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1.
Langmuir ; 37(14): 4137-4146, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33813823

RESUMO

Hydroxyapatite (HA) is the main inorganic component of human bones and teeth. It has good biocompatibility and bioactivity, which promotes its good application prospects in the field of bone drug carriers. In this study, tetraethylenepentamine-graphene (rGO-TEPA)/CaCO3:HA composite microspheres were prepared via microwave hydrothermal synthesis using rGO-TEPA/CaCO3 solid microspheres as intermediates. Furthermore, the incompletely transformed CaCO3 was removed by soaking in a citric acid buffer to obtain rGO-TEPA/HA hollow composite microspheres. The two types of as-prepared composite microspheres exhibited sea urchin-like structures, large BET surface areas, and good dispersibility. Mouse preosteoblast cells (MC3T3-E1) were used for in vitro cytotoxicity experiments. The in vitro cell viability test showed that the two composite drug carriers exhibited noncytotoxicity. Moreover, the doxorubicin (DOX) loading and releasing investigations revealed that the two types of prepared carriers had mild storage-release behaviors and good pH responsiveness. Hence, these rGO-TEPA/HA hollow microspheres have promising applications as bone drug carriers.


Assuntos
Materiais Biomiméticos , Osso e Ossos/metabolismo , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Durapatita , Grafite , Microesferas , Ouriços-do-Mar , Animais , Osso e Ossos/citologia , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/farmacologia , Etilenodiaminas , Concentração de Íons de Hidrogênio , Camundongos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos
2.
Mar Pollut Bull ; 163: 111914, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33385800

RESUMO

For short development species, like the sea urchin Heliocidaris erythrogramma, the entire planktonic duration can be impacted by marine heatwaves (MHW). Developmental thermal tolerance of this species through metamorphosis was investigated over a broad range (7.6-28.0 °C), including temperatures across its distribution and MHW conditions. In controls (19.5-21.0 °C), 80% of individuals developed to metamorphosis at day 5, doubling to 10 days at 14.0 °C. The thermal range (14.4-21.2 °C) of metamorphosis on day 7 reflected the realised thermal niche with 25.9 °C the upper temperature for success (T40). By day 10, juvenile tolerance narrowed to the local range (16.2-19.0 °C), similar to levels tolerated by adults, indicating negative carryover effects across the metamorphic transition. Without phenotypic adjustment or adaptation, regional warming will be detrimental, although populations may be sustained by thermotolerant offspring. Our results show the importance of the metamorphic transition in understanding the cumulative sensitivity of species to MHW.


Assuntos
Anthocidaris , Aclimatação , Adaptação Fisiológica , Animais , Humanos , Ouriços-do-Mar , Temperatura
3.
J Environ Manage ; 281: 111862, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33385898

RESUMO

Management of dredged materials disposal is regulated by several environmental normative requirements, and it is often supported by the integration of chemical data with ecotoxicological characterization. The reliability of a bioassay to assess the potential toxicity of dredged sediments requires the selection of quality criteria that should be based on simple analytical methods and easily understandable hazard for politicians and environmental managers. The sea urchin embryo-toxicity bioassay is considered an essential component for evaluating the quality of sediments in harbour areas but its use, when based exclusively on the observation of normal vs. abnormal embryos, may alter the interpretation of the results, overestimating the risk assessment. To improve the reliability of this assay in establishing a causative relationship between quality of sediments and sea urchin embryonic development, here we developed and validated three Integrative Toxicity Indexes (ITI 2.0, ITI 3.0, ITI 4.0), modifying the already-known ITI (here ITI 1.0). Based on this aim, we used Taranto harbour as a model pilot-study to compare results to those obtained from standard criteria. Among the tested indexes, the ITI 4.0, discriminating strictly developmental delay and morphological defects from fertilized egg to gastrula stage, resulted in the most promising.


Assuntos
Sedimentos Geológicos , Ouriços-do-Mar , Animais , Bioensaio , Embrião não Mamífero , Projetos Piloto , Reprodutibilidade dos Testes
4.
Ecotoxicol Environ Saf ; 208: 111665, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396175

RESUMO

Microplastics are ubiquitous in aquatic ecosystems, but little information is currently available on the dangers and risks to living organisms. In order to assess the ecotoxicity of environmental microplastics (MPs), samples were collected from the beaches of two islands in the Guadeloupe archipelago, Petit-Bourg (PB) located on the main island of Guadeloupe and Marie-Galante (MG) on the second island of the archipelago. These samples have a similar polymer composition with mainly polyethylene (PE) and polypropylene (PP). However, these two samples are very dissimilar with regard to their contamination profile and their toxicity. MPs from MG contain more lead, cadmium and organochlorine compounds while those from PB have higher levels of copper, zinc and hydrocarbons. The leachates of these two samples of MPs induced sublethal effects on the growth of sea urchins and on the pulsation frequency of jellyfish ephyrae but not on the development of zebrafish embryos. The toxic effects are much more marked for samples from the PB site than those from the MG site. This work demonstrates that MPs can contain high levels of potentially bioavailable toxic substances that may represent a significant ecotoxicological risk, particularly for the early life stages of aquatic animals.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Ecossistema , Ecotoxicologia , Ilhas , Microplásticos/química , Cifozoários/efeitos dos fármacos , Cifozoários/crescimento & desenvolvimento , Ouriços-do-Mar/efeitos dos fármacos , Ouriços-do-Mar/crescimento & desenvolvimento , Poluentes Químicos da Água/química
5.
Methods Mol Biol ; 2219: 195-216, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33074542

RESUMO

Identifying the location of a specific RNA in a cell, tissue, or embryo is essential to understand its function. Here we use echinoderm embryos to demonstrate the power of fluorescence in situ RNA hybridizations to localize sites of specific RNA accumulation in whole mount embryo applications. We add to this technology the use of various probe-labeling technologies to colabel multiple RNAs in one application and we describe protocols for incorporating immunofluorescence approaches to maximize the information obtained in situ. We offer alternatives for these protocols and troubleshooting advice to identify steps in which the procedure may have failed. Overall, echinoderms are wonderfully suited for these technologies, and these protocols are applicable to a wide range of cells, tissues, and embryos.


Assuntos
Equinodermos/genética , Equinodermos/ultraestrutura , Hibridização in Situ Fluorescente/métodos , RNA/genética , Animais , Imuno-Histoquímica/métodos , Microscopia Confocal/métodos , RNA/análise , Ouriços-do-Mar/genética , Ouriços-do-Mar/ultraestrutura , Fixação de Tecidos/métodos
6.
Chemosphere ; 263: 128276, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297220

RESUMO

Intense seaweed grazing by sea urchins has destroyed kelp forests and accelerated the transformation of these forests into barren areas known as urchin barrens. Once the sea urchins occupy the barren ground, it becomes more challenging to restore the kelp forests. Although phlorotannin, a primary herbivore defense chemical secreted by kelp, has been reported to discourage feeding activities of marine herbivores but the direct application of naturally extracted phlorotannin does not effectively repel sea urchins. In this study, we applied a simple and green Tannin-FeIII (TA-FeIII) coating on substrates as a sea urchin repellent using a cheap, ecofriendly tannin (TA) obtained from biomass as an alternative to phlorotannin. In a model aquarium experiment, most of the sea urchins (Anthocidaris crassispina) in the tank evaded the TA-FeIII-coated substrates. In field tests with 300 sea urchins, the majority of sea urchins could not crawl over the TA-FeIII-coated rope for more than 2 h in contrast to the control group. Hence, the safety, cost-effectiveness, and scalability of the TA-FeIII coating make it a practical candidate to protect the kelp ecosystem from sea urchins.


Assuntos
Ecossistema , Cadeia Alimentar , Animais , Compostos Férricos , Oceanos e Mares , Ouriços-do-Mar , Taninos
7.
Ambio ; 50(1): 163-173, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32720251

RESUMO

In this contribution, we propose fishery driven predator release as the cause for the largest grazing event ever observed in the NE Atlantic. Based on the evolving appreciation of limits to population connectivity, published and previously unpublished data, we discuss whether overfishing caused a grazer bloom of the sea urchin (Strongylocentrotus droebachiensis) resulting in overgrazing of more than 2000 km2 kelp (Laminaria hyperborea) forest along Norwegian and Russian coasts during the 1970 s. We show that coastal fisheries likely depleted predatory coastal fish stocks through modernization of fishing methods and fleet. These fish were important predators on urchins and the reduction coincided with the urchin bloom. From this circumstantial evidence, we hypothesize that coastal predatory fish were important in regulating sea urchins, and that a local population dynamics perspective is necessary in management of coastal ecosystems.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Pesqueiros , Peixes , Cadeia Alimentar , Federação Russa , Ouriços-do-Mar
8.
Methods Mol Biol ; 2179: 303-314, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32939729

RESUMO

An epithelial-mesenchymal transition (EMT) occurs in almost every metazoan embryo at the time mesoderm begins to differentiate. Several embryos have a long record as models for studying an EMT given that a known population of cells enters the EMT at a known time thereby enabling a detailed study of the process. Often, however, it is difficult to learn the molecular details of these model EMT systems because the transitioning cells are a minority of the population of cells in the embryo and in most cases there is an inability to isolate that population. Here we provide a method that enables an examination of genes expressed before, during, and after the EMT with a focus on just the cells that undergo the transition. Single cell RNA-seq (scRNA-seq) has advanced as a technology making it feasible to study the trajectory of gene expression specifically in the cells of interest, in vivo, and without the background noise of other cell populations. The sea urchin skeletogenic cells constitute only 5% of the total number of cells in the embryo yet with scRNA-seq it is possible to study the genes expressed by these cells without background noise. This approach, though not perfect, adds a new tool for uncovering the mechanism of EMT in this cell type.


Assuntos
Biologia Computacional/métodos , Transição Epitelial-Mesenquimal , RNA-Seq/métodos , Análise de Célula Única/métodos , Animais , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Ouriços-do-Mar
9.
Methods Mol Biol ; 2219: 253-265, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33074546

RESUMO

Cis-regulatory elements (CREs) and transcription factors (TFs) associated with them determine temporal and spatial domains of gene expression. Therefore, identification of these CREs and TFs is crucial to elucidating transcriptional programs across taxa. With chromatin accessibility facilitating transcription factor access to DNA, the identification of regions of open chromatin sheds light both on the function of the regulatory elements and their evolution, thus allowing the recognition of potential CREs. Buenrostro and colleagues have developed a novel method for exploring chromatin accessibility: assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq), which can be used for the purpose of identifying putative CREs. This method was shown to have considerable advantages when compared to traditional methods such as sequence conservation analyses or functional assays. Here we present the adaptation of the ATAC-seq method to echinoderm species and discuss how it can be used for CRE discovery.


Assuntos
Cromatina/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Ouriços-do-Mar/embriologia , Animais , DNA/genética , Fertilização In Vitro/métodos , Reação em Cadeia da Polimerase/métodos , Sequências Reguladoras de Ácido Nucleico , Ouriços-do-Mar/genética , Strongylocentrotus/embriologia , Strongylocentrotus/genética
10.
Dis Aquat Organ ; 142: 63-73, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33210613

RESUMO

Echinoderms such as sea urchins are important in marine ecosystems, particularly as grazers, and unhealthy sea urchins can have important ecological implications. For instance, unexplained mortalities of Diadema antillarum in the Caribbean were followed by algal overgrowth and subsequent collapse of coral reef ecosystems. Unfortunately, few tools exist to evaluate echinoderm health, making management of mortalities or other health issues problematic. Hematology is often used to assess health in many animal groups, including invertebrates, but is seldom applied to echinoderms. We used a standard gravitometric technique to concentrate fixed coelomocytes from the collector sea urchin Tripneustes gratilla onto microscope slides, permitting staining and enumeration. Using Romanowsky stain and electron microscopy to visualize cell details, we found that urchin cells could be partitioned into different morphotypes. Specifically, we enumerated phagocytes, phagocytes with perinuclear cytoplasmic dots, vibratile cells, colorless spherule cells, red spherule cells, and red spherule cells with pink granules. We also saw cell-in-cell interactions characterized by phagocytes apparently phagocytizing mainly the motile cells including red spherule cells, colorless spherule cells, and vibratile cells disproportionate to underlying populations of circulating cells. Cell-in-cell interactions were seen in 71% of sea urchins, but comprised <1% of circulating cells. Finally, about 40% of sea urchins had circulating phagocytes that were apparently phagocytizing spicules. The coelomic fluid collection and slide preparation methods described here are simple, field portable, and might be a useful complementary tool for assessing health of other marine invertebrates, revealing heretofore unknown physiological phenomena in this animal group.


Assuntos
Ecossistema , Ouriços-do-Mar , Animais , Região do Caribe , Comunicação Celular , Recifes de Corais
11.
PLoS One ; 15(10): e0239136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33035224

RESUMO

Ocean warming, ocean acidification and overfishing are major threats to the structure and function of marine ecosystems. Driven by increasing anthropogenic emissions of CO2, ocean warming is leading to global redistribution of marine biota and altered ecosystem dynamics, while ocean acidification threatens the ability of calcifying marine organisms to form skeletons due to decline in saturation state of carbonate Ω and pH. In Tasmania, the interaction between overfishing of sea urchin predators and rapid ocean warming has caused a phase-shift from productive kelp beds to overgrazed sea urchin barren grounds, however potential impacts of ocean acidification on this system have not been considered despite this threat for marine ecosystems globally. Here we use automated loggers and point measures of pH, spanning kelp beds and barren grounds, to reveal that kelp beds have the capacity to locally ameliorate effects of ocean acidification, via photosynthetic drawdown of CO2, compared to unvegetated barren grounds. Based on meta-analysis of anticipated declines in physiological performance of grazing urchins to decreasing pH and assumptions of nil adaptation, future projection of OA across kelp-barrens transition zones reveals that kelp beds could act as important pH refugia, with urchins potentially becoming increasingly challenged at distances >40 m from kelp beds. Using spatially explicit simulation of physicochemical feedbacks between grazing urchins and their kelp prey, we show a stable mosaicked expression of kelp patches to emerge on barren grounds. Depending on the adaptative capacity of sea urchins, future declines in pH appear poised to further alter phase-shift dynamics for reef communities; thus, assessing change in spatial-patterning of reef-scapes may indicate cascading ecological impacts of ocean acidification.


Assuntos
Kelp , Oceanos e Mares , Refúgio de Vida Selvagem , Animais , Organismos Aquáticos/metabolismo , Mudança Climática , Simulação por Computador , Conservação dos Recursos Naturais , Ecossistema , Pesqueiros , Cadeia Alimentar , Concentração de Íons de Hidrogênio , Kelp/metabolismo , Ouriços-do-Mar/metabolismo , Água do Mar/química , Tasmânia
12.
Mar Environ Res ; 162: 105194, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33126114

RESUMO

Changing oceans represent a serious threat for a wide range of marine organisms, with severe cascading effects on ecosystems and their services. Sea urchins are particularly sensitive to decreased pH expected for the end of the century and their key ecological role in regulating community structure and functioning could be seriously compromised. An integrated approach of laboratory and field experiments has been implemented to investigate the effects of decreased pH on predator-prey interaction involving sea urchins and their predators. Our results suggest that under future Ocean Acidification scenarios adult sea urchins defence strategies, such as spine length, test robustness and oral plate thickness, could be compromised together with their survival chance to natural predators. Sea urchins represent the critical linkage between top-down and bottom-up processes along Mediterranean rocky reefs, and the cumulative impacts of global and local stressors could lead to a decline producing cascading effects on benthic ecosystems.


Assuntos
Ecossistema , Água do Mar , Animais , Peixes , Concentração de Íons de Hidrogênio , Oceanos e Mares , Ouriços-do-Mar
13.
BMC Evol Biol ; 20(1): 121, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938400

RESUMO

BACKGROUND: As global change and anthropogenic pressures continue to increase, conservation and management increasingly needs to consider species' potential to adapt to novel environmental conditions. Therefore, it is imperative to characterise the main selective forces acting on ecosystems, and how these may influence the evolutionary potential of populations and species. Using a multi-model seascape genomics approach, we compare putative environmental drivers of selection in three sympatric southern African marine invertebrates with contrasting ecology and life histories: Cape urchin (Parechinus angulosus), Common shore crab (Cyclograpsus punctatus), and Granular limpet (Scutellastra granularis). RESULTS: Using pooled (Pool-seq), restriction-site associated DNA sequencing (RAD-seq), and seven outlier detection methods, we characterise genomic variation between populations along a strong biogeographical gradient. Of the three species, only S. granularis showed significant isolation-by-distance, and isolation-by-environment driven by sea surface temperatures (SST). In contrast, sea surface salinity (SSS) and range in air temperature correlated more strongly with genomic variation in C. punctatus and P. angulosus. Differences were also found in genomic structuring between the three species, with outlier loci contributing to two clusters in the East and West Coasts for S. granularis and P. angulosus, but not for C. punctatus. CONCLUSION: The findings illustrate distinct evolutionary potential across species, suggesting that species-specific habitat requirements and responses to environmental stresses may be better predictors of evolutionary patterns than the strong environmental gradients within the region. We also found large discrepancies between outlier detection methodologies, and thus offer a novel multi-model approach to identifying the principal environmental selection forces acting on species. Overall, this work highlights how adding a comparative approach to seascape genomics (both with multiple models and species) can elucidate the intricate evolutionary responses of ecosystems to global change.


Assuntos
Braquiúros/genética , Ecossistema , Gastrópodes/genética , Genética Populacional , Ouriços-do-Mar/genética , Seleção Genética , Animais , Genômica , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Temperatura
14.
Proc Biol Sci ; 287(1934): 20201506, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32900308

RESUMO

The sea urchin embryo develops a calcitic endoskeleton through intracellular formation of amorphous calcium carbonate (ACC). Intracellular precipitation of ACC, requires [Formula: see text] concentrating as well as proton export mechanisms to promote calcification. These processes are of fundamental importance in biological mineralization, but remain largely unexplored. Here, we demonstrate that the calcifying primary mesenchyme cells (PMCs) use Na+/H+-exchange (NHE) mechanisms to control cellular pH homeostasis during maintenance of the skeleton. During skeleton re-calcification, pHi of PMCs is increased accompanied by substantial elevation in intracellular [Formula: see text] mediated by the [Formula: see text] cotransporter Sp_Slc4a10. However, PMCs lower their pHi regulatory capacities associated with a reduction in NHE activity. Live-cell imaging using green fluorescent protein reporter constructs in combination with intravesicular pH measurements demonstrated alkaline and acidic populations of vesicles in PMCs and extensive trafficking of large V-type H+-ATPase (VHA)-rich acidic vesicles in blastocoelar filopodial cells. Pharmacological and gene expression analyses underline a central role of the VHA isoforms Sp_ATP6V0a1, Sp_ATP6V01_1 and Sp_ATPa1-4 for the process of skeleton re-calcification. These results highlight novel pH regulatory strategies in calcifying cells of a marine species with important implications for our understanding of the mineralization process in times of rapid changes in oceanic pH.


Assuntos
Bicarbonatos/metabolismo , Ouriços-do-Mar/fisiologia , Animais , Transporte Biológico , Calcificação Fisiológica , Carbonato de Cálcio , Concentração de Íons de Hidrogênio , Oceanos e Mares , Prótons , Água do Mar
15.
Phys Rev Lett ; 125(9): 098002, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32915620

RESUMO

Many biological systems display intriguing chiral patterns and dynamics. Here, we present an active nematic theory accounting for individual spin to explore the collective handedness in chiral rod-shaped aggregations. We show that coordinated individual spin and motility can engender a vortex-array pattern with chirality and drive ordering of topological defects. During this chiral process, the stationary trefoil-like defects self-organize into a periodic, hexagon-dominated polygonal network, which segregates persistently rotating cometlike defects in pairs within each polygon, leading to a translation symmetry at the global scale while a broken reflection symmetry at the local scale. Such defect ordering agrees exactly with the Voronoi tiling of two-dimensional space and the emergence of the hexagonal symmetry is deciphered in analogy with topological charge neutralization. We calculate energy barriers to the topological transition of the defect ordering and explain the existing metastable states with nonhexagonal polygons. Our findings shed light on the chiral morphodynamics in life processes and also suggest a potential route towards tuning self-organization in active materials.


Assuntos
Flagelos/fisiologia , Modelos Biológicos , Espermatozoides/fisiologia , Animais , Fenômenos Fisiológicos Bacterianos , Masculino , Movimento/fisiologia , Ouriços-do-Mar
16.
Sci Total Environ ; 747: 141206, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32777501

RESUMO

Mortality and metabolic responses of four-armed larvae of Strongylocentrotus intermedius under CO2-induced seawater acidification were investigated. Gametes of S. intermedius were fertilized and developed to the four-armed larval stage in either current natural seawater pH levels (as Control; pH = 7.99 ± 0.01) or laboratory-controlled acidified conditions (OA1: ΔpH = -0.3 units; OA2: ΔpH = -0.4 units; OA3: ΔpH = -0.5 units) according to the predictions of the Intergovernmental Panel on Climate Change (IPCC). The degrees of spicule exposure and asymmetry and mortality of four-armed larvae of S. intermedius were observed; each had a significant linearly increasing trend as the seawater pH level decreased. Comparative metabolome analysis identified a total of 87 significantly differentially expressed metabolites (SDMs, UP: 57, DOWN: 30) in OA-treated groups compared with the control group. Twenty-three SDMs, including carnitine, lysophosphatidylcholine (LPC) 18:3, lysophosphatidyl ethanolamine (LPE) 16:1, glutathione (GSH) and L-ascorbate, exhibited a linear increasing trend with decreasing seawater pH. Nine SDMs exhibited a linear decreasing trend as the seawater pH declined, including hypoxanthine, guanine and thymidine. Among all SDMs, we further mined 48 potential metabolite biomarkers responding to seawater acidification in four-armed larvae of S. intermedius. These potential metabolite biomarkers were mainly enriched in five pathways: glycerophospholipid metabolism, glutathione metabolism, purine metabolism, pyrimidine metabolism and the tricarboxylic acid cycle (TCA cycle). Our results will enrich our knowledge of the molecular mechanisms employed by sea urchins in response to CO2-induced seawater acidification.


Assuntos
Strongylocentrotus , Animais , Dióxido de Carbono/toxicidade , Concentração de Íons de Hidrogênio , Larva , Metaboloma , Ouriços-do-Mar , Água do Mar
17.
PLoS One ; 15(8): e0237257, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785267

RESUMO

Global climate change is driving the redistribution of marine species and thereby potentially restructuring endemic communities. Understanding how localised conservation measures such as protection from additional human pressures can confer resilience to ecosystems is therefore an important area of research. Here, we examine the resilience of a no-take marine reserve (NTR) to the establishment of urchin barrens habitat. The barrens habitat is created through overgrazing of kelp by an invading urchin species that is expanding its range within a hotspot of rapid climate change. In our study region, a multi-year monitoring program provides a unique time-series of benthic imagery collected by an Autonomous Underwater Vehicle (AUV) within an NTR and nearby reference areas. We use a Bayesian hierarchical spatio-temporal modelling approach to estimate whether the NTR is associated with reduced formation of urchin barrens, and thereby enhances local resilience. Our approach controls for the important environmental covariates of depth and habitat complexity (quantified as rugosity derived from multibeam sonar mapping), as well as spatial and temporal dependence. We find evidence for the NTR conferring resilience with a strong reserve effect that suggests improved resistance to the establishment of barrens. However, we find a concerning and consistent trajectory of increasing barrens cover in both the reference areas and the NTR, with the odds of barrens increasing by approximately 32% per year. Thus, whereas the reserve is demonstrating resilience to the initial establishment of barrens, there is currently no evidence of recovery once barrens are established. We also find that depth and rugosity covariates derived from multibeam mapping provide useful predictors for barrens occurrence. These results have important management implications as they demonstrate: (i) the importance of monitoring programs to inform adaptive management; (ii) that NTRs provide a potential local conservation management tool under climate change impacts, and (iii) that technologies such as AUVs and multibeam mapping can be harnessed to inform regional decision-making. Continuation of the current monitoring program is required to assess whether the NTR can provide long term protection from a phase shift that replaces kelp with urchin barrens.


Assuntos
Ouriços-do-Mar , Distribuição Animal , Animais , Organismos Aquáticos/fisiologia , Teorema de Bayes , Mudança Climática , Conservação dos Recursos Naturais , Ouriços-do-Mar/fisiologia
18.
Mar Pollut Bull ; 158: 111437, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753220

RESUMO

Microplastic pollution is an increasing problem in the marine environment. This study had three objectives: 1) determine if seagrass beds and adjacent sand flats in the Florida Keys differed in microplastics concentration, 2) determine if sea cucumbers from the Florida Keys and sand dollars from the panhandle of Florida contain microplastics, and 3) conduct a laboratory experiment on the sand dollar Mellita tenuis to determine if it will ingest plastic microbeads contained in sediment. Both seagrass beds and sand flats in the Florida Keys contained microplastics. Sediment near Pensacola Beach and in St. Joseph Bay contained microplastics. Sea cucumbers from the Florida Keys and sand dollars from the panhandle of Florida contained microplastics in their gut contents. In the laboratory, M. tenuis ingested microbeads in slightly lower proportions compared to surrounding sediment. Both sea cucumbers and sand dollars may make useful animals for monitoring sandy environments for microplastics pollution.


Assuntos
Pepinos-do-Mar , Poluentes Químicos da Água/análise , Animais , Equinodermos , Monitoramento Ambiental , Florida , Microplásticos , Plásticos , Ouriços-do-Mar
19.
Mar Pollut Bull ; 159: 111493, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32736201

RESUMO

The consumption of anticancer agents has increased in the recent decades, and these substances may be present in sewage. Consequently, they may reach the environment when sanitation infrastructure is ineffective. This study evaluated the toxicity of three anticancer agents-Tamoxifen (TAM), Cisplatin (CisPt), and Cyclophosphamide (CP)-on the development of embryos of the sand-dollar Mellita quinquiesperforata. Adult individuals were collected in sandy beaches, and gametes were obtained. Freshly-fertilized eggs were exposed to increasing sets of concentrations of each compound, and the effective concentrations needed to cause a 50% effect in the organisms (EC50) were calculated. The three compounds were toxic, and their EC50 values were 16.78 ± 2.42 ng·L-1 (TAM), 27.20 ± 38.26 ng·L-1 (CisPt), and 101.82 ± 70.96 ng·L-1 (CP). There is no information on the environmental levels of these compounds in Brazil, but as they were already detected in ng·L-1 levels worldwide, it can be expected that these substances pose environmental risks to the marine biota.


Assuntos
Antineoplásicos , Poluentes Químicos da Água/análise , Animais , Brasil , Ecotoxicologia , Ouriços-do-Mar , Testes de Toxicidade
20.
PLoS One ; 15(8): e0236200, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32846430

RESUMO

Indo-Pacific lionfish have become invasive throughout the western Atlantic. Their predatory effects have been the focus of much research and are suggested to cause declines in native fish abundance and diversity across the invaded range. However, little is known about their non-consumptive effects, or their effects on invertebrates. Lionfish use shelters on the reef, thus there is potential for competition with other shelter-dwelling organisms. We demonstrate similar habitat associations between invasive lionfish, native spiny lobsters (Panulirus argus) and native long-spined sea urchins (Diadema antillarum), indicating the potential for competition. We then used a laboratory experiment to compare activity and shelter use of each species when alone and when lionfish were paired with each native species. Spiny lobsters increased their activity but did not change their shelter use in the presence of a lionfish, whilst long-spined sea urchins changed neither their activity nor shelter use. However, lionfish reduced their shelter use in the presence of spiny lobsters and long-spined sea urchins. This study highlights the importance not only of testing for the non-consumptive effects of invasive species, but also exploring whether native species exert non-consumptive effects on the invasive.


Assuntos
Peixes/fisiologia , Comportamento de Retorno ao Território Vital , Espécies Introduzidas , Palinuridae/fisiologia , Ouriços-do-Mar/fisiologia , Distribuição Animal , Animais , Região do Caribe , Recifes de Corais , Dinâmica Populacional
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