Metal pollution in surface sediments from Rodrigo de Freitas Lagoon (Rio de Janeiro, Brazil): Toxic effects on marine organisms.

The Rodrigo de Freitas Lagoon (RFL - Rio de Janeiro, RJ, Brazil) is a highly polluted and eutrophic lacustrine system, which has been often used for the practice of aquatic sports, including during the 2016 Summer Olympic Games. This study proposes the evaluation of metal concentrations in surface sediments from the RFL before and after urban interventions performed for the 2016 Olympics, as well as their toxicity to the benthic amphipod Tiburonella viscana and embryos of the sea-urchin Echinometra lucunter. Metal concentrations determined in 2017 were significantly higher than those obtained in 2015 (especially Cu, Cd and Ni), suggesting that the interventions performed to fulfill the requirements of the Olympics increased metal contents in sediments. The sediments from the northern sector of the RFL were muddier, more organically enriched, exhibited higher metal concentrations and were more toxic to T. viscana when compared to the sediments collected in the southern sector. This fact is particularly important since the practice of sports, including during the 2016 Olympics, has been preferably performed in the northern sector. Metal distribution was strongly correlated with organic matter and mud contents. The toxicity to E. lucunter embryos was high for both northern and southern sediments; most of the samples led to 100% lack or abnormal embryonic development. The integration of physical, chemical and ecotoxicological data indicates that the mortality to T. viscana was correlated with metal contents, whereas the toxicity to E. lucunter was apparently related to the release of ammonia from the sediment to water column. Finally, high metal concentrations and the toxicity to aquatic organisms evidence the ecological risks to the biota from RFL.

Levels of metals and toxicity in sediments from a Ramsar site influenced by former mining activities.

This study aimed to evaluate the sediment quality in a Ramsar site located in the Southeast Brazil, by using several lines of evidence (LOEs). Chemical and sedimentological analyses, ecotoxicological tests, and whole-sediment Toxicity Identification Evaluation (TIE) were performed. The sediments were predominantly composed of fine sands and muds. Higher concentrations of metals in the sediments collected close to Iguape were observed; however according to the SEM/AVS analyses, most sediments should not be toxic and the potentially toxic samples could occur along the whole channel. In fact, sediments of most stations were toxic in at least one survey. The PCA revealed associations between mud, metals and toxicity. Acutely toxic sediments presented Pb concentrations above the threshold effect levels, while chronic toxicity seemed to be influenced also by SEM. The most contaminated and toxic areas are not necessarily those located close to the primary sources, but are actually those with finer sediments. Toxicity Identification and Evaluation (TIE) showed that metals and ammonia were responsible for the toxicity. The results suggest that metals from former mining areas located at the upper Ribeira de Iguape River are transported to the Cananéia Iguape Peruíbe Protected Area and accumulate in the sediments at potentially toxic levels. The location of muddy and more contaminated sediments appears to move along the estuary, accompanying the displacement of the maximum turbidity zone, which, in turn, depends on seasonal freshwater inputs. The results also showed that using several lines of evidences to asses contamination in a protected area provides reliable information to subsidise further actions to control the sources of contaminants.

Effects of the water-soluble fraction of diesel oil (WSD) on the fertilization and development of a sea urchin (Echinometra lucunter).

Considering the high number of accidents with diesel oil spills occurring in the marine ecosystem, toxicity tests aimed at assessing the effects of this pollutant on biota are necessary and urgent. Thus, the present study aimed to evaluate the toxicity of the soluble fraction of diesel oil (WSD) in the fertilization success of gametes and pluteu larvae of the sea urchin Echinometra lucunter. To do this, gametes and embryos were exposed to concentrations of 0% (control group), 0.5%, 1.5% and 2.5% of WSD. The fertilization success of exposed gametes and embryos were reduced significantly when compared to the control group in all tested concentrations. With this finding, it is evident that diesel oil can be significantly promoted in the early and adult life stages of a particular organism, and a better way of evaluating this toxicity is through the analysis of contaminant effects throughout the reproductive cycle of a species.

Sediment toxicity identification evaluation (TIE phases I and II) based on microscale bioassays for diagnosing causes of toxicity in coastal areas affected by domestic sewage.

Domestic sewage is a major problem in highly urbanized coastal areas worldwide. In the present study, toxicity identification evaluation (TIE) phases I and II were applied to sediment interstitial water from 2 locations along the São Paulo coast in southeastern Brazil: the sewage outfalls from the city of Santos, a densely urbanized area, and the city of Bertioga, a less urbanized area. An adapted microscale sea urchin embryo-larval development bioassay was employed. Phase TIE-I manipulations were 1) ethylenediamine tetraacetic acid (EDTA) addition, 2) aeration at modified pH, 3) C18 solid-phase extraction (SPE), and 4) addition of Na2 S2 O3 . The results of the Santos TIE-I indicated toxicity by sulfides and substances with affinity to C18 resin. In Bertioga, toxicity was the result of NH3 , metals, and arsenic, as well as substances with affinity to C18 resin. Phase TIE-II aimed to specify the causes of toxicity by testing the toxicity of eluates of the sublation and C18 SPE manipulation. The results reinforced the role of both surfactants and nonpolar compounds as causative agents of toxicity in both Santos and Bertioga. Chemical analyses of sediment interstitial water or whole sediment ruled out the influence of polycyclic aromatic hydrocarbons (PAHs) or polychlorinated biphenyls (PCBs) in the toxicity of both sampling sites. Other hydrophobic substances may play a role in the toxicity of Santos and Bertioga effluents. Efforts to remove such substances from sanitary effluents must be prioritized. Environ Toxicol Chem 2017;36:1820-1832. © 2017 SETAC.

Early time course of variation in coelomic fluid ionic concentrations in sea urchins abruptly exposed to hypo- and hyper-osmotic salinity challenges: Role of size and cross-section area of test holes.

Echinoderms are restricted to the marine environment and are osmoconformer invertebrates. However, some species live in unstable environments. Especially those species, and those of larger body size, tend to show variable, albeit transient, ionic gradients between their coelomic fluid and external seawater. In order to further examine how sea urchin size relates to apparent ionic permeability of their body wall/epithelia, specimens of Echinometra lucunter, Lytechinus variegatus, Paracentrotus gaimardi, and Arbacia lixula-A. lixula of two distinct populations, Rio de Janeiro and Santa Catarina-were abruptly transferred from 35 psu to either 25 or 45 psu. Sodium, chloride, magnesium, and potassium concentrations were assayed in their coelomic fluids after 0, 1, 2, and 3 hr of exposure. Relative area of putative permeable (i.e., cross section areas of soft tissues, or test holes) surfaces (PPS) was estimated in empty tests as the sum of the peristomial area (oral hole in the empty test) and the total cross-section area of ambulacral holes, divided by the total volume (TV) of the test. L. variegatus and E. lucunter, the largest species, had PPS/TV values similar to that of the much smaller P. gaimardi. A. lixula was the "most putatively-permeable and conformer" among them all, especially urchins from the Santa Catarina population. Internal ionic levels equilibrated faster with external water in 45 than in 25, and differences among ions were observed. Body size is relevant, among many other factors, to aid conformers such as sea urchins to dwell in intertidal unstable habitats.

Photoprotective effect of coumarin and 3-hydroxycoumarin in sea urchin gametes and embryonic cells.

Ultraviolet radiation B (UVB) represents 5% of all solar UV radiation and chronic exposure can induce harmful biological responses, including skin cancer. Prospection of new drugs with photoprotective properties and less toxic effects is constant and natural products have been the main options in this field. Coumarins are a group of natural phenolic compounds that shows several pharmacological activities. The aim of present work was to investigate the effect of coumarin and six derivatives in sea urchin gametes and zygotes exposed to UVB. Embryonic development assay was used to monitor UVB embryotoxicity. Firstly, we demonstrated that coumarin inhibited first embryonic cell division from 5 µM (EC50 = 52.9 µM) and its derivatives showed an embryotoxic effect ten times higher. Then, gametes or zygotes were treated with coumarin compounds before or after UVB exposure (UVB doses ranged from 0.056 to 0.9 kJm(-2)). Pretreatment of gametes or zygotes with coumarin or 3-hydroxycoumarin (1 µM, both) decreased UVB embryotoxic effect. Protective effect of the compounds was observed only when cells were treated previous to UVB exposure. Coumarin derivatives 4-hydroxycoumarin, 6-hydroxycoumarin, 7-hydroxycoumarin, 6,7-dihydroxycoumarin and 6-methoxy-7-hydroxycoumarin did not exhibit photoprotective activity. Our data provides evidences that coumarin and 3-hydroxycoumarin can be a promising class of photoprotective drugs.

Sediment quality assessment in a tropical estuary: the case of Ceará River, Northeastern Brazil.

The present study aimed to assess the sediment quality in a tropical estuary located in the northeast of Brazil under semi-arid conditions and multiple sources of contamination, using both toxicity bioassays and metal distribution. The metal distribution followed a concentration gradient decreasing one order of magnitude from the inner station toward the outer estuary, with amounts in the following order: Fe > Al > Zn > Cr > Pb > Cu. The index of geoaccumulation indicated a metal enrichment in the Ceará river sediment, mainly at inner sites, considered from moderately to strongly contaminated by Al, Cu, Cr and Zn. Sediment samples were considered toxic by means of whole sediment tests with copepods (reproduction) and amphipods (survival), and also elutriate fraction and sediment-water interface with sea urchin embryos (development). Acute and chronic toxicity did not exhibit a significant correlation with metals, emphasizing the influence of other contaminants mainly related to the pollution sources installed in the mid-estuary.

Geochemical and ecotoxicological assessment for estuarine surface sediments from Southern Brazil.

Sediments from Guaratuba Bay (PR, Brazil), a marine protected area, were collected and evaluated for geochemistry and toxicity. High levels of P and acute toxicity were observed in some samples. Concentrations of Cu, Cd, Pb and Zn were relatively low; however, Cd levels eventually exceeded Threshold Effect Level. Toxicities were associated to nutrients and metals enrichment. Results suggest that impacts are incipient and occur only at specific sites, associated to multiple contamination sources. Despite sediments quality seems to range between good and fair, attention is required to land-use planning around Guaratuba Bay and controlling local pollution sources.

Involvement of ABCB1 and ABCC1 transporters in sea urchin Echinometra lucunter fertilization.

Fertilization is an ordered sequence of cellular interactions that promotes gamete fusion to form a new individual. Since the pioneering work of Oskar Hertwig conducted on sea urchins, echinoderms have contributed to the understanding of cellular and molecular aspects of the fertilization processes. Studies on sea urchin spermatozoa reported the involvement of a plasma membrane protein that belongs to the ABC proteins superfamily in the acrosome reaction. ABC transporters are expressed in membranes of eukaryotic and prokaryotic cells, and are associated with the transport of several compounds or ions across biomembranes. We aimed to investigate ABCB1 and ABCC1 transporter activity in sea urchin spermatozoa and their involvement in fertilization. Our results indicate that Echinometra lucunter spermatozoa exhibit a low intracellular calcein accumulation (18.5% stained cells); however, the ABC blockers reversin205, verapamil, and MK571 increased dye accumulation (93.0-96.6% stained cells). We also demonstrated that pharmacologically blocking ABCB1 and ABCC1 decreased spermatozoa fertilizing capacity (70% inhibition), and this phenotype was independent of extracellular calcium. These data suggest that functional spermatozoa ABCB1 and ABCC1 transporters are crucial for a successful fertilization. Additional studies must be performed to investigate the involvement of membrane lipid homeostasis in the fertilization process.

Sea urchin coelomocytes are resistant to a variety of DNA damaging agents.

Increasing anthropogenic activities are creating environmental pressures that threaten marine ecosystems. Effective environmental health assessment requires the development of rapid, sensitive, and cost-effective tools to predict negative impacts at the individual and ecosystem levels. To this end, a number of biological assays using a variety of cells and organisms measuring different end points have been developed for biomonitoring programs. The sea urchin fertilization/development test has been useful for evaluating environmental toxicology and it has been proposed that sea urchin coelomocytes represent a novel cellular biosensor of environmental stress. In this study we investigated the sensitivity of coelomocytes from the sea urchin Lytechinus variegatus to a variety of DNA-damaging agents including ultraviolet (UV) radiation, hydrogen peroxide (H(2)O(2)), methylmethane sulfonate (MMS) and benzo[a]pyrene (BaP). LD(50) values determined for coelomocytes after 24h of exposure to these DNA damaging agents indicated a high level of resistance to all treatments. Significant increases in the formation of apurinic/apyrimidinic (AP or abasic) sites in DNA were only detected using high doses of H(2)O(2), MMS and UV radiation. Comparison of sea urchin coelomocytes with hemocytes from the gastropod mollusk Aplysia dactylomela and the decapod crustacean Panulirus argus indicated that sensitivity to different DNA damaging agents varies between species. The high level of resistance to genotoxic agents suggests that DNA damage may not be an informative end point for environmental health assessment using sea urchin coelomocytes however, natural resistance to DNA damaging agents may have implications for the occurrence of neoplastic disease in these animals.

Evaluation of effectiveness of EDTA and sodium thiosulfate in removing metal toxicity toward sea urchin embryo-larval applying the TIE.

Since the development of the TIE (Toxicity Identification and Evaluation) in 1988 it has been assumed that the capacity of EDTA and sodium thiosulfate to complex some metals, and thus remove their toxicity, can be applied to both freshwater and seawater ecotoxicological tests and the results subsequently interpreted. However, it is now known that there is a wide variability in the extent of this complexation. In this context, the removal of toxicity caused by the presence of Hg(2+), Cd(2+), Cu(2+), Cr(6+), Zn(2+), Ni(2+), Pb(2+), Ag(1+) and Se(2+), through metal complexation by EDTA and sodium thiosulfate, in relation to the performance of embryo-larval tests with the sea urchin Arbacia lixula was investigated. It was observed that EDTA was capable of removing the toxicity of Pb(2+), Zn(2+) and Cu(2+) while sodium thiosulfate only reduced the toxicity of Ag(1+). Compared to the complexation observed in freshwater ecotoxicological tests, the complexing agents used in this study (EDTA and sodium thiosulfate) have a lower capacity to complex metals in the marine ecotoxicological test with A. lixula.

Comparative toxicity of antifouling compounds on the development of sea urchin.

In the present study, embryotoxicity experiments using the sea urchin Lytechinus variegatus were carried out to better clarify the ecotoxicological effects of tributyltin (TBT) and triphenyltin (TPT) (the recently banned antifouling agents), and Irgarol and Diuron (two of the new commonly used booster biocides). Organisms were individually examined to evaluate the intensity and type of effects on embryo-larval development, this procedure has not been commonly used, however it showed to be a potentially suitable approach for toxicity assessment. NOEC and LOEC were similar for compounds of same chemical class, and IC10 values were very close and showed overlapping of confidence intervals between TBT and TPT, and between Diuron and Irgarol. In addition, IC10 were similar to NOEC values. Regardless of this, the observed effects were different. Embryo development was interrupted at the gastrula and blastula stages at 1.25 and 2.5 µg l(-1) of TBT, respectively, whereas pluteus stage was reached with the corresponding concentrations of TPT. Furthermore, embryos reached the prism and morula stages at 5 µg l(-1) of TPT and TBT, respectively. The effects induced by Irgarol were also more pronounced than those caused by Diuron. Pluteus stage was always reached at any tested Diuron concentration, while embryogenesis was interrupted at blastula/gastrula stages at the highest concentrations of Irgarol. Therefore, this study proposes a complementary approach for interpreting embryo-larval responses that may be employed together with the traditional way of analysis. Consequently, this application leads to a more powerful ecotoxicological assessment tool focused on embryotoxicity.

Toxicity of water-soluble fractions of biodiesel fuels derived from castor oil, palm oil, and waste cooking oil.

Concerns over the sustained availability of fossil fuels and their impact on global warming and pollution have led to the search for fuels from renewable sources to address worldwide rising energy demands. Biodiesel is emerging as one of the possible solutions for the transport sector. It shows comparable engine performance to that of conventional diesel fuel, while reducing greenhouse gas emissions. However, the toxicity of products and effluents from the biodiesel industry has not yet been sufficiently investigated. Brazil has a very high potential as a biodiesel producer, in view of its climatic conditions and vast areas for cropland, with consequent environmental risks because of possible accidental biodiesel spillages into water bodies and runoff to coastal areas. This research determined the toxicity to two marine organisms of the water-soluble fractions (WSF) of three different biodiesel fuels obtained by methanol transesterification of castor oil (CO), palm oil (PO), and waste cooking oil (WCO). Microalgae and sea urchins were used as the test organisms, respectively, for culture-growth-inhibition and early-life-stage-toxicity tests. The toxicity levels of the analyzed biodiesel WSF showed the highest toxicity for the CO, followed by WCO and the PO. Methanol was the most prominent contaminant; concentrations increased over time in WSF samples stored up to 120 d.

Harmonised framework for ecological risk assessment of sediments from ports and estuarine zones of North and South Atlantic.

This paper presents a harmonised framework of sediment quality assessment and dredging material characterisation for estuaries and port zones of North and South Atlantic. This framework, based on the weight-of-evidence approach, provides a structure and a process for conducting sediment/dredging material assessment that leads to a decision. The main structure consists of "step 1" (examination of available data); "step 2" (chemical characterisation and toxicity assessment); "decision 1" (any chemical level higher than reference values? are sediments toxic?); "step 3" (assessment of benthic community structure); "step 4" (integration of the results); "decision 2" (are sediments toxic or benthic community impaired?); "step 5" (construction of the decision matrix) and "decision 3" (is there environmental risk?). The sequence of assessments may be interrupted when the information obtained is judged to be sufficient for a correct characterisation of the risk posed by the sediments/dredging material. This framework brought novel features compared to other sediment/dredging material risk assessment frameworks: data integration through multivariate analysis allows the identification of which samples are toxic and/or related to impaired benthic communities; it also discriminates the chemicals responsible for negative biological effects; and the framework dispenses the use of a reference area. We demonstrated the successful application of this framework in different port and estuarine zones of the North (Gulf of Cádiz) and South Atlantic (Santos and Paranaguá Estuarine Systems).

Integrative ecotoxicological assessment of sediment in Portmán Bay (southeast Spain).

Portmán Bay, southeast Spain, contains the most seriously metal-contaminated sediments of the Mediterranean Sea. From 1958 to 1991, approximately 50 million tons of mine tailings were dumped into the bay, completely filling up the bay and dispersing over an extensive area of the continental platform and continental slope. The objective of our study was to characterize the nature and extent of metal contamination and the responses of natural communities to it and to assess the toxicity of the sediment deposits 10 years after mining had ceased. We studied the physical and chemical characteristics of the sediments and toxicity (of the porewater and sediment-water interface) using two sea urchin species (Arbacia lixula and Paracentrotus lividus). Metal bioavailability and patterns of macroinvertebrate community composition along the contamination gradient were also studied. Univariate and multivariate analyses showed positive correlation between the sediment metal concentrations associated to the all biological effects (sea urchins toxicity tests and benthic indices). The effects of sediment contamination on the benthic community structure are visible among sampling stations.

Integrated sediment quality assessment in Paranaguá Estuarine System, Southern Brazil.

Sediment quality from Paranaguá Estuarine System (PES), a highly important port and ecological zone, was evaluated by assessing three lines of evidence: (1) sediment physical-chemical characteristics; (2) sediment toxicity (elutriates, sediment-water interface, and whole sediment); and (3) benthic community structure. Results revealed a gradient of increasing degradation of sediments (i.e. higher concentrations of trace metals, higher toxicity, and impoverishment of benthic community structure) towards inner PES. Data integration by principal component analysis (PCA) showed positive correlation between some contaminants (mainly As, Cr, Ni, and Pb) and toxicity in samples collected from stations located in upper estuary and one station placed away from contamination sources. Benthic community structure seems to be affected by both pollution and natural fine characteristics of the sediments, which reinforces the importance of a weight-of-evidence approach to evaluate sediments of PES.

Brown seaweed defensive chemicals: a structure-activity relationship approach for the marine environment.

The literature describes several diterpenes from brown seaweeds that act as defensive chemicals against natural enemies, such as competitors, epiphytes, pathogenic bacteria and herbivores. A structure-activity relationship is here presented using a new molecular modeling approach to identify structural and chemical features important to the defensive profile of four structurally related diterpenes (three dolastanes and one seco-dolastane) from Canistrocarpus cervicornis against the feeding process of the omnivorous sea urchin Lytechinus variegatus. Our experimental data revealed the herbivory inhibitory profile (HIE) for three of these evaluated compounds with (4R,7R, 14S)-4alpha,7alpha-diacetoxy-14-hydroxydolast-1(15),8-diene presenting the highest effect (HIE = 70%). Interestingly, the molecular modeling results infer that this biological activity seems to be related to several different structural features, including HOMO distribution, the molecular structure conformation, and the fulfillment of minimum requirements regarding molecular weight. These results reinforce the hypothesis about the intricate biological mechanism of these molecules due to the complexity of their chemical structures. Our work may help in the understanding of these defensive mechanisms and point to a new perspective of ecological and/or evolutionary evaluation in this area.

Yangambin cytotoxicity: a pharmacologically active lignan obtained from Ocotea duckei vattimo (Lauraceae).

The in vitro cytotoxic potential of yangambin was evaluated. Yangambin is a pharmacologically active furofuran lignan obtained from the leaves of Ocotea duckei. It is the major compound from the lignoids fraction. Yangambin presented low cytotoxicity in all in vitro models analyzed. Its cytotoxicity to murine macrophages was measured by the Trypan blue dye exclusion test and MTT reduction assay, resulting in high CC50 values of 187.0 microg/mL (383.3 microM) and 246.7 microg/mL (504.3 microM), respectively. The difference obtained in the inhibitory concentrations aforementioned can be explained, at least in part, by the different principles of the methods. While the MTT reduction assay evaluates the ability of yangambin to inhibit the activity of the mitochondrial enzyme succinate dehydrogenase, the Trypan blue dye exclusion test evaluates possible damages to the integrity of the cytoplasmic membrane which result in cell death. The capacity of yangambin to inhibit the sea urchin embryonic development showed that it has low antimitotic and teratogenic potential, once continued exposure of embryos to concentrations up to 500 microg/mL (1.025 microM) did not result in an inhibitory effect on the first egg cleavages. Such low in vitro cytotoxicity is correlated with the low acute toxicity previously studied. All these data, together with the various therapeutic properties of yangambin, make this lignan a promising one for a new drug.

Short-term silver accumulation in tissues of three marine invertebrates: shrimp Penaeus duorarum, sea hare Aplysia californica, and sea urchin Diadema antillarum.

The present study was carried out to examine possible differential silver distribution among several tissues of three marine invertebrate species: the shrimp Penaeus duorarum, the sea hare Aplysia californica, and the sea urchin Diadema antillarum. Animals were exposed to sub-lethal concentrations of silver (1 or 10 microg/L) in seawater for 48 h. In gill-breathing species (shrimp and sea hare), higher silver accumulation in gills were associated with higher hemolymph silver levels. Furthermore, sea urchin showed lower hemolymph silver concentrations than shrimp and sea hare. These findings suggest that gills are an important route for silver uptake in marine invertebrates. In both sea hare and shrimp, hepatopancreas silver accumulation was concentration-dependent and this organ accumulated the most silver after 48 h of exposure, suggesting a possible involvement of the hepatopancreas in both silver accumulation and detoxification in marine invertebrates. In shrimp and sea hare, substantial silver accumulation in nervous tissues was detected, suggesting the need for further studies on possible behavioral effects of silver in these invertebrate species. In sea urchin, egg mass accumulated more silver than other tissues analyzed, indicating the need for future studies on possible reproductive effects of silver in sea urchin. In all three species, the lowest silver concentrations were observed in muscle, suggesting a low potential of this tissue for trophic transfer of silver.

Biological activity of some Patagonian plants.

Citotoxicity (inhibition of cell division in fertilized eggs of Loxechinus albus) and general toxicity (using embryos of Artemia salina) of plants belonging to the genera Senecio, Deschampsia, Alstroemeria, Anarthrophyllum, Chloraea and Geranium were investigated.