Niemeyer Misty E.

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Niemeyer

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Misty E.

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Compositional discrimination of decompression and decomposition gas bubbles in bycaught seals and dolphins

(Public Library of Science, 2013-12-19) Bernaldo de Quirós, Yara ; Seewald, Jeffrey S. ; Sylva, Sean P. ; Greer, William ; Niemeyer, Misty E. ; Bogomolni, Andrea L. ; Moore, Michael J.

Gas bubbles in marine mammals entangled and drowned in gillnets have been previously described by computed tomography, gross examination and histopathology. The absence of bacteria or autolytic changes in the tissues of those animals suggested that the gas was produced peri- or post-mortem by a fast decompression, probably by quickly hauling animals entangled in the net at depth to the surface. Gas composition analysis and gas scoring are two new diagnostic tools available to distinguish gas embolisms from putrefaction gases. With this goal, these methods have been successfully applied to pathological studies of marine mammals. In this study, we characterized the flux and composition of the gas bubbles from bycaught marine mammals in anchored sink gillnets and bottom otter trawls. We compared these data with marine mammals stranded on Cape Cod, MA, USA. Fresh animals or with moderate decomposition (decomposition scores of 2 and 3) were prioritized. Results showed that bycaught animals presented with significantly higher gas scores than stranded animals. Gas composition analyses indicate that gas was formed by decompression, confirming the decompression hypothesis.
Static inflation and deflation pressure–volume curves from excised lungs of marine mammals

( 2011-06-28) Fahlman, Andreas ; Loring, Stephen H. ; Ferrigno, Massimo ; Moore, Colby D. ; Early, Greg A. ; Niemeyer, Misty E. ; Lentell, Betty J. ; Wenzel, Frederick W. ; Joy, Ruth ; Moore, Michael J.

Excised lungs from 8 marine mammal species (harp [Pagophilus groenlandicus], harbor [Phoca vitulina], and gray seal [Halichoerus grypus], Atlantic white-sided [Lagenorhynchus acutus], common [Delphinus delphis] and Risso's dolphin [Grampus griseus], long finned pilot whale [Globicephala melas], and harbor porpoise [Phocoena phocoena]) were used to determine minimum air volume of the relaxed lung (MAV, n = 15) and the elastic properties (pressure-volume curves, n = 24) of the respiratory system, and total lung capacity (TLC). Our data indicate that mass-specific TLC (sTLC, l • kg-1) does not differ between species or groups (odontocete vs. phocid) and agree with that estimated (TLCest) from body mass (Mb) by: TLCest = 0.135 • Mb 0.92. Measured MAV was on average 7% of TLC, with a range from 0% to 16%. The pressure-volume curves were similar among species on inflation but diverged during deflation in phocids as compared with odontocetes. These differences provide a structural basis for observed species differences in depth at which lungs collapse and gas exchange ceases.
Hematological, biochemical, and morphological parameters as prognostic indicators for stranded common dolphins (Delphinus delphis) from Cape Cod, Massachusetts, U.S.A.

(John Wiley & Sons, 2013-12-06) Sharp, Sarah M. ; Knoll, Joyce S. ; Moore, Michael J. ; Moore, Kathleen M. T. ; Harry, Charles T. ; Hoppe, Jane M. ; Niemeyer, Misty E. ; Robinson, Ian ; Rose, Kathryn S. ; Sharp, W. Brian ; Rotstein, David S.

The current paucity of published blood values and other clinically relevant data for short-beaked common dolphins, Delphinus delphis, hinders the ability of veterinarians and responders to make well-informed diagnoses and disposition decisions regarding live strandings of this species. This study examined hematologic, clinical chemistry, and physical parameters from 26 stranded common dolphins on Cape Cod, Massachusetts, in light of their postrelease survival data to evaluate each parameter's efficacy as a prognostic indicator. Statistically and clinically significant differences were found between failed and survived dolphins, including lower hematocrit, hemoglobin, TCO2, and bicarbonate and higher blood urea nitrogen, uric acid, and length-to-girth ratios in animals that failed. In general when compared to survivors, failed dolphins exhibited acidosis, dehydration, lower PCVs, and decreased body condition. Additionally, failed dolphins had the highest ALT, AST, CK, LDH, GGT, and lactate values. These blood values combined with necropsy findings indicate that there are likely a variety of factors affecting postrelease survival, including both preexisting illness and stranding-induced conditions such as capture myopathy. Closer evaluation of these parameters for stranded common dolphins on point of care analyzers in the field may allow stranding personnel to make better disposition decisions in the future.
Spectral reflectance of whale skin above the sea surface: a proposed measurement protocol

(Wiley Open Access, 2020-03-10) Cubaynes, Hannah C. ; Rees, W. Gareth ; Jackson, Jennifer A. ; Moore, Michael J. ; Sformo, Todd L. ; McLellan, William A. ; Niemeyer, Misty E. ; George, John C. ; van der Hoop, Julie ; Forcada, Jaume ; Trathan, Phil N. ; Fretwell, Peter T.

Great whales have been detected using very‐high‐resolution satellite imagery, suggesting this technology could be used to monitor whales in remote areas. However, the application of this method to whale studies is at an early developmental stage and several technical factors need to be addressed, including capacity for species differentiation and the maximum depth of detection in the water column. Both require knowledge of the spectral reflectance of the various whale species just above the sea surface, as when whales bodies break the surface of the water to breath, log or breach, there is, at times, no sea water between the whale's skin and the satellite sensor. Here we tested whether such reflectance could be measured on dead whale tissue. We measured the spectral reflectance of fresh integument collected during the bowhead subsistence harvest, and of thawed integument samples from various species obtained following strandings and stored at −20°C. We show that fresh and thawed samples of whale integument have different spectral properties. The reflectance of fresh samples was higher than the reflectance of thawed samples, as integument appears to darken after death and with time, even under frozen conditions. In this study, we present the first whale reflectance estimates (without the influence of sea water and for dead tissue). These provide a baseline for additional work, needed to advance the use of satellite imagery to monitor whales and facilitate their conservation.
An assessment of temporal, spatial and taxonomic trends in harmful algal toxin exposure in stranded marine mammals from the US New England coast

(Public Library of Science, 2021-01-06) Fire, Spencer E. ; Bogomolni, Andrea L. ; DiGiovanni, Robert A., Jr. ; Early, Greg A. ; Leighfield, Tod A. ; Matassa, Keith A. ; Miller, Glenn A. ; Moore, Kathleen M. T. ; Moore, Michael J. ; Niemeyer, Misty E. ; Pugliares, Katie R. ; Wang, Zhihong ; Wenzel, Frederick W.

Despite a long-documented history of severe harmful algal blooms (HABs) in New England coastal waters, corresponding HAB-associated marine mammal mortality events in this region are far less frequent or severe relative to other regions where HABs are common. This long-term survey of the HAB toxins saxitoxin (STX) and domoic acid (DA) demonstrates significant and widespread exposure of these toxins in New England marine mammals, across multiple geographic, temporal and taxonomic groups. Overall, 19% of the 458 animals tested positive for one or more toxins, with 15% and 7% testing positive for STX and DA, respectively. 74% of the 23 different species analyzed demonstrated evidence of toxin exposure. STX was most prevalent in Maine coastal waters, most frequently detected in common dolphins (Delphinus delphis), and most often detected during July and October. DA was most prevalent in animals sampled in offshore locations and in bycaught animals, and most frequently detected in mysticetes, with humpback whales (Megaptera novaeangliae) testing positive at the highest rates. Feces and urine appeared to be the sample matrices most useful for determining the presence of toxins in an exposed animal, with feces samples having the highest concentrations of STX or DA. No relationship was found between the bloom season of toxin-producing phytoplankton and toxin detection rates, however STX was more likely to be present in July and October. No relationship between marine mammal dietary preference and frequency of toxin detection was observed. These findings are an important part of a framework for assessing future marine mammal morbidity and mortality events, as well as monitoring ecosystem health using marine mammals as sentinel organisms for predicting coastal ocean changes.
Discrimination between bycatch and other causes of cetacean and pinniped stranding

(Inter-Research, 2018-01-31) Bernaldo de Quirós, Yara ; Hartwick, Meghan ; Rotstein, David S. ; Garner, Michael M. ; Bogomolni, Andrea L. ; Greer, William ; Niemeyer, Misty E. ; Early, Greg A. ; Wenzel, Frederick W. ; Moore, Michael J.

The challenge of identifying cause of death in discarded bycaught marine mammals stems from a combination of the non-specific nature of the lesions of drowning, the complex physiologic adaptations unique to breath-holding marine mammals, lack of case histories, and the diverse nature of fishing gear. While no pathognomonic lesions are recognized, signs of acute external entanglement, bulging or reddened eyes, recently ingested gastric contents, pulmonary changes, and decompression-associated gas bubbles have been identified in the condition of peracute underwater entrapment (PUE) syndrome in previous studies of marine mammals. We reviewed the gross necropsy and histopathology reports of 36 cetaceans and pinnipeds including 20 directly observed bycaught and 16 live stranded animals that were euthanized between 2005 and 2011 for lesions consistent with PUE. We identified 5 criteria which present at significantly higher rates in bycaught marine mammals: external signs of acute entanglement, red or bulging eyes, recently ingested gastric contents, multi-organ congestion, and disseminated gas bubbles detected grossly during the necropsy and histologically. In contrast, froth in the trachea or primary bronchi, and lung changes (i.e. wet, heavy, froth, edema, congestion, and hemorrhage) were poor indicators of PUE. This is the first study that provides insight into the different published parameters for PUE in bycatch. For regions frequently confronted by stranded marine mammals with non-specific lesions, this could potentially aid in the investigation and quantification of marine fisheries interactions.
Humpback whale populations share a core skin bacterial community : towards a health index for marine mammals?

(Public Library of Science, 2014-03-26) Apprill, Amy ; Robbins, Jooke ; Eren, A. Murat ; Pack, Adam A. ; Reveillaud, Julie ; Mattila, David K. ; Moore, Michael J. ; Niemeyer, Misty E. ; Moore, Kathleen M. T. ; Mincer, Tracy J.

Microbes are now well regarded for their important role in mammalian health. The microbiology of skin – a unique interface between the host and environment - is a major research focus in human health and skin disorders, but is less explored in other mammals. Here, we report on a cross-population study of the skin-associated bacterial community of humpback whales (Megaptera novaeangliae), and examine the potential for a core bacterial community and its variability with host (endogenous) or geographic/environmental (exogenous) specific factors. Skin biopsies or freshly sloughed skin from 56 individuals were sampled from populations in the North Atlantic, North Pacific and South Pacific oceans and bacteria were characterized using 454 pyrosequencing of SSU rRNA genes. Phylogenetic and statistical analyses revealed the ubiquity and abundance of bacteria belonging to the Flavobacteria genus Tenacibaculum and the Gammaproteobacteria genus Psychrobacter across the whale populations. Scanning electron microscopy of skin indicated that microbial cells colonize the skin surface. Despite the ubiquity of Tenacibaculum and Psychrobater spp., the relative composition of the skin-bacterial community differed significantly by geographic area as well as metabolic state of the animals (feeding versus starving during migration and breeding), suggesting that both exogenous and endogenous factors may play a role in influencing the skin-bacteria. Further, characteristics of the skin bacterial community from these free-swimming individuals were assembled and compared to two entangled and three dead individuals, revealing a decrease in the central or core bacterial community members (Tenacibaculum and Psychrobater spp.), as well as the emergence of potential pathogens in the latter cases. This is the first discovery of a cross-population, shared skin bacterial community. This research suggests that the skin bacteria may be connected to humpback health and immunity and could possibly serve as a useful index for health and skin disorder monitoring of threatened and endangered marine mammals.
Bubbles in live-stranded dolphins

(The Royal Society, 2011-10-12) Dennison, Sophie ; Moore, Michael J. ; Fahlman, Andreas ; Moore, Kathleen M. T. ; Sharp, Sarah M. ; Harry, Charles T. ; Hoppe, Jane M. ; Niemeyer, Misty E. ; Lentell, Betty J. ; Wells, Randall S.

Bubbles in supersaturated tissues and blood occur in beaked whales stranded near sonar exercises, and post-mortem in dolphins bycaught at depth and then hauled to the surface. To evaluate live dolphins for bubbles, liver, kidneys, eyes and blubber–muscle interface of live-stranded and capture-release dolphins were scanned with B-mode ultrasound. Gas was identified in kidneys of 21 of 22 live-stranded dolphins and in the hepatic portal vasculature of 2 of 22. Nine then died or were euthanized and bubble presence corroborated by computer tomography and necropsy, 13 were released of which all but two did not re-strand. Bubbles were not detected in 20 live wild dolphins examined during health assessments in shallow water. Off-gassing of supersaturated blood and tissues was the most probable origin for the gas bubbles. In contrast to marine mammals repeatedly diving in the wild, stranded animals are unable to recompress by diving, and thus may retain bubbles. Since the majority of beached dolphins released did not re-strand it also suggests that minor bubble formation is tolerated and will not lead to clinically significant decompression sickness.
Myoglobin concentration and oxygen stores in different functional muscle groups from three small cetacean species

(MDPI, 2021-02-09) Arregui, Marina ; Singleton, Emily M. ; Saavedra, Pedro ; Pabst, D. Ann ; Moore, Michael J. ; Sierra, Eva ; Rivero, Miguel A. ; Câmara, Nakita ; Niemeyer, Misty E. ; Fahlman, Andreas ; McLellan, William A. ; Bernaldo de Quirós, Yara

Compared with terrestrial mammals, marine mammals possess increased muscle myoglobin concentrations (Mb concentration, g Mb · 100g−1 muscle), enhancing their onboard oxygen (O2) stores and their aerobic dive limit. Although myoglobin is not homogeneously distributed, cetacean muscle O2 stores have been often determined by measuring Mb concentration from a single muscle sample (longissimus dorsi) and multiplying that value by the animal’s locomotor muscle or total muscle mass. This study serves to determine the accuracy of previous cetacean muscle O2 stores calculations. For that, body muscles from three delphinid species: Delphinus delphis, Stenella coeruleoalba, and Stenella frontalis, were dissected and weighed. Mb concentration was calculated from six muscles/muscle groups (epaxial, hypaxial and rectus abdominis; mastohumeralis; sternohyoideus; and dorsal scalenus), each representative of different functional groups (locomotion powering swimming, pectoral fin movement, feeding and respiration, respectively). Results demonstrated that the Mb concentration was heterogeneously distributed, being significantly higher in locomotor muscles. Locomotor muscles were the major contributors to total muscle O2 stores (mean 92.8%) due to their high Mb concentration and large muscle masses. Compared to this method, previous studies assuming homogenous Mb concentration distribution likely underestimated total muscle O2 stores by 10% when only considering locomotor muscles and overestimated them by 13% when total muscle mass was considered.
A comparative analysis of marine mammal tracheas

( 2013-11) Moore, Colby D. ; Moore, Michael J. ; Trumble, Stephen J. ; Niemeyer, Misty E. ; Lentell, Betty J. ; McLellan, William A. ; Costidis, Alexander M. ; Fahlman, Andreas

In 1940, Scholander suggested that stiffened upper airways remained open and received air from highly compressible alveoli during marine mammal diving. There are little data available on the structural and functional adaptations of the marine mammal respiratory system. The aim of this research was to investigate the anatomical (gross) and structural (compliance) characteristics of excised marine mammal tracheas. Here we defined different types of tracheal structures, categorizing pinniped tracheas by varying degrees of continuity of cartilage (categories 1-4) and cetacean tracheas by varying compliance values (categories 5A and 5B). Some tracheas fell into more than one category, along their length, for example, the harbor seal (Phoca vitulina) demonstrated complete rings cranially, and as the trachea progressed caudally tracheal rings changed morphology. Dolphins and porpoises had less stiff, more compliant spiraling rings while beaked whales had very stiff, less compliant spiraling rings. The pressure-volume (P-V) relationships of isolated tracheas from different species were measured to assess structural differences between species. These findings lend evidence for pressure-induced collapse and re-inflation of lungs, perhaps influencing variability in dive depth or ventilation rates of the species investigated.
A comparison of postrelease survival parameters between single and mass stranded delphinids from Cape Cod, Massachusetts, U.S.A.

(John Wiley & Sons, 2015-07-29) Sharp, Sarah M. ; Harry, Charles T. ; Hoppe, Jane M. ; Moore, Kathleen M. T. ; Niemeyer, Misty E. ; Robinson, Ian ; Rose, Kathryn S. ; Sharp, W. Brian ; Landry, Scott ; Richardson, Jessica ; Moore, Michael J.

The viability of healthy single stranded dolphins as immediate release candidates has received little attention. Responders have been reluctant to release lone delphinids due to their social needs, even when they pass the same health evaluations as mass stranded animals. This study tracked postrelease success of 34 relocated and released satellite tagged delphinids from single and mass strandings. Three postrelease survival parameters (transmission duration, swim speed, and daily distance) were examined to evaluate whether they differed among single stranded/single released (SS/SR), mass stranded/single released (MS/SR), or mass stranded/mass released (MS/MR) dolphin groups. Comparisons were also made between healthy and borderline release candidates. Satellite tags transmitted for a mean of 21.2 d (SD = 19.2, range = 1–79), daily distance traveled was 42.0 km/d (11.25, 20.96–70.72), and swim speed was 4.3 km/h (1.1, 2.15–8.54). Postrelease parameters did not differ between health status groups, however, SS/SR dolphins transmitted for a shorter mean duration than MS/MR and MS/SR groups. Postrelease vessel-based surveys confirmed conspecific group location for two healthy, MS/SR dolphins. Overall, these results support the potential to release healthy stranded single delphinids; however, further refinement of health assessment protocols for these challenging cases is needed.
Characterization of lipids in adipose depots associated with minke and fin whale ears : comparison with “acoustic fats” of toothed whales

( 2014-01) Yamato, Maya ; Koopman, Heather N. ; Niemeyer, Misty E. ; Ketten, Darlene R.

In an underwater environment where light attenuates much faster than in air, cetaceans have evolved to rely on sound and their sense of hearing for vital functions. Odontocetes (toothed whales) have developed a sophisticated biosonar system called echolocation, allowing them to perceive their environment using their sense of hearing (Schevill and McBride 1956, Kellogg 1958, Norris et al. 1961). Echolocation has not been demonstrated in mysticetes (baleen whales). However, mysticetes rely on low frequency sounds, which can propagate very long distances under water, to communicate with potential mates and other conspecifics (Cummings and Thompson 1971).

Niemeyer Misty E.

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