189 research outputs found

    Monitoring cetaceans in the North Pacific: analysis of retrospective SOSUS data and acoustic detection on the Northern Edge Range

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    To comply with environmental laws, the U.S. Navy has increasingly relied on acoustic detection and tracking for marine mammal monitoring/mitigation. In the North Pacific, much of what is known about large whale seasonal occurrence comes from Sound Surveillance System (SOSUS) arrays. SOSUS provides broad basin-scale assessments of large whale seasonal occurrence, but cannot provide detail at the regional level, in particular here for the Navy's Northern Edge (Training) Range in the northern Gulf of Alaska. Here, data from long-term acoustic observations of basin-wide data, and from a short-term, nearshore acoustic deployment in the NER, are presented. For the long-term observations, Navy-analyst derived detections of blue and fin whales were compared with spectral data to determine if there is a reliable way to separate the two species in the spectral data. Although the degree to which detections matched the spectra varied with frequency range, generally blue and fin whale detections matched the spectra. However, when only blue, and no fin, whales (or vice versa) were detected by analysts, there were no discernable differences in the spectral levels of different frequency ranges. This suggests that, absent other confirmation of the presence of blue and fin whale vocalizations, these species cannot be reliably discerned from spectra data alone in regions and seasons where the two overlap

    Monitoring cetaceans in the North Pacific

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    Two projects were undertaken in order to monitor cetaceans in the North Pacific. The first was designed to obtain passive acoustic data from the U.S. Navy's Northern Edge Range. Three instruments were deployed in April 2008 to monitor both high (up to 25 kHz) and low (up to 1 kHz) frequencies for odontocetes and mysticetes, respectively. Unfortunately, these instruments did not record any data. The second project was to analyses retrospective data obtained by analysts at the Whidbey Island NAVFAC for broad regions of the North Pacific. Long-term (1996-2002) trends of blue and fin whale vocalizations were found to have strong seasonal and geographic differences. Furthermore, the number of fin whale call events detected increased significantly over time throughout the North Pacific. Onset and continuation of fin whale calling seemed to be primarily driven by day length, while blue whale calling behavior was influenced by combinations of sea surface temperature, surface chlorophyll a concentration, and day length.N00244-07-1-0017

    DNP Practice Inquiry Project Report: Depression Screening in Primary Care

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    Depression affects many people worldwide and is a leading cause of disability. National guidelines and recommendations have been created that support screening for depression in the primary care setting, however due to many barriers depression screening is often not performed or documented. This capstone project consists of three manuscripts, which evaluate the lack of depression screening in the primary care setting. The first manuscript is an integrative review of the literature to support depression screening in primary care and to address barriers to depression screening. The second manuscript is a guideline analysis of a national guideline published by the Institute for Clinical Systems Improvement which recommends depression screening in the primary care setting and provides follow-up and treatment recommendations for primary care providers. The third manuscript discusses the planning and implementation of a depression screening program at a large university student health clinic. The project evaluated changes in depression screening rates due to the use of a provider educational session and the implementation of a depression screening tool within the clinic’s electronic sign-in forms. The results of this study showed a statistically significant increase in depression screening documentation with the standardized use of a depression screening tool and provider education, but also discusses the necessity of resources to provide appropriate evaluation and treatment. This pilot study shows depression screening can be effective within a primary care setting in which support resources are in place for the treatment of depressed patients

    Fine-scale spatial and temporal acoustic occurrence of island-associated odontocetes near a mid-oceanic atoll in the northern Indian Ocean

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Panicker, D., Baumgartner, M. F., & Stafford, K. M. Fine-scale spatial and temporal acoustic occurrence of island-associated odontocetes near a mid-oceanic atoll in the northern Indian Ocean. Marine Ecology Progress Series, 683, (2022): 195–208, https://doi.org/10.3354/meps13947.Temporal patterns of oceanic predators can provide valuable information on both lunar and diel influences not just on the distributions of these predators, but also on prey patches that are often difficult to study. Mid-oceanic island chains in the northern Indian Ocean have high odontocete occurrence, but the ecology of these animals is not well characterized. We investigated fine-scale spatial and temporal patterns of island-associated odontocetes using passive acoustic monitoring from January 2019 to January 2020 around Kavaratti Island, Lakshadweep, India. Based on opportunistic recordings in the presence of odontocetes, the majority of the detected whistles were likely made by spinner dolphins Stenella longirostris. We identified a resident population whose whistle occurrence was significantly influenced by month, site, and diel and lunar cycles. More acoustic detections were made in the northeast monsoon month of November and fewer during pre-monsoon and southwest monsoon periods. Distinct day-night differences along with fine-scale temporal variability were also observed, suggesting that delphinids use nearshore waters as a daytime resting habitat. Odontocete detections were highest during the new moon period and lowest during the first quarter phase. Detection rates were higher on the south side of the island. Our study shows that solar and lunar cycles modulate odontocete vocal occurrence, presumably through influences on their prey. Similarities of odontocete occurrence around Lakshadweep to other mid-oceanic island chains suggests that an island-associated micronekton community may exist around Lakshadweep that may also be important to other pelagic species targeted by local fisheries.Funding was provided by the Office of Naval Research Marine Mammal Biology Program, USA, under grant N000141812795. We thank Ajith Kumar, the National Centre for Biological Sciences and Idrees Babu for in-country support

    Seasonal occurrence of fin whale song off Juan Fernandez, Chile

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Buchan, S. J., Gutierrez, L., Balcazar-Cabrera, N., & Stafford, K. M. Seasonal occurrence of fin whale song off Juan Fernandez, Chile. Endangered Species Research, 39, (2019): 135-145, doi:10.3354/esr00956.Fin whales Balaenoptera physalus were the species of baleen whale most widely caught by commercial whaling fleets off the Chilean coast and are globally classified as Endangered. However, very little is known about the present distribution and seasonal movements of fin whales off the coast of Chile. Passive acoustic data collected at the HA03 station of the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization off the Juan Fernandez Archipelago (JFA) between 2007 and 2016 were analyzed. The temporal occurrence of fin whale song was examined using automatic detection via spectrogram cross-correlation of song notes and by calculating the average acoustic power in the frequency bands of fin whale song. Fin whale song off JFA was composed of regular 17 Hz notes associated with high-frequency components at 85 Hz, with singlet phrasing at a dominant primary inter-note interval of 14.4 s and a secondary interval of 30.8 s. There was a clear seasonal pattern in acoustic presence that was consistent across all years: low or no song during the austral summer and a peak in song occurrence in austral winter. A propagation loss model estimated the detection range at this site to be 186 km. Where the fin whales that are heard off JFA spend the summer months remains an open question. Possible locations include the Western Antarctic Peninsula and/or off northern-central mainland Chile. Further studies should be pursued to better understand the distribution and seasonal movements and to support the conservation of this Endangered species.We thank the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization and the Chilean Commission of Nuclear Energy for proving the data used in this study. S.J.B. and N.B.C. were supported by the Center for Oceanographic Research COPAS Sur-Austral, CONICYT PIA PFB31. S.J.B. was also supported during analysis and writing by the Office of Naval Research Global (awards N62909-16-2214 and N00014-17-2606), and a grant to the Centro de Estudios Avanzados enZonas Áridas (CEAZA) ‘Proyecto CEAZA, 3er Fortalec-imiento de Centros Regionales, Programa Regional CONI-CYT R16A10003’. Our greatest thanks to John Hodgson MSc, Technical Director at Ocean Acoustic Developments and Adrian Brown of the Defence Science and Technology Laboratory (UK) for carrying out the propagation modelling free of charge. Many thanks to Rex Andrew for his help with PSD figure preparation in R. Thanks also go to Nathan Merchant for his kind help with PAMGuide. Many thanks to Michael Pitzrick for his guidance with XBAT. Many thanks to the members of the Southern Ocean Research Partnership Blue and Fin Whale Acoustic Trends Working group for useful discussions that improved the quality of this study

    Seasonal variation of the Beaufort shelfbreak jet and its relationship to Arctic cetacean occurrence

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    Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 121 (2016): 8434–8454, doi:10.1002/2016JC011890.Using mooring time series from September 2008 to August 2012, together with ancillary atmospheric and satellite data sets, we quantify the seasonal variations of the shelfbreak jet in the Alaskan Beaufort Sea and explore connections to the occurrences of bowhead and beluga whales. Wind patterns during the 4 year study period are different from the long-term climatological conditions that the springtime peak in easterly winds shifted from May to June and the autumn peak was limited to October instead of extending farther into the fall. These changes were primarily due to the behavior of the two regional atmospheric centers of action, the Aleutian Low and Beaufort High. The volume transport of the shelfbreak jet, which peaks in the summer, was decomposed into a background (weak wind) component and a wind-driven component. The wind-driven component is correlated to the Pt. Barrow, AK alongcoast wind speed record although a more accurate prediction is obtained when considering the ice thickness at the mooring site. An upwelling index reveals that wind-driven upwelling is enhanced in June and October when storms are stronger and longer-lasting. The seasonal variation of Arctic cetacean occurrence is dominated by the eastward migration in spring, dictated by pack-ice patterns, and westward migration in fall, coincident with the autumn peak in shelfbreak upwelling intensity.Support for the most recent deployments of the shelfbreak moorings was provided by grants ARC-0856244 and ARC-855828 from the Office of Polar Programs of the National Science Foundation. P.L. acknowledges the financial support of the China Scholarship Council.2017-06-0

    Unraveling the consequences of the terminal Pleistocene megafauna extinction on mammal community assembly

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    Recent studies connecting the decline of large predators and consumers with the disintegration of ecosystems often overlook that this natural experiment already occurred. As recently as 14 ka, tens of millions of large-bodied mammals were widespread across the American continents. Within 1000 yr of the arrival of humans, ∼80% were extinct including all \u3e 600 kg. While the cause of the late Pleistocene (LP) extinction remains contentious, largely overlooked are the ecological consequences of the loss of millions of large-bodied animals. Here, we examine the influence of the LP extinction on a local mammal community. Our study site is Hall’s Cave in the Great Plains of Texas, which has unparalleled fine-grained temporal resolution over the past 20 ka, allowing characterization of the community before and after the extinction. In step with continental patterns, this community lost 80% of large-bodied herbivores and 20% of apex predators at the LP extinction. Using tightly constrained temporal windows spanning full glacial to modern time periods and comprehensive faunal lists, we reconstruct mammal associations and body size distributions over time. We find changes in alpha and beta diversity, and in the statistical moments associated with periods of climate change as well as with the LP extinction event. Additionally, there is a fundamental change in the composition of herbivores, with grazers being replaced by frugivores/granivores starting about 15 ka; the only large-bodied grazer remaining today is the bison Bison bison. Moreover, the null model program PAIRS reveals interesting temporal patterns in the disassociation or co-occurrence of species through the terminal Pleistocene and Holocene. Extinct species formed more significant associations than modern ones, and formed more aggregated pairs than do modern species. Further, negative species associations were about three times stronger than positive

    Cetacean sightings around the Republic of the Maldives, April 1998

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    In April 1998, as part of a project to collect biopsy samples of putative pygmy blue whales (Balaenoptera musculus brevicauda) in the waters around the Republic of the Maldives, Indian Ocean, incidental sightings of cetaceans encountered were recorded. Using modified line-transect methods and handheld binoculars, a total of 267 sightings of 16 species of whales and dolphins were recorded during 20 at-sea days in the northeastern part of the atoll. Significant results include the following: (1) cetaceans were abundant and species diversity was high, including nearly every pantropical species of pelagic cetacean; (2) the spinner dolphin (Stenella longirostris) was by far the most common species encountered (56 sightings) and also had the largest mean school size ( = 50.3 individuals); (3) blue whales were rare; only four individuals were sighted; (4) a large concentration of Bryde’s whales (28 sightings in two days) was apparently feeding in nearshore waters; (5) this paper reports the first records for the Maldives of Cuvier’s beaked whale (Ziphius cavirostris), Blainville’s beaked whale (Mesoplodon densirostris) and the dwarf sperm whale (Kogia sima): the latter was particularly common (17 sightings); (6) the spotted dolphin (Stenella attenuata) was rare and almost always associated with yellowfin tuna (Thunnus albacares), spinner dolphin, or seabirds, as has been reported in the eastern Pacific and western Indian oceans
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