Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Mar Pollut Bull ; 202: 116294, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38537499

RESUMO

Shipping is one of the largest industries globally, with well-known negative impacts on the marine environment. Despite the known negative short-term (minutes to hours) impact of shipping on individual animal behavioural responses, very little is understood about the long-term (months to years) impact on marine species presence and area use. This study took advantage of a planned rerouting of a major shipping lane leading into the Baltic Sea, to investigate the impact on the presence and foraging behaviour of a marine species known to be sensitive to underwater noise, the harbour porpoise (Phocoena phocoena). Passive acoustic monitoring data were collected from 15 stations over two years. Against predictions, no clear change occurred in monthly presence or foraging behaviour of the porpoises, despite the observed changes in noise and vessel traffic. However, long-term heightened noise levels may still impact communication, echolocation, or stress levels of individuals, and needs further investigation.


Assuntos
Ecossistema , Phocoena , Navios , Animais , Monitoramento Ambiental , Ruído , Ruído dos Transportes
2.
Methods Protoc ; 6(4)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37623919

RESUMO

Geriatric assessment (GA) is fundamental to optimising cancer care in older adults, yet implementing comprehensive GA tools in real-world clinical settings remains a challenge. This study aims to assess the feasibility and acceptability of integrating information from patient-derived photographs (PhotoVoice) into enhanced supportive care (ESC) for older adults with cancer. A feasibility randomised controlled trial will be conducted at a regional cancer care centre in Australia. Participants aged 70 and above will be randomised into two groups: PhotoVoice plus ESC or usual care (ESC) alone. In the PhotoVoice group, participants will provide four photographs for deduction of representations of different aspects of their lives using photo-elicitation techniques. ESC will be conducted for both groups, incorporating PhotoVoice analysis in the intervention group. PhotoVoice may improve patient-centred care outcomes, including enhanced communication, shared decision making, and identification of patient priorities and barriers. Findings will provide insights into implementing PhotoVoice in geriatric assessment and guide future trials in cancer among older adults.

3.
J Acoust Soc Am ; 150(5): 3353, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34852621

RESUMO

Crabeater seals are circumpolar, ice-dependent seals that produce distinct vocalizations during the breeding season. This study provides the first description of the acoustic repertoire of the crabeater seal in East Antarctica, using data from a stationary hydrophone at 1.8 km depth in the Southern Kerguelen Plateau region in 2014-2015. Two call types were identified in the data set: the low and the high moan calls. Of the 8821 calls detected, 92.5% were classified as low moan calls and 7.5% were high moan calls. The mean duration of the two call types was similar (2.3 and 2.8 s, respectively), however, the high moan calls had a higher frequency range (1020-4525 Hz, n = 11) than the low moan calls (360-2753 Hz, n = 120). The calls were primarily detected in the austral spring. Diel analysis showed that the low moan calls were mostly made at nighttime or proximal to dusk and dawn. The results of this study could aid in the development of automated detectors for crabeater seal vocalizations. This would facilitate comparisons of the distribution and abundance of the species using extant acoustic data and could increase knowledge on the breeding behavior of crabeater seals.


Assuntos
Caniformia , Focas Verdadeiras , Acústica , Animais , Regiões Antárticas , Estações do Ano , Vocalização Animal
4.
Commun Biol ; 4(1): 149, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33526835

RESUMO

Finding prey is essential to survival, with marine predators hypothesised to track chemicals such as dimethyl sulfide (DMS) while foraging. Many predators are attracted to artificially released DMS, and laboratory experiments have shown that zooplankton grazing on phytoplankton accelerates DMS release. However, whether natural DMS concentrations are useful for predators and correlated to areas of high prey biomass remains a fundamental knowledge gap. Here, we used concurrent hydroacoustic surveys and in situ DMS measurements to present evidence that zooplankton biomass is spatially correlated to natural DMS concentration in air and seawater. Using agent simulations, we also show that following gradients of DMS would lead zooplankton predators to areas of higher prey biomass than swimming randomly. Further understanding of the conditions and scales over which these gradients occur, and how they are used by predators, is essential to predicting the impact of future changes in the ocean on predator foraging success.


Assuntos
Organismos Aquáticos/fisiologia , Comportamento Predatório/efeitos dos fármacos , Sulfetos/farmacologia , Migração Animal/efeitos dos fármacos , Migração Animal/fisiologia , Animais , Organismos Aquáticos/efeitos dos fármacos , Biomassa , Relação Dose-Resposta a Droga , Cadeia Alimentar , Massachusetts , Concentração Osmolar , Fitoplâncton/metabolismo , Percepção de Quorum/fisiologia , Água do Mar/química , Sulfetos/metabolismo , Zooplâncton/metabolismo , Zooplâncton/fisiologia
5.
Anal Chem ; 91(16): 10484-10491, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31337210

RESUMO

An automated device has been developed to measure aqueous dimethyl sulfide (DMSaq), its precursor dimethylsulfoniopropionate (DMSP), and atmospheric gaseous dimethyl sulfide (DMSg). In addition to having a role in the oceanic atmosphere, DMS and DMSP have recently gained substantial interest within the biosciences and are suspected as chemoattractants for predators searching for prey. To provide the spatial resolution relevant for biogeochemical functions, fast and on-site analysis of these compounds is an important technique. The system described measures the dimethyl sulfur compounds by sequential vaporization of DMSaq and DMSP to their gas phase, which is then analyzed by chemiluminescence detection (SVG-CL). The device has five analysis modes (full, DMS, water, gas, and DMSP mode) that can be selected by the user depending on the required analyte or desired sampling rate. Seawater analyses were performed by the developed SVG-CL system and, simultaneously, by an ion molecule reaction-mass spectrometer and a gas chromatograph-flame photometric detector to verify quantitative analysis results. Results obtained by the new method/device agreed well with those by the other methods. Detection limits of the SVG-CL system are 0.02 ppbv and 0.04 nM for DMSg and DMSaq/DMSP, respectively, which are much better than those of the mass spectrometer. The SVG-CL system can be easily installed and operated on a boat. Spatial variability in DMS and DMSP off the coast of Japan were obtained, showing significant changes in the concentrations of the components at the brackish/saline water interface and at the channel between the closed and open seas.

6.
Mitochondrial DNA B Resour ; 2(2): 797-799, 2017 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-33473985

RESUMO

The Mohave tui chub (Siphateles bicolor mohavensis) is an endangered cyprinid fish endemic to the Mojave Desert region of southeastern California, USA. Here, we describe the complete 16,607 base pair (bp) mitochondrial genome of S. b. mohavensis. The mitogenome has a nucleotide base composition of A (29.08%), T (26.91%), G (17.58%), and C (26.43%), and encodes 13 protein subunits, 22 tRNAs, a 12S rRNA of 956 bp and 16S rRNA of 1691 bp, and a 929 bp D-loop control region, each located in the conserved mtDNA structure typical for cyprinid fishes. All protein-coding genes have initiation codons of ATG or GTG, and only the ND1, CO1, ATPase8, NDL4, ND4, ND5, and ND6 genes have complete stop codons. Phylogenetic analyses confirmed the relationship of S. b. mohavensis to several genera of cyprinids (e.g. Gila, Acrocheilus) also endemic to western North America. This characterized mitogenome may help inform management practices for S. b. mohavensis by facilitating future studies on how allopatric populations of this imperiled species are evolving across refuge habitats.

7.
PLoS One ; 6(9): e24047, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21935372

RESUMO

Small coastal dolphins endemic to south-eastern Australia have variously been assigned to described species Tursiops truncatus, T. aduncus or T. maugeanus; however the specific affinities of these animals is controversial and have recently been questioned. Historically 'the southern Australian Tursiops' was identified as unique and was formally named Tursiops maugeanus but was later synonymised with T. truncatus. Morphologically, these coastal dolphins share some characters with both aforementioned recognised Tursiops species, but they also possess unique characters not found in either. Recent mtDNA and microsatellite genetic evidence indicates deep evolutionary divergence between this dolphin and the two currently recognised Tursiops species. However, in accordance with the recommendations of the Workshop on Cetacean Systematics, and the Unified Species Concept the use of molecular evidence alone is inadequate for describing new species. Here we describe the macro-morphological, colouration and cranial characters of these animals, assess the available and new genetic data, and conclude that multiple lines of evidence clearly indicate a new species of dolphin. We demonstrate that the syntype material of T. maugeanus comprises two different species, one of which is the historical 'southern form of Tursiops' most similar to T. truncatus, and the other is representative of the new species and requires formal classification. These dolphins are here described as Tursiops australis sp. nov., with the common name of 'Burrunan Dolphin' following Australian aboriginal narrative. The recognition of T. australis sp. nov. is particularly significant given the endemism of this new species to a small geographic region of southern and south-eastern Australia, where only two small resident populations in close proximity to a major urban and agricultural centre are known, giving them a high conservation value and making them susceptible to numerous anthropogenic threats.


Assuntos
Golfinhos/classificação , Golfinhos/fisiologia , Animais , Golfinho Nariz-de-Garrafa/classificação , Golfinho Nariz-de-Garrafa/fisiologia , Classificação , Análise por Conglomerados , Citocromos b/metabolismo , DNA Mitocondrial/metabolismo , Variação Genética , Haplótipos , Repetições de Microssatélites , Filogenia , Análise de Sequência de DNA , Austrália do Sul
8.
PLoS One ; 6(2): e16457, 2011 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-21364748

RESUMO

Understanding the foraging ecology and diet of animals can play a crucial role in conservation of a species. This is particularly true where species are cryptic and coexist in environments where observing feeding behaviour directly is difficult. Here we present the first information on the foraging ecology of a recently identified species of dolphin (Southern Australian bottlenose dolphin (SABD)) and comparisons to the common bottlenose dolphin (CBD) in Victoria, Australia, using stable isotope analysis of teeth. Stable isotope signatures differed significantly between SABD and CBD for both δ(13)C (-14.4‰ vs. -15.5‰ respectively) and δ(15)N (15.9‰ vs. 15.0‰ respectively), suggesting that the two species forage in different areas and consume different prey. This finding supports genetic and morphological data indicating that SABD are distinct from CBD. In Victoria, the SABD is divided into two distinct populations, one in the large drowned river system of Port Phillip Bay and the other in a series of coastal lakes and lagoons called the Gippsland Lakes. Within the SABD species, population differences were apparent. The Port Phillip Bay population displayed a significantly higher δ(15)N than the Gippsland Lakes population (17.0‰ vs. 15.5‰), suggesting that the Port Phillip Bay population may feed at a higher trophic level--a result which is supported by analysis of local food chains. Important future work is required to further understand the foraging ecology and diet of this newly described, endemic, and potentially endangered species of dolphin.


Assuntos
Golfinho Nariz-de-Garrafa , Ecossistema , Cadeia Alimentar , Marcação por Isótopo , Dente/química , Animais , Austrália , Golfinho Nariz-de-Garrafa/metabolismo , Golfinho Nariz-de-Garrafa/fisiologia , Dieta , Espécies em Perigo de Extinção , Monitoramento Ambiental/métodos , Comportamento Alimentar/fisiologia , Feminino , Marcação por Isótopo/métodos , Marcação por Isótopo/veterinária , Masculino , Isótopos de Nitrogênio/farmacocinética , Densidade Demográfica , Dinâmica Populacional , Dente/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA