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1.
J Environ Manage ; 301: 113919, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731944

RESUMO

Coral bleaching has increasingly impacted reefs worldwide over the past four decades. Despite almost 40 years of research into the mechanistic, physiological, ecological, biophysical and climatic drivers of coral bleaching, metrics to allow comparison between ecological observations and experimental simulations still do not exist. Here we describe a novel metric - experimental Degree Heating Week (eDHW) - with which to standardise the persistently variable thermal conditions employed across experimental studies of coral bleaching by modify the widely used Degree Heating Week (DHW) metric used in ecological studies to standardise cumulative heat loading.


Assuntos
Antozoários , Temperatura Alta , Animais , Recifes de Corais
2.
Sci Total Environ ; 806(Pt 1): 150392, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34583073

RESUMO

Plastic pollution and climate change have commonly been treated as two separate issues and sometimes are even seen as competing. Here we present an alternative view that these two issues are fundamentally linked. Primarily, we explore how plastic contributes to greenhouse gas (GHG) emissions from the beginning to the end of its life cycle. Secondly, we show that more extreme weather and floods associated with climate change, will exacerbate the spread of plastic in the natural environment. Finally, both issues occur throughout the marine environment, and we show that ecosystems and species can be particularly vulnerable to both, such as coral reefs that face disease spread through plastic pollution and climate-driven increased global bleaching events. A Web of Science search showed climate change and plastic pollution studies in the ocean are often siloed, with only 0.4% of the articles examining both stressors simultaneously. We also identified a lack of regional and industry-specific life cycle analysis data for comparisons in relative GHG contributions by materials and products. Overall, we suggest that rather than debate over the relative importance of climate change or marine plastic pollution, a more productive course would be to determine the linking factors between the two and identify solutions to combat both crises.


Assuntos
Mudança Climática , Gases de Efeito Estufa , Recifes de Corais , Ecossistema , Plásticos
3.
Sci Total Environ ; 804: 150178, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798733

RESUMO

Coral reefs are likely to be exposed to more intense cyclones under climate change. Cyclone impacts are spatially highly variable given complex hydrodynamics, and coral-specific sensitivity to wave impacts. Predicting reef vulnerability to cyclones is critical to management but requires high resolution environmental data that are difficult to obtain over broad spatial scales. Using 30m-resolution wave modelling, we tested cyclonic and non-cyclonic wave metrics as predictors of coral damage on 22 reefs after severe cyclone Ita impacted the northern Great Barrier Reef, Australia in 2014. Analyses of coral cover change accounting for the type of coral along a gradient of vulnerability to wave damage (e.g., massive, branching, Acroporids) excluded cyclone-generated surface wave metrics (derived from wave height) as important predictors. Increased bottom stress wave environment (near-bed wave orbital velocity) due to Ita (Ita-Ub) explained spatial patterns of 17% to 46% total coral cover loss only when the initial abundance of Acroporids was accounted for, and only when exceeding 35% cover. Greater coral losses occurred closer to the cyclone path irrespective of coral type. Massive and encrusting corals, however, had losses exacerbated in higher non-cyclonic bottom-wave energy environments (nc-Ub). The effect of community composition on structural vulnerability to wave damage was more important predicting damage that the magnitude of the cyclone-generated waves, especially when reefs are surveyed well beyond where damaging waves are expected to occur. Exposure to Ita-Ub was greater in typically high nc-Ub environments with relatively low cover of the most fragile morphologies explaining why these were the least affected overall. We reveal that the common surface-wave metrics of cyclone intensity may not always be able to predict spatial impacts and conclude that reef vulnerability assessments need to account for chronic wave patterns and differences in community composition in order to provide predictive tools for future conservation and restoration.


Assuntos
Antozoários , Tempestades Ciclônicas , Animais , Benchmarking , Mudança Climática , Recifes de Corais , Ecossistema
4.
Sci Total Environ ; 805: 150261, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34536859

RESUMO

We assessed the importance of boulder reefs to the oxygen dynamics of a shallow estuary during two growing seasons in 2017 and 2018. Using open-system diel oxygen measurements and benthic and pelagic incubations, we evaluated the relative contribution of pelagic and benthic habitats to the ecosystem metabolism along a depth gradient in two areas, with (Reef) and without (Bare) boulder reefs in the Limfjorden, Denmark. System integrated areal rates of gross primary production (GPP) and ecosystem respiration (ER) both increased with depth in both areas. Benthic contribution to system GPP and ER was highest at shallow depth where it represented 47 and 53% respectively. However, with increasing depth pelagic processes dominated GPP and ER (98 and 94%) even in the Reef area. Although the Reef area had higher biomass of auto- and heterotrophic organisms (macroalgae and macrofauna), benthic GPP was at similar level in both areas, due to a significant contribution from micro-phytobenthic organisms. The Reef area had lower sediment pools of organic matter, nitrogen and phosphorous and was slightly more oxygenated compared to the nearby Bare area. Extreme temperatures and higher levels of nutrients in 2018 caused a marked increase in benthic ER rates resulting in net heterotrophy (NEM = GPP - ER < 0) in 2018 compared to net autotrophy (NEM > 0) in 2017. Under current eutrophic conditions, boulder reefs do not contribute positively to the oxygen dynamics in the estuary. Reoccurring blooms of phytoplankton with high organic matter decomposition combined with high temperatures and dominance of fauna stimulate depletion of oxygen around the reefs. Significant improvements in water clarity are needed to regrow perennial macroalgae and induce net autotrophy. Under current turbid conditions, it is only recommended to establish boulder reefs in shallow (<3 m) parts of the estuary.


Assuntos
Ecossistema , Estuários , Biomassa , Recifes de Corais , Oxigênio/análise , Fitoplâncton
5.
Chemosphere ; 287(Pt 1): 132125, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34523460

RESUMO

Organophosphate flame retardant (OPFR) pollution in marine environment has attracted increasing attention in recent years. Coral reefs are regarded as significant marine ecosystems, however, research on OPFR contamination in coral reefs is limited. In the present work, 9 OPFR compounds were analyzed in fish samples collected from the Zhubi Reef and Yongshu Reef of the Nansha Islands, South China Sea, to evaluate the biomagnification and potential threats of OPFRs in the coral reef ecosystems. ∑OPFR concentrations in the coral reef fish ranged from 38.7 to 2090 ng/g lipid weight (lw), with an average of 420 ± 491 ng/g lw. Alkyl OPFRs were more abundant than chlorinated OPFRs and aryl OPFRs. Individually, TBEP and TCPP were the two most abundant OPFR compounds. Biomagnification potential was indicated for TCPP, TCEP, TBP, TBEP and TEHP along the marine food web, with trophic magnification factors being greater than one. The estimated dietary intakes of OPFRs via coral fish consumption were 0-1.11 ng/kg bw/d and 0.01-2.06 ng/kg bw/d, respectively, for rural and urban residents. Additionally, the hazard quotients of OPFR compounds ranged from 2 × 10-7 to 7.41 × 10-5 for rural residents and from 4 × 10-7 to 1.37 × 10-4 for urban residents. Although the risk to human health from exposure to OPFRs via consuming coral reef fish from the South China Sea was low, further investigation of these chemicals is still recommended.


Assuntos
Retardadores de Chama , Animais , Bioacumulação , China , Recifes de Corais , Ecossistema , Humanos , Ilhas , Organofosfatos/toxicidade
6.
Dis Aquat Organ ; 147: 47-61, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34789587

RESUMO

Sponges are fundamental components of coral reef communities and, unfortunately, like other major benthic members, they too have been impacted by epizootic and panzootic events. We report on the prevalence of disease-like conditions affecting populations of the giant barrel sponge Xestospongia muta across shallow and mesophotic coral reefs off La Parguera Natural Reserve (LPNR) and Mona Island Marine Reserve (MIMR) in Puerto Rico. Four different conditions affecting X. muta were observed during our surveys, of which 3 have been previously reported: cyclic spotted bleaching (CSB; apparently non-lethal), Xestospongia-tissue wasting disease (X-TWD; apparently lethal), and sponge orange band disease (SOB; sparsely associated with X-TWD infected individuals). Additionally, we describe a fourth condition, Xestospongia-tissue hardening condition (X-THC), a previously unreported disease recently observed along the insular shelf margin off LPNR and MIMR. Within LPNR, a total of 764 specimens of X. muta were inspected and measured. Of these, 590 sponges (72.2%) had CSB, 25 (3.27%) had signs of X-TWD, 7 (0.92%) had SOB, and the remaining 142 (18.6%) were apparently healthy. Three colonies inhabiting upper mesophotic depths on the LPNR insular shelf showed signs of CSB and X-TWD. At MIMR, video-transect surveys revealed a total of 514 colonies, of which 40 (7.78%) had signs of CSB and/or XTWD, 14 (2.72%) were affected by X-THC, while the remaining 460 (89.5%) showed no external signs of disease and appeared healthy. The presence of 4 concomitant disease-like conditions in barrel sponges of Puerto Rico is alarming, and indicative of the deteriorating status of Caribbean coral reefs.


Assuntos
Antozoários , Xestospongia , Animais , Recifes de Corais , Ecossistema , Porto Rico/epidemiologia
7.
Environ Monit Assess ; 193(12): 828, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34796405

RESUMO

Within Pacific Small Island Developing States (Pacific SIDS), the ridge-to-reef (R2R) approach has emerged as a framework for monitoring river connectivity between terrestrial and marine ecosystems. The study measured water quality, including pH, over 88.40 km of the Ba River in Fiji. The sampling design focused on measuring spatio-temporal variability in pH throughout the sugarcane season with three rapid sampling periods (RSP1, 2 & 3) along the Ba River, together with continuous measurement of temperature and pH using stationary data loggers at two locations upstream and downstream of the sugar mill. Spatial variability in pH and water quality was characterised before (RSP1 and RSP2) and during (RSP3) the sugarcane season. Mean pH measured before the sugarcane crushing season for RSP1 and RSP2 were 8.16 (± 0.49) and 8.20 (± 0.61) respectively. During the sugarcane crushing season (RSP3), mean pH declined by 3.06 units to 6.94 within 42 m downstream of the sugar mill (P ≤ 0.001). The 3.06 unit decline in pH for RSP3 exceeded both the mean diurnal variation in pH of 0.39 and mean seasonal variation in pH of 2.01. This decline in pH could be a potential source of acidification to downstream coastal ecosystems with implications for coral reefs, biodiversity and fishery livelihoods.


Assuntos
Antozoários , Saccharum , Animais , Recifes de Corais , Ecossistema , Monitoramento Ambiental , Fiji , Concentração de Íons de Hidrogênio , Estações do Ano
8.
Anal Chem ; 93(46): 15306-15314, 2021 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-34761917

RESUMO

Coral reefs are one of the most biologically diverse ecosystems, and the accurate identification of the species is essential for diversity assessment and conservation. Current genus determination approaches are time-consuming and resource-intensive and can be highly subjective. To explore the hypothesis that the small-molecule profiles of coral are genus-specific and can be used as a rapid tool to catalogue and distinguish between coral genera, the small-molecule chemical fingerprints of the species Acanthastrea echinata, Catalaphyllia jardinei, Duncanopsammia axifuga, Echinopora lamellosa, Euphyllia divisa, Euphyllia paraancora, Euphyllia paradivisa, Galaxea fascicularis, Herpolitha limax, Montipora confusa, Monitpora digitata, Montipora setosa, Pachyseris rugosa, Pavona cactus, Plerogyra sinuosa, Pocillopora acuta, Seriatopora hystrix, Sinularia dura, Turbinaria peltata, Turbinaria reniformis, Xenia elongata, and Xenia umbellata were generated using direct analysis in real time-high resolution mass spectrometry (DART-HRMS). It is demonstrated here that the mass spectrum-derived small-molecule profiles for coral of different genera are distinct. Multivariate statistical analysis processing of the DART-HRMS data enabled rapid genus-level differentiation based on the chemical composition of the coral. Coral samples were analyzed with no sample preparation required, making the approach rapid and efficient. The resulting spectra were subjected to kernel discriminant analysis (KDA), which furnished accurate genus differentiation of the coral. Leave-one-out cross-validation (LOOCV) was carried out to determine the classification accuracy of each model and confirm that this approach can be used for coral genus attribution with prediction accuracies ranging from 86.67 to 97.33%. The advantages and application of the statistical analysis to DART-HRMS-derived coral chemical signatures for genus-level differentiation are discussed.


Assuntos
Antozoários , Animais , Recifes de Corais , Ecossistema , Espectrometria de Massas , Análise Multivariada
9.
Zootaxa ; 5032(1): 47-79, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34811144

RESUMO

A study involving experiments on a natural Brazilian coral reef, with the aim of assessing the impacts that may be caused by an increase in sea level on benthic fauna, showed that Chromadoridae Filipjev, 1917 was the most abundant and diverse family of Nematoda. Our results also showed that Chromadora Bastian, 1865 was the most abundant and diverse genus, represented by three species: C. serrambi sp. nov., C. pernambucana sp. nov. and C. macrolaimoides Steiner, 1915. Chromadora serrambi sp. nov. is the only Chromadora species where pre-cloacal supplements are absent. Chromadora pernambucana sp. nov. is differentiated by gubernaculum shape and by three supplements, of which two are cup-shaped (small and slightly sclerotized) and a pre-cloacal papilla very close to the cloaca. Chromadora macrolaimoides is very similar to specimens described previously. Here, we propose a grouping of species based on features considered to be most relevant for species identification and present it as an illustrated guide. The diagnostic characteristics of all species were considered, and following discussions, C. micropapillata was revalidated. Finally, the most relevant diagnostic characteristics for the differentiation of Chromadora species were highlighted.


Assuntos
Recifes de Corais , Nematoides , Animais , Brasil , Cromadoria
10.
Zootaxa ; 5031(1): 1-112, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34811146

RESUMO

Until now, 127 species of marine sponges have been recorded in the southern Gulf of Mexico (SGoM). In this study, we describe the sponge fauna recorded on 16 coral reefs of the SGoM, defined as the Mexican waters of the Gulf of Mexico (GoM), during a period from 2005 to 2019. We report 80 sponge species, including 34 first geographic records for the southern GoM region. The latter are fully described and illustrated, taking into account 24 that represent new records for the GoM: Agelas conifera, Agelas sventres, Agelas wiedenmayeri, Prosuberites carriebowensis, Desmanthus meandroides, Cliona aprica, Cliona dioryssa, Placospongia ruetzleri, Haliclona (Gellius) megasclera, Haliclona (Reniera) aff. portroyalensis, Neopetrosia proxima, Xestospongia arenosa, Calyx podatypa, Shiphonodictyon xamaycaense, Acarnus innominatus, Iotrochota arenosa, Polymastia tenax, Svenzea cristinae, Svenzea flava, Svenzea tubulosa, Svenzea zeai, Timea stenosclera, Stellettinopsis megastylifera, Suberea flavolivescens. The present work highlights the understimated and remarkable diversity of reef-associated sponges within the Campeche Bank Coral reef systems. Present work data was compiled with existing published information to produce an updated list of 161 known sponges in the southern GoM.


Assuntos
Agelas , Haliclona , Animais , Recifes de Corais , Golfo do México
11.
Zootaxa ; 4996(1): 1-48, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34810546

RESUMO

Sponges that excavate and inhabit calcareous substrate, predominantly of the Clionaidae, are widely distributed in marine habitats, but are particularly diverse and abundant on coral reefs. Unfortunately, their cryptic habit and difficult taxonomy mean respective taxa are poorly understood, and therefore they are rarely included in reef surveys. This is particularly true of the Southeast Asian Indo-Pacific, where a diverse faunistic record is contrasted with a very limited understanding of eco-physiological requirements of these sponges. In light of this, in situ surveys of the most common bioeroding sponges in the Wakatobi region of Southeast Sulawesi, Indonesia were conducted, followed by morphological and molecular analysis. The seven most common species in the Wakatobi included five species with a wide Indo-Pacific distribution and two new species. Four species, Cliona orientalis, Cliona aff. schmidtii, Spheciospongia cf. vagabunda trincomaliensis and Cliothosa hancocki have been previously reported from Indonesian waters, while Zyzzya criceta is a new record for Indonesia. Two brown sponges belonging to the Cliona viridis species complex, Cliona wakatobiensis sp. nov. and Cliona cribripora sp. nov., are here described as new to science. They were morphologically distinct from other species in the sample region and could not conclusively be allocated to any other known clionaid species. A maximum likelihood analysis of ITS1 rDNA revealed them to be phylogenetically closer to other Indo-Pacific species such as Cliona orientalis and Cliona thomasi than to other species within this taxon complex.


Assuntos
Recifes de Corais , Poríferos , Animais , DNA Ribossômico , Ecossistema , Indonésia
12.
Mar Genomics ; 60: 100877, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34627550

RESUMO

The settlement and metamorphosis of coral larvae are the bottleneck of coral recruitment. They are critical for the extension of coral population, which is the basis of the restoration of degraded coral reef ecosystem. In this study, we described the genomic characteristics of Metabacillus sp. cB07, which can efficiently induce larvae settlement and metamorphosis of coral Pocillopora damicornis. This function is first reported in the genus Metabacillus. Strain cB07 was isolated from the coral Porites pukoensis, and comprised one circular chromosome of 4,148,576 bp (44.14 mol% G + C content), containing 4148 protein coding sequences. To explore the potential mechanism of coral larvae settlement and metamorphosis induced by Metabacillus sp. cB07, we predicted that numerous genes related to the bacterial inductive ability. The genome of Metabacillus sp. cB07 will be helpful for further insights into the mechanism of bacterial induction of settlement and metamorphosis of coral larvae.


Assuntos
Antozoários , Animais , Antozoários/genética , Recifes de Corais , Ecossistema , Larva/genética , Metamorfose Biológica
13.
Mar Environ Res ; 172: 105484, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34695696

RESUMO

Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum. To elucidate settlement-related biofilm features, here we analyse the structure and composition of marine biofilms over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm coverage on the substratum and the reduction of the eukaryotic abundance and diversity. The prokaryotic assemblage become, over time, more similar to that found on the reef-associated biofilm. Vermetids may detect these differences and selectively settle on those biofilms which show an advantageous structure and composition. These outcomes may support the production of ideal substrates for vermetid colonization and their further translocation to repopulate degraded reefs.


Assuntos
Biofilmes , Invertebrados , Animais , Recifes de Corais
14.
Mar Environ Res ; 172: 105508, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34710739

RESUMO

Temperate reefs are being tropicalized worldwide. In temperate Western Australia, a marine heatwave led to a regime shift from kelp (Ecklonia radiata) dominated to canopy-free reefs, together with an increase in tropical herbivorous fishes that contribute to keeping low kelp abundances and even prevent kelp reestablishment in northern regions. However, whether tropical herbivorous fishes prefer kelps over other seaweeds and/or whether this preference changes with latitude remains untested. Multiple-choice experiments (young kelp vs. other seaweeds) with tropical, subtropical and temperate herbivorous fishes show shifting species-specific preferences and fish-to-fish interference shifting with latitude (assays replicated in two regions four degrees of latitude apart). Against expectations, only the temperate Kyphosus sydneyanus preferred kelp over other seaweeds, but only in the lower latitude region. Siganus fuscescens, the most abundant tropical herbivore in both regions, preferred grazing on turf, suggesting that tropical fish might reduce kelp recruitment by consuming microscopic sporophytes in turf matrix.


Assuntos
Kelp , Alga Marinha , Animais , Recifes de Corais , Ecossistema , Peixes , Herbivoria
15.
Mar Environ Res ; 172: 105505, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34717128

RESUMO

Concrete cubic frames and decommissioned steel naval vessels have been deployed in Thailand liberally to act as artificial substrates for coral restoration and marine recreation. We assessed recruitment at such substrate types at Koh Tao, Gulf of Thailand, and compared the community structure of scleractinian corals between artificial substrates and nearby natural reefs. Our results from a sample of 2677 recruits from nine sites highlighted significant differences in community structure between both reef types. Investigations of variables including time since deployment, distance from the natural reef, and seafloor depth revealed only the latter as a possible influencing factor. The diversity of recruits could not be explained by dynamics in coral spawning, and were found to represent groups with lower structural complexity. Our results suggest that coral community structure on artificial and natural reefs differs and supports distinct ecological and functional roles.


Assuntos
Antozoários , Animais , Recifes de Corais , Tailândia
16.
Mar Environ Res ; 172: 105504, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34717129

RESUMO

Carnivorous fish are a key part of the Indonesian human population sustenance, and it is important to design marine protected areas that include environmental features that allow these species to thrive. Many studies report the role of coral cover and habitat complexity in determining fish distribution on coral reefs but broader environmental factors such as current velocity and productivity are less studied. Southern Indonesia is characterised by upwellings and strong currents, stemming from the tidal cycle and the Indonesian Throughflow. In this study we investigate how current velocity, chlorophyll-a (chl-a), sea surface height and temperature relate to the biomass of carnivorous fish, considering the influence of habitat complexity and coral cover. Data were collected by surveying seven sites around Nusa Penida MPA for a total of 97 h of observation. Serranids and Lutjanids showed higher dependency on coral cover than fish from family Lethrinidae, Carangidae and Scombridae for which current, sea surface height, chl-a, and temperature were more influential predictors. Considering the similar trophic ecology of these species, the different relationship with oceanographic factors is likely related to different body shapes, living, and feeding habits between fish families. Changes in sea surface temperature and current velocity induced by vertical mixing are affecting coral reef fisheries-targeted species distribution in Nusa Penida and investigating these relationships on a broader scale will better inform marine spatial planning decisions.


Assuntos
Antozoários , Recifes de Corais , Animais , Biomassa , Ecossistema , Pesqueiros , Peixes , Humanos
17.
PLoS One ; 16(10): e0253867, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34610033

RESUMO

Sharks have declined worldwide and remote sanctuaries are becoming crucial for shark conservation. The southwest Indian Ocean is a hotspot of both terrestrial and marine biodiversity mostly impacted by anthropogenic damage. Sharks were observed during surveys performed from April to June 2013 in the virtually pristine coral reefs around Europa Island, a remote Marine Protected Area located in the southern Mozambique Channel. Observation events comprised 67 1-hour scientific dives between 5 - 35m depth and 7 snorkeling inspections, as well as 4 dinghy-based observations in the shallow lagoon. In a period of 24 days, 475 sharks were tallied. Carcharhinus galapagensis was most encountered and contributed 20% of the abundance during diving, followed by C. albimarginatus (10%). Both species were more abundant between 11-14h, and on the exposed sides of the island. Numbers of Sphyrna lewini were highest with 370 individuals windward and leeward, mostly schooling. S. lewini aggregations in the area are hypothesized to be attracted to the seamount archipelago offering favorable conditions for deep incursions and of which Europa Island forms part. C. amblyrhynchos, Galeocerdo cuvier and S. mokarran were uncommon, while there was an additional observation of Rhincodon typus. The lagoon of Europa was a nursery ground for C. melanopterus where it was the only species present. A total of 8 species was recorded, contributing to the shark diversity of 15 species reported from Europa since 1952 in the scientific and gray literature. Overall, with the occurrence of several species of apex predators in addition to that of R. typus, large schools of S. lewini, fair numbers of reef sharks and a nursery of C. melanopterus, Europa's sharks constitute a significant reservoir of biodiversity, which contributes to preserve the functioning of the ecosystem. Our observations highlight the relevance of Europa Island for shark conservation and the need for shark-targeted management in the EEZ of both Europa and Bassas da India.


Assuntos
Tubarões/fisiologia , Animais , Biodiversidade , Conservação dos Recursos Naturais/métodos , Recifes de Corais , Ecossistema , Oceano Índico , Moçambique , Densidade Demográfica , Especificidade da Espécie
18.
Mar Environ Res ; 172: 105490, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34628146

RESUMO

Emerging evidence have been supporting the idea that the better known South Atlantic coral reefs (located between 18°S and 24°S) are now essentially senescent structures that have experienced little or no additional vertical reef growth over the past millennia. This has often coincided with a shift to a dominance of non-coral calcifying organisms becoming the main CaCO3 producers in these high latitude and marginal marine settings. Here, we used Calcification Accretion Units (CAUs) and census-based methods to measure non-coral rates of CaCO3 production on the geologically senescent reef and adjacent rhodolith beds within the southernmost subtropical Atlantic reef (i.e., Queimada Grande Reef, QGR). The reef habitat is currently producing CaCO3 at rates of ∼126 g m-2 yr-1. In contrast, fragments of dead corals skeletons deposited adjacent to the reef over the last ∼2000 years are now colonized by crustose coralline red algae. These form a rhodolith bed that produces CaCO3 at rates of 858 g m-2 yr-1. Our results indicate that, whilst not sufficient to promote active net framework accumulation, CaCO3 production by coralline algae and bryozoans on the QGR appears to be sufficient to at least limit net large-scale erosion of the underlying reef structure, allowing the reef structure to persist in a state close to budgetary stasis. Finally, our results are also of relevance for providing insights regarding the balance of CaCO3 production/dissolution/erosion processes in coral reefs, especially in these less understood marginal reefs.


Assuntos
Antozoários , Briozoários , Animais , Carbonato de Cálcio , Recifes de Corais , Ecossistema
19.
Nat Commun ; 12(1): 5731, 2021 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-34593802

RESUMO

As coral reefs struggle to survive under climate change, it is crucial to know whether they have the capacity to withstand changing conditions, particularly increasing seawater temperatures. Thermal tolerance requires the integrative response of the different components of the coral holobiont (coral host, algal photosymbiont, and associated microbiome). Here, using a controlled thermal stress experiment across three divergent Caribbean coral species, we attempt to dissect holobiont member metatranscriptome responses from coral taxa with different sensitivities to heat stress and use phylogenetic ANOVA to study the evolution of gene expression adaptation. We show that coral response to heat stress is a complex trait derived from multiple interactions among holobiont members. We identify host and photosymbiont genes that exhibit lineage-specific expression level adaptation and uncover potential roles for bacterial associates in supplementing the metabolic needs of the coral-photosymbiont duo during heat stress. Our results stress the importance of integrative and comparative approaches across a wide range of species to better understand coral survival under the predicted rise in sea surface temperatures.


Assuntos
Aclimatação/genética , Antozoários/microbiologia , Dinoflagelados/genética , Resposta ao Choque Térmico , Microbiota/genética , Animais , Antozoários/fisiologia , Região do Caribe , Recifes de Corais , Dinoflagelados/metabolismo , Evolução Molecular , Redes e Vias Metabólicas/genética , Fotossíntese/genética , Filogenia , Simbiose/genética
20.
Braz J Biol ; 83: e245922, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34468513

RESUMO

Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesn't have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tile's material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.


Assuntos
Antozoários , Animais , Recifes de Corais , Ecossistema , Concentração de Íons de Hidrogênio , Indonésia , Larva , Água do Mar
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