Sarasota, FL, United States
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Cremer M.J.,University of the Region of Joinville | Holz A.C.,University of the Region of Joinville | Bordino P.,Fundacion Aquamarina | Wells R.S.,Sarasota Dolphin Research Program | Simoes-Lopes P.C.,Federal University of Santa Catarina
Journal of the Acoustical Society of America | Year: 2017

Franciscana dolphin (Pontoporia blainvillei) whistles were documented for the first time during 2003-2013 in Babitonga Bay estuary, South Brazil, together with burst pulses. Recordings were made from small boats under good sea conditions, and recording equipment that allowed analysis of sounds up to 96 kHz. The recordings were made in the presence of 2-31 franciscana dolphins. During 23 h and 53 min, 90 whistles and 51 burst pulse series were recorded. Although Guiana dolphins (Sotalia guianensis) inhabit nearby waters, none were observed in the area during the recordings. The authors recorded ten types of whistles. The initial frequency varied between 1.6 and 94.6 kHz, and the final frequency varied between 0.7 and 94.5 kHz; the authors were not able to determine if dolphin whistles exceeded the 96 kHz recording limit of the authors' equipment, although that is likely, especially because some whistles showed harmonics. Whistle duration varied between 0.008 and 0.361 s. Burst pulses had initial frequencies between 69 and 82.1 kHz (77 ± 3.81). These results showed that P. blainvillei produces whistles and burst pulses, although they seem to be produced infrequently. © 2017 Acoustical Society of America.


Hornsby F.E.,Western EcoSystems Technology Inc. | McDonald T.L.,Western EcoSystems Technology Inc. | Balmer B.C.,National Oceanic and Atmospheric Administration | Speakman T.R.,National Oceanic and Atmospheric Administration | And 7 more authors.
Endangered Species Research | Year: 2017

Following the Deepwater Horizon (DWH) oil spill, numerous studies were conducted to determine impacts on common bottlenose dolphins Tursiops truncatus. Common bottlenose dolphins are found in estuarine environments of the northern Gulf of Mexico which vary in salinity, depending on location (e.g. distance to freshwater source), season, and ocean tides. Although common bottlenose dolphins can be found in low-salinity waters (<15 ppt), they cannot tolerate very low salinity for long periods of time. We matched dolphin telemetry data in Barataria Bay, Louisiana (USA), with contemporaneous estimates of salinity to establish a salinity threshold and identify preferred dolphin habitat. Dolphins frequently used areas where salinity was higher than ~11 ppt, sometimes used areas for short periods of time with predicted salinity of ~8 ppt, and avoided waters with salinities below ~5 ppt. While not a hard boundary, the ~8 ppt threshold can be used to delineate reasonable polygons of preferred dolphin habitat. We temporally averaged the location of the ~8 ppt isohaline from 2005 through 2012 to establish areas of preferred dolphin habitat. In Barataria Bay, the polygon of dolphin habitat encompasses 1167 km2, and extends from the bay's barrier islands to approximately half-way through marshes in northern parts of the bay. This polygon of suitable common bottlenose dolphin habitat was then ultimately used to quantify cetacean injury due to DWH oil. © Outside the USA the US Government 2017.


Janik V.M.,University of St. Andrews | King S.L.,University of St. Andrews | Sayigh L.S.,Woods Hole Oceanographic Institution | Wells R.S.,Sarasota Dolphin Research Program
Marine Mammal Science | Year: 2013

Bottlenose dolphins (Tursiops truncatus) have individually distinctive signature whistles. Each individual dolphin develops its own unique frequency modulation pattern and uses it to broadcast its identity. However, underwater sound localization is challenging, and researchers have had difficulties identifying signature whistles. The traditional method to identify them involved isolating individuals. In this context, the signature whistle is the most commonly produced whistle type of an animal. However, most studies on wild dolphins cannot isolate animals. We present a novel method, SIGnature IDentification (SIGID), that can identify signature whistles in recordings of groups of dolphins recorded via a single hydrophone. We found that signature whistles tend to be delivered in bouts with whistles of the same type occurring within 1-10 s of each other. Nonsignature whistles occur with longer or shorter interwhistle intervals, and this distinction can be used to identify signature whistles in a recording. We tested this method on recordings from wild and captive bottlenose dolphins and show thresholds needed to identify signature whistles reliably. SIGID will facilitate the study of signature whistle use in the wild, signature whistle diversity between different populations, and potentially allow signature whistles to be used in mark-recapture studies. © 2012 by the Society for Marine Mammalogy.


PubMed | Mote Marine Laboratory, Murdoch University, Sarasota Dolphin Research Program and University of Aberdeen
Type: Journal Article | Journal: Royal Society open science | Year: 2017

Food provisioning of wildlife is a major concern for management and conservation agencies worldwide because it encourages unnatural behaviours in wild animals and increases each individuals risk for injury and death. Here we investigate the contributing factors and potential fitness consequences of a recent increase in the frequency of human interactions with common bottlenose dolphins (


Venn-Watson S.,Foundation Medicine | Smith C.R.,Foundation Medicine | Stevenson S.,Foundation Medicine | Parry C.,Foundation Medicine | And 7 more authors.
Frontiers in Endocrinology | Year: 2013

Similar to people with metabolic syndrome, bottlenose dolphins (Tursiops truncatus) can have a sustained postprandial hyperglycemia and hyperinsulinemia, dyslipidemia, and fatty liver disease. A panel of potential postprandial blood-based indicators of insulin resistance and metabolic syndrome were compared among 34 managed collection dolphins in San Diego Bay, CA, USA (Group A) and 16 wild, free-ranging dolphins in Sarasota Bay, FL, USA (Group B). Compared to Group B, Group A had higher insulin (2.1 ± 2.5 and 13 ± 13 μIU/ml), glucose (87 ± 19 and 108 ± 12 mg/dl), and triglycerides (75 ± 28 and 128 ± 45 mg/dl) as well as higher cholesterol (total, high-density lipoprotein cholesterol, and very low density lipoprotein cholesterol), iron, transferrin saturation, gamma-glutamyl transpeptidase (GGT), alanine transaminase, and uric acid. Group A had higher percent unmodified adiponectin. While Group A dolphins were older, the same blood-based differences remained when controlling for age. There were no differences in body mass index (BMI) between the groups, and comparisons between Group B and Group A dolphins have consistently demonstrated lower stress hormones levels in Group A. Group A dolphins with high insulin (greater than 14 μIU/ml) had higher glucose, iron, GGT, and BMI compared to Group A dolphins with lower insulin. These findings support that some dolphin groups may be more susceptible to insulin resistance compared to others, and primary risk factors are not likely age, BMI, or stress. Lower high-molecular weight adiponectin has been identified as an independent risk factor for type 2 diabetes in humans and may be a target for preventing insulin resistance in dolphins. Future investigations with these two dolphin populations, including dietary and feeding differences, may provide valuable insight for preventing and treating insulin resistance in humans. © 2013 Venn-Watson, Smith, Stevenson, Parry, Daniels, Jensen, Cendejas, Balmer, Janech, Neely and Wells.


PubMed | Stanford University, Space and Naval Warfare Systems Center Pacific, Foundation Medicine and Sarasota Dolphin Research Program
Type: | Journal: Nature communications | Year: 2016

Marine mammals play crucial ecological roles in the oceans, but little is known about their microbiotas. Here we study the bacterial communities in 337 samples from 5 body sites in 48 healthy dolphins and 18 healthy sea lions, as well as those of adjacent seawater and other hosts. The bacterial taxonomic compositions are distinct from those of other mammals, dietary fish and seawater, are highly diverse and vary according to body site and host species. Dolphins harbour 30 bacterial phyla, with 25 of them in the mouth, several abundant but poorly characterized Tenericutes species in gastric fluid and a surprisingly paucity of Bacteroidetes in distal gut. About 70% of near-full length bacterial 16S ribosomal RNA sequences from dolphins are unique. Host habitat, diet and phylogeny all contribute to variation in marine mammal distal gut microbiota composition. Our findings help elucidate the factors structuring marine mammal microbiotas and may enhance monitoring of marine mammal health.


Tyson R.B.,Duke University | Tyson R.B.,Sarasota Dolphin Research Program | Friedlaender A.S.,Duke University | Friedlaender A.S.,Oregon State University | Nowacek D.P.,Duke University
Animal Behaviour | Year: 2016

Optimal foraging theory (OFT) suggests that air-breathing diving animals should minimize costs associated with feeding under water (e.g. travel time, oxygen loss) while simultaneously maximizing benefits gained from doing so (e.g. foraging time, energy gain). Humpback whales, Megaptera novaeangliae, foraging along the Western Antarctic Peninsula appear to forage according to OFT, but the direct costs and benefits in terms of their behaviours (e.g. allocation of time) have not been examined. We compared the foraging behaviour of humpback whales in this region inferred from multisensor high-resolution recording tags to their behaviour predicted by OFT time allocation models assuming the following currencies were being maximized: (1) the proportion of time spent foraging, (2) the net rate of energetic gain and/or (3) the ratio of energy gained to energy expended (i.e. efficiency). Model predictions for all three currencies were similar, suggesting any of these OFT models were suitable for comparison with the observed data. However, agreement between observed and optimal behaviours varied widely depending on the physiological and behavioural values used to derive optimal predictions, highlighting the need for an improved understanding of cetacean physiology. Despite this, many of the theoretical OFT predictions were supported: shallow dives (i.e. <100 m), which were short and executed most frequently, yielded the highest proportions of foraging time, and the greatest net rates of energy gain and were the most efficient. In addition, dive and foraging times increased in duration rapidly with increasing maximum dive depths to approximately 100 m and then at lower rates with deeper dives. Our findings offer a thorough examination of the applicability of time allocation OFT models to the behaviours of a large, air-breathing, diving predator and provide insights into the foraging ecology and physiology of humpback whales in the Western Antarctic Peninsula. © 2016 The Association for the Study of Animal Behaviour.


Correa L.,University of Alaska Fairbanks | Castellini J.M.,University of Alaska Fairbanks | Wells R.S.,Sarasota Dolphin Research Program | O'Hara T.,University of Alaska Fairbanks
Environmental Toxicology and Chemistry | Year: 2013

Total mercury and selenium concentrations ([THg], [Se]) in serum, plasma, whole blood, and packed cells were examined in a resident population of free-ranging bottlenose dolphins (Tursiops truncatus) from Sarasota Bay, Florida, USA. The authors determined how these elements partition in blood and assess compartment-specific associations. Determining the distribution of Se and THg can provide physiologic insight into potential association of Hg with selenol-containing biomolecules (e.g., antioxidants) in blood compartments. Concentrations of THg were ranked serum


McHugh K.A.,Sarasota Dolphin Research Program | Allen J.B.,Sarasota Dolphin Research Program | Barleycorn A.A.,Sarasota Dolphin Research Program | Wells R.S.,Sarasota Dolphin Research Program
Marine Mammal Science | Year: 2011

Harmful algal blooms (HABs) are natural stressors in the coastal environment that may be increasing in frequency and severity. This study investigates whether severe red tide blooms, caused by Karenia brevis, affect the behavior of resident coastal bottlenose dolphins in Sarasota Bay, Florida through changes to juvenile dolphin activity budgets, ranging patterns, and social associations. Behavioral observations were conducted on free-ranging juvenile dolphins during the summer months of 2005-2007, and behavior during red tide blooms was compared to periods of background K. brevis abundance. We also utilized dolphin group sighting data from 2004 to 2007 to obtain comparison information from before the most severe recent red tide of 2005 and incorporate social association information from adults in the study area. We found that coastal dolphins displayed a suite of behavioral changes associated with red tide blooms, including significantly altered activity budgets, increased sociality, and expanded ranging behavior. At present, we do not fully understand the mechanism behind these red tide-associated behavioral effects, but they are most likely linked to underlying changes in resource availability and distribution. These behavioral changes have implications for more widespread population impacts, including increased susceptibility to disease outbreaks, which may contribute to unusual mortality events during HABs. © 2010 by the Society for Marine Mammalogy.


McHugh K.A.,Sarasota Dolphin Research Program | Allen J.B.,Sarasota Dolphin Research Program | Barleycorn A.A.,Sarasota Dolphin Research Program | Wells R.S.,Sarasota Dolphin Research Program
Journal of Mammalogy | Year: 2011

Movement patterns and habitat selection are influenced by factors such as resource availability, predation risk, and social interactions, and the relative importance of each of these variables can change over an animal's life span. Although ranging patterns and habitat use of adult dolphins have been explored in some areas, relatively little is known about how these behaviors develop as young dolphins mature. This study explored natal philopatry during the juvenile period and behavioral development of ranging and habitat-use patterns in newly independent bottlenose dolphins (Tursiops truncatus) at a long-term study site in Sarasota Bay, Florida. To achieve this we used both long-term sighting data from the resident dolphin community in Sarasota Bay and new information on movements, habitat selection, and social associations collected through boat-based focal-animal behavioral observations on 27 individually identifiable juveniles during 20052008. We documented differences in ranging patterns and habitat use of juvenile dolphins by sex, season, and age, and investigated the degree of maternal influence on these behaviors and the functional significance of juvenile groups. We found that male and female dolphins in Sarasota Bay had similar ranging and habitat-selection patterns during the juvenile period. Both sexes exhibited a high degree of philopatry to natal areas as juveniles, with dispersal occurring only rarely by members of either sex. Seasonal and age-related differences in juvenile behavior were evident, and lasting maternal influences on habitat selection and ranging patterns postindependence are apparent. These findings provide some of the 1st information on juvenile marine mammal behavior that contributes to our understanding of resident inshore dolphin behavior throughout the life history and are potentially important to management and conservation efforts. © 2011 American Society of Mammalogists.

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