[MARMAM] Abstracts - Aquatic Mammals, vol. 35(1); 2009

Dear Marmam and ECS-mailbase subscribers, Apologies to those of you who will get duplicate emails due to cross-posting. The following are abstracts from the most recent issue of Aquatic Mammals, the scientific peer-reviewed journal of the European Association for Aquatic Mammals (EAAM). Abstracts are presented as a courtesy to the EAAM and the journal editors – Drs. Jeanette Thomas (managing editor; aquaticmammals@gmail.com) and Kathleen Dudzinski (co-editor; kdudzinski@dolphincommunicationproject.org). The journal publishes papers dealing with all aspects of the care, conservation, medicine and science of aquatic mammals. The journal receives support of the Alliance of Marine Mammal Parks and Aquariums and the International Marine Animal Trainers' Association (IMATA). For more information on the journal, please go to: http://www.aquaticmammalsjournal.org/. Contact information is provided for the corresponding author for each article. Please do not contact the listserve editors or me for pdfs or copies of the articles. Thank you for your continued interest in the journal and these postings. With regards, Dagmar Fertl Ziphius EcoServices dfertl@gmail.com http://www.ziphiusecoservices.com Neale, J. C. C.*, K. R. Schmelzer, J. T. Harvey, E. A. Berg, R. J. Small, E. K. Grigg, S. G. Allen, and R. S. Tjeerdema. 2009. PCB and DDE contamination in harbor seals (Phoca vitulina) from north-central California and Bristol Bay, Alaska. Aquatic Mammals 35 (1):1-11. *Department of Natural Resources, American River College, 4700 College Oak Drive, Sacramento, CA 95841, USA; E-mail: nealej@arc.losrios.edu In recent years, concerns have increased regarding accumulation of persistent, lipophilic contami­nants by marine mammals. We quantified blood levels of the two most prevalent organochlorine (OC) contaminants of the marine ecosystem in a model species, the harbor seal (Phoca vitulina) from three north-central California populations and a population in Bristol Bay, Alaska. Intensive sampling (n = 190) produced robust quantifica­tion of blood concentrations of selected PCBs and DDE, and allowed us to investigate factors affecting levels of these contaminants in seal pop­ulations with distinct environments and exposure histories. In the Alaskan samples, PCB and DDE levels were most strongly related to sex and age; OCs increased with age in males and decreased with age in females, likely due to cumulative exposure in males and load-dumping during lac­tation in females. Among females, an inverse relationship was observed between condition and PCB blood levels. In contrast, in the California seals, in which loads were generally much greater, pups had greater levels of PCBs and DDE than subadults and adults, suggesting stable to decreas­ing environmental contaminant levels. Spatial het­erogeneity and seasonal differences also contrib­uted substantially to variation among harbor seals in contaminant loads. These findings underscore the importance of accounting for demographic, geographic, seasonal, and physiological effects in toxicological studies of marine mammals. ************* Galindo, J. A.*, A. Serrano, L. Vázquez-Castán, c. González-Gándara, and M. López-Ortega. 2009. Cetacean diversity, distribution, and abundance in northern Veracruz, Mexico. Aquatic Mammals 35 (1):12-18. *Laboratorio de Mamíferos Marinos, Universidad Veracruzana, Tuxpan, Veracruz, Mexico, CP 92850; E-mail: arserrano@uv.mx or arturoserrano@prodigy.net.mx The distribution and abundance of marine mam­mals along the United States coast of the Gulf of Mexico are well-documented, but similar studies for the Mexican coast of the Gulf of Mexico are lacking. Furthermore, these animals are important indicators of the marine ecosystem health, and sci­entific research is needed to develop appropriate conservation strategies. Thus, the objective of this study was to determine the diversity, distribution, and relative abundance of marine mammals in the northern coasts of Veracruz, Mexico. Boat-based surveys and aerial surveys were carried out from March 2005 to August 2006. The following spe­cies were observed: bottlenose dolphins (Tursiops truncatus), spotted dolphin (Stenella attenu­ata), spinner dolphin (S. longirostris), rough-toothed dolphin (Steno bredanensis), pilot whale (Globicephala macrorhynchus), and an uniden­tified species of a dolphin. Also, the remains of a sperm whale (Physeter macrocephalus) and a humpback whale (Megaptera novaeangliae) were observed. The Margalef Diversity Index showed a value of 1.82 for the entire study area. There were differences in the species sightings across seasons. The abundance for the entire study area was 10,824 (%CV 25.05); the density was 1.45 cetaceans/km2 (%CV 25.05), and the cluster den­sity was 0.71 cetaceans/km2 (%CV 15.25). The dry season showed a relative abundance of 1.98 cetaceans/h; the rainy season, 1.07 cetaceans/h; and the cold front season, 1.28 cetaceans/h. This is a first glimpse of cetacean population sizes in Mexico. Mexican authorities consider all marine mammal species to be under some conservation status, but they do not have population estimates. Supplementary studies will extend the information presented here for further refinement of cetacean diversity and distribution in Mexican waters of the Gulf of Mexico. Special effort is needed in deeper waters of the Mexican part of the Gulf of Mexico since there is no information about diversity and abundance of marine mammals for those areas. ********************** Richmond, J. P., and S. A. Zinn. 2009. Validation of heterologous radioimmunoassays (RIA) for growth hormone (GH) and insulin-like growth factor (IGF)-I in phocid, otariid, and cetacean species. Aquatic Mammals 35 (1):19-31. University of Connecticut, Department of Animal Science, 3636 Horsebarn Road Ext., Unit 4040, Storrs, CT 06269, USA; E-mail: julie.richmond@uconn.edu Growth hormone (GH) is a homeorhetic hormone that coordinates diverse physiological processes to partition nutrients toward lean tissue accretion and milk production, and to inhibit utilization of nutri­ents by adipose tissue, especially during periods of energy deficiency. Due to age-related declines in GH, GH is negatively correlated with overall growth rate and lipid accretion but positively asso­ciated with protein accretion. Circulating GH influ­ences peripheral tissues directly or indirectly and is primarily mediated via an insulin-like growth factor (IGF)-I. Similar to GH, age and nutrition influence IGF-I secretion. In general, IGF-I is positively associated with growth rate and accre­tion of protein. Since purified pinniped or cetacean GH and IGF-I are not available, heterologous assay techniques must be employed to quantify concen­trations of these hormones. Critical to the reliabil­ity of heterologous assays are the proper execution of validations to demonstrate the accuracy and pre­cision of the assay for each new species of interest. In this study, we developed and validated heterolo­gous radioimmunoassays for seven marine mammal species using porcine and human antisera for GH and IGF-I quantification, respectively. Sensitivity, recovery of mass, assay precision, parallelism, and dilution linearity were determined for each assay and species. Both assays exhibited excellent paral­lelism and linearity. Appropriate concentrations of hormone were quantified throughout the range of the standard curve. Importantly, using these assays, we have demonstrated that serum concentrations of GH and IGF-I change with age and nutrient intake in these species. Validation of these assays allows evaluation of metabolic hormones that may provide unique perspectives on physiological regulation of differential growth and nutrient allocation for diverse marine mammal species. ************************ Kastelein, R. A.*, M. F. van Dooren, and D. Tibboel. 2009. A case study of congenital diaphragmatic hernia in a juvenile striped dolphin (Stenella coeruleoalba). Aquatic Mammals 35 (1):32-35. *SEAMARCO (Sea Mammal Research Company), Julianalaan 46, 3843 CC Harderwijk, The Netherlands; E-mail: Researchteam@zonnet.nl Congenital Diaphragmatic Hernia (CDH) was observed in a stranded juvenile male striped dol­phin. The 2- to 3-y-old animal had survived with its stomachs and intestines in the thoracic cavity, which had caused a large size difference between its two lungs. The animal also had a relatively small penis. The animal’s combination of anoma­lies was either due to a genetic syndrome or caused by maternal exposure to toxic agents. ******************** Dennison, S. E.*, L. Forrest, and F. M. D. Gulland. 2009. Normal thoracic radiographic anatomy of immature California sea lions (Zalophus californianus) and immature northern elephant seals (Mirounga angustirostris). Aquatic Mammals 35 (1):36-42. * Department of Surgical Sciences (Radiology), School of Veterinary Medicine, 2015 Linden Drive, Madison, WI 53706, USA; E-mail: dennison@svm.vetmed.wisc.edu Immature California sea lions (Zalophus califor­nianus) and northern elephant seals (Mirounga angustirostris) without evidence of thoracic disease were radiographed under anesthesia. Important species-specific variations were noted on thoracic radiographs. For the California sea lions, the mean vertebral heart score was 8.65 from the left lat­eral view, and the cardiac silhouette occupied a mean of 66% of the internal thoracic width. The tracheal bifurcation in California sea lions was located at the level of the first thoracic vertebral body. For the northern elephant seals, there was variation in the number of thoracic vertebrae and ribs from 12 to 15, a lack of pulmonary lobation, and an indistinct cardiac silhouette. Cardiac mea­surements could only be made on ventrodorsal (VD) and dorsoventral (DV) digital radiographs where the cardiac silhouette occupied a mean of 62% of the internal thoracic width. The combina­tion of smooth to rounded lung lobe margins with border effacement of the cardiac silhouette and diaphragmatic margin is an important, normal, species-specific finding of the northern elephant seal that could be easily mistaken for pleural effu­sion. The carina in the northern elephant seals was at the level of the fifth thoracic vertebral body. In both species, the aortic bulb was evident as a focal, fairly symmetrical cranial mediastinal widening cranial to the cardiac silhouette on the VD and DV views, resulting in the aorta being identifiable on both the right and the left. This is an important normal finding in marine mammals that should not be mistaken for pathology. Both species had a diffuse bronchointerstitial pulmonary pattern that was slightly more prominent in California sea lions. This finding was consistent with variation between these species in the tissues supporting the small airways.This prospective study serves as a normal refer­ence for immature California sea lions and north­ern elephant seals in veterinary care. ********************* Howells, E. M.*, J. S. Reif, S. E. Sarah E. Bechdel, M. E. Murdoch, G. D. Bossart, S. D. McCulloch, and M. S. Mazzoil. 2009. A novel case of non-offspring adoption in a free-ranging Atlantic bottlenose dolphin (Tursiops truncatus) inhabiting the Indian River Lagoon, Florida. Aquatic Mammals 35 (1):43-47. *Center for Marine Ecosystem Health, Marine Mammal Research and Conservation, Harbor Branch Oceanographic Institute at Florida Atlantic University, 5600 U.S. 1 North, Ft. Pierce, FL 34946, USA; E-mail: ehowells@hboi.fau.edu Wild and captive epimeletic care has been reported worldwide in many different species of cetaceans. Epimeletic care can be described as nurturant or succorant in nature. While adoption can be con­sidered an example of nurturant behavior, to date there have been no reported cases of permanent adoption among wild cetaceans. During routine photo-identification surveys, an adult female bot­tlenose dolphin (Tursiops truncatus) was found in the presence of a young calf that was not her own. This mother-calf-like relationship lasted nearly 2 y until the death of the allomother. This paper documents a novel case of free-ranging bottlenose dolphin adoption that occurred in the Indian River Lagoon, Florida. ************** Mignucci-Giannoni, A. A.*, R. J. Rosario-Delestre, M. M. Alsina-Guerrero, L. Falcón-Matos, L. Guzmán-Ramírez, J. Williams, E.H., G. D. Bossart, and J. S. Reidenberg. 2009. Asphyxiation in a bottlenose dolphin (Tursiops truncatus) from Puerto Rico due to choking on a black margate (Anisotremus surinamensis). Aquatic Mammals 35 (1):48-54. *Red Caribeña de Varamientos, P.O. Box 361715, San Juan, Puerto Rico 00936; E-mail: mignucci@manatipr.org Bottlenose dolphins (Tursiops truncatus) are found in the coastal and offshore waters of Puerto Rico. However, little is known about causes of their mortal­ity in the Caribbean. On 18 February 2002, a female bottlenose dolphin was found dead in Bahía de San Juan, Puerto Rico. Remarkably, a black margate (Anisotremus surinamensis) was firmly lodged in the dolphin’s oral cavity and the pharynx. The throat of the dolphin was markedly swollen; the larynx was dislocated; and signs of agonal death were evi­dent. Grossly, the cause of death was determined to be asphyxiation due to choking. Fifty strandings of bottlenose dolphins have been reported between 1937 and 2006 in Puerto Rico and the Virgin Islands. In those for which a cause of death was determined, four were human related and 11 died of natural causes (including this case). The present case study fits the definitions of “choking” and “asphyxia­tion.” The evolved respiratory anatomy of cetaceans in which the larynx is inserted into the nasal pas­sages leading to the blowhole makes asphyxiation due to choking unlikely in odontocetes. However, if the larynx is irreversibly dislodged from its normal position during swallowing, this may cause the dol­phin to stop breathing or even drown. Thus, respira­tory blockage from a natural prey item represents an uncommon mortality factor associated with piscivo­rous cetaceans and is the first record of such marine mammal mortality in the Caribbean. ************ Rivas, M.*, and M. Trimble. 2009. Aggregation behaviour in South American sea lion (Otaria flavescens) pups at Isla de Lobos, Uruguay. Aquatic Mammals 35 (1):55-61. *Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo 11400, Uruguay; E-mail: rivas.mayda@gmail.com When otariid females leave the colony to forage at sea, pups stay in the rookery and gather in groups in which they rest and play. The major selective benefits of these groups are to develop social skills and physical abilities, as well as to reduce the risk of aggression by adults. The aim of this research was to study the aggregation behaviour in South American sea lion (Otaria flavescens) pups at Isla de Lobos, Uruguay, during the first 2 mo of life. During the breeding season of 2007 (January to March), from 0800 to 1800 h, instantaneous scan-samples were conducted every 2 h to record the number of groups in the area, number of pups per group, behavioral state, and location (land or sea). The number of groups increased during the first month, being positively correlated with the total number of pups in the area. A group size of two pups was most frequent (60.2%), followed by three pups (20.1%). Rest was the most frequent activity during most of the study period, and pup group activity did not vary over the weeks. The type of activity varied according to the time of day, with pups most active early in the morning, and also according to group size (the larger the group size, the higher the proportion of individuals rest­ing in the group). The proportion of groups at sea increased with pup age, and interactions in a large group were more frequent at sea than on land. This research represents one of the first detailed analy­ses about aggregation behaviour in otariid pups. **************** Bacchus, M.-L. C., S. G. Dunbar, and C. Self-Sullivan. 2009. Characterization of resting holes and their use by the Antillean manatee (Trichechus manatus manatus) in the Drowned Cayes, Belize. Aquatic Mammals 35 (1):62-71. * Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA 92350, USA; E-mail: mlbacchus@gmail.com In the Drowned Cayes area of Belize, manatees (Trichechus manatus manatus) are commonly observed resting in depressions in the substrate, locally referred to as manatee resting holes. To understand why manatees prefer locations with resting holes, the physical and environmental attributes of the depressions were characterized and diurnal and nocturnal use by manatees at four resting hole sites were documented over two sum­mers. Twelve resting hole sites were compared with 20 non-resting hole sites in the Drowned Cayes, using water depth, substrate type, vegeta­tion, water velocity, salinity, and water tempera­ture. Four resting holes were chosen for repeated diurnal and nocturnal observations, during which sea and weather conditions were recorded in addi­tion to the presence/absence of manatees. Resting holes were significantly deeper and had slower surface water velocity than areas without resting holes. A total of 168 point scans were conducted over 55 d, resulting in 39 manatee sightings over two summers. There was a significant difference in the number of sightings between research years and between day and night scans. Given the large number of resting holes in the Drowned Cayes, many of which are in sheltered areas with slow currents, it is possible that manatees select these spots based on the tranquility of the water and environment. The combination of slow currents, protection from waves, low numbers of boats, and nearby seagrass beds would make these ideal rest­ing areas. These findings have implications for the conservation of important manatee habitat. ******** Hoson, O.*, S. Kawada, and S. Oda. 2009. Ossification patterns of cranial sutures in the Florida manatee (Trichechus manatus latirostris) (Sirenia, Trichechidae). Aquatic Mammals 35 (1):72-81. *Laboratory of Animal Management and Resources, Graduate School of Bio-Agricultural Sciences, Nagoya University, Nagoya 464-8601, Japan; E-mail: osasonosa@yahoo.co.jp Although morphological skull characters are used to identify species or subspecies of the genus Trichechus, little information is available on the growth of the manatee skull. We examined the ossification of the skull of the Florida manatee (Trichechus manatus latirostris) with regard to its growth pattern. We observed ten sutures in 137 crania (70 males and 67 females). Based on these results, the sutures can be classified into two groups by their ossification pattern. The first group contains the maxilloincisive suture, median palatine suture, frontal suture, and coronal suture. This group begins to ossify early in growth. The age of suture closure does not differ among the sexes. The second group consists of sutures related to the basicranium. This group is characterised by slower ossification compared to the first group. Suture ossification in this group proceeds from anterior to posterior. In this suture series, ossifica­tion occurred at later ages in males than in females. A notable feature is the formation of the occipital bone. Ossification of the spheno-occipital syn­chondrosis occurred earlier than that of the occipi­tal condyle. This pattern is unique among mam­mals, including the dugong. Osteological maturity was determined by the status of the sutures. The sutures of the basicranium ossify slowly, and thus they are more valuable in evaluating the growth status of the skull than those of the viscerocranium and calvaria. The supraoccipital-exoccipital syn­chondrosis was the last to begin ossification, start­ing when individuals were more than 15 y old and 11 y old in males and females, respectively. We conclude that the ossification of the basicranium exhibits a unique pattern in the Florida manatee and that it is possible to determine the osteological maturity of the skull from the ossification of the supraoccipital-exoccipital synchondrosis. ************ Boyd, I. L. 2009. The history of marine mammal research in the United Kingdom: An exploration of the interaction of human socioeconomics and marine mammal ecology. Aquatic Mammals 35 (1):82-93. Dr. Ian Boyd reviews the history of marine mammal research in the UK. ******* Hofman, R. 2009. The continuing legacies of the Marine Mammal Commission and its Committee of Scientific Advisors on Marine Mammals. Aquatic Mammals 35 (1):94-129. Dr. Robert Hofman reviews the legacy of the U.S. Marine Mammal Commission. ************* Fertl, D. 2009. Book Review: Marine Wildlife and Tourism Management: Insights from the Natural and Social Sciences. Editors: James Higham and Michael Lück. Oxford University Press, Oxford, UK, 2008. Aquatic Mammals 35(1):130-131. Ziphius EcoServices, 8112 Springmoss Drive, Plano, TX 75025, USA; E-mail: dfertl@gmail.com _________________________________________________________________ Hotmail® is up to 70% faster. Now good news travels really fast. http://windowslive.com/online/hotmail?ocid=TXT_TAGLM_WL_HM_70faster_032009