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1.
Zootaxa ; 5399(3): 254-264, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38221158

RESUMO

Booralana nickorum sp. nov. is described from the deep-water slope of the Exuma Sound, The Bahamas, from depths of 540 to 560 metres. It is the fourth species to be assigned to the genus and the second species described from the Western North Atlantic. The species can be distinguished from Booralana tricarinata Camp and Heard, 1988 and the other species by the sub-triangular pleotelson and the uropodal exopod of mature males being far longer than endopod, with both rami extending well beyond the posterior margin of the pleotelson. Additionally, pleopods 3 and 4 lack a prominent angle at midpoint of ramus.


Assuntos
Isópodes , Masculino , Animais , Bahamas , Crustáceos
2.
Cureus ; 15(8): e43248, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37692620

RESUMO

Introduction The association of acute appendicitis with caecal or colorectal cancer is known. One of the proposed theories for acute appendicitis is luminal blockage by mass at the base of the appendix. There have been no national recommendations or guidelines for follow-up with patients aged 40 and older after an emergency appendicectomy. The purpose of this study was to evaluate the prevalence of caecal and colonic cancer or polyps in patients over the age of 40 who have undergone an appendicectomy. This shall enable us to develop the necessary strategies to investigate and diagnose associated caecal and colonic pathology in acute appendicitis to prevent delayed diagnosis of colon cancer. Methods All patients who underwent appendicectomy between October 2011 and October 31, 2021, and who were 40 years of age or older were included in this retrospective cohort study. Patients aged 40 to 54 years old and patients 55 years or older underwent subgroup analyses. We looked at any investigations of the colon (CT pneumocolon or colonoscopy) within three years before the appendicectomy or three years after an appendicectomy. All colorectal cancers diagnosed within five years of the index episode of appendicitis were included in the analysis. Results A total of 1076 appendicectomies were performed on patients aged 40 and older during the study period of 10 years. A total of 769 patients were confirmed to have appendicitis on histology. One hundred and fifty-seven patients had colonic investigations within three years of the diagnosis of acute appendicitis. In our study, 51 of the 769 patients (6.63%) were found to have colorectal neoplasms. Eight patients (8/769, 1.04%) were diagnosed with colorectal cancers, and the occurrence of caecal cancer was 0.26% (2/769). The mortality rate was 75% (6/8) in these patients diagnosed with colorectal cancer. Four out of six died due to advanced metastatic colonic cancer. In comparison to patients aged 40 to 54, patients over the age of 55 had a statistically significant increased risk of caecal pathology (polyp and cancer) (p = 0.07). Conclusion There seems to be an increased risk of significant colorectal neoplasm in patients over the age of 55 who are admitted with acute appendicitis, and there appears to be an increased severity with a poor prognosis of cancer in these individuals. We recommend the use of routine colonoscopy or CT pneumocolon, particularly for those over the age of 55 who present with acute appendicitis or the histology of appendicular neoplasms.

3.
Conserv Physiol ; 11(1): coad048, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37425482

RESUMO

Tissue and blood gas embolism (GE) associated with fisheries bycatch are likely a widespread, yet underestimated, cause of sea turtle mortality. Here, we evaluated risk factors associated with tissue and blood GE in loggerhead turtles caught incidentally by trawl and gillnet fisheries on the Valencian coastline of Spain. Of 413 turtles (303 caught by trawl, 110 by gillnet fisheries), 54% (n = 222) exhibited GE. For sea turtles caught in trawls, the probability and severity of GE increased with trawl depth and turtle body mass. In addition, trawl depth and the GE score together explained the probability of mortality (P[mortality]) following recompression therapy. Specifically, a turtle with a GE score of 3 caught in a trawl deployed at 110 m had a P[mortality] of ~50%. For turtles caught in gillnets, no risk variables were significantly correlated with either the P[GE] or GE score. However, gillnet depth or GE score, separately, explained P[mortality], and a turtle caught at 45 m or with a GE score between 3 and 4 had a P[mortality] of 50%. Differences in the fishery characteristics precluded direct comparison of GE risk and mortality between these gear types. Although P[mortality] is expected to be significantly higher in untreated turtles released at sea, our findings can improve estimates of sea turtle mortality associated with trawls and gillnets, and help guide associate conservation efforts.

4.
Sensors (Basel) ; 23(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36991891

RESUMO

Soil colour is one of the most important factors in agriculture for monitoring soil health and determining its properties. For this purpose, Munsell soil colour charts are widely used by archaeologists, scientists, and farmers. The process of determining soil colour from the chart is subjective and error-prone. In this study, we used popular smartphones to capture soil colours from images in the Munsell Soil Colour Book (MSCB) to determine the colour digitally. These captured soil colours are then compared with the true colour determined using a commonly used sensor (Nix Pro-2). We have observed that there are colour reading discrepancies between smartphone and Nix Pro-provided readings. To address this issue, we investigated different colour models and finally introduced a colour-intensity relationship between the images captured by Nix Pro and smartphones by exploring different distance functions. Thus, the aim of this study is to determine the Munsell soil colour accurately from the MSCB by adjusting the pixel intensity of the smartphone-captured images. Without any adjustment when the accuracy of individual Munsell soil colour determination is only 9% for the top 5 predictions, the accuracy of the proposed method is 74%, which is significant.

5.
Biology (Basel) ; 12(2)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36829502

RESUMO

The burrowing crustacean decapod Nephrops norvegicus is a significant species in European Atlantic and Mediterranean fisheries. Research over the decades has mainly focused on behavioral and physiological aspects related to the burrowing lifestyle, since animals can only be captured by trawls when engaged in emergence on the seabed. Here, we performed a global bibliographic survey of all the scientific literature retrieved in SCOPUS since 1965, and terminology maps were produced with the VOSviewer software to reveal established and emerging research areas. We produced three term-map plots: term clustering, term citation, and term year. The term clustering network showed three clusters: fishery performance, assessment, and management; biological cycles in growth, reproduction, and behavior; and finally, physiology and ecotoxicology, including food products. The term citation map showed that intense research is developed on ecotoxicology and fishery management. Finally, the term year map showed that the species was first studied in its morphological and physiological aspects and more recently in relation to fishery and as a food resource. Taken together, the results indicate scarce knowledge on how burrowing behavior and its environmental control can alter stock assessment, because of the poor use of current and advanced monitoring technologies.

6.
SN Soc Sci ; 2(12): 267, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36531139

RESUMO

Respectful maternity care (RMC) is part of a global movement addressing the previous absence of human rights in global safe maternal care guidance. RMC is grounded in kindness, compassion, dignity and respectful working conditions. The decolonisation movement in healthcare seeks to dismantle structural biases set up from a historically white, male, heteronormative Eurocentric medical system. This article applies a decolonising lens to the RMC agenda and examines barriers to its implementation in UK healthcare systems. Searches of peer-reviewed journals about decolonising maternity care in the UK revealed little. Drawing from wider information bases, we examine power imbalances constructed throughout a history of various colonial biases yet lingering in maternity care. The overarching findings of our analysis revealed 3 areas of focus: professional structures and institutional biases; power imbalances between types of staff and stakeholders of care; and person-centred care through a decolonial lens. To uproot inequity and create fairer and more respectful maternity care for women, birthing people and staff, it is vital that contemporary maternity institutions understand the decolonial perspective. This novel enquiry offers a scaffolding to undertake this process. Due to significant differences in colonial history between Western colonising powers, it is important to decolonise with respect to these different territories, histories and challenges.

7.
J Therm Biol ; 110: 103342, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36462853

RESUMO

Sea turtles generally lay several clutches of eggs in a single nesting season. While a negative correlation between water temperatures and the time required between constitutive nesting events (termed the internesting interval) has been previously reported in loggerhead Caretta caretta and green turtles Chelonia mydas, it is not understood whether this relationship remains constant across other sea turtle species. Here, we expanded upon these previous studies on loggerhead and green turtles by using larger sample sizes and including data from species with a wider range of body-sizes; specifically: hawksbill Eretmochelys imbricata, leatherback Dermochelys coriacea, and olive ridley turtles Lepidochelys olivacea. In total, we compiled temperature data from biologgers deployed over internesting intervals on 23 loggerhead, 22 green, 7 hawksbill, 26 leatherback and 11 olive ridley turtles from nesting sites in 8 different countries. The relationship between the duration of the internesting interval and water temperatures in green and loggerhead turtles were statistically similar yet it differed between all other turtle species. Specifically, hawksbill turtles had much longer internesting intervals than green or loggerhead turtles even after controlling for temperature. In addition, both olive ridley and leatherback turtles exhibited thermal independence of internesting intervals presumably due to the large body-size of leatherback turtles and the unique capacity of ridley turtles to delay oviposition. The observed interspecific differences in the relationship between the length of the internesting interval and water temperatures indicate the complex and variable responses that each sea turtle species may exhibit due to environmental fluctuations and climate change.


Assuntos
Tartarugas , Feminino , Animais , Temperatura , Água , Mudança Climática , Tamanho Corporal
8.
PLoS One ; 17(10): e0276382, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36256654

RESUMO

The recent commercialization of unoccupied aerial vehicles (UAVs) has facilitated their incorporation into a variety of ecological studies. While UAVs are able to provide accurate visual data of marine species from an aerial perspective, these devices have some limitations that make measuring marine animals below the surface challenging. Many marine organisms are often visible from the air, but are deeper in the water column, and current methods cannot measure animals below the surface. Here, we developed and tested a stereo-video camera (SVC) system that was mounted onto a commercially-available UAV. We used the SVC-UAV to conduct remote body-size measurements for two marine species: the green sea turtle (Chelonia mydas) and the nurse shark (Ginglymostoma cirratum). When comparing SVC measurements to those taken by hand, the SVC-UAV had a mean absolute error (MAE) of 4.44 cm (n = 6; mean percent error (MPE) = 10.6%) for green sea turtles and 7.16 cm absolute error (n = 1; PE = 3.6%) for the nurse shark. Using a linear model, we estimated the slope of the SVC versus hand measurements for green sea turtles to be 1.085 (±0.099 SE), and accounting for the standard error, a measurement bias was not apparent. Using model selection, based on a global model predicting MAE from animal distance to the SVC and body size, the top ranked model was the intercept-only model. This indicates that neither animal distance nor body size strongly influenced measurement error. Incorporating SVC systems into UAVs can allow for relatively accurate measurements of near surface-dwelling marine species. To our knowledge, there is no other stand-alone SVC for UAVs available that offers similar accuracy and utility.


Assuntos
Tubarões , Tartarugas , Animais , Organismos Aquáticos , Água
9.
Sci Rep ; 12(1): 15116, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36068258

RESUMO

Our understanding of the importance of microbiomes on large aquatic animals-such as whales, sea turtles and manatees-has advanced considerably in recent years. The latest observations indicate that epibiotic diatom communities constitute diverse, polyphyletic, and compositionally stable assemblages that include both putatively obligate epizoic and generalist species. Here, we outline a successful approach to culture putatively obligate epizoic diatoms without their hosts. That some taxa can be cultured independently from their epizoic habitat raises several questions about the nature of the interaction between these animals and their epibionts. This insight allows us to propose further applications and research avenues in this growing area of study. Analyzing the DNA sequences of these cultured strains, we found that several unique diatom taxa have evolved independently to occupy epibiotic habitats. We created a library of reference sequence data for use in metabarcoding surveys of sea turtle and manatee microbiomes that will further facilitate the use of environmental DNA for studying host specificity in epizoic diatoms and the utility of diatoms as indicators of host ecology and health. We encourage the interdisciplinary community working with marine megafauna to consider including diatom sampling and diatom analysis into their routine practices.


Assuntos
Diatomáceas , Tartarugas , Animais , Diatomáceas/genética , Ecologia , Ecossistema , Tartarugas/genética
10.
Proc Biol Sci ; 288(1960): 20211620, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34610769

RESUMO

Movement is a fundamental characteristic of life, yet some invertebrate taxa, such as barnacles, permanently affix to a substratum as adults. Adult barnacles became 'sessile' over 500 Ma; however, we confirm that the epizoic sea turtle barnacle, Chelonibia testudinaria, has evolved the capacity for self-directed locomotion as adults. We also assess how these movements are affected by water currents and the distance between conspecifics. Finally, we microscopically examine the barnacle cement. Chelonibia testudinaria moved distances up to 78.6 mm yr-1 on loggerhead and green sea turtle hosts. Movements on live hosts and on acrylic panels occasionally involved abrupt course alterations of up to 90°. Our findings showed that barnacles tended to move directly against water flow and independent of nearby conspecifics. This suggests that these movements are not passively driven by external forces and instead are behaviourally directed. In addition, it indicates that these movements function primarily to facilitate feeding, not reproduction. While the mechanism enabling movement remained elusive, we observed that trails of cement bore signs of multi-layered, episodic secretion. We speculate that proximal causes of movement involve one or a combination of rapid shell growth, cement secretion coordinated with basal membrane lifting, and directed contraction of basal perimeter muscles.


Assuntos
Thoracica , Tartarugas , Animais , Locomoção , Reprodução
11.
Front Physiol ; 12: 678555, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539425

RESUMO

Sea turtles, like other air-breathing diving vertebrates, commonly experience significant gas embolism (GE) when incidentally caught at depth in fishing gear and brought to the surface. To better understand why sea turtles develop GE, we built a mathematical model to estimate partial pressures of N2 (PN2), O2 (PO2), and CO2 (PCO2) in the major body-compartments of diving loggerheads (Caretta caretta), leatherbacks (Dermochelys coriacea), and green turtles (Chelonia mydas). This model was adapted from a published model for estimating gas dynamics in marine mammals and penguins. To parameterize the sea turtle model, we used values gleaned from previously published literature and 22 necropsies. Next, we applied this model to data collected from free-roaming individuals of the three study species. Finally, we varied body-condition and cardiac output within the model to see how these factors affected the risk of GE. Our model suggests that cardiac output likely plays a significant role in the modulation of GE, especially in the deeper diving leatherback turtles. This baseline model also indicates that even during routine diving behavior, sea turtles are at high risk of GE. This likely means that turtles have additional behavioral, anatomical, and/or physiologic adaptions that serve to reduce the probability of GE but were not incorporated in this model. Identifying these adaptations and incorporating them into future iterations of this model will further reveal the factors driving GE in sea turtles.

12.
Ecol Evol ; 11(12): 8226-8237, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34188882

RESUMO

Point 1: Stereo-video camera systems (SVCSs) are a promising tool to remotely measure body size of wild animals without the need for animal handling. Here, we assessed the accuracy of SVCSs for measuring straight carapace length (SCL) of sea turtles. Point 2: To achieve this, we hand captured and measured 63 juvenile, subadult, and adult sea turtles across three species: greens, Chelonia mydas (n = 52); loggerheads, Caretta caretta (n = 8); and Kemp's ridley, Lepidochelys kempii (n = 3) in the waters off Eleuthera, The Bahamas and Crystal River, Florida, USA, between May and November 2019. Upon release, we filmed these individuals with the SVCS. We performed photogrammetric analysis to extract stereo SCL measurements (eSCL), which were then compared to the (manual) capture measurements (mSCL). Point 3: mSCL ranged from 25.9 to 89.2 cm, while eSCL ranged from 24.7 to 91.4 cm. Mean percent bias of eSCL ranged from -0.61% (±0.11 SE) to -4.46% (±0.31 SE) across all species and locations. We statistically analyzed potential drivers of measurement error, including distance of the turtle to the SVCS, turtle angle, image quality, turtle size, capture location, and species. Point 4: Using a linear mixed effects model, we found that the distance between the turtle and the SVCS was the primary factor influencing measurement error. Our research suggests that stereo-video technology enables high-quality measurements of sea turtle body size collected in situ without the need for hand-capturing individuals. This study contributes to the growing knowledge base that SVCS are accurate for body size measurements independent of taxonomic clade.

14.
Clin Teach ; 18(3): 252-257, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33280253

RESUMO

BACKGROUND: Simulation training is an effective tool for improving confidence in healthcare workers. During the recent COVID-19 pandemic, large numbers of staff required re-training to manage unfamiliar situations. We present a set of medical student-led clinical simulation sessions and evaluate their effects on (i) confidence among redeployed healthcare workers managing COVID-19 patients and (ii) medical students' confidence as educators. METHODS: Half-day simulation training sessions consisting of three COVID-related clinical scenarios were devised by senior medical students and delivered to a group of approximately 150 healthcare workers over six repeated sessions prior to redeployment to COVID-19 wards. We distributed an anonymous pre- and post-simulation questionnaire to 36 participants in the final group exploring their experiences. The confidence scores were analysed using the Wilcoxon signed-rank test. Following the delivery of teaching, medical students completed a questionnaire assessing their personal experiences of designing and delivering the exercises. RESULTS: Data are available for 35/36 participants approached. Respondents reported being significantly more confident after the training in all aspects of managing COVID-19 patients, including triage, complex discharge, recognising deterioration, initiating basic life support, managing symptoms and advising on visiting policies (p < 0.001); 97% of respondents rated the training as useful. Thematic analysis of medical students' responses demonstrated mutual benefit. DISCUSSION: This study demonstrates the strengths of simulation training in helping to build staff confidence in a rapidly evolving situation and highlights the value of medical students in supporting a hospital's response to an outbreak. We recommend further studies of student-led simulation exercises, including longer-term follow-up.


Assuntos
COVID-19 , Treinamento por Simulação , Estudantes de Medicina , COVID-19/diagnóstico , COVID-19/terapia , Humanos , Pandemias
15.
F1000Res ; 9: 1305, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34354820

RESUMO

Background: A growing ability to collect data, together with the development and adoption of the FAIR guiding principles, has increased the amount of data available in many disciplines. This has given rise to an urgent need for robust metadata. Within the Australian grains industry, data from thousands of on-farm research trials (Trial Projects) have been made available via the Online Farm Trials (OFT) website. OFT Trial Project metadata were developed as filters to refine front-end database searches, but could also be used as a dataset to investigate trends in metadata elements. Australian grains crops are being sown earlier, but whether on-farm research trials reflect this change is currently unknown. Methods: We investigated whether OFT Trial Project metadata could be used to detect trends in sowing dates of on-farm crop research trials across Australia, testing the hypothesis that research trials are being sown earlier in line with local farming practices. The investigation included 15 autumn-sown, winter crop species listed in the database, with trial records from 1993 to 2019. Results: Our analyses showed that (i) OFT Trial Project metadata can be used as a dataset to detect trends in sowing date; and (ii) cropping research trials are being sown earlier in Victoria and Western Australia, but no trend exists within the other states. Discussion/Conclusion: Our findings show that OFT Trial Project metadata can be used to detect trends in crop sowing date, suggesting that metadata could also be used to detect trends in other elements such as harvest date. Because OFT is a national database of research trials, further assessment of metadata may uncover important agronomic, cultural or economic trends within or across the Australian cropping regions. New information could then be used to lead practice change and increase productivity within the Australian grains industry.


Assuntos
Agricultura , Produtos Agrícolas , Austrália , Fazendas , Estações do Ano
16.
PLoS One ; 14(9): e0218838, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31490927

RESUMO

There is a wealth of published information on the epibiont communities of sea turtles, yet many of these studies have exclusively sampled epibionts found only on the carapace. Considering that epibionts may be found on almost all body-surfaces and that it is highly plausible to expect different regions of the body to host distinct epibiont taxa, there is a need for quantitative information on the spatial variation of epibiont communities on turtles. To achieve this, we measured how total epibiont abundance and biomass on olive ridley turtles Lepidochelys olivacea varies among four body-areas of the hosts (n = 30). We showed that epibiont loads on olive ridleys are higher, both in terms of number and biomass, on the skin than they are on the carapace or plastron. This contrasts with previous findings for other hard-shelled sea turtles, where epibionts are usually more abundant on the carapace or plastron. Moreover, the arguably most ubiquitous epibiont taxon for other hard-shelled sea turtles, the barnacle Chelonibia spp., only occurred in relatively low numbers on olive ridleys and the barnacles Stomatolepas elegans and Platylepas hexastylos are far more abundant. We postulate that these differences between the epibiont communities of different sea turtle taxa could indicate that the carapaces of olive ridley turtles provide a more challenging substratum for epibionts than do the hard shells of other sea turtles. In addition, we conclude that it is important to conduct full body surveys when attempting to produce a holistic qualitative or quantitative characterization of the epibiont communities of sea turtles.


Assuntos
Distribuição Animal , Simbiose , Thoracica/fisiologia , Tartarugas/fisiologia , Animais , Biodiversidade , Biomassa , Costa Rica , Thoracica/patogenicidade , Tartarugas/parasitologia
17.
Sci Rep ; 9(1): 9783, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31278292

RESUMO

Sea turtle species in the genus Lepidochelys exhibit an unusual behavioural polymorphism, nesting in both aggregations and solitarily. Aggregated nesting events, termed 'arribadas', involve hundreds of thousands of females congregating at a single nesting beach over a few days to oviposit their eggs. Aggregate and solitary nesting behaviours are associated with distinct inter-nesting intervals, three and four weeks for non-arribada and arribada nesters respectively. Consequently, embryos are maintained in pre-ovipositional embryonic arrest in the hypoxic oviduct for different lengths of time depending on the mother's reproductive behaviour. However, sea turtle embryos are limited in their capacity to remain in arrest and will subsequently die if held in hypoxia too long. Here, we tested whether embryos oviposited during arribada or non-arribada nesting differ in their capacity to be maintained in pre-ovipositional arrest. Olive ridley turtle (Lepidochelys olivacea) eggs from eight clutches (four from each nesting tactic) were divided among seven treatments after oviposition; normoxia (control; 21% O2), or hypoxia (1% O2) for 3, 3.5, 4, 8, 15 or 30 days, before being returned to normoxia. Arribada eggs were capable of extending pre-ovipositional arrest for longer, with some eggs from the 8- and 15-day hypoxia treatment still hatching while no non-arribada eggs hatched after more than four days in hypoxia. This difference in embryonic capacity to survive extended periods of arrest may be an important mechanism facilitating arribada behaviour by allowing longer inter-nesting intervals. Our finding provides an intriguing insight into the physiological mechanisms that are integral to this unique mass-nesting behaviour.


Assuntos
Comportamento de Nidação/fisiologia , Oviposição/fisiologia , Tartarugas/embriologia , Tartarugas/fisiologia , Animais , Feminino , Hipóxia , Oviductos/fisiologia , Reprodução/fisiologia , Areia
18.
Mar Pollut Bull ; 138: 37-48, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30660286

RESUMO

The impact of ghost fishing in large coastal ecosystems has generated considerable interest. In smaller, understudied systems with fewer stakeholders, derelict fishing gear (DFGs) may have impacts similar to these larger systems at the same relative scale. Four years of side scan sonar surveys in the Mullica River-Great Bay Estuary (New Jersey, USA) supported the recovery of 1776 DFGs off-season by commercial partners. Locations with high densities of recovered DFGs (>200 DFGs/km2) occupied intersections of recreational vessel traffic and commercial crabbing activity. Condition and depth-in-sediment of recovered DFGs was used to evaluate true bycatch (terrapins, whelks, blue crabs) versus species utilizing degraded gear as habitat (juvenile tautog, oyster toadfish). Critically, gear recovered in-season with low cost sonars (an additional 225 DFGs) prevented the accumulation of new DFGs which likely generate the highest percentages of bycatch. Removal of DFGs in this system led to significant ecological (reduced bycatch), economic (>$61,000 in direct pay, reused gear), and anticipated future benefits (increased harvest).


Assuntos
Pesqueiros , Poluição da Água/análise , Animais , Baías , Meio Ambiente , Monitoramento Ambiental , Equipamentos e Provisões , Estuários , New Jersey , Rios , Poluição da Água/prevenção & controle
19.
PeerJ ; 6: e4714, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29736346

RESUMO

Olivid gastropods of the genus Agaronia are dominant predators within invertebrate communities on sandy beaches throughout Pacific Central America. At Playa Grande, on the Pacific Coast of Costa Rica, we observed 327 natural predation events by Agaronia propatula. For each predation event, we documented prey taxa and body size of both predator and prey. The relationship between predator and prey size differed for each of the four main prey taxa: bivalves, crustaceans, heterospecific gastropods, and conspecific gastropods (representing cannibalism). For bivalve prey, there was increased variance in prey size with increasing predator size. Crustaceans were likely subdued only if injured or otherwise incapacitated. Heterospecific gastropods (mostly Olivella semistriata) constituted half of all prey items, but were only captured by small and intermediately sized A. propatula. Large O. semistriata appeared capable of avoiding predation by A. propatula. Cannibalism was more prevalent among large A. propatula than previously estimated. Our findings suggested ontogenetic niche shifts in A. propatula and a significant role of cannibalism in its population dynamics. Also indicated were size-dependent defensive behavior in some prey taxa and a dynamic, fine-scale zonation of the beach. The unexpected complexity of the trophic relations of A. propatula was only revealed though analysis of individual predation events. This highlights the need for detailed investigations into the trophic ecology of marine invertebrates to understand the factors driving ecosystem structuring in sandy beaches.

20.
Sci Rep ; 6: 37851, 2016 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-27886262

RESUMO

Previous studies have shown that the world's largest reptile - the leatherback turtle Dermochelys coriacea - conducts flexible foraging migrations that can cover thousands of kilometres between nesting sites and distant foraging areas. The vast distances that may be travelled by migrating leatherback turtles have greatly complicated conservation efforts for this species worldwide. However, we demonstrate, using a combination of satellite telemetry and stable isotope analysis, that approximately half of the nesting leatherbacks from an important rookery in South Africa do not migrate to distant foraging areas, but rather, forage in the coastal waters of the nearby Mozambique Channel. Moreover, this coastal cohort appears to remain resident year-round in shallow waters (<50 m depth) in a relatively fixed area. Stable isotope analyses further indicate that the Mozambique Channel also hosts large numbers of loggerhead turtles Caretta caretta. The rare presence of a resident coastal aggregation of leatherback turtles not only presents a unique opportunity for conservation, but alongside the presence of loggerhead turtles and other endangered marine megafauna in the Mozambique Channel, highlights the importance of this area as a marine biodiversity hotspot.


Assuntos
Migração Animal , Comportamento Alimentar , Tartarugas/fisiologia , Animais , Conservação dos Recursos Naturais , Comunicações Via Satélite , África do Sul , Telemetria/instrumentação
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