RESUMO
Cagarras Islands Archipelago, a no-take MPA in Southeast Brazil, was designated as Natural Monument (MONA Cagarras) and, more recently, recognized as Hope Spot for biodiversity conservation. This study aimed to assess plastic contamination by analyzing marine litter and microplastics in MONA Cagarras and surrounding waters. Marine litter (34.12 kg) was caught by artisanal fishermen in MONA Cagarras proximities, and plastics represented â¼79 %. Personal hygiene items and strains of hair were found, suggesting sewage-derived contamination from Ipanema SSO. Microplastics were detected in MONA Cagarras surface waters. Fragments and black particle were the most frequently found microplastic shape and color, respectively. µ-FTIR analysis identified, in descending order of occurrence, polystyrene-PS, polyethylene-PE, polyvinyl chloride-PVC, polypropylene-P, and polyamide-PA. Our integrated results of macro and microplastic contamination highlight an issue of effective conservation and health of marine biodiversity in MONA Cagarras and surrounding waters and a concern for better management of Brazilian MPAs.
Assuntos
Biodiversidade , Monitoramento Ambiental , Plásticos , Esgotos , Poluentes Químicos da Água , Brasil , Plásticos/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Microplásticos/análise , Ilhas , Conservação dos Recursos NaturaisRESUMO
Coastal and marine environments have been strongly influenced by anthropogenic activities, which may lead to high concentrations of different pollutants in sediments. Our study aimed to assess sediment contamination by polycyclic aromatic hydrocarbons (PAHs), phthalates (PAEs) and bisphenol A (BPA) in nine coastal and marine environments at Rio de Janeiro-Brazil. Physical and chemical water variables, grain-size parameters, moisture, and organic-matter content in sediments were assessed by sampling station. Multivariate analysis evidenced environmental differences between coastal lagoon and oceanic beaches, mostly influenced by marine waters. Differences among bay's beaches were mostly evidenced by sediment characteristics. PAHs and BPA were not detected in samples. For the first time, PAEs were found in sediments at Rio de Janeiro coast (South Atlantic). DEHP was detected in all coastal and marine environments, DBP was found in coastal lagoon and three marine environments. DnOP and DINP were solely found in the coastal lagoon.
Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Brasil , Oceanos e Mares , Hidrocarbonetos Policíclicos Aromáticos/análiseRESUMO
Microplastic contamination is a global concern due to its conspicuous presence in aquatic ecosystems and its toxic nature to environmental and human health. False mussels are among the most notable fresh- and brackish water invaders. The invasive Mytilopsis leucophaeata in Rodrigo de Freitas Lagoon-RFL (Rio de Janeiro, Brazil) is the most abundant macrofaunal invertebrate, widely established and distributed throughout the lagoon. This study aimed to assess microplastic contamination in this invasive filter feeder and evaluate its potential use as a bioindicator. Agglomerates (~100 mussels) were manually collected using a stainless-steel spatula in ten sampling areas distributed throughout the whole lagoon and kept frozen. In the laboratory, 60 individuals were sorted by area for soft-tissue digestion. Each pool of 10 soft-tissue mussels (n = 6 by area) was wet-weighted and then placed in a 150-mL decontaminated glass beaker with 50 mL of 10% KOH. Samples were heated (40 °C) for 48 h, and digested samples were filtered in glass-fiber membranes. Microplastics were found in all samples of mussels (n = 60) from RFL; the particles were mostly lower than 100 µm with a mean concentration (±SD) of 35.96 ± 47.64 MPs g wet-weight-1. Microplastics were distinguished in seven shapes with different occurrences in samples (%): fiber (43.3%); fragment (34.3%); film (16.3%); sponge/foam (4.9%); pellet (0.57%), rope/filaments (0.17%); and undefined (0.4%). Thirteen colors of microplastics were found, but transparent (54.94%), black (10.77%), and white (9.36%) were the most common. Mytilopsis leucophaeata were useful to assess microplastic contamination in RFL and might be preferentially used in other invaded brackish systems instead of native and often threatened bivalves. Our results confirm the effective application of bivalves as an indicator of coastal microplastic pollution.
Assuntos
Bivalves , Microplásticos , Humanos , Animais , Plásticos , Ecossistema , BrasilRESUMO
Total and partial restrictions to beach access during COVID-19 pandemic created an opportunity to evaluate its effect on coastal pollution. We aimed to determine the impact of access restrictions on solid waste pollution at Copacabana beach, Brazil. Solid waste amount was analyzed considering beach access restrictions: unrestricted, total closure, partial restriction, new normal. Relationships of atmospheric temperature and precipitation with access restrictions were assessed and confounding effects controlled for further analyses. Beach access restrictions significantly reduced solid waste pollution at Copacabana beach, beach closure reduced waste amount in 72 %. Partial restrictions and new normal periods have significantly reduced solid wastes amount on the beach in 60 % and 36.88 %, respectively. Qualitative data revealed that most of solid wastes were single-use plastics recently disposed at Copacabana beach, reflecting beachgoer's effects on waste left on the beach. A positive impact of COVID-19 pandemic restrictions was detected on solid waste pollution at Copacabana beach.
Assuntos
Praias , COVID-19 , Brasil , COVID-19/epidemiologia , Monitoramento Ambiental , Humanos , Pandemias , Plásticos , Resíduos Sólidos , Resíduos/análiseRESUMO
Besides human health risks, phycotoxins may cause physiological injuries on molluscan shellfish and, consequently, damages to marine ecosystems and global fisheries production. In this way, this review aimed to present an overview of HABs impacts on marine shellfish by evaluating the effects of cultivated molluscs exposure to microalgae and cyanobacteria that form blooms and/or synthesize toxins. More specifically, it was assessed the main molluscan shellfish responses to harmful algae, trophic transfer and dynamics of phycotoxins, and the risks for human health. Of the 2420 results obtained from literature search, 150 scientific publications were selected after thorough inspections for subject adherence. In total, 70 molluscan species and 37 taxa of harmful algae were assessed from retrieved scientific publications. A significant positive correlation was found between the marine production of molluscs and the number of available studies by molluscan category. Molluscan responses to HABs and phycotoxins were categorized and discussed in three sub-sections: effects on grazing and behavior, metabolic and physiological reactions, and fitness consequences. The main histopathological injuries and toxin concentrations in molluscan tissues were also compiled and discussed. Bivalves often accumulate more toxins than gastropods and cephalopods, occasionally exceeding recommended levels for safe consumption, representing a risk for human health. Harmful algae impact on molluscan shellfish are complex to trace and predict; however, considering the perspective of increase in the occurrence and intensity of HABs, the intensification of efforts to expand the knowledge about HABs impacts on marine molluscs is crucial to mitigate the damages on economy and human health.
Assuntos
Bivalves , Proliferação Nociva de Algas , Animais , Ecossistema , Humanos , Alimentos Marinhos , Frutos do MarRESUMO
Oyster production in Brazil has been highlighted as an important economic activity and is directly impacted by the quality of the environment, which is largely the result of human interference and climate change. Harmful algal blooms occur in aquatic ecosystems worldwide, including coastal marine environments which have been increasing over the last decades as a result of global change and anthropogenic activities. In this study, the native oysters Crassostrea gasar from Northeast of Brazil were exposed to two toxic benthic dinoflagellate species, Prorocentrum lima and Ostreopsis cf. ovata. Their respective effects on C. gasar physiology and defense mechanisms were investigated. Oyster hemocytes were first exposed in vitro to different concentrations of both dinoflagellate species to assess their effects on hemocyte functions, such as phagocytosis, production of reactive oxygen species, as well as mortality. Results highlighted an alteration of hemocyte phagocytosis and viability in presence of O. cf. ovata, whereas P. lima did not affect the measured hemocyte functions. In a second experiment, oysters were exposed for 4 days in vivo to toxic culture of O. cf. ovata to assess its effects on hemocyte parameters, tissues damages and pathogenic Perkinsus spp. infection. An increase in hemocyte mortality was also observed in vivo, associated with a decrease of ROS production. Histopathological analyses demonstrated a thinning of the epithelium of the digestive tubules of the digestive gland, inflammatory reaction and a significant increase in the level of infection by Perkinsus spp. in oysters exposed to O. cf. ovata. These results indicate that oysters C. gasar seem to be pretty resilient to an exposure to P. lima and may be more susceptible to O. cf. ovata. Furthermore, the latter clearly impaired oyster physiology and defense mechanisms, thus highlighting that harmful algal blooms of O. cf. ovata could potentially lead to increased susceptibility of C. gasar oysters to parasite infections.
Assuntos
Crassostrea/imunologia , Dinoflagellida/fisiologia , Proliferação Nociva de Algas , Animais , Brasil , Crassostrea/efeitos dos fármacos , Ecossistema , Hemócitos/imunologia , Humanos , Imunidade , FagocitoseRESUMO
The present study aimed to assess corocoro grunt use as bioindicator of Hg contamination in coastal marine systems by testing environmental (seasons) and biological effects (sexual maturity, size and weight) on THg accumulation and assessing human health risk. Fish was captured in winter and summer seasons at Vermelha Beach, Rio de Janeiro, Southeast Brazil. Adult O. ruber showed significantly higher THg than juveniles, and THg concentrations were positively correlated to fish length and weight. Fish THg concentrations did not differ between seasons and were below the accepted limit for human consumption. Human exposure risk by fish consumption was 0.31 µg MeHg kg-1 week-1 and the hazard quotient was 0.44 (0.11-1.84). Our results confirm the applied use of O. ruber as sentinel species for Hg contamination monitoring and highlight concern for its consumption, especially for local fishermen populations that highly consume this fish and may be more susceptible to Hg adverse effects.
Assuntos
Mercúrio , Compostos de Metilmercúrio , Poluentes Químicos da Água , Animais , Fatores Biológicos , Brasil , Monitoramento Ambiental , Peixes , Humanos , Mercúrio/análise , Medição de Risco , Espécies Sentinelas , Poluentes Químicos da Água/análiseRESUMO
The dark false mussel Mytilopsis leucophaeata occurs as non-native species in Asia, Europe and South America. Despite the low population density usually found in its native range, M. leucophaeata forms dense clusters in newly invaded areas which lead to impacts on local organisms and environment. Some of the impacts of non-native species on newly colonized areas may be positive. However, despite the empirical evidences of increase in water transparency by freshwater dresseinids, the hypothesis that dark false mussel enhances the quality of brackish water has never been tested so far. Thus, the present study aimed to determine M. leucophaeata impacts on the water quality of a nutrient-enriched coastal lagoon by (1) analyzing a historical water dataset for pre- and post-invasion at Rodrigo de Freitas Lagoon (Brazil) and (2) experimentally testing dark false mussel direct effects on water quality. Historical field data evidenced significant lower phytoplankton abundance and chlorophyll a, and higher water transparency for the post-invasion period. These pattens were also supported by time-series analyses, which detected a decreasing trend for total coliforms density and an increased trend for dissolved oxygen over time. Moreover, time series indicated a gradual increase in lagoon water level with time, but none or minor changes were evidenced for floodgates operation routine, meteorological variables, and the frequency of sewage input. In microcosms, M. leucophaeata was effective to increase water transparency and decrease E. coli densities. The combination of field and laboratory data partially supported the hypothesis that M. leucophaeata invasion promoted an improvement in lagoon water quality, but increased phosphorus availability through excretion in microcosm assays. Management of dark false mussel populations seems to be a potential strategy for water quality improvement within already invaded systems where high sewage-enriched effluents are released. However, as non-native species often unbalance ecological relationships and functioning of the invaded ecosystems, new introductions of M. leucophaeata must be avoided.
Assuntos
Bivalves , Espécies Introduzidas , Animais , Brasil , Clorofila A , Ecossistema , Escherichia coli , Europa (Continente) , Melhoria de Qualidade , Água , Qualidade da ÁguaRESUMO
: Recurrent blooms of Ostreopsis cf. ovata have been reported in Brazil and the Mediterranean Sea with associated ecological, and in the latter case, health impacts. Molecular data based on the D1-D3 and D8-D10 regions of the LSU rDNA and ITS loci, and the morphology of O. cf. ovata isolates and field populations from locations along the Brazilian tropical and subtropical coastal regions and three oceanic islands are presented. Additional ITS sequences from three single cells from the tropical coast are provided. Toxin profiles and quantities of PLTX and their analogues; OVTXs; contained in cells from two clonal cultures and two field blooms from Rio de Janeiro were investigated. Morphology was examined using both light and epifluorescence microscopy. Morphometric analysis of different strains and field populations from diverse locations were compared. Molecular analysis showed that six of the seven sequences grouped at the large "Atlantic/Mediterranean/Pacific" sub-clade, while one sequence branched in a sister clade with sequences from Madeira Island and Greece. The toxin profile of strains and bloom field samples from Rio de Janeiro were dominated by OVTX-a and -b, with total cell quotas (31.3 and 39.3 pg cell-1) in the range of that previously reported for strains of O. cf. ovata.
Assuntos
Dinoflagellida/genética , Brasil , Dinoflagellida/química , Toxinas Marinhas/análise , FilogeniaRESUMO
Harmful algae may differently affect their primary grazers, causing sub-lethal effects and/or leading to their death. The present study aim to compare the effects of three toxic benthic dinoflagellates on clearance and grazing rates, behavioral changes, and survival of Artemia salina. Feeding assays consisted in 1-h incubations of brine shrimps with the toxic Prorocentrum lima, Gambierdiscus excentricus and Ostreopsis cf. ovata and the non-toxic Tetraselmis sp. Brine shrimps fed unselectively on all toxic and non-toxic algal preys, without significant differences in clearance and ingestion rates. Acute toxicity assays were performed with dinoflagellate cells in two growth phases during 7-h to assess differences in cell toxicity to A. salina. Additionally, exposure to cell-free medium was performed to evaluate its effects on A. salina survival. The behavior of brine shrimps significantly changed during exposure to the toxic dinoflagellates, becoming immobile at the bottom by the end of the trials. Dinoflagellates significantly affected A. salina survival with 100% mortality after 7-h exposure to cells in exponential phase (all treatments) and to P. lima in stationary phase. Mortality rates of brine shrimps exposed to O. cf. ovata and G. excentricus in stationary phase were 91% and 75%, respectively. However, incubations of the brine shrimps with cell-free medium did not affect A. salina survivorship. Significant differences in toxic effects between cell growth phases were only found in the survival rates of A. salina exposed to G. excentricus. Acute exposure to benthic toxic dinoflagellates induced harmful effects on behavior and survival of A. salina. Negative effects related to the toxicity of benthic dinoflagellates are thus expected on their primary grazers making them more vulnerable to predation and vectors of toxins through the marine food webs.
Assuntos
Artemia/fisiologia , Comportamento Animal , Dinoflagellida , Comportamento Alimentar , AnimaisRESUMO
The aim of this study was to determine the influence of temperature increase combined to conditions of light incidence on functional response of Heleobia australis. Experiments were conducted using nine to ten food concentrations for each treatment: 20°C without light; 30°C without light and, 30°C under low light intensity. For each experiment, the functional response type III (sigmoidal) was fitted and equation parameters were determined. Results suggest that, if the sediment temperature increases, H. australis will not have its ingestion rates affected negatively, whilst its feeding behavior seems to be negatively affected by light. Ingestion rates estimated for organic content in the Guanabara Bay were: 0.34 µgC ind-1h-1 at 20°C without light, 1.44 µgC ind-1h-1 at 30°C without light and 0.64 µgC ind-1h-1 at 30°C under light incidence. Higher ingestion rates were estimated at the high temperature, even under light incidence, and temperature seems to have outweighed the light effect. In contrast, if higher carbon content is considered, despite high temperature, the experiment conducted with light incidence showed lower ingestion rates than those from the experiment at 20°C without light. This study provides the first quantification of H. australis ingestion rates and the effects that changes in temperature and light have on its feeding behavior.