenetic clade, close to that formed by B. ceti isolates from dolphins inhabiting the Atlantic Ocean. Our study confirms the severity of pathological signs in stranded dolphins and the relevance of B. ceti as a pathogen in the Mediterranean Sea.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-014-0206-7) contains supplementary material, which is available to authorized users.

Morphological variation and modularity in the mandible of three Mediterranean dolphin species

Geometric morphometric studies of dolphins have traditionally concentrated on the skull, while the mandible and its modularity have been little explored. We investigated the mandible variability and modularity in three strictly related Mediterranean dolphins: Stenella coeruleoalba, Delphinus delphis and Tursiops truncatus. The aims were to describe the interspecific differences in the size and shape of the mandible as a whole, and of its structural modules, and to detect the influence of adaptive pressures on trait variation. Data were collected on 96 specimens from the Mediterranean Sea. Eight and 10 two-dimensional landmarks were recorded respectively in the lateral and medial sides of the mandible. After General Procrustes Analysis (GPA) transformation, measurement error, sexual dimorphism and ontogenetic allometry were first investigated to allow further pooling of samples. Univariate analysis of variance (ANOVA) of centroid size was used to evaluate size differences among the species; multivariate ordination, classification and clustering methods were used to investigate interspecific variation of shape variables. Different subsets of landmarks representing distinct mandibular subunits were tested for modular integration through the RV coefficient; two-block partial least squares statistics was used to explore the patterns of covariation between modules. Size and shape differences in the whole mandible of the three species evidenced a clear morphological divergence of Tursiops truncatus and a close similarity of Stenella coeruleoalba and Delphinus delphis. The analysis of modularity identified the corpus and the ramus, with its internal foramen, as distinct modules. The corpus and ramus patterns of variation could discriminate between T. truncatus vs. the other two species. The mandibular foramen was the only trait able to discriminate each species, and the corresponding shape differences were related to selective pressures toward the differentiation of communication patterns.

New Prey Fishes in Diet of Black Sea Bottlenose Dolphins, Tursiops truncatus (Mammalia, Cetacea)

Abstract We report 7 new prey fishes in diet of the Black Sea bottlenose dolphins Tursiops truncatus (Montagu, 1821) and the first records of 9 prey items from their stomach contents: herring (Alosa sp.), sand smelt (Atherina sp.), horse mackerel (Trachurus mediterraneus), picarel (Spicara flexuosa), Mediterranean sand eel (Gymnammodytes cicerellus), Atlantic stargazer (Uranoscopus scaber), garfish (Belone belone), gobies (Gobiidae indet.) and blennies (Blenniidae indet.). Th e Atlantic stargazer was recorded as a prey species for the common bottlenose dolphin for the first time. Th e horse mackerel and the picarel, formerly recorded in the diet of Mediterranean bottlenose dolphins, now were frequently found in the examined Black Sea dolphins. Th e list of prey fishes for Black Sea bottlenose dolphins now includes 23 items, with many small pelagic and demersal fishes, and it is similar to that of Mediterranean dolphins. Whiting (Merlangius merlangus) is still an important prey species, as 50-70 years ago, whereas turbot (Psetta maeotica), not recorded by us, could lose its importance due to population decline. As before, red mullet (Mullus barbatus) is recorded in winter feeding. Feeding on mullets (Mugilidae) is not a universal trait, and it is possibly restricted to local geographical areas.

Tissue-Related Polychlorinated Biphenyls Accumulation in Mediterranean Cetaceans: Assessment of Toxicological Status

Polychlorinated biphenyls (PCBs) have been synthesized for use as technical mixtures in a multitude of industrial applications such as impregnating wood, paper and fabric, and as engine oil additives, capacitor fluids, transformer coolants, paint and sealant plasticizers. These compounds are lipophilic in nature and biomagnify through food chains, so bioaccumulation in the lipid fraction of tissues of long living species that occupy a top trophic position might be of special concern. Cetaceans, in particular, being typical end-points in the marine food chain, and possessing a limited capacity to metabolize these toxic contaminants (Tanabe et al., 1988; Tanabe, 2002), have a high accumulation potential and, as a consequence, are most vulnerable to the long-term toxic effects of such chemicals. Cetacean populations living in the Mediterranean basin are especially exposed to this type of pollution because of the semi-enclosed nature of this sea, surrounded by highly industrialized countries. The morbillivirus infection of Mediterranean dolphins during the last decades has been linked to the presence of elevated PCB concentrations in the corpses of dead animals (Kannan et al., 1993; Aguilar and Borrell, 1994). Known organochlorine-mediated toxic effects in marine mammals include immune system depression and thereby increase in susceptibly to microbial and parasitic infections, as well as reproductive impairment, alteration of growth and skeletal deformities (Addison, 1989; Helle et al., 1990; Zakharov et al., 1997). In this context, the need for a continuous monitoring of organochlorine load in these species is obvious. Such an observation is reinforced by the proposal that, globally, PCB concentrations in marine biota will continue increasing in forthcoming decades since only a small fraction of the total amount released has reached the oceans (Tanabe, 1988; Reijnders, 1996). Reijnders (1996) estimated that only about 1% of the PCB produced had reached the ocean in the mid-1990s, and Tateya et al. (1988) suggested that levels of PCBs in marine mammals would peak between 2000 and 2030. Taking into account all these facts, this study presents the results from analyses of PCBs and their distribution in liver, kidney, lung, and tissue muscle of 12 specimens of Mediterranean bottlenose dolphins (Tursiops truncatus). Furthermore, toxic equivalent concentrations (TEQs) based on available toxic equivalent factors (Van den Berg et al., 1998) of a number of congeners are calculated and their relative contribution to the total toxic burden in the analyzed tissues is presented.

Comparative analysis of the attachment protein gene (H) of dolphin morbillivirus

DMV, dolphin morbillivirus, a paramyxovirus of uncertain origin recently emerged in Mediterranean dolphins. This study presents the complete nucleotide sequence of the hemagglutinin (H) gene including the gene boundaries. The single open reading frame of the DMV H gene encodes a protein of 604 residues which exhibits overall sequence characteristics similar to the H genes of other morbilliviruses. When compared to its closest homologues, measles virus (MV) and rinderpest virus (RPV), DMV has, respectively, 44 and 46% of amino acid residues in identical positions. The primary sequence of the DMV H protein is markedly less conserved than that of the fusion protein. The comparative data at the genomic level correspond with cross-neutralization studies with different morbilliviruses. Retrospective serogical studies dating back to 1983 indicate DMV-like infections in whales of the eastern Atlantic. The presented data support and extend previous studies suggesting that this novel morbillivirus is one of the phylogenetically oldest morbilliviruses known to circulate today. The relationship of DMV and established morbilliviruses to the newly emerged candidate morbillivirus infecting horse and man is discussed.

Persistent contaminants in dolphins: an indication of chemical pollution in the Mediterranean Sea

Concentrations of metals (mercury and methylmercury, selenium, cadmium, lead), chlorinated pesticides and polychlorinated byphenyls (PCB) have been determined in tissues and organs of Stenella coeruleoalba dolphins beached along the Adriatic and Ionian coasts of Apulia (Southern Italy). The results obtained confirm that in Mediterranean dolphins the accumulation of contaminants is higher than in similar species living in the Atlantic. Therefore cetaceans can be considered “organisms indicating pollution”. Accumulation is influenced by factors such as diet, age and sex. Reproduction plays a fundamental role in the elimination of toxic compounds in females. Correlation between contamination and death has not been found; however it is clear that pollutants at sub-lethal doses have neuro-toxic effects, increase stress and alter immune defences, leaving the organism at a greater risk from disease.

Morbilliviruses in aquatic mammals: report on round table discussion

A workshop was organised to ascertain the current situation with regard to morbillivirus infections in aquatic animals. The great interest generated by the discovery of these new virus infections in 1988 has to some extent abated but much high quality research has continued in this field as the workshop showed. There is some serological evidence that the viruses have continued to circulate in most areas since the initial epizootics. As to their origin, it appers that the most likely source of the European seal morbillivirus (PDV-1) is the North Atlantic and Arctic seal populations. As to the origin of the Mediterranean dolphin morbillivirus and the morbilliviruses isolated from porpoises, there is serological evidence that the viruses are widespread in many cetacean species in the Atlantic and 93% of long-finned pilot whales ( Globicephala melas) which mass stranded between 1982 and 1993 were morbillivirus seropositive. The epizootic in freshwater seals in Lake Baikal was unrelated to events in the european marine mammal populations. The virus which infected these animals (PDV-2) is indistinguishable from canine distemper field strains. Serological and molecular biological studies provided evidence for the presence of the virus in the seals, at least as late as the Summer of 1992 when the animals were last sampled.

Persistent contaminants in dolphins: An indication of chemical pollution in the mediterranean sea

Concentrations of metals (mercury and methylmercury, selenium, cadmium, lead), chlorinated pesticides and polychlorinated byphenyls (PCB) have been determined in tissues and organs of Stenella coeruleoalba dolphins beached along the Adriatic and Ionian coasts of Apulia (Southern Italy). The results obtained confirm that in Mediterranean dolphins the accumulation of contaminants is higher than in similar species living in the Atlantic. Therefore cetaceans can be considered “organisms indicating pollution”. Accumulation is influenced by factors such as diet, age and sex. Reproduction plays a fundamental role in the elimination of toxic compounds in females. Correlation between contamination and death has not been found; however it is clear that pollutants at sub-lethal doses have neurotoxic effects, increase stress and alter immune defences, leaving the organism at a greater risk from disease.

Comparative analysis of the gene encoding the nucleocapsid protein of dolphin morbillivirus reveals its distant evolutionary relationship to measles virus and ruminant morbilliviruses

A morbillivirus of uncertain origin recently killed hundreds of Mediterranean dolphins. This is the first report of the nucleotide and deduced amino acid sequence of a dolphin morbillivirus (DMV) gene. The sequence of the nucleocapsid (N) gene including boundaries was determined. When the DMV N gene coding region was compared with the corresponding sequences of other morbilliviruses a distant evolutionary relationship between these viruses and DMV was apparent. Phylogenetic analysis of the sequence data provided further evidence that DMV is not closely related to any known morbillivirus, whereas phocine distemper virus exhibits a relatively close relationship to canine distemper virus.

Nucleic acid hybridization analyses confirm the presence of a hitherto unknown morbillivirus in mediterranean dolphins

In 1990 an epidemic caused by a morbillivirus was noticed among Mediterranean dolphins. RNA was extracted from the tissues of dolphins and from cell cultures infected with a corresponding dolphin morbillivirus isolate. By nucleic acid hybridization this RNA was compared to RNA extracted from animal tissue or cell cultures infected with canine distemper virus (CDV), phocine distemper virus (PDV) or measles virus (MV). The presence of morbillivirus RNA in the dolphin tissue was demonstrated. Morbillivirus N, P, M and F gene mRNAs were detected in the RNA from dolphin morbillivirus infected cells. These mRNA species seemed to be of approximately the same size as the corresponding mRNA species of CDV, PDV and MV. The results of the comparison demonstrated that the dolphin morbillivirus is genetically different from CDV, PDV and MV. No indication of a close relationship between the dolphin isolate and either CDV, PDV or MV was found.