Tursiops truncatus‎

RESUME : Un site manque en Europe pour réadapter à la vie sauvage les Grands dauphins, Tursiops truncatus, captifs dans les zoos marins contrevenant aux normes. Le canal du Rove, un canal de navigation désaffecté, qui reliait la mer à l’étang de Berre, conviendrait à cet effet malgré la forte contamination chimique de son fond. Ce travail s’efforce d’évaluer les risques sanitaires pour les dauphins accueillis, risques qui pourraient être amplifiés par l’immunodépression résultant d’effets combinés de la pollution, de la captivité antérieure et du stress du transfert. Les principaux dangers sanitaires proviennent de la faune locale ainsi que des cyanobactéries toxiques et de Clostridium botulinum, agent du botulisme présents sur le site. Toutefois, la discussion de l’ensemble des données fondées sur la littérature et sur les résultats des analyses concernant l’étang de Berre ne semble pas faire apparaitre de problème sanitaire insurmontable au regard des prophylaxies proposées.

Écologie! et! comportement! du! grand! dauphin! (Tursiops( truncatus)! dans! un! écosystème!côtier!sous!l’influence!de!la!conchyliculture! Résumé. !L'étude!de!l'écologie!des!cétacés!vivant!sous!la!pression!d'activités!anthropiques!est!essentielle! pour!leur!conservation.!Cependant,!il!existe!peu!d'informations!sur!les!cétacés!et!la!conchyliculture.!À! l'aide! d'un! ensemble! de! données! collectées! à! long! terme,! cette! étude! examine! l'écologie! et! le! comportement! d'un! cétacé! côtier,! le! grand! dauphin! (Tursiops( truncatus),! vivant! dans! une! zone! importante! pour! la! conchyliculture! (Ría! d’Arousa,! NordZOuest! de! l'Espagne).! Le! grand! dauphin! était! présent!à!l'année!dans!cette!région.!Leur!abondance!saisonnière!variait!de!56!à!144!individus!et!leur! survie! apparente! était! élevée.! Parmi! les! facteurs! environnementaux! étudiés,! la! profondeur! et! la! présence! de! fermes! conchylicoles! influaient! sur! leur! utilisation! de! l’habitat,! et! la! chlorophylleZa! et! l’oxygène! dissous! influaient! sur! leurs! modes! d’agrégation! spatioZtemporelle.! Leur! comportement! alimentaire!dépendait!principalement!de!la!température!de!la!surface!de!la!mer,!de!l’heure!de!la!journée! et!du!fait!que!les!dauphins!s’alimentent!dans!les!zones!conchylicoles,!les!dauphins!ayant!une!probabilité! plus! élevée! de! se! nourrir! à! l'intérieur! de! ces! zones,! qu'à! l'extérieur! (57%Z43%).! Certains! individus! s’alimentaient! plus! fréquemment! que! d'autres! autour! des! fermes! conchylicoles.! À! leur! tour,! les! individus!qui!se!nourrissaient!fréquemment!autour!des!fermes!avaient!des!associations!plus!faibles!que! les! autres.! Cette! étude! génère! des! informations! clés! sur! l'écologie!et! le! comportement! d'un! cétacé! vivant!sous!la!pression!de!l'industrie!conchylicole,!sur!les!priorités!de!conservation!des!cétacés!vivant! sous!de!telles!pressions,!ainsi!que!sur!les!réglementations!applicables!au!secteur!de!la!conchyliculture. ! !

5 Tropical Dolphin Research Foundation, USA * Corresponding author. E-mail: fdamseaux@ulg.ac.be The bottlenose dolphin (Tursiops truncatus) is a major apex predator and the most common cetacean species found in nearshore waters of South Florida, including the Lower Florida Keys (LFK) and the Everglades National Park (ENP). The objective of this study was 1) to assess contamination levels of total mercury (T-Hg) in skin and persistent organic pollutants (PCBs, PBDEs, DDT, HCH, HCB, DLCs and PCDD/Fs) in blubber samples of bottlenose dolphins from the LFK (T-Hg : n males = 10; POPs : n males

KEYWORDS: BOTTLENOSE DOLPHIN, PHOTO-ID, CONSERVATION INTRODUCTION The common bottlenose dolphin (Tursiops truncatus) can be found in all the temperate and tropical marine waters of the world (Perrin et al., 2002). The apparent regional form of T. truncatus in the Southwest Atlantic was suggested to be considered as the subspecies T. t. gephyreus or even the species T. gephyreus, typical for Argentina, Uruguay and South Brazil (Bastida and Rodriguez, 2003; Barreto, 2004). Nevertheless, further research is needed to accurately address this point of discussion.

In the bottlenose dolphin, Tursiops truncatus (Montagu 1821), a distinction can be made between pelagic (or offshore) and coastal (or nearshore) ecotypes (see Hoelzel et al. 1998b for a review). Mitochondrial and nuclear DNA analyses have revealed the existence of genetic differentiation between the two ecotypes in the North-West Atlantic (Hoelzel et al. 1998b). Recently, a comprehensive study showed significant differentiation between several coastal populations and two highly polymorphic pelagic populations, one in the north-eastern Pacific and one in the north-western Atlantic (Natoli et al. 2004). Some coastal populations appeared to be morphologically and genetically sufficiently distinct to be classified as a separate species, such as T. aduncus in Chinese waters (Wang et al. 1999; Wang et al. 2000) and a potential third species along the South African coast (Natoli et al. 2004). Pelagic forms have been reported to range primarily between the 200- and 2000 m-isobaths (cf. Wells et al. 1999). Genetic differentiation between ecotypes has been used to characterise ecotype distribution according to water depth and/or distance to the coast. In the North-West Atlantic, the pelagic ecotype occurs mainly in waters beyond 34 km from shore and 34 m depth while the coastal one occurs at least up to 7.5 km from shore (Torres et al. 2003). In the Gulf of California, a distribution break is found around the 60m-isobath (Segura et al. 2006). At a regional scale, genetic analyses evidenced differentiation between the eastern and western basins of the Mediterranean Sea (Natoli et al. 2005), as well as between coastal populations of the Gulf of Mexico (Sellas et al. 2005) and the Northern Bahamas (Parsons et al. 2006). Despite the broad geographic coverage of all these studies, bottlenose dolphins have only been studied in peri-continental areas, and virtually nothing is known about distant offshore regions. The aim of the present study was to fill in this gap, by studying the population structure of bottlenose dolphins around two of the most isolated archipelagos in the North Atlantic, the Portuguese archipelagos of the Azores and Madeira.

Free University of Brussels, Department of Biology, Pleinlaan 2, Brussels, Belgium Contact e-mail: elsvermeulen5@gmail.com The abundance and time-budget of bottlenose dolphins (Tursiops truncatus) was assessed in Bahía San Antonio, Patagonia (Argentina) in the years 2009 and 2010. A total of 366.4 boat-based survey hours resulted in 64 contact hours with a total of 88 dolphin groups. Mark-recapture abundance estimations, based on 63 identified dolphins, resulted in a corrected maximum estimate of 97 and 83 individuals during winter, and a minimum of 34 and 38 individuals during autumn of 2009 and 2010 respectively. Between 25% and 68% of the population consisted of unidentifiable individuals depending on the season, indicating the high presence of juveniles and calves.

17 l’ouverture du parc en 1970. Tursiops truncatus est aujourd’hui l’espèce de dauphin la plus répandue dans les parcs aquatiques. L’amélioration de nos connaissances quant aux besoins et bien-être animal de cette espèce a permis d’accroitre le succès d’entretien en captivité. Les taux de naissance et de survie dépassent parfois ceux des populations sauvages. A cause du déclin des populations de T. truncatus, beaucoup de pays ont interdit sa pêche. Cependant elle reste légale dans de nombreuses régions comme les Iles Féroé, le Sri Lanka, le Pérou et le Japon, pour la consommation humaine ou en guise d’appât. En effet, la chair des cétacés peut être utilisée par les pêcheurs pour capturer les poissons (Perrin W. F, Würsig Bernd 2018). Des individus peuvent être accidentellement pêchés dans des filets à senne coulissante destinés aux thons, sardines ou anchois (figure 3). Les sennes sont des filets rectangulaires utilisés en surface pour encercler les bancs de poissons. Les sennes tournantes peuvent dépasser une longueur d’un kilomètre pour une hauteur de 100 à 200 mètres. Des flotteurs sont fixés sur la partie supérieure tandis que la partie inférieure est lestée. Une coulisse permet le boursage de la partie inférieure du filet (Ifremer 2012). Dans certains cas, les pêcheurs abattent des dauphins pour les empêcher de détériorer le matériel, voler les prises ou encore les appâts.

La distinction des deux activités permet néanmoins de dégager des différences entre les deux : La capture/prise de nourriture a été observée plus loin des côtes (P<0.01) mais dans de[r]

A la sortie d'une position de radeau, le Dauphin fait émerger lentement la partie avant du corps jusqu'à avoir le menton en l'air tandis que le pédoncule caudal es[r]

Bien évidemment, dans la pratique le recours à l’anesthésie est, autant que faire se peut, évitée pour des raisons pratiques et pour minimiser le stress de l’animal mais dans certaines[r]

Pour fournir quelques données en vue d'études ultérieures plus documentées sur la taxonomie et la variabilité de l'espèce (ou de la super-espèce), nous pensons qu[r]

They described a malformed embryo of a striped dolphin (Stenella coeruleoalba), found in Japan in 1981, which was a duplicate anterior characterised by the presence of two distinct heads[r]

Ensuring global food security, nutrition and livelihood is one of the main challenges for the 21st century. Nowadays, maize ( Zea mays L.), extensively grown in America, Asia and some parts of Africa, is the largest staple crop produced worldwide, which alone contributes over 20% of as food calories in parts of Africa and Mesoamerica [ 1 ]. In Sub-Saharan Africa, maize is widely consumed among many people and covers lean periods in some parts of these coun- tries [ 2 , 3 ]. In these regions, production is generally seasonal while consumer needs extend throughout the year [ 4 ]. Thus, the storage of maize assures the food resources availability, which is one of the important factors of food security. However, huge amount of maize pro- duction is lost [ 5 ] between harvest and consumption. During storage, insects are the principal pests of maize [ 6 ] and one of the most important insects is the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera; Bostrichidae) [ 7 – 9 ]. The infestation starts in the field and adults attack mainly whole or broken grains and flour during storage [ 10 , 11 ]. In developing coun- tries, this insect is a serious pest of economic importance, causing maize-grain losses during storage ranging from 30% [ 12 ] to greater 40% of total production in 6 months [ 13 ]. This beetle reduces maize germination, increases the grain’s moisture content [ 14 , 15 ] and facilitates the storage contamination by fungi and bacteria [ 16 ]. These fungi, particularly Aspergillus flavus, introduce a lot of aflatoxins in food products [ 10 ]. This carcinogenic substance poses many problems for consumers’ health (consumed part) and for the export of African food products. Prostephanus truncatus was intercepted in Senegal in 2007 [ 17 ], and represents since then a threat to maize conservation in the country. The management actions taken against pests to reduce storage losses were primarily chemical. More recently, the fumigants (CO 2 , N 2 ,. . .) and hermetical storage structures (walls, zinc, drums,. . .) are also used on P. truncatus control. However, residual insecticides currently used in grain storage are also subject to human health, environmental safety and pest resistance considerations due to misuse [ 18 ]. In developing countries, most of farmers have not access to hermetic storage structures and fumigants due to availability and cost reasons.

Exocoetidae sp., in the open sea (22°35’S 166°28’E; Feb. 2002). DISCUSSION The similarities in pigmentation patterns and habitat characteristics of morphotype-A and morphotype-B bottlenose dolphins from New Caledonia (present report), and, respectively, T. aduncus and T. truncatus from southern Queensland (Hale et al. 2000) and from elsewhere in the Indo-Pacific (Wang and Yang 2009) are strong enough to suggest that morphotype A corresponds to T. aduncus under its current definition (Rice 1998) and morphotype B, to T. truncatus. However, pending more genetic evidence, in the following we will refer to “T. aduncus-like” and ‘T. truncatus-like” bottlenose dolphins in New Caledonian waters. Also, adult T. aduncus generally exhibit dark spots on the posterior ventral half of the body (Hale et al. 2000), but T. aduncus populations from New South Wales and southeastern Australia are “apparently more or less unspotted” (Ross and Cockroft 1990; Wang and Yang 2009). When present, only light spotting on the posterior part of the body was noticed by us on some New Caledonian morphotype-A individuals (Fig. 1D). The presence or absence of a pale-grey blaze below the dorsal fin remained the easiest way to distinguish between the two forms in the field.

Une certaine quantité de la formulation en poudre (BAYTHROID à 0,1 ~ de cyflutllr1ne ou K-OTHRliE à 0,2 ~ de deI taméthrine) a été dispersée de manière homogène sur chaque lot de 40 kg d[r]