Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 218
Filtrar
1.
Mar Pollut Bull ; 205: 116631, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38917503

RESUMEN

The causes of the physiological effects of microplastic pollution, potentially harming reef-building corals, are unclear. Reasons might include increased energy demands for handling particles and immune reactions. This study is among the first assessing the effects of long-term microplastic exposure on coral physiology at realistic concentrations (200 polyethylene particles L-1). The coral species Acropora muricata, Pocillopora verrucosa, Porites lutea, and Heliopora coerulea were exposed to microplastics for 11 months, and energy reserves, metabolites, growth, and photosymbiont state were analyzed. Results showed an overall low impact on coral physiology, yet species-specific effects occurred. Specifically, H. coerulea exhibited reduced growth, P. lutea and A. muricata showed changes in photosynthetic efficiency, and A. muricata variations in taurine levels. These findings suggest that corals may possess compensatory mechanisms mitigating the effects of microplastics. However, realistic microplastic concentrations only occasionally affected corals. Yet, corals exposed to increasing pollution scenarios will likely experience more negative impacts.


Asunto(s)
Antozoos , Arrecifes de Coral , Microplásticos , Fotosíntesis , Polietileno , Contaminantes Químicos del Agua , Animales , Antozoos/efectos de los fármacos , Antozoos/fisiología , Microplásticos/toxicidad , Fotosíntesis/efectos de los fármacos , Polietileno/toxicidad , Contaminantes Químicos del Agua/toxicidad , Monitoreo del Ambiente
2.
Mar Pollut Bull ; 203: 116491, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38754321

RESUMEN

Endosymbionts (Symbiodiniaceae) play a vital role in the health of corals. Seawater pollution can harm these endosymbionts and dispersants used during oil spill cleanup can be extremely toxic to these organisms. Here, we examined the impact of oil and a specific dispersant, Corexit-9500, on two representative endosymbionts - Symbiodinium and Cladocopium - from the Southwestern endemic coral Mussismilia braziliensis. The survival and photosynthetic potential of the endosymbionts decreased dramatically after exposure to the dispersant and oil by ~25 % after 2 h and ~50 % after 7 days. Low concentrations of dispersant (0.005 ml/l) and dispersed oil (Polycyclic Aromatic Hydrocarbons, 1132 µg/l; Total Petroleum Hydrocarbons, 595 µg/l) proved highly toxic to both Symbiodinium and Cladocopium. These levels triggered a reduction in growth rate, cell size, and cell wall thickness. After a few hours of exposure, cellular organelles were damaged or destroyed. These acute toxic effects underline the fragile nature of coral endosymbionts.


Asunto(s)
Antozoos , Dinoflagelados , Contaminación por Petróleo , Petróleo , Simbiosis , Contaminantes Químicos del Agua , Antozoos/efectos de los fármacos , Antozoos/fisiología , Animales , Petróleo/toxicidad , Dinoflagelados/fisiología , Dinoflagelados/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Lípidos , Tensoactivos/toxicidad
3.
PeerJ ; 12: e17259, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38699194

RESUMEN

Iron (Fe) plays a fundamental role in coral symbiosis, supporting photosynthesis, respiration, and many important enzymatic reactions. However, the extent to which corals are limited by Fe and their metabolic responses to inorganic Fe enrichment remains to be understood. We used respirometry, variable chlorophyll fluorescence, and O2 microsensors to investigate the impact of increasing Fe(III) concentrations (20, 50, and 100 nM) on the photosynthetic capacity of two Mediterranean coral species, Cladocora caespitosa and Oculina patagonica. While the bioavailability of inorganic Fe can rapidly decrease, we nevertheless observed significant physiological effects at all Fe concentrations. In C. caespitosa, exposure to 50 nM Fe(III) increased rates of respiration and photosynthesis, while the relative electron transport rate (rETR(II)) decreased at higher Fe(III) exposure (100 nM). In contrast, O. patagonica reduced respiration, photosynthesis rates, and maximum PSII quantum yield (Fv/Fm) across all iron enrichments. Both corals exhibited increased hypoxia (<50 µmol O2 L-1) within their gastric cavity at night when exposed to 50 and 100 nM Fe(III), leading to increased polyp contraction time and reduced O2 exchange with the surrounding water. Our results indicate that C. caespitosa, but not O. patagonica, might be limited in Fe for achieving maximal photosynthetic efficiency. Understanding the multifaceted role of iron in corals' health and their response to environmental change is crucial for effective coral conservation.


Asunto(s)
Antozoos , Hierro , Oxígeno , Fotosíntesis , Antozoos/efectos de los fármacos , Antozoos/metabolismo , Animales , Fotosíntesis/efectos de los fármacos , Hierro/metabolismo , Oxígeno/metabolismo , Mar Mediterráneo , Simbiosis
4.
PLoS One ; 17(2): e0263061, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35192627

RESUMEN

Cold-water coral (CWC) reefs are numerous and widespread along the Norwegian continental shelf where oil and gas industry operate. Uncertainties exist regarding their impacts from operational discharges to drilling. Effect thresholds obtained from near-realistic exposure of suspended particle concentrations for use in coral risk modeling are particularly needed. Here, nubbins of Desmophyllum pertusum (Lophelia pertusa) were exposed shortly (5 days, 4h repeated pulses) to suspended particles (bentonite BE; barite BA, and drill cuttings DC) in the range of ~ 4 to ~ 60 mg.l-1 (actual concentration). Physiological responses (respiration rate, growth rate, mucus-related particulate organic carbon OC and particulate organic nitrogen ON) and polyp mortality were then measured 2 and 6 weeks post-exposure to assess long-term effects. Respiration and growth rates were not significantly different in any of the treatments tested compared to control. OC production was not affected in any treatment, but a significant increase of OC:ON in mucus produced by BE-exposed (23 and 48 mg.l-1) corals was revealed 2 weeks after exposure. Polyp mortality increased significantly at the two highest DC doses (19 and 49 mg.l-1) 2 and 6 weeks post-exposure but no significant difference was observed in any of the other treatments compared to the control. These findings are adding new knowledge on coral resilience to short realistic exposure of suspended drill particles and indicate overall a risk for long-term effects at a threshold of ~20 mg.l-1.


Asunto(s)
Adaptación Fisiológica , Antozoos/efectos de los fármacos , Sulfato de Bario/farmacología , Bentonita/farmacología , Material Particulado/farmacología , Frecuencia Respiratoria/efectos de los fármacos , Animales , Antozoos/crecimiento & desarrollo , Carbono/química , Carbono/metabolismo , Arrecifes de Coral , Industria Procesadora y de Extracción/métodos , Humanos , Longevidad/efectos de los fármacos , Nitrógeno/química , Nitrógeno/metabolismo , Noruega , Frecuencia Respiratoria/fisiología , Agua/química
5.
Sci Rep ; 11(1): 21636, 2021 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-34737333

RESUMEN

Over 30 herbicides have been detected in catchments and waters of the Great Barrier Reef (GBR) and their toxicity to key tropical species, including the coral endosymbiotic algae Symbiodiniaceae, is not generally considered in current water quality guideline values (WQGVs). Mutualistic symbionts of the family Symbiodiniaceae are essential for the survival of scleractinian corals. We tested the effects of nine GBR-relevant herbicides on photosynthetic efficiency (ΔF/Fm') and specific growth rate (SGR) over 14 days of cultured coral endosymbiont Cladocopium goreaui (formerly Symbiodinium clade C1). All seven Photosystem II (PSII) herbicides tested inhibited ΔF/Fm' and SGR, with toxicity thresholds for SGR ranging between 2.75 and 320 µg L-1 (no effect concentration) and 2.54-257 µg L-1 (EC10). There was a strong correlation between EC50s for ΔF/Fm' and SGR for all PSII herbicides indicating that inhibition of ΔF/Fm' can be considered a biologically relevant toxicity endpoint for PSII herbicides to this species. The non-PSII herbicides haloxyfop and imazapic did not affect ΔF/Fm' or SGR at the highest concentrations tested. The inclusion of this toxicity data for Symbiodiniaceae will contribute to improving WQGVs to adequately inform risk assessments and the management of herbicides in tropical marine ecosystems.


Asunto(s)
Antozoos/efectos de los fármacos , Antozoos/metabolismo , Herbicidas/efectos adversos , Animales , Conservación de los Recursos Naturales/métodos , Arrecifes de Coral , Ecosistema , Herbicidas/farmacología , Herbicidas/toxicidad , Fotosíntesis/efectos de los fármacos , Complejo de Proteína del Fotosistema II/efectos de los fármacos , Simbiosis/fisiología , Contaminantes Químicos del Agua/farmacología
6.
Curr Probl Dermatol ; 55: 259-265, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34698047

RESUMEN

Recent and pending bans in specific jurisdictions of some organic ultraviolet (UV) filters have resulted in significant concern and controversy over the potential impacts of these contaminants in the marine environment. Organic UV filters have been quantified in the aquatic environment as contaminants in water, sediments, and the tissues of aquatic organisms. The limited available laboratory studies on the toxicity of UV filters to keystone marine species such as reef-building corals describe a wide variety of impacts, from significant acute effects to no observed effects. However, interpretation of results is complicated by differences in methodology, and exposures to single agents in vitro may not reflect the effects of longer exposure to finished sunscreens containing UV filters in combination with numerous other chemicals. Relatively short-term observations of laboratory effects thus may not translate to real-life field conditions, where organisms may be subject to the effects of long-term chronic exposure to UV filters as well as other environmental contaminants and stressors. The lack of current understanding of the full impacts of UV filters, both in the laboratory and in the environment, represents a significant challenge in interpreting the environmental risk associated with the widespread use of sunscreens.


Asunto(s)
Antozoos/efectos de los fármacos , Organismos Acuáticos/efectos de los fármacos , Agua de Mar/química , Protectores Solares/efectos adversos , Contaminación Química del Agua/prevención & control , Animales , Seguridad de Productos para el Consumidor/legislación & jurisprudencia , Seguridad de Productos para el Consumidor/normas , Monitoreo del Ambiente/estadística & datos numéricos , Humanos , Medición de Riesgo , Natación , Rayos Ultravioleta/efectos adversos
7.
Sci Rep ; 11(1): 13165, 2021 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-34162916

RESUMEN

Coral reefs, especially those located near-shore, are increasingly exposed to anthropogenic, eutrophic conditions that are often chronic. Yet, corals under unperturbed conditions may frequently receive natural and usually temporary nutrient supplementation through biological sources such as fishes. We compared physiological parameters indicative of long- and short-term coral health (day and night calcification, fragment surface area, productivity, energy reserves, and tissue stoichiometry) under continuous and temporary nutrient enrichment. The symbiotic coral Acropora intermedia was grown for 7 weeks under continuously elevated (press) levels of ammonium (14 µmol L-1) and phosphate (10 µmol L-1) as separate and combined treatments, to discern the individual and interactive nutrient effects. Another treatment exposed A. intermedia twice-daily to an ammonium and phosphate pulse of the same concentrations as the press treatments to simulate natural biotic supplementation. Press exposure to elevated ammonium or phosphate produced mixed effects on physiological responses, with little interaction between the nutrients in the combined treatment. Overall, corals under press exposure transitioned resources away from calcification. However, exposure to nutrient pulses often enhanced physiological responses. Our findings indicate that while continuous nutrient enrichment may pose a threat to coral health, episodic nutrient pulses that resemble natural nutrient supplementation may significantly benefit coral health and physiology.


Asunto(s)
Compuestos de Amonio/farmacología , Antozoos/efectos de los fármacos , Fosfatos/farmacología , Compuestos de Amonio/administración & dosificación , Animales , Antozoos/crecimiento & desarrollo , Antozoos/metabolismo , Calcificación Fisiológica/efectos de los fármacos , Ritmo Circadiano , Fosfatos/administración & dosificación , Fotosíntesis , Distribución Aleatoria , Agua de Mar
8.
Sci Rep ; 11(1): 10871, 2021 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-34050204

RESUMEN

Methylene blue (MB) is a century-old medicine, a laboratory dye, and recently shown as a premier antioxidant that combats ROS-induced cellular aging in human skins. Given MB's molecular structure and light absorption properties, we hypothesize that MB has the potential to be considered as a sunscreen active for UV radiation protection. In this study, we tested the effects of MB on UVB ray-induced DNA double-strand breaks in primary human keratinocytes. We found that MB treatment reduced DNA damages caused by UVB irradiation and subsequent cell death. Next, we compared MB with Oxybenzone, which is the most commonly used chemical active ingredient in sunscreens but recently proven to be hazardous to aquatic ecosystems, in particular to coral reefs. At the same concentrations, MB showed more effective UVB absorption ability than Oxybenzone and significantly outperformed Oxybenzone in the prevention of UVB-induced DNA damage and the clearance of UVA-induced cellular ROS. Furthermore, unlike Oxybenzone, MB-containing seawater did not affect the growth of the coral species Xenia umbellata. Altogether, our study suggests that MB has the potential to be a coral reef-friendly sunscreen active ingredient that can provide broad-spectrum protection against UVA and UVB.


Asunto(s)
Envejecimiento/efectos de los fármacos , Antozoos/efectos de los fármacos , Azul de Metileno/farmacología , Piel/efectos de los fármacos , Envejecimiento/patología , Envejecimiento/efectos de la radiación , Animales , Antioxidantes/farmacología , Benzofenonas/efectos adversos , Arrecifes de Coral , Roturas del ADN de Doble Cadena/efectos de los fármacos , Roturas del ADN de Doble Cadena/efectos de la radiación , Daño del ADN/efectos de los fármacos , Daño del ADN/efectos de la radiación , Ecosistema , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/efectos de la radiación , Luz/efectos adversos , Azul de Metileno/química , Protección Radiológica , Piel/efectos de la radiación , Protectores Solares/efectos adversos , Rayos Ultravioleta/efectos adversos
9.
Sci Rep ; 11(1): 8566, 2021 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-33883581

RESUMEN

Stony coral tissue loss disease (SCTLD) was first observed in Florida in 2014 and has since spread to multiple coral reefs across the wider Caribbean. The northern section of Florida's Coral Reef has been heavily impacted by this outbreak, with some reefs experiencing as much as a 60% loss of living coral tissue area. We experimentally assessed the effectiveness of two intervention treatments on SCTLD-affected Montastraea cavernosa colonies in situ. Colonies were tagged and divided into three treatment groups: (1) chlorinated epoxy, (2) amoxicillin combined with CoreRx/Ocean Alchemists Base 2B, and (3) untreated controls. The experimental colonies were monitored periodically over 11 months to assess treatment effectiveness by tracking lesion development and overall disease status. The Base 2B plus amoxicillin treatment had a 95% success rate at healing individual disease lesions but did not necessarily prevent treated colonies from developing new lesions over time. Chlorinated epoxy treatments were not significantly different from untreated control colonies, suggesting that chlorinated epoxy treatments are an ineffective intervention technique for SCTLD. The results of this experiment expand management options during coral disease outbreaks and contribute to overall knowledge regarding coral health and disease.


Asunto(s)
Antozoos , Amoxicilina/uso terapéutico , Animales , Antozoos/efectos de los fármacos , Cloro/uso terapéutico , Arrecifes de Coral , Compuestos Epoxi/uso terapéutico , Florida
10.
Commun Biol ; 4(1): 431, 2021 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-33785849

RESUMEN

Microplastics are recognised as a potential global threat to marine ecosystems, but the biological mechanisms determining their impact on marine life are still largely unknown. Here, we investigated the effects of microplastics on the red coral, a long-lived habitat-forming organism belonging to the Corallium genus, which is present at almost all latitudes from shallow-water to deep-sea habitats. When exposed to microplastics, corals preferentially ingest polypropylene, with multiple biological effects, from feeding impairment to mucus production and altered gene expression. Microplastics can alter the coral microbiome directly and indirectly by causing tissue abrasions that allow the proliferation of opportunistic bacteria. These multiple effects suggest that microplastics at the concentrations present in some marine areas and predicted for most oceans in the coming decades, can ultimately cause coral death. Other habitat-forming suspension-feeding species are likely subjected to similar impacts, which may act synergistically with climate-driven events primarily responsible for mass mortalities.


Asunto(s)
Antozoos/efectos de los fármacos , Microplásticos/toxicidad , Polipropilenos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Arrecifes de Coral
11.
Sci Rep ; 11(1): 2767, 2021 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-33531587

RESUMEN

Synthetic estrogens such as ethinylestradiol (EE2) are persistent micropollutants that are not effectively removed from wastewater by conventional treatments. These contaminants are released into waterbodies, where they disrupt endocrine systems of organisms and cause harmful effects such as feminization, infertility, reproduction problems and genital malformations. The consequences of this pollution for key marine ecosystems such as coral reefs and their associated microbiomes are underexplored. We evaluated the effects of EE2 concentrations of 100 ng L-1 and 100 µg L-1 on the coral metaorganism Mussismilia harttii. The results indicated no effects on visible bleaching or Fv/Fm ratios in the corals during a 17-day microcosm experiment. However, next-generation sequencing of 16S rDNA revealed a statistically significant effect of high EE2 concentrations on OTU richness, and shifts in specific microbial groups after treatments with or without EE2. These groups might be bioindicators of early shifts in the metaorganism composition caused by EE2 contamination.


Asunto(s)
Antozoos/efectos de los fármacos , Arrecifes de Coral , Congéneres del Estradiol/toxicidad , Etinilestradiol/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales
12.
Sci Rep ; 11(1): 529, 2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-33436804

RESUMEN

Coral reefs are keystone coastal ecosystems that are at risk of exposure to petroleum from a range of sources, and are one of the highest valued natural resources for protection in Net Environmental Benefit Analysis (NEBA) in oil spill response. Previous research evaluating dissolved hydrocarbon impacts to corals reflected no clear characterization of sensitivity, representing an important knowledge gap in oil spill preparedness related to the potential impact of oil spills to the coral animal and its photosymbiont zooxanthellae. This research addresses this gap, using a standardized toxicity protocol to evaluate effects of a dissolved reference hydrocarbon on scleractinian corals. The relative sensitivity of five Atlantic scleractinian coral species to hydrocarbon exposure was assessed with 48-h assays using the reference polycyclic aromatic hydrocarbon 1-methylnaphthalene, based on physical coral condition, mortality, and photosynthetic efficiency. The threatened staghorn coral Acropora cervicornis was found to be the most sensitive to 1-methylnaphthalene exposure. Overall, the acute and subacute endpoints indicated that the tested coral species were comparatively more resilient to hydrocarbon exposure than other marine species. These results provide a framework for the prediction of oil spill impacts and impact thresholds on the coral animal and related habitats, essential for informing oil spill response in coastal tropical environments.


Asunto(s)
Antozoos/efectos de los fármacos , Biología Marina , Naftalenos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Antozoos/fisiología , Arrecifes de Coral , Petróleo/toxicidad , Contaminación por Petróleo/efectos adversos , Fotosíntesis/efectos de los fármacos , Hidrocarburos Policíclicos Aromáticos/toxicidad , Especificidad de la Especie , Clima Tropical
13.
Artículo en Inglés | MEDLINE | ID: mdl-33122134

RESUMEN

It is widely known that metals can alter enzyme functioning, however, little is known about the mechanisms of metal toxicity in energy metabolism enzymes of corals. Thus, the present study had two objectives: firstly, we evaluated the activity of eight metabolic enzymes of the coral Mussismilia harttii to clarify metabolic functioning under field conditions. After that, we investigated the in vitro effect of copper (Cu) exposure in the activity of an enzyme representative of each metabolism stage. We evaluated enzymes involved in glycolysis (hexokinase, HK; phosphofructokinase, PFK; pyruvate kinase, PK and lactate dehydrogenase, LDH), Krebs cycle (citrate synthase, CS and isocitrate dehydrogenase, IDH), electron transport chain (electron transport system activity, ETS) and pentose phosphate pathway (glucose-6-phosphate dehydrogenase, G6PDH). The in vitro tests were performed through contamination of the reaction medium using Cu concentrations of 0, 1.4, 3.7 and 14.2 µg L-1. The results showed that M. harttii has elevated activity of HK, PK and CS in field conditions compared to the activity of other energy metabolism enzymes evaluated. Moreover, lower activities of LDH and ETS in exposed samples were observed. In conclusion, in field conditions this species has elevated aerobic metabolism and glucose may be an important energetic fuel. Also, exposure to Cu in vitro caused inhibition of LDH and ETS by direct binding.


Asunto(s)
Antozoos/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Metales/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Antozoos/enzimología , Antozoos/metabolismo , Citrato (si)-Sintasa/metabolismo , Cobre/toxicidad , Glucosa/metabolismo , Glucosafosfato Deshidrogenasa/metabolismo , Glucólisis/efectos de los fármacos , Hexoquinasa/metabolismo , L-Lactato Deshidrogenasa/metabolismo , Vía de Pentosa Fosfato/efectos de los fármacos , Piruvato Quinasa/metabolismo
14.
Sci Rep ; 10(1): 11975, 2020 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-32686736

RESUMEN

Mass coral bleaching represents one of the greatest threats to coral reefs and has mainly been attributed to seawater warming. However, reduced water quality can also interact with warming to increase coral bleaching, but this interaction depends on nutrient ratios and forms. In particular, nitrate (NO3-) enrichment reduces thermal tolerance while ammonium (NH4+) enrichment tends to benefit coral health. The biochemical mechanisms underpinning the different bleaching responses of corals exposed to DIN enrichment still need to be investigated. Here, we demonstrated that the coral Stylophora pistillata underwent a severe oxidative stress condition and reduced aerobic scope when exposed to NO3- enrichment combined with thermal stress. Such condition resulted in increased bleaching intensity compared to a low-nitrogen condition. On the contrary, NH4+ enrichment was able to amend the deleterious effects of thermal stress by favoring the oxidative status and energy metabolism of the coral holobiont. Overall, our results demonstrate that the opposite effects of nitrate and ammonium enrichment on coral bleaching are related to the effects on corals' energy/redox status. As nitrate loading in coastal waters is predicted to significantly increase in the future due to agriculture and land-based pollution, there is the need for urgent management actions to prevent increases in nitrate levels in seawater. In addition, the maintenance of important fish stocks, which provide corals with recycled nitrogen such as ammonium, should be favoured.


Asunto(s)
Compuestos de Amonio/farmacología , Antozoos/fisiología , Nitratos/farmacología , Análisis de Varianza , Animales , Antozoos/efectos de los fármacos , Antioxidantes/metabolismo , Calcificación Fisiológica/efectos de los fármacos , Clorofila/metabolismo , Metabolismo Energético/efectos de los fármacos , Ácido Láctico/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Modelos Biológicos , Óxido Nítrico/biosíntesis , Nitrosación , Estrés Oxidativo/efectos de los fármacos , Fotosíntesis/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Simbiosis/efectos de los fármacos , Tirosina/metabolismo
15.
Sci Rep ; 10(1): 9601, 2020 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-32541793

RESUMEN

Metabolomic profiling of the hexacoral Pocillopora damicornis exposed to solar filters revealed a metabolomic signature of stress in this coral. It was demonstrated that the concentration of the known steroid (3ß, 5α, 8α) -5, 8-epidioxy- ergosta- 6, 24(28) - dien- 3- ol (14) increased in response to octocrylene (OC) and ethylhexyl salicylate (ES) at 50 µg/L. Based on the overall coral response, we hypothesize that steroid 14 mediates coral response to stress. OC also specifically altered mitochondrial function at this concentration and above, while ES triggered a stress/inflammatory response at 300 µg/L and above as witnessed by the significant increases in the concentrations of polyunsaturated fatty acids, lysophosphatidylcholines and lysophosphatidylethanolamines. Benzophenone-3 increased the concentration of compound 14 at 2 mg/L, while the concentration of stress marker remained unchanged upon exposition to the other solar filters tested. Also, our results seemed to refute earlier suggestions that platelet-activating factor is involved in the coral inflammatory response.


Asunto(s)
Antozoos/efectos de los fármacos , Contaminantes Químicos del Agua/efectos adversos , Animales , Antozoos/metabolismo , Antozoos/fisiología , Ácidos Grasos Insaturados/efectos adversos , Ácidos Grasos Insaturados/análisis , Metabolómica , Estrés Fisiológico/efectos de los fármacos , Contaminantes Químicos del Agua/análisis
16.
Biochem Biophys Res Commun ; 525(3): 576-580, 2020 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-32115151

RESUMEN

Coral calcification is intricately linked to the chemical composition of the fluid in the extracellular calcifying medium (ECM), which is situated between the calcifying cells and the skeleton. Here we demonstrate that the acid-base sensing enzyme soluble adenylyl cyclase (sAC) is expressed in calcifying cells of the coral Stylophora pistillata. Furthermore, pharmacological inhibition of sAC in coral microcolonies resulted in acidification of the ECM as estimated by the pH-sensitive ratiometric indicator SNARF, and decreased calcification rates, as estimated by calcein labeling of crystal growth. These results indicate that sAC activity modulates some of the molecular machinery involved in producing the coral skeleton, which could include ion-transporting proteins and vesicular transport. To our knowledge this is the first study to directly demonstrate biological regulation of the alkaline pH of the coral ECM and its correlation with calcification.


Asunto(s)
Equilibrio Ácido-Base , Adenilil Ciclasas/metabolismo , Antozoos/enzimología , Antozoos/fisiología , Calcificación Fisiológica , Equilibrio Ácido-Base/efectos de los fármacos , Inhibidores de Adenilato Ciclasa/farmacología , Álcalis/metabolismo , Animales , Antozoos/efectos de los fármacos , Calcificación Fisiológica/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Concentración de Iones de Hidrógeno , Solubilidad
17.
Aquat Toxicol ; 222: 105454, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32179335

RESUMEN

Recent oil spill responses such as the Deepwater Horizon event have underscored the need for crude oil ecotoxicological threshold data for shallow water corals to assist in natural resource damage assessments. We determined the toxicity of a mechanically agitated oil-seawater mixture (high-energy water-accommodated fraction, HEWAF) of a sweet crude oil on a branched stony coral, Pocillopora damicornis. We report the results of two experiments: a 96 h static renewal exposure experiment and a "pulse-chase" experiment of three short-term exposure durations followed by a recovery period in artificial seawater. Five endpoints were used to determine ecotoxicological values: 1) algal symbiont chlorophyll fluorescence, 2) a tissue regeneration assay and a visual health metric with three endpoints: 3) tissue integrity, 4) tissue color, and 5) polyp behavior. The sum of 50 entrained polycyclic aromatic hydrocarbons (tPAH50) was used as a proxy for oil exposure. For the 96 h exposure dose response experiment, dark-adapted maximum quantum yield (Fv/Fm) of the dinoflagellate symbionts was least affected by crude oil (EC50 = 913 µg/L tPAH50); light-adapted effective quantum yield (EQY) was more sensitive (EC50 =  428 µg/L tPAH50). In the health assessment, polyp behavior (EC50 = 27 µg/L tPAH50) was more sensitive than tissue integrity (EC50 = 806 µg/L tPAH50) or tissue color (EC50 = 926 µg/L tPAH50). Tissue regeneration proved to be a particularly sensitive measurement for toxicity effects (EC50 = 10 µg/L tPAH50). Short duration (6-24 h) exposures using 503 µg/L tPAH50 (average concentration) resulted in negative impacts to P. damicornis and its symbionts. Recovery of chlorophyll a fluorescence levels for 6-24 h oil exposures was observed in a few hours (Fv/Fm) to several days (EQY) following recovery in fresh seawater. The coral health assessments for tissue integrity and tissue color were not affected following short-term oil exposure durations, but the 96 h treatment duration resulted in significant decreases for both. A reduction in polyp behavior (extension) was observed for all treatment durations, with recovery observed for the short-term (6-24 h) exposures within 1-2 days following placement in fresh seawater. Wounded and intact fragments exposed to oil treatments were particularly sensitive, with significant delays observed in tissue regeneration. Estimating ecotoxicological values for P. damicornis exposed to crude oil HEWAFs provides a basis for natural resource damage assessments for oil spills in reef ecosystems. These data, when combined with ecotoxicological values for other coral reef species, will contribute to the development of species sensitivity models.


Asunto(s)
Antozoos/efectos de los fármacos , Monitoreo Biológico/métodos , Arrecifes de Coral , Petróleo/toxicidad , Hidrocarburos Policíclicos Aromáticos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Antozoos/crecimiento & desarrollo , Antozoos/metabolismo , Clorofila A/metabolismo , Dinoflagelados/efectos de los fármacos , Dinoflagelados/crecimiento & desarrollo , Ecosistema , Louisiana , Contaminación por Petróleo/análisis , Agua de Mar/química
18.
Sci Rep ; 10(1): 3910, 2020 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-32127622

RESUMEN

An emerging disturbance for Caribbean reefs is the massive arrival of pelagic Sargassum, which deteriorates water quality due to the production of leachates. The highest arrivals of Sargassum took place when broadcasting corals spawned. We experimentally determined the effect of Sargassum leachates on swimming behavior of Acropora palmata larvae through five treatments (control, stain (simulating 100% leachate color), and 25%, 50% and 100% Sargassum leachate concentrations) during 30 min (10 min of videos and 20 min of post-observations). In the videos, larvae with leachates reduced swimming speed, were positively geotactic, the percentage of individuals that swam in a spiral pattern increased, and most behavioral displacements occurred at lower frequencies than larvae without leachates. Moreover, symptomatic spiral behavior was higher in the presence of leachates, suggesting that this behavior may be an effect of pollution. During post-observations, most larvae with leachates were motionless. This is the first time that Sargassum leachates have been documented modifying larval swimming behavior, which may reduce larval dispersion and genetic diversity. We suggest that a future evaluation of the effects of leachates at lower concentrations and over longer periods of exposure is needed. The resilience of corals may be compromised if Sargassum arrivals become frequent events.


Asunto(s)
Antozoos/efectos de los fármacos , Antozoos/fisiología , Larva/efectos de los fármacos , Larva/fisiología , Sargassum/metabolismo , Natación , Animales , Reproducción/efectos de los fármacos
19.
Sci Rep ; 10(1): 1768, 2020 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-32019964

RESUMEN

There are numerous studies highlighting the impacts of direct and indirect stressors on marine organisms, and multi-stressor studies of their combined effects are an increasing focus of experimental work. Lophelia pertusa is a framework-forming cold-water coral that supports numerous ecosystem services in the deep ocean. These corals are threatened by increasing anthropogenic impacts to the deep-sea, such as global ocean change and hydrocarbon extraction. This study implemented two sets of experiments to assess the effects of future conditions (temperature: 8 °C and 12 °C, pH: 7.9 and 7.6) and hydrocarbon exposure (oil, dispersant, oil + dispersant combined) on coral health. Phenotypic response was assessed through three independent observations of diagnostic characteristics that were combined into an average health rating at four points during exposure and recovery. In both experiments, regardless of environmental condition, average health significantly declined during 24-hour exposure to dispersant alone but was not significantly altered in the other treatments. In the early recovery stage (24 hours), polyp health returned to the pre-exposure health state under ambient temperature in all treatments. However, increased temperature resulted in a delay in recovery (72 hours) from dispersant exposure. These experiments provide evidence that global ocean change can affect the resilience of corals to environmental stressors and that exposure to chemical dispersants may pose a greater threat than oil itself.


Asunto(s)
Antozoos/efectos de los fármacos , Antozoos/fisiología , Contaminación Ambiental/efectos adversos , Estrés Fisiológico/fisiología , Contaminantes Químicos del Agua/efectos adversos , Animales , Arrecifes de Coral , Ecosistema , Calor , Hidrocarburos/administración & dosificación , Océanos y Mares , Temperatura , Agua
20.
Sci Rep ; 10(1): 988, 2020 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-31969660

RESUMEN

Coral reefs are vital for the marine ecosystem and their potential disappearance can have unequivocal consequences on our environment. Aside from pollution-related threats (changes in water temperature, plastics, and acidity), corals can be injured by diseases, predators, humans and other invasive species. Diseases play an important role in this decline, but so far very few mitigation strategies have been proposed and developed to control this threat. In this work, we demonstrate that recently developed bi-layer human skin wound treatment patches containing antiseptics and natural antioxidants with controlled-release capacity can be adapted to treat scleractinian coral wounds effectively. A hydrophilic bilayer film based on polyvinylpyrrolidone (PVP) and hyaluronic acid was used to cover the open wounds while delivering the antiseptics for rapid action. Afterwards, the hydrophilic bi-layer covered wound was sealed with an antioxidant and hydrophobic ε-caprolactone-p-coumaric acid copolymer by melt injection at low temperatures. Treated coral injuries were monitored both in aquaria system and in natural environment in Maldives for over 4 months to reduce the number of entry points for organisms that could lead to diseases. The corals well-tolerated both biomaterials as well as the antiseptics incorporated in these materials. The treatments displayed self-adhering properties, tuneable dissolution time, and biocompatibility and stimulated regeneration properties within the coral wound. As such, this work demonstrates that certain human skin wound treatment materials can be successfully adapted to the curing of coral wounds and delivery of specific drugs to slow down, reduce or even stop the spread of diseases in scleractinian corals as well as in all other benthic organisms affected by uncontrolled pathologies.


Asunto(s)
Antozoos/efectos de los fármacos , Antiinfecciosos Locales/farmacología , Antioxidantes/farmacología , Conservación de los Recursos Naturales/métodos , Arrecifes de Coral , Animales , Biopolímeros
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...