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At least 37 records · Page 2Linked to original sources
USGS2009

Sexing sirenians: Validation of visual and molecular sex determination in both wild dugongs (Dugong dugon) and Florida manatees (Trichechus manatus latirostris)

Sexing wild marine mammals that show little to no sexual dimorphism is challenging. For sirenians that are difficult to catch or approach closely, molecular sexing from tissue biopsies offers an alternative method to visual discrimination. This paper reports the results of a field study to validate the use of two sexing methods: (1) visual discrimination of sex vs (2) molecular sexing based on a multiplex PCR assay which amplifies the male-specific SRY gene and differentiates ZFX and ZFY gametologues. Skin samples from 628 dugongs (Dugong dugon) and 100 Florida manatees (Trichechus manatus latirostris) were analysed and assigned as male or female based on molecular sex. These individuals were also assigned a sex based on either direct observation of the genitalia and/or the association of the individual with a calf. Individuals of both species showed 93 to 96% congruence between visual and molecular sexing. For the remaining 4 to 7%, the discrepancies could be explained by human error. To mitigate this error rate, we recommend using both of these robust techniques, with routine inclusion of sex primers into microsatellite panels employed for identity, along with trained field observers and stringent sample handling.

Aquatic Mammals↗
USGS2010

Physiological response of wild dugongs ( Dugong dugon ) to out-of-water sampling for health assessment

The dugong ( Dugong dugon ) is a vulnerable marine mammal with large populations living in urban Queensland waters. A mark-recapture program for wild dugongs has been ongoing in southern Queensland since 2001. This program has involved capture and in-water sampling of more than 700 dugongs where animals have been held at the water surface for 5 min to be gene-tagged, measured, and biopsied. In 2008, this program expanded to examine more comprehensively body condition, reproductive status, and the health of wild dugongs in Moreton Bay. Using Sea World's research vessel, captured dugongs were lifted onto a boat and sampled out-of-water to obtain accurate body weights and morphometrics, collect blood and urine samples for baseline health parameters and hormone profiles, and ultrasound females for pregnancy status. In all, 30 dugongs, including two pregnant females, were sampled over 10 d and restrained on deck for up to 55 min each while biological data were collected. Each of the dugongs had their basic temperature-heart rate-respiration (THR) monitored throughout their period of handling, following protocols developed for the West Indian manatee ( Trichechus manatus ). This paper reports on the physiological response of captured dugongs during this out-of-water operation as indicated by their vital signs and the suitability of the manatee monitoring protocols to this related sirenian species. A recommendation is made that the range of vital signs of these wild dugongs be used as benchmark criteria of normal parameters for other studies that intend to sample dugongs out-of-water.

Queensland↗
USGS2006

Assessment of gamete quality for the eastern oyster (Crassostrea virginica) by use of fluorescent dyes

Evaluation of sperm motility is the single most widely used parameter to determine semen quality in mammals and aquatic species. While a good indicator for fresh sperm viability, post-thaw motility is not always effective at predicting fertilizing ability. Techniques using fluorescent dyes can assess functionality of mammalian sperm, but have not been widely applied in aquatic organisms. The eastern oyster Crassostrea virginica is an important mollusk in the United States, and cryopreservation protocols have been developed to preserve sperm and larvae to assist research and hatchery production. In this study, protocols were developed to assess sperm cell membrane integrity and mitochondrial function by flow cytometry and to assess viability of eggs by fluorescence microscopy. The fluorescent dyes SYBR 14 and propidium iodide (PI) (to assess membrane integrity) and rhodamine 123 (R123) (to assess mitochondrial membrane potential) were used to evaluate the quality of thawed oyster sperm previously cryopreserved with different cryoprotectant and thawing treatments. Membrane integrity results were correlated with motility of thawed sperm and mitochondrial membrane potential with fertilizing ability. Fluorescein diacetate (FDA) was used to assess cytotoxicity of cryoprotectant solutions and post-thaw damage to oyster eggs. The results indicated that membrane integrity (P = 0.004) and thawing treatments (P = 0.04), and mitochondrial membrane potential (P = 0.0015) were correlated with motility. Fertilizing ability was correlated with cryoprotectant treatments (P = 0.0258) and with mitochondrial membrane potential (P = 0.001). The dye FDA was useful in indicating structural integrity of fresh and thawed eggs. Exposure of eggs, without freezing, to dimethyl sulfoxide yielded higher percentages of stained eggs and fertilization rate than did exposure to propylene glycol (P = 0.002). Thawed eggs were not stained with FDA (<1%) and larvae were not produced.

Cryobiology↗
USGS2010

First report of a Florida manatee (Trichechus manatus latirostris) in Cuba

Manatees ( Trichechus manatus latirostris ) in Florida utilize intake and effluent canals of power plants as resting and thermoregulatory habitat. We report the use of a power plant canal in Cuba by a known Florida manatee, the first documented case of movement by a manatee between Florida and Cuba. In January, February, and April 2007, two manatees (mother and calf) were reported entering a power plant canal in north Havana, Cuba. The larger manatee had several distinctive scars which were photographed. Digital images were matched to a previously known Florida manatee (CR131) with a sighting history dating from December 1979 to July 2006. Exchanges of individuals between Florida and Cuba may have important genetic implications, particularly since there appears to be little genetic exchange between the Florida manatee subspecies with populations of the Antillean manatee subspecies ( T. m. manatus ) in Puerto Rico and the Dominican Republic.

Aquatic Mammals↗
USGS2010

Lesions and behavior associated with forced copulation of juvenile Pacific harbor seals (Phoca vitulina richardsi) by southern sea otters (Enhydra lutris nereis)

Nineteen occurrences of interspecific sexual behavior between male southern sea otters ( Enhydra lutris nereis ) and juvenile Pacific harbor seals ( Phoca vitulina richardsi ) were reported in Monterey Bay, California, between 2000 and 2002. At least three different male sea otters were observed harassing, dragging, guarding, and copulating with harbor seals for up to 7 d postmortem. Carcasses of 15 juvenile harbor seals were recovered, and seven were necropsied in detail by a veterinary pathologist. Necropsy findings from two female sea otters that were recovered dead from male sea otters exhibiting similar behavior are also presented to facilitate a comparison of lesions. The most frequent lesions included superficial skin lacerations; hemorrhage around the nose, eyes, flippers, and perineum; and traumatic corneal erosions or ulcers. The harbor seals sustained severe genital trauma, ranging from vaginal perforation to vagino-cervical transection, and colorectal perforations as a result of penile penetration. One harbor seal developed severe pneumoperitoneum subsequent to vaginal perforation, which was also observed in both female sea otters and has been reported as a postcoital lesion in humans. This study represents the first description of lesions resulting from forced copulation of harbor seals by sea otters and is also the first report of pneumoperitoneum secondary to forced copulation in a nonhuman animal. Possible explanations for this behavior are discussed in the context of sea otter biology and population demographics.

California↗
USGS2011

Observations and relocation of a West Indian Manatee ( Trichechus manatus ) off Bimini, The Bahamas

West Indian manatees ( Trichechus manatus ) are listed as vulnerable (IUCN Red List, 7 March 2009; Deutsch et al., 2008), with the subspecies Trichechus manatus latirostris and T. m. manatus (Florida and Antillean, respectively) considered endangered (IUCN Red List, 21 January 2011; Deutsch, 2008; Self-Sullivan & Mignucci-Giannoni, 2008). Manatees are not native to The Bahamas; however, sightings have been recorded periodically since 1904, with an increase in sightings documented in the 1990s (Lefebvre et al., 2001). In the area of Bimini, The Bahamas, the first recorded manatee sighting was in 1904 of a single individual that was apparently killed (Allen, 1942). The second was not until 1996, which was poorly documented. The small adult remained for approximately 6 wks before disappearing (Lefebvre et al., 2001). In 1998, a third sighting was reported off Bimini of a single individual. Although the animal was seen for several weeks and was relatively habituated to human presence (Al Sweeting, Jr., pers. comm., 28 November 2008), no data were collected on this individual nor any photographs suitable for identification purposes.

Bimini↗
USGS2012

Monitoring oral temperature, heart rate, and respiration rate of West Indian manatees (Trichechus manatus) during capture and handling in the field

West Indian manatees (Trichechus manatus) are captured, handled, and transported to facilitate conservation, research, and rehabilitation efforts. Monitoring manatee oral temperature (OT), heart rate (HR), and respiration rate (RR) during out-of-water handling can assist efforts to maintain animal well-being and improve medical response to evidence of declining health. To determine effects of capture on manatee vital signs, we monitored OT, HR, and RR continuously for a 50-min period in 38 healthy, awake, juvenile and adult Florida manatees (T. m. latirostris) and 48 similar Antillean manatees (T. m. manatus). We examined creatine kinase (CK), potassium (K+), serum amyloid A (SAA), and lactate values for each animal to assess possible systemic inflammation and muscular trauma. OT range was 29.5 to 36.2° C, HR range was 32 to 88 beats/min, and RR range was 0 to 17 breaths/5 min. Antillean manatees had higher initial OT, HR, and RR than Florida manatees (p < 0.001). As monitoring time progressed, mean differences between the subspecies were no longer significant. High RR over monitoring time was associated with high lactate concentration. Antillean manatees had higher overall lactate values ([mean ± SD] 20.6 ± 7.8 mmol/L) than Florida manatees (13.7 ± 6.7 mmol/L; p < 0.001). We recommend monitoring manatee OT, HR, and RR during capture and handling in the field or in a captive care setting.

Aquatic Mammals↗
USGS2013

Movements and dive patterns of short-finned pilot whales (Globicephala macrorhynchus) released from a mass stranding in the Florida Keys

Short-finned pilot whales ( Globicephala macrorhynchus ) are among the most common cetaceans to engage in mass strandings in the southeastern United States. Because these are primarily pelagic, continental shelf-edge animals, much of what is known about this species has derived from mass stranding events. Post-release monitoring via satellite-linked telemetry was conducted with two adult males determined on-site to be healthy, and released directly from a mass stranding of 23 pilot whales in May 2011, near Cudjoe Key, Florida. Tracking provided an opportunity to evaluate the decision for immediate release vs rehabilitation, and to learn more about the lives of members of this difficult-to-study species in the wild. The two pilot whales remained together for at least 16 d before transmissions from one pilot whale (Y-404) ceased. Dive patterns and travel rates suggested that Y-404’s condition deteriorated prior to signal loss. Pilot Whale Y-400 was tracked for another 51 d, moving from the Blake Plateau to the Greater Antilles, remaining in the Windward Passage east of Cuba for the last 17 d of tracking. Once he reached the Antilles, Y-400 remained in high-relief habitat appropriate for the species and made dives within or exceeding the reported range for depth and duration for this species, following expected diel patterns, presumably reflecting continued good health. Telemetry data indicate that he made at least one dive to 1,000 to 1,500 m, and several dives lasted more than 40 min. Although the fates of the two released pilot whales may have been different, the concept of evaluating health and releasing individuals determined to be healthy at the time of stranding appears to have merit as an alternative to bringing all members of mass-stranded pilot whale groups into rehabilitation.

Florida↗
USGS2016

Twenty-six years of post-release monitoring of Florida manatees (Trichechus manatus latirostris): evaluation of a cooperative rehabilitation program

The rescue, rehabilitation, and release of Florida manatees (Trichechus manatus latirostris) into the wild has occurred since 1974; however, a comprehensive evaluation of the outcomes of the releases has never been conducted. Herein, we examined data for 136 Florida manatees that were rehabilitated and released with telemetry tags between 1988 and 2013 to determine release outcome of each individual as either success (acclimation) or failure after at least 1 y. Ten predictor variables were statistically evaluated for potential relationships to release outcome. To assess the contribution of each predictor variable to release outcome, each variable was tested for significance in univariate analyses. Manatees born in captivity experienced poor success after release (14%), whereas the overall success of wild-born individuals was higher (72%). When compared with other variables in our dataset, number of days in captivity was the strongest predictor for determining success. Manatees rescued as calves and held in captivity for more than 5 y had a high likelihood of failure, while subadults and adults had a high likelihood of success, regardless of the amount of time spent in captivity. Ensuring the success of individual manatees after release is critical for evaluating the contribution of the manatee rehabilitation program to the growth of the wild population.

Florida↗
USGS2016

Morphometric body condition indices of wild Florida manatees ( Trichechus manatus latirostris )

In many species, body weight (W) increases geometrically with body length (L), so W/L 3 provides a body condition index (BCI) that can be used to evaluate nutritional status once a normal range has been established. No such index has been established for Florida manatees ( Trichechus manatus latirostris ). This study was designed to determine a normal range of BCIs of Florida manatees by comparing W in kg with straight total length (SL), curvilinear total length (CL), and umbilical girth (UG) in m for 146 wild manatees measured during winter health assessments at three Florida locations. Small calves to large adults of SL from 1.47 to 3.23 m and W from 77 to 751 kg were compared. BCIs were significantly greater in adult females than in adult males ( p < 0.05). W scaled proportionally to L 3 in females but not in males, which were slimmer than females. The logarithms of W and of each linear measurement were regressed to develop amended indices that allow for sex differences. The regression slope for log W against log SL was 2.915 in females and 2.578 in males; W/SL 2.915 ranged from 18.9 to 29.6 (mean 23.2) in females and from 24.6 to 37.3 (mean 29.8) in males. Some BCIs were slightly (4%), but significantly ( p ≤ 0.05), higher for females in Crystal River than in Tampa Bay or Indian River, but there was no evidence of geographic variation in condition among males. These normal ranges should help evaluate the nutritional status of both wild and rehabilitating captive manatees.

Florida↗
USGS2017

Genetic composition and connectivity of the Antillean manatee (Trichechus manatus manatus) in Panama

Genetic diversity and haplotype composition of the West Indian manatee (Trichechus manatus) population from the San San Pond Sak wetland in Bocas del Toro, Panama was studied using a segment of mitochondrial DNA (D’loop). No genetic information has been published to date for Panamanian populations. Due to the secretive behavior and small population size of the species in the area, DNA extraction was conducted from opportunistically collected fecal (N=20), carcass tissue (N=4) and bone (N=4) samples. However, after DNA processing only 10 samples provided good quality DNA for sequencing (3 fecal, 4 tissue and 3 bone samples). We found three haplotypes in total; two of these haplotypes are reported for the first time, J02 (N=3) and J03 (N=4), and one J01 was previously published (N=3). Genetic diversity showed similar values to previous studies conducted in other Caribbean regions with moderate values of nucleotide diversity (π= 0.00152) and haplotipic diversity (Hd= 0.57). Connectivity assessment was based on sequence similarity, genetic distance and genetic differentiation between San San population and other manatee populations previously studied. The J01 haplotype found in the Panamanian population is shared with populations in the Caribbean mainland and the Gulf of Mexico showing a reduced differentiation corroborated with Fst value between HSSPS and this region of 0.0094. In contrast, comparisons between our sequences and populations in the Eastern Caribbean (South American populations) and North Western Caribbean showed fewer similarities (Fst =0.049 and 0.058, respectively). These results corroborate previous phylogeographic patterns already established for manatee populations and situate Panamanian populations into the Belize and Mexico cluster. In addition, these findings will be a baseline for future studies and comparisons with manatees in other areas of Panama and Central America. These results should be considered to inform management decisions regarding conservation of genetic diversity, future controlled introductions, connectivity and effective population size of the West Indian manatee along the Central American corridor.

Bocas del Toro↗
USGS2018

Movements and dive patterns of pygmy killer whales (Feresa attenuata) released in the Gulf of Mexico following rehabilitation

The habits and habitats of pygmy killer whales ( Feresa attenuata ) in the Gulf of Mexico (GoM) are poorly known outside of strandings and line-transect surveys. Two adult male pygmy killer whales were found live-stranded in the state of Mississippi (USA) on 1 September 2015 and were subsequently rehabilitated and returned to the offshore waters of the GoM on 11 July 2016. To monitor the animals post-release, both were tagged with satellite-linked location and dive behavior tags. Tags were programed to record and transmit dive duration and depth (when dives were ≥ 30 m deep for ≥ 30 s), duration of time spent above 30 m depth, and estimate locations using the Argos system. The tags transmitted for 15 and 88 days, respectively, providing a total of 1,027 filtered locations and 3,150 dive duration and maximum depth records. The animals began diving after two and four days, respectively, post-release. More than 96% of dives occurred at night. The longest recorded dive was more than 9 min in duration, and the deepest was to 368 m. More than 98% of the locations were over the GoM shelf break, spanning water 200 to 1,200 m deep. Diving patterns indicate that this species is most active at night in the GoM, suggesting its prey species are likely diel migrators that are below reachable depths during daylight hours. Near simultaneous location data from both animals confirmed that they stayed in close proximity but did not dive synchronously. Success of the rehabilitation and release was inconclusive for pygmy killer whale ID 30IMMS, whereas 31IMMS met the established criteria for success with ≥ 6 weeks of documented post-release survival. Follow-up monitoring through satellite-linked telemetry provided not only important data for evaluating the success of the rehabilitation but also for documenting the activity and habitat use of these seldom-observed cetaceans.

Aquatic Mammals↗
USGS2020

Post-release monitoring of a stranded and rehabilitated short-finned pilot whale (Globicephala macrorhynchus) reveals current-assisted travel

A subadult female short-finned pilot whale (Globicephala macrorhynchus), stranded on the northeastern Gulf of Mexico coast of Florida in June 2017, was rehabilitated for 38 days and then monitored with a satellite-linked, time-depth recording tag for 32 days after being released off the West Florida Shelf. The individual, “Gale,” appeared to regularly use ocean currents to facilitate a southeastward movement around Florida, and then a northward movement along the continental shelf break to the waters off Cape Hatteras, North Carolina. Indeed, 57% of her travel along the coast of Florida was at speeds consistent with the surface speed and direction of the Gulf Stream. Overall, current-assisted travel contributed to a 19% increase in distance traveled (4,152 km), and to an average rate of travel (130 km·day-1) that was higher than previously reported for Globicephala spp. Gale’s dive behavior was typical of other short-finned pilot whale observations, with average dive depths (243 ± 136 m, max = 712 m) and durations (7.9 ± 2.2 min, max = 16.0 min) within the range of reported values for Globicephala spp. Gale also occupied habitats known to be used by pilot whales, and her movements and behaviors were consistent with those observed in other short-finned pilot whales in the Gulf of Mexico and northwestern Atlantic Ocean. The information presented here contributes to a better understanding of short-finned pilot whales, and to the assessment of rehabilitation and release protocols.

Florida, Georgia, North Carolina, South Carolina↗
USGS2021

Historic population estimates for bottlenose dolphins (Tursiops truncatus) in Aragua, Venezuela indicate monitoring need

This study reports historic capture-mark-recapture survival and abundance estimates of common bottlenose dolphins ( Tursiops truncatus ) based on photo-identification surveys of coastal Venezuela (along the Aragua coast between Turiamo Bay and Puerto Colombia). We used the most recent data available: dolphins identified by unique dorsal fin marks during wet and dry season surveys conducted from 2004 to 2008. Dolphin encounter histories were analyzed in the Closed Capture Robust Design framework, with the top model including random movement, constant survival, and capture-recapture probabilities that varied by secondary periods. Survival of marked adults was estimated at 0.99 (95% CI = 0.97 to 1.00). Population estimates for all adults (marked and unmarked) averaged 31 animals (SD = 13.8), and for all dolphins (all adults and calves), 41 animals (SD = 17.2). Coastal bottlenose dolphins face numerous threats, including ship strikes, oil spills, conflict with recreational and industrial fisheries, other negative human interactions, biotoxins, chemicals, noise, freshwater discharge, and coastal development. Further, small populations are, in general, at increased risk due to reduced resiliency and recovery potential when exposed to such threats and to expected environmental and demographic stochasticity. These historic estimates of abundance and survival are critical for establishing a reference state and indicate a need for ongoing monitoring of the small dolphin population while the Aragua coast is still, as of yet, relatively little impacted by humans. Should coastal development increase (as is the global trend) and/or environmental catastrophes (e.g., harmful algal blooms, hurricanes, and oil spills) occur, these historic estimates will be essential for assessing impacts and guiding management and conservation interventions. Our results show year-round dolphin presence and highlight the Venezuelan coastal–oceanic landscape as an area of both future research and conservation importance.

Aragua↗
USGS2022

Longman's Beaked Whale (Indopacetus pacificus) in Fiji

Beaked whales (Ziphidae) are the second largest family of cetaceans with 23 currently recognized species, and the Longman's beaked whale (Indopacetus pacificus) is one of the least known globally (Reeves et al., 2003; Yamada et al., 2019). Longman's beaked whales occur in tropical waters from the western Indian Ocean to the eastern Pacific (Jefferson et al., 2015), with strandings in the Pacific reported from Hawaii, the Philippines, Taiwan, Japan, and New Caledonia (Figure 1) (West et al., 2013; Garrigue et al., 2016; Acebes et al., 2019; Kobayashi et al., 2021). Here we report the first record of this species in Fiji.

Aquatic Mammals↗
USGS1966

Methodology for determining toxicity of pesticides to wild vertebrates

The effects of pesticidal contamination of wildlife habitats may be expected to be proportional to the toxicity of the compounds, the rate and manner of application, persistence of the basic chemical and/or any toxic metabolites, and the extent to which these substances are stored in animal tissues or concentrated by successive elements of wildlife food chains. Measurement of these effects under field conditions is difficult, but the need for field studies may be reduced or eliminated by controlled laboratory tests. Representatives of the birds, mammals and aquatic animals in treated areas should be examined at all stages in the life cycle. Suitable species include laboratory rats, rabbits, dogs, bobwhite or coturnix quail, ringneck pheasant, trout, sunfish, oysters. The quantity of pesticide (ppm in diet or environment; mg/kg consumed) should be determined which produces acute or chronic poisoning or which shows measurable sublethal effects on growth or reproduction. Tissues (including gonads and eggs) should be analysed at each degree of exposure.

Book chapter↗
USGS2016

Toward a national animal telemetry network for aquatic observations in the United States

Animal telemetry is the science of elucidating the movements and behavior of animals in relation to their environment or habitat. Here, we focus on telemetry of aquatic species (marine mammals, sharks, fish, sea birds and turtles) and so are concerned with animal movements and behavior as they move through and above the world&rsquo;s oceans, coastal rivers, estuaries and great lakes. Animal telemetry devices (&ldquo;tags&rdquo;) yield detailed data regarding animal responses to the coupled ocean&ndash;atmosphere and physical environment through which they are moving. Animal telemetry has matured and we describe a developing US Animal Telemetry Network (ATN) observing system that monitors aquatic life on a range of temporal and spatial scales that will yield both short- and long-term benefits, fill oceanographic observing and knowledge gaps and advance many of the U.S. National Ocean Policy Priority Objectives. ATN has the potential to create a huge impact for the ocean observing activities undertaken by the U.S. Integrated Ocean Observing System (IOOS) and become a model for establishing additional national-level telemetry networks worldwide.

Animal Biotelemetry↗