Information and Research on Cetaceans

Pobladura de Pelayo García, Spain

Information and Research on Cetaceans

Pobladura de Pelayo García, Spain
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Louis M.,CNRS Chizé Center for Biological Studies | Louis M.,CNRS Coastal and Marine Environment Laboratory | Louis M.,GECC Groupe dEtude des Cetaces du Cotentin | Viricel A.,CNRS Coastal and Marine Environment Laboratory | And 19 more authors.
Molecular Ecology | Year: 2014

Despite no obvious barrier to gene flow, historical environmental processes and ecological specializations can lead to genetic differentiation in highly mobile animals. Ecotypes emerged in several large mammal species as a result of niche specializations and/or social organization. In the North-West Atlantic, two distinct bottlenose dolphin (Tursiops truncatus) ecotypes (i.e. 'coastal' and 'pelagic') have been identified. Here, we investigated the genetic population structure of North-East Atlantic (NEA) bottlenose dolphins on a large scale through the analysis of 381 biopsy-sampled or stranded animals using 25 microsatellites and a 682-bp portion of the mitochondrial control region. We shed light on the likely origin of stranded animals using a carcass drift prediction model. We showed, for the first time, that coastal and pelagic bottlenose dolphins were highly differentiated in the NEA. Finer-scale population structure was found within the two groups. We suggest that distinct founding events followed by parallel adaptation may have occurred independently from a large Atlantic pelagic population in the two sides of the basin. Divergence could be maintained by philopatry possibly as a result of foraging specializations and social organization. As coastal environments are under increasing anthropogenic pressures, small and isolated populations might be at risk and require appropriate conservation policies to preserve their habitats. While genetics can be a powerful first step to delineate ecotypes in protected and difficult to access taxa, ecotype distinction should be further documented through diet studies and the examination of cranial skull features associated with feeding. © 2014 John Wiley & Sons Ltd.

Bentaleb I.,Montpellier University | Martin C.,Montpellier University | Vrac M.,French Climate and Environment Sciences Laboratory | Mate B.,Oregon State University | And 5 more authors.
Marine Ecology Progress Series | Year: 2011

We investigated seasonal shifts in diet and distribution of fin whales Bala en optera physalus occurring in the western Mediterranean Sea. For this purpose, we combined carbon and nitrogen stable isotope ratios (δ 13C, δ 13N) along 10 baleen plates collected from stranded fin whales between 1975 and 2002 with satellite tag deployments on 11 fin whales during summer 2003. Baleen plate stable isotopes were compared with those of the krill Meganyctiphanes norvegica, the main prey of fin whales in the northwestern Mediterranean Sea. Two plates collected near Malaga, Spain, exhibited larger δ 13C variations, while only smaller variations could be detected in the other 8. While all mean baleen plate results were consistent with the δ 13C signature of Mediterranean M. norvegica, the most depleted δ 13C values were intermediate between those of Atlantic and Mediterranean M. norvegica, suggesting westward migrations perhaps extending to the Strait of Gibraltar but not extensive, prolonged feeding in the Northeast Atlantic. This pattern was confirmed by satellite tracking; 1 out of 8 fin whales we successfully tracked left the Mediterranean for the Atlantic. Longer-term changes in isotopic signatures of baleen plates exhibited significant depletion trends, indicating that changes due to increasing input of nutrients and anthropogenic carbon are occurring in the western Mediterranean Sea ecosystem. © Inter-Research 2011.

Carpinelli E.,Information and Research on Cetaceans | Carpinelli E.,Tethys Research Institute | Carpinelli E.,University of Pavia | Gauffier P.,Information and Research on Cetaceans | And 12 more authors.
Aquatic Conservation: Marine and Freshwater Ecosystems | Year: 2014

The Mediterranean sperm whale sub-population is considered 'Endangered' by both ACCOBAMS and the IUCN. Conservation policies require protected species populations to be monitored, but the distribution and movements of sperm whales across the Mediterranean Sea are still poorly understood. To provide insight into sperm whale movements, the photo-identification catalogue from the Strait of Gibraltar was compared with seven other collections: (a) the North Atlantic and Mediterranean Sperm Whale Catalogue (NAMSC), and with photo-identification catalogues from (b) the Alboran Sea, Spain, (c) the Balearic Islands, Spain, (d) the Corso-Provençal Basin, France, (e) the Western Ligurian Sea, Italy, (f) the Tyrrhenian Sea, Italy, and (g) the Hellenic Trench, Greece. Of 47 sperm whales identified in the Strait of Gibraltar between 1999 and 2011 a total of 15 animals (32%) were photographically recaptured in other sectors of the western Mediterranean Sea in different years. None of the Strait of Gibraltar sperm whales were resighted in Atlantic waters or in the eastern Mediterranean basin. These results indicate long-range movements of the species throughout the whole western Mediterranean Sea, with a maximum straight-line distance of about 1600km. The absence of any photographic recaptures between the Mediterranean Sea and the North Atlantic Ocean supports the genetic evidence of an isolated sub-population within the Mediterranean Sea. Long-term photo-identification efforts and data sharing between institutions should be further encouraged to provide basic information necessary for the implementation of effective sperm whale conservation measures in the whole basin. Copyright © 2014 John Wiley & Sons, Ltd. 24 S1 July 2014 10.1002/aqc.2446 Supplement Article Research Articles Copyright © 2014 John Wiley & Sons, Ltd.

PubMed | University of Barcelona, Natural History Museum in London, Coordinadora para o Estudio dos Mamiferos Marinos CEMMA, UK Institute of Zoology and 12 more.
Type: | Journal: Scientific reports | Year: 2016

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established 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, south-west 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.

Esteban R.,Information and Research on Cetaceans | Verborgh P.,Information and Research on Cetaceans | Gauffier P.,Information and Research on Cetaceans | Gimenez J.,CSIC - Doñana Biological Station | And 11 more authors.
Ecological Indicators | Year: 2016

A key goal for wildlife managers is identifying discrete, demographically independent conservation units. Previous genetic work assigned killer whales that occur seasonally in the Strait of Gibraltar (SoG) and killer whales sampled off the Canary Islands (CI) to the same population. Here we present new analyses of photo-identification and individual genotypes to assess the level of contemporary gene flow and migration between study areas, and analyses of biomarkers to assess ecological differences. We identified 47 different individuals from 5 pods in the SoG and 16 individuals in the CI, with no matches found between the areas. Mitochondrial DNA control region haplotype was shared by all individuals sampled within each pod, suggesting that pods have a matrifocal social structure typical of this species, whilst the lack of shared mitogenome haplotypes between the CI and SoG individuals suggests that there was little or no female migration between groups. Kinship analysis detected no close kin between CI and SoG individuals, and low to zero contemporary gene flow. Isotopic values and organochlorine pollutant loads also suggest ecological differences between study areas. We further found that one individual from a pod within the SoG not seen in association with the other four pods and identified as belonging to a potential migrant lineage by genetic analyses, had intermediate isotopic values and contaminant between the two study areas. Overall our results suggest a complex pattern of social and genetic structuring correlated with ecological variation. Consequently at least CI and SoG should be considered as two different management units. Understanding this complexity appears to be an important consideration when monitoring and understanding the viability of these management units. Understand the viability will help the conservation of these threatened management units. © 2016 Elsevier Ltd. All rights reserved.

Perez S.,Information and Research on Cetaceans | Garcia-Lopez A.,Institute Ciencias Marinas Of Andalucia | De Stephanis R.,CSIC - Doñana Biological Station | Gimenez J.,Information and Research on Cetaceans | And 4 more authors.
Marine Biology | Year: 2011

We tested the possibility of measuring progesterone levels in bubbler samples collected from free-ranging live bottlenose dolphins (n = 11) and long-finned pilot whales (n = 2) as a tool to evaluate the pregnancy status of individuals. Samples were collected during January 2004 and September-October 2005 in the Strait of Gibraltar and Gulf of Cadiz and used for sex-determination by genetic methods (skin samples) and for quantification of progesterone levels by enzyme immunoassay. Photo-identification tracking of females after taking the biopsy was used to observe the presence of newborns and, in this way, to determine if the female was pregnant at the time of sampling. Mean progesterone levels from pregnant bottlenose dolphins (n = 2) were around 9 times higher than those from non-pregnant females (n = 9), with no overlap between concentration ranges demonstrating that this method could constitute an effective tool for determining pregnancy in wild populations of bottlenose dolphins and other cetacean species. © 2011 Springer-Verlag.

Esteban R.,Information and Research on Cetaceans | Verborgh P.,Information and Research on Cetaceans | Gauffier P.,Information and Research on Cetaceans | Gimenez J.,CSIC - Doñana Biological Station | And 2 more authors.
Biological Conservation | Year: 2016

A complex balance has arisen between the bluefin tuna, killer whales, and human activities in the Strait of Gibraltar. Recent changes in fishing effort have dramatically decreased tuna stocks, breaking this balance. Killer whales exhibit two strategies for feeding on tuna: active hunting and depredation on a drop-line fishery. From 1999 to 2011, a small community of 39 individuals was observed in the Strait in spring and summer. All individuals displayed active hunting and 18 of themalso depredated on the fishery. These differences in foraging behaviour influenced life-history parameters. Adult survival for interacting and non-interacting individuals was estimated at 0.991 (SE=0.011) and 0.901 (SE=0.050), respectively. Juvenile survival could only be estimated for interacting individuals as 0.966 (SE = 0.024), because only one juvenile and one calf were observed among non-interacting individuals. None of the interacting calves survived after 2005, following the decrease in drop-line fishery catches. Calving rate was estimated at 0.22 (SE = 0.02) for interacting individuals and 0.02 (SE = 0.01) for non-interacting. Calving interval, which could only be calculated for interacting groups, was 7 years. The population growth rate was positive at 4% for interacting individuals, and no growth was observed for non-interacting individuals. These differences in demographic parameters could be explained by access to larger tuna through depredation. Consequently, we found that whales would need more tuna to cover their daily energy requirementswhile actively hunting. Therefore, our findings suggest an effect of artificial food provisioning on their survival and reproductive output. Urgent actions are needed to ensure the conservation of this, already small, community of killer whales. These include its declaration as Endangered, the implementation of a conservation plan, the creation of a seasonal management area where activities producing underwater noise (i.e. military exercise, seismic surveys or evenwhale watching activities) are forbidden fromMarch to August, and the promotion of bluefin tuna conservation. Additionally, energetic requirements of this whale community should be taken into account when undertaking ecosystem-based fishery management for the Atlantic bluefin tuna stock. In the meantime, as marine predators are most sensitive to changes in fish abundance when prey abundance is low, we suggest an urgent short-term action. Artisanal fisheries, such as drop-lines, should be promoted instead of purse seiners in the Mediterranean Sea. This will help to maintain the survival and reproductive output of the whale community until showing clear signs of recovery and stability, and/or their prey stock recovers. © 2015 Elsevier Ltd.

Esteban R.,Information and Research on Cetaceans | Verborgh P.,Information and Research on Cetaceans | Gauffier P.,Information and Research on Cetaceans | Gimenez J.,CSIC - Doñana Biological Station | And 3 more authors.
Behavioral Ecology and Sociobiology | Year: 2016

The primary prey of killer whales (Orcinus orca) in the Strait of Gibraltar is the bluefin tuna (Thunnus thynnus). All killer whales observed in this area hunt tuna by chasing individual fish until they become exhausted and can be overcome. However, a subset of pods also interact with a dropline tuna fishery which has developed since 1995. Here, we investigated the social structure within and among social units (pods). Our data suggested that social structure was shaped by maternal kinship, which appears to be a species-specific trait, but also by foraging behavior, which is less common at the intra-population level. At the start of the study, only one cohesive pod interacted with the fishery, which during the course of the study underwent fission into two socially differentiated pods. Social structure within these two fishery-interacting pods was more compact and homogenous with stronger associations between individuals than in the rest of the population. Three other pods were never seen interacting with the fishery, despite one of these pods being regularly sighted in the area of the fishery during the summer. Sociality can influence the spread of the novel foraging behaviors and may drive population fragmentation, which, in this example, is already a critically small community. Observations of social changes in relation to changes in foraging at the earliest stages of diversification in foraging behavior and social segregation may provide insights into the processes that ultimately result in the formation of socially isolated discrete ecotypes in killer whales. © 2015, Springer-Verlag Berlin Heidelberg.

Wierucka K.,Information and Research on Cetaceans | Verborgh P.,Information and Research on Cetaceans | Meade R.,Information and Research on Cetaceans | Colmant L.,Information and Research on Cetaceans | And 4 more authors.
Marine Ecology Progress Series | Year: 2014

Long-finned pilot whales Globicephala melas are a commonly encountered species in the Mediterranean Sea. In 2006-2007, an outbreak of the dolphin morbillivirus in the Western Mediterranean resulted in increased mortality of this species. The aim of this study was to determine whether survival rates differed between clusters of Spanish Medi - terranean pilot whales, and how the epizootic in - fluenced these survival rates. Photo-identification surveys were conducted between 1992 and 2009. Association indices were used to define clusters of individuals that associate with each other more frequently than with others. Based on a Cormack-Jolly- Seber survival rate model, apparent survival rate estimates varied from 0.821 to 0.995 over 11 clusters for the 1992-2009 period. When the effect of the morbillivirus outbreak was modeled, 3 clusters with distinctly lower survival rates from previous models presented lower estimates after the outbreak (survival rate dropped from 0.919 [95% CI: 0.854-0.956] to 0.547 [95% CI: 0.185-0.866]), suggesting a negative influence of the epizootic or other unknown additive factors on certain clusters. This information is critical for the conservation of long-finned pilot whales, since they are listed as 'data deficient' in the Mediterranean Sea by the IUCN and as 'vulnerable' in the Spanish National Catalogue of Endangered Species. © Inter-Research 2014.

De Stephanis R.,CSIC - Doñana Biological Station | Gimenez J.,CSIC - Doñana Biological Station | Carpinelli E.,Information and Research on Cetaceans | Gutierrez-Exposito C.,CSIC - Doñana Biological Station | Canadas A.,Alnilam Research and Conservation
Marine Pollution Bulletin | Year: 2013

Marine debris has been found in marine animals since the early 20th century, but little is known about the impacts of the ingestion of debris in large marine mammals. In this study we describe a case of mortality of a sperm whale related to the ingestion of large amounts of marine debris in the Mediterranean Sea (4th published case worldwide to our knowledge), and discuss it within the context of the spatial distribution of the species and the presence of anthropogenic activities in the area that could be the source of the plastic debris found inside the sperm whale. The spatial distribution modelled for the species in the region shows that these animals can be seen in two distinct areas: near the waters of Almería, Granada and Murcia and in waters near the Strait of Gibraltar. The results shows how these animals feed in waters near an area completely flooded by the greenhouse industry, making them vulnerable to its waste products if adequate treatment of this industry's debris is not in place. Most types of these plastic materials have been found in the individual examined and cause of death was presumed to be gastric rupture following impaction with debris, which added to a previous problem of starvation. The problem of plastics arising from greenhouse agriculture should have a relevant section in the conservation plans and should be a recommendation from ACCOBAMS due to these plastics' and sperm whales' high mobility in the Mediterranean Sea. © 2013 Elsevier Ltd.

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