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1.
Biol Lett ; 17(5): 20210038, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33975488

RESUMO

There are major concerns about the ecological impact of extreme weather events. In the oceans, marine heatwaves (MHWs) are an increasing threat causing, for example, recent devastation to coral reefs around the world. We show that these impacts extend to adjacent terrestrial systems and could negatively affect the breeding of endangered species. We demonstrate that during an MHW that resulted in major coral bleaching and mortality in a large, remote marine protected area, anomalously warm temperatures also occurred on sea turtle nesting beaches. Granger causality testing showed that variations in sea surface temperature strongly influenced sand temperatures on beaches. We estimate that the warm conditions on both coral reefs and sandy beaches during the MHW were unprecedented in the last 70 years. Model predictions suggest that the most extreme female-biased hatchling sex ratio and the lowest hatchling survival in nests in the last 70 years both occurred during the heatwave. Our work shows that predicted increases in the frequency and intensity of MHWs will likely have growing impacts on sea turtle nesting beaches as well as other terrestrial coastal environments.


Assuntos
Antozoários , Tartarugas , Animais , Recifes de Corais , Feminino , Oceanos e Mares , Temperatura
2.
Glob Chang Biol ; 24(6): 2447-2462, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29504709

RESUMO

As in the tropical Atlantic, Acropora populations in the southern Persian/Arabian Gulf plummeted within two decades after having been ecosystem engineers on most wave-exposed reefs since the Pleistocene. Since 1996/1998 live coral cover in the Gulf declined by over 90% in many areas, primarily due to bleaching and diseases caused by rising temperatures. In the formerly dominant table-coral species A. downingi, population dynamics corresponding to disturbance regimes was quantified in three transition matrices (lower disturbance pre-1996; moderate disturbance from 1998 to 2010 and 2013 to 2017, disturbed in 1996/1998, 2010/11/12, 2017). Increased disturbance frequency and severity caused progressive reduction in coral size, cover, and population fecundity. Small size-classes were bolstered more by partial colony mortality than sexual recruitment. Some large corals had a size refuge and resisted die-back but were also lost with increasing disturbance. Matrix and biophysical larval flow models suggested one metapopulation. Southern, Arabian, populations could be connected to northern, Iranian, populations but this connectivity was lost under assumptions of pelagic larval duration at rising temperatures shortened to a third. Then, the metapopulation disintegrated into isolated populations. Connectivity required to avoid extinctions increased exponentially with disturbance frequency and correlation of disturbances across the metapopulation. Populations became unsustainable at eight disturbances in 15 years, when even highest theoretical recruitment no longer compensated mortality. This lethal disturbance frequency was 3-fold that of the moderately disturbed monitoring period and 4-fold of the preceding low-disturbance period-suggesting ongoing shortening of the disturbance-free period. Observed population collapse and environmental changes in the Gulf suggest that A. downingi is heading toward at least functional extinction mainly due to increasingly frequent temperature-induced mortality events, clearly linked to climate change.


Assuntos
Antozoários/fisiologia , Mudança Climática , Recifes de Corais , Temperatura Alta , Animais , Oceano Índico , Irã (Geográfico) , Dinâmica Populacional , Temperatura
3.
Emerg Radiol ; 25(3): 275-280, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29330668

RESUMO

PURPOSE: The regionalization of trauma in the USA results in frequent transfers of patients from a primary hospital ED to a higher level trauma facility. While many hospitals have a Picture Archive Communication System (PACS) which captures digital radiological images, these are often not available to the receiving institution resulting in duplicate imaging. The state of Arkansas instituted a trauma image repository (TIR) in July 2013. We examined whether implementation of this repository would impact CT scan duplication in the trauma system. METHODS: This was a retrospective analysis of trauma patients transferred from outlying hospitals in Arkansas and Missouri to a single level 1 trauma hospital in Missouri between July 2012 and June 2015. We compared the duplicate CT rate for patients transferred from Arkansas and Missouri hospitals before and after the repository was implemented for Arkansas. RESULTS: Prior to implementation (July 2012-June 2013) of Arkansas TIR, duplicate CT rates were similar for patients transferred from Arkansas (11.5% ± 2.8) or Missouri (16.3% ± 7.5). Following implementation (July 2013-June 2014), the duplicate CT rate for patients transferred from Arkansas was significantly lower (Arkansas = 10.1% vs. Missouri 16.2%; CI 95%, p = 0.02), and significance continued (Arkansas = 9.0% vs. Missouri = 17.8%; CI 95%, p = 0.02) during follow-up (July 2014-June 2015). CONCLUSION: Fewer patients received duplicated scans within the Arkansas as compared with the Missouri-based trauma referral systems regardless of Injury Severity Scores (ISS). Our findings suggest that TIR adoption coupled with PACS improved transferability of radiographic studies and could improve patient care while reducing costs in trauma transfers.


Assuntos
Transferência de Pacientes , Sistemas de Informação em Radiologia , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Centros de Traumatologia , Ferimentos e Lesões/diagnóstico por imagem , Adulto , Idoso , Arkansas , Feminino , Humanos , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Missouri , Estudos Retrospectivos
4.
Nature ; 425(6955): 294-7, 2003 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-13679917

RESUMO

In 1998, more than 90% of shallow corals were killed on most Indian Ocean reefs. High sea surface temperature (SST) was a primary cause, acting directly or by interacting with other factors. Mean SSTs have been forecast to rise above the 1998 values in a few decades; however, forecast SSTs rarely flow seamlessly from historical data, or may show erroneous seasonal oscillations, precluding an accurate prediction of when lethal SSTs will recur. Differential acclimation by corals in different places complicates this further. Here I scale forecast SSTs at 33 Indian Ocean sites where most shallow corals died in 1998 (ref. 1) to identify geographical patterns in the timing of probable repeat occurrences. Reefs located 10-15 degrees south will be affected every 5 years by 2010-2025. North and south from this, dates recede in a pattern not directly related to present SSTs; paradoxically, some of the warmest sites may be affected last. Temperatures lethal to corals vary in this region by 6 degrees C, and acclimation of a modest 2 degrees C by corals could prolong their survival by nearly 100 years.


Assuntos
Aclimatação , Antozoários/fisiologia , Animais , Ecossistema , Geografia , Oceano Índico , Modelos Teóricos , Dinâmica Populacional , Probabilidade , Taxa de Sobrevida , Temperatura , Fatores de Tempo
5.
Mar Pollut Bull ; 154: 111075, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32319906

RESUMO

The global decline of reef corals has been driven largely by several marine heatwaves. This has greatly reduced coral cover but has reduced coral diversity also. While there is a lack of data in most locations to detect coral species losses, reefs of the Chagos Archipelago, central Indian Ocean, have long term monitoring data extending back to the late 1970s. Severe declines in cover have occurred since the 1970s, with regional extinctions of some species and key species assemblages. There is a severe decline in coral settlement, along with a substantial loss of habitat quality which has reduced the habitat available for settlement. This is a clear precursor to positive feedback. Regional species extinctions here occur mainly when total coral cover is <10% of pre-warming levels. Climate models predict more frequent and more severe marine heatwaves, and even if this ecosystem recovers it will contain fewer species.


Assuntos
Antozoários , Animais , Clima , Recifes de Corais , Ecossistema , Oceano Índico
6.
RSC Adv ; 8(70): 39837-39848, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-35558230

RESUMO

Mn substituted Mn x Zn1-x Co2O4 (x = 0, 0.3, 0.5, 0.7, 1) oxides were synthesized by a facile co-precipitation method followed by calcination at 600 °C. The presence of manganese ions causes appreciable changes in the structural and magnetic properties of the Mn-substituted ZnCo2O4. The morphologies, structures, and electronic properties of Mn-Zn-Co oxide microspheres were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The X-ray diffraction and Fourier transform infrared spectroscopy results confirmed the formation of spinel Mn x Zn1-x Co2O4. It was shown that the Mn-Zn-Co oxide microspheres increase in size and become regular in shape with increasing Mn concentration with the crystal size lying in the range from 19.1 nm to 51.3 nm. Magnetization measurements were carried out using a vibrating sample magnetometer at room temperature and 10 K. The saturation magnetization is observed to increase with increasing Mn concentration from x = 0 to x = 1.

8.
Adv Mar Biol ; 89: xxxi-xxxii, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34583817
9.
Mar Pollut Bull ; 105(2): 593-8, 2016 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-26490413

RESUMO

This article discusses two key issues: firstly, the demise of reefs in the Gulf which is happening probably more rapidly than elsewhere; and secondly, the reasons why this remains such an intractable problem. Most reasons for this decline are scientifically well understood, though clearly not by the region's managers. Several factors may cause people to ignore the problem, even though habitat loss is vastly costly to the region. About 70% of the Gulf's reefs have essentially disappeared in a few decades, and although scientific indicators confirm that this is happening, it is commonly discounted as even being a possibility. Management of human interactions with the Gulf's marine systems remains very inadequate, to the detriment of the Gulf's marine systems and its people. It is clear that this not a scientific issue any longer but rather it is a political problem and failure.


Assuntos
Antozoários/crescimento & desenvolvimento , Conservação dos Recursos Naturais , Recifes de Corais , Animais , Antozoários/efeitos dos fármacos , Barein , Mudança Climática , Conservação dos Recursos Naturais/legislação & jurisprudência , Conservação dos Recursos Naturais/métodos , Ecossistema , Sedimentos Geológicos/química , Regulamentação Governamental , Humanos , Oceano Índico , Água do Mar/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Mar Environ Res ; 60(3): 389-96, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15769506

RESUMO

Sea surface temperature (SST) data with monthly resolution are provided for 38 cells in the Caribbean Sea and Bahamas region, plus Bermuda. These series are derived from the HadISST1 data set for historical time (1871-1999) and from the HadCM3 coupled climate model for predicted SST (1950-2099). Statistical scaling of the forecast data sets are performed to produce confluent SST series according to a now established method. These SST series are available for download. High water temperatures in 1998 killed enormous amounts of corals in tropical seas, though in the Caribbean region the effects at that time appeared less marked than in the Indo-Pacific. However, SSTs are rising in accordance with world-wide trends and it has been predicted that temperature will become increasingly important in this region in the near future. Patterns of SST rise within the Caribbean region are shown, and the importance of sub-regional patterns within this biologically highly interconnected area are noted.


Assuntos
Previsões/métodos , Modelos Teóricos , Água do Mar , Temperatura , Região do Caribe , Geografia , Oceanos e Mares
13.
Ambio ; 31(1): 40-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11928357

RESUMO

Three years after most corals died on the central Indian Ocean reefs of Chagos, erosion and recovery were studied to 30 m depth. Mortality was near-total to 15 m deep in northern atolls, and to > 35 m in central and southern atolls. Some reef surfaces have 'dropped' 1.5 m due to the loss of dense coral thickets. Coral bioerosion is substantial, reducing 3-D reef 'structure' and forming unconsolidated rubble. Juvenile corals are abundant, though mostly on eroding or unstable substrates, and are of less robust species. Reef fish abundance and diversity at 15 m depth remains high; species dependent on corals have diminished, while some herbivores and detritivores have increased. A new sea surface temperature (SST) data set shows that mean SST has risen 0.65 degree C since 1950. The critical SST causing the mortality in Chagos was 29.9 degrees C.


Assuntos
Clima , Cnidários , Ecossistema , Animais , Monitoramento Ambiental , Peixes , Oceano Índico , Mortalidade , Dinâmica Populacional , Temperatura
14.
Mar Pollut Bull ; 49(1-2): 12-6, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15234869

RESUMO

Monthly sea surface temperature is provided for 14 locations around the UK for a 230 year period. These series are derived from the HadISST1 data set for historical time (1871-1999) and from the HadCM3 climate model for predicted SST (1950-2099). Two adjustments of the forecast data sets are needed to produce confluent SST series: the 50 year overlap is used for a gross adjustment, and a statistical scaling on the forecast data ensures that annual variations in forecast data match those of historical data. These monthly SST series are available on request. The overall rise in SST over time is clear for all sites, commencing in the last quarter of the 20th century. Apart from expected trends of overall warmer mean SST with more southerly latitudes and overall cooler mean SST towards the East, more interesting statistically significant general trends include a greater decadal rate of rise from warmer starting conditions. Annual temperature variation is not affected by absolute temperature, but is markedly greater towards the East. There is no correlation of annual range of SST with latitude, or with present SST values.


Assuntos
Monitoramento Ambiental/história , Efeito Estufa , Modelos Teóricos , Temperatura , Oceano Atlântico , Clima , História do Século XIX , História do Século XX , Água do Mar , Reino Unido
16.
Mar Pollut Bull ; 44(4): 303-8, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12139320

RESUMO

The HadISST1 sea surface temperature data set is examined for two contrasting areas: the Chagos Archipelago, central Indian Ocean which has a small (approximately 3 degrees C) annual temperature fluctuation, and Abu Dhabi in the southern Arabian Gulf whose annual air temperature fluctuation of approximately 24 degrees C is the largest known for coral reef habitats. The HadISST1 data are shown to match air temperature records closely, both in terms of annual moving averages and residual analysis. Temperatures in 1998 caused massive mortality of corals in the Indian Ocean: sea surface temperature (SST) values causing this were 33.8 degrees C in the Arabian Gulf at a time when average daily air temperature was over 40 degrees C, while in Chagos the SST lethal to corals was 29.8-29.9 degrees C, when air temperatures peaked at about 31 degrees C. The HadISST1 record was searched back to 1870 for previous abnormal peaks: one of 29.7 degrees C was found for Chagos SST in 1972, though this did not cause coral mortality. Analysis of 12-month running means of the residuals from the annual cycle show that, between 1870 and 1999, the largest SST deviations occurred between October 1997 and May 1998 in Chagos and between August 1998 and July 1999 near Abu Dhabi. The event of 1998-1999 was the largest in these regions for at least 130 years. SSTs have risen over the last three decades at rates of about 0.22 degrees or 0.23 degrees per decade in both locations.


Assuntos
Antozoários/fisiologia , Ecossistema , Temperatura , Animais , Antozoários/crescimento & desenvolvimento , Clima , Gelo , Oceano Índico , Mortalidade , Dinâmica Populacional , Água do Mar
17.
Mar Pollut Bull ; 85(1): 8-23, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24997002

RESUMO

Over 1.3 billion people live on tropical coasts, primarily in developing countries. Many depend on adjacent coastal seas for food, and livelihoods. We show how trends in demography and in several local and global anthropogenic stressors are progressively degrading capacity of coastal waters to sustain these people. Far more effective approaches to environmental management are needed if the loss in provision of ecosystem goods and services is to be stemmed. We propose expanded use of marine spatial planning as a framework for more effective, pragmatic management based on ocean zones to accommodate conflicting uses. This would force the holistic, regional-scale reconciliation of food security, livelihoods, and conservation that is needed. Transforming how countries manage coastal resources will require major change in policy and politics, implemented with sufficient flexibility to accommodate societal variations. Achieving this change is a major challenge - one that affects the lives of one fifth of humanity.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais , Ecossistema , Animais , Antozoários , Simulação por Computador , Demografia , Ecologia , Monitoramento Ambiental/métodos , Pesqueiros , Geografia , Humanos , Oceanos e Mares
18.
Mar Pollut Bull ; 56(5): 799-800, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18440029
20.
Mar Pollut Bull ; 74(2): 526-39, 2013 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-23816307

RESUMO

Most reviews concerning the impact of climate change on coral reefs discuss independent effects of warming or ocean acidification. However, the interactions between these, and between these and direct local stressors are less well addressed. This review underlines that coral bleaching, acidification, and diseases are expected to interact synergistically, and will negatively influence survival, growth, reproduction, larval development, settlement, and post-settlement development of corals. Interactions with local stress factors such as pollution, sedimentation, and overfishing are further expected to compound effects of climate change. Reduced coral cover and species composition following coral bleaching events affect coral reef fish community structure, with variable outcomes depending on their habitat dependence and trophic specialisation. Ocean acidification itself impacts fish mainly indirectly through disruption of predation- and habitat-associated behavior changes. Zooxanthellate octocorals on reefs are often overlooked but are substantial occupiers of space; these also are highly susceptible to bleaching but because they tend to be more heterotrophic, climate change impacts mainly manifest in terms of changes in species composition and population structure. Non-calcifying macroalgae are expected to respond positively to ocean acidification and promote microbe-induced coral mortality via the release of dissolved compounds, thus intensifying phase-shifts from coral to macroalgal domination. Adaptation of corals to these consequences of CO2 rise through increased tolerance of corals and successful mutualistic associations between corals and zooxanthellae is likely to be insufficient to match the rate and frequency of the projected changes. Impacts are interactive and magnified, and because there is a limited capacity for corals to adapt to climate change, global targets of carbon emission reductions are insufficient for coral reefs, so lower targets should be pursued. Alleviation of most local stress factors such as nutrient discharges, sedimentation, and overfishing is also imperative if sufficient overall resilience of reefs to climate change is to be achieved.


Assuntos
Aclimatação , Antozoários/fisiologia , Mudança Climática , Conservação dos Recursos Naturais/métodos , Recifes de Corais , Animais , Dióxido de Carbono/análise , Dióxido de Carbono/toxicidade , Oceanos e Mares , Alga Marinha/fisiologia , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Poluição Química da Água/estatística & dados numéricos
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