Harms
Craig A.
Harms
Craig A.
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ArticleFecal glucocorticoids and anthropogenic injury and mortality in North Atlantic right whales Eubalaena glacialis(Inter-Research, 2017-11-30) Rolland, Rosalind M. ; McLellan, William A. ; Moore, Michael J. ; Harms, Craig A. ; Burgess, Elizabeth A. ; Hunt, Kathleen E.As human impacts on marine ecosystems escalate, there is increasing interest in quantifying sub-lethal physiological and pathological responses of marine mammals. Glucocorticoid hormones are commonly used to assess stress responses to anthropogenic factors in wildlife. While obtaining blood samples to measure circulating hormones is not currently feasible for free-swimming large whales, immunoassay of fecal glucocorticoid metabolites (fGCs) has been validated for North Atlantic right whales Eubalaena glacialis (NARW). Using a general linear model, we compared fGC concentrations in right whales chronically entangled in fishing gear (n = 6) or live-stranded (n = 1), with right whales quickly killed by vessels (n = 5) and healthy right whales (n = 113) to characterize fGC responses to acute vs. chronic stressors. fGCs in entangled whales (mean ± SE: 1856.4 ± 1644.9 ng g-1) and the stranded whale (5740.7 ng g-1) were significantly higher than in whales killed by vessels (46.2 ± 19.2 ng g-1) and healthy whales (51.7 ± 8.7 ng g-1). Paired feces and serum collected from the live-stranded right whale provided comparison of fGCs in 2 matrices in a chronically stressed whale. Serum cortisol and corticosterone in this whale (50.0 and 29.0 ng ml-1, respectively) were much higher than values reported in other cetaceans, in concordance with extremely elevated fGCs. Meaningful patterns in fGC concentration related to acute vs. chronic impacts persisted despite potential for bacterial degradation of hormone metabolites in dead whales. These results provide biological validation for using fGCs as a biomarker of chronic stress in NARWs.
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ArticleBirds of a feather eat plastic together: high levels of plastic ingestion in Great Shearwater adults and juveniles across their annual migratory cycle(Frontiers Media, 2022-01-05) Robuck, Anna R. ; Hudak, Christine A. ; Agvent, Lindsay ; Emery, Gwenyth ; Ryan, Peter G. ; Perold, Vonica ; Powers, Kevin D. ; Pedersen, Johanna ; Thompson, Michael A. ; Suca, Justin J. ; Moore, Michael J. ; Harms, Craig A. ; Bugoni, Leandro ; Shield, Gina ; Glass, Trevor ; Wiley, David N. ; Lohmann, RainerLimited work to date has examined plastic ingestion in highly migratory seabirds like Great Shearwaters (Ardenna gravis) across their entire migratory range. We examined 217 Great Shearwaters obtained from 2008–2019 at multiple locations spanning their yearly migration cycle across the Northwest and South Atlantic to assess accumulation of ingested plastic as well as trends over time and between locations. A total of 2328 plastic fragments were documented in the ventriculus portion of the gastrointestinal tract, with an average of 9 plastic fragments per bird. The mass, count, and frequency of plastic occurrence (FO) varied by location, with higher plastic burdens but lower FO in South Atlantic adults and chicks from the breeding colonies. No fragments of the same size or morphology were found in the primary forage fish prey, the Sand Lance (Ammodytes spp., n = 202) that supports Great Shearwaters in Massachusetts Bay, United States, suggesting the birds directly ingest the bulk of their plastic loads rather than accumulating via trophic transfer. Fourier-transform infrared spectroscopy indicated that low- and high-density polyethylene were the most common polymers ingested, within all years and locations. Individuals from the South Atlantic contained a higher proportion of larger plastic items and fragments compared to analogous life stages in the NW Atlantic, possibly due to increased use of remote, pelagic areas subject to reduced inputs of smaller, more diverse, and potentially less buoyant plastics found adjacent to coastal margins. Different signatures of polymer type, size, and category between similar life stages at different locations suggests rapid turnover of ingested plastics commensurate with migratory stage and location, though more empirical evidence is needed to ground-truth this hypothesis. This work is the first to comprehensively measure the accumulation of ingested plastics by Great Shearwaters over the last decade and across multiple locations spanning their yearly trans-equatorial migration cycle and underscores their utility as sentinels of plastic pollution in Atlantic ecosystems.
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ArticleTemporary noise-induced underwater hearing loss in an aquatic turtle (Trachemys scripta elegans)(Acoustical Society of America, 2023-08-16) Salas, Andria K. ; Capuano, Alyssa M. ; Harms, Craig A. ; Piniak, Wendy E. D. ; Mooney, T. AranNoise pollution in aquatic environments can cause hearing loss in noise-exposed animals. We investigated whether exposure to continuous underwater white noise (50–1000 Hz) affects the auditory sensitivity of an aquatic turtle Trachemys scripta elegans (red-eared slider) across 16 noise conditions of differing durations and amplitudes. Sound exposure levels (SELs) ranged between 155 and 193 dB re 1 μPa2 s, and auditory sensitivity was measured at 400 Hz using auditory evoked potential methods. Comparing control and post-exposure thresholds revealed temporary threshold shifts (TTS) in all three individuals, with at least two of the three turtles experiencing TTS at all but the two lowest SELs tested, and shifts up to 40 dB. There were significant positive relationships between shift magnitude and exposure duration, amplitude, and SEL. The mean predicted TTS onset was 160 dB re 1 μPa2 s. There was individual variation in susceptibility to TTS, threshold shift magnitude, and recovery rate, which was non-monotonic and occurred on time scales ranging from < 1 h to > 2 days post-exposure. Recovery rates were generally greater after higher magnitude shifts. Sound levels inducing hearing loss were comparatively low, suggesting aquatic turtles may be more sensitive to underwater noise than previously considered.
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Technical ReportReport of the live large whale stranding response workshop(Woods Hole Oceanographic Institution, 2024-11) Sharp, Sarah M. ; Moore, Michael J. ; Harms, Craig A. ; Wilkin, Sarah M. ; Sharp, W. Brian ; Patchett, Kristen M. ; Rose, Kathryn S.Reasoned triage and management of live large whale stranding events prompted this workshop. Safety is paramount for humans and must be mitigated for them and whales during responses. Clinical assessment is critical, with emaciation and poor prognosis often worsening welfare if released. Accurate length and estimated weight data are essential. Supportive care and treatments depend on understanding the underlying pathophysiology of stranding. Maintaining an airway, monitoring breathing, minimizing stress, protecting eyes, modulating temperature, and preventing sunburn are priorities. Additional strategies can include mild sedation, fluid administration, and flipper excavation to relieve pressure. Tools to indicate post-release survival include photographs, genetic samples, paint sticks, and identification, VHF, or satellite-linked tags. Acceptable rescue techniques included towing offshore with a tackle or lines over or under the body and around the axillae, inflatable lift bags, and trenching. Nets and towing by the flukes are unsuitable. Refloating of stranded large whales can be considered if a clinical examination suggests a favorable prognosis, and a release method could be safely undertaken without undue stress and trauma to the animal. However, in many cases euthanasia is the most humane option if practical, or letting nature take its course if need be.
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ArticleFrequency-dependent temporary threshold shifts in the Eastern painted turtle (Chrysemys picta picta)(Acoustical Society of America, 2024-05-14) Salas, Andria K. ; Capuano, Alyssa M. ; Harms, Craig A. ; Piniak, Wendy E. D. ; Mooney, T. AranTestudines are a highly threatened group facing an array of stressors, including alteration of their sensory environment. Underwater noise pollution has the potential to induce hearing loss and disrupt detection of biologically important acoustic cues and signals. To examine the conditions that induce temporary threshold shifts (TTS) in hearing in the freshwater Eastern painted turtle (Chrysemys picta picta), three individuals were exposed to band limited continuous white noise (50–1000 Hz) of varying durations and amplitudes (sound exposure levels ranged from 151 to 171 dB re 1 μPa2 s). Control and post-exposure auditory thresholds were measured and compared at 400 and 600 Hz using auditory evoked potential methods. TTS occurred in all individuals at both test frequencies, with shifts of 6.1–41.4 dB. While the numbers of TTS occurrences were equal between frequencies, greater shifts were observed at 600 Hz, a frequency of higher auditory sensitivity, compared to 400 Hz. The onset of TTS occurred at 154 dB re 1 μPa2 s for 600 Hz, compared to 158 dB re 1 μPa2 s at 400 Hz. The 400-Hz onset and patterns of TTS growth and recovery were similar to those observed in previously studied Trachemys scripta elegans, suggesting TTS may be comparable across Emydidae species.
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ArticleNarrowband noise induces frequency-specific underwater temporary threshold shifts in freshwater turtles(Acoustical Society of America, 2024-08-21) Salas, Andria K. ; Sims, Michele A. ; Harms, Craig A. ; Piniak, Wendy E. D. ; Mooney, T. AranFreshwater turtles exhibit temporary threshold shifts (TTS) when exposed to broadband sound, but whether frequency-restricted narrowband noise induces TTS was unknown. Underwater TTS was investigated in two freshwater turtle species (Emydidae) following exposures to 1/6 -octave narrowband noise (155–172 dB re 1 μPa2 s). While shifts occurred in all turtles at the noise center frequency (400 Hz), there were more instances of TTS and greater shift magnitudes at 1/2 octave above the center frequency, despite considerably lower received levels. These frequency-specific data provide new insight into how TTS manifests in turtles and expand empirical models to predict freshwater turtle TTS.