Integrated sediment quality assessment in Paranaguá Estuarine System, Southern Brazil

Innovative in vivo and in vitro bioassays for the establishment of toxicity thresholds of pollutants in sediment quality assessment using polychaetes and their immune cells

Sediment toxicity testing has become a crucial component for assessing the risks posed by contaminated sediments and for the development of sediment quality assessment strategies. Commonly used organisms for bioassays with estuarine sediments include amphipods, Arenicola marina polychaetes and echinoids. Among the latter, the Sea Urchin Embryo test (SET) is the most widely used. However, one relevant limitation of this bioassay is the unavailability of gametes all year-round, particularly outside the natural spawning seasons. Consequently, the establishment of an appropriate and complementary model organism for a continuous assessment of sediment quality is recommended. A reliable assessment of the hazards resulting from pollutants in sediments or pore water, can be achieved with ecologically relevant species of sediment such as the polychaete Hediste diversicolor, which is widespread in estuaries and has the capacity to accumulate pollutants. The aim of this work was to develop reliable in vivo and in vitro bioassays with H. diversicolor and its coelomocytes (immune cells) to determine the toxicity thresholds of different contaminants bounded to sediments or resuspended into water. Polychaetes were exposed to sublethal concentrations of CuCl₂ (in vivo) and a non-invasive method for collection of polychaetes coelomocytes was applied for the in vitro bioassay, exposing cells to a series of CuCl₂ and AgNPs concentrations. Same reference toxicants were used to expose Paracentrotus lividus following the SET (ICES Nº 51; Beiras et al., 2012) and obtained toxicity thresholds were compared between the two species. In vivo exposure of polychaetes to high concentrations of Cu produced weight loss and histopathological alterations. After in vitro approaches, a significant decrease in coelomocytes viability was recorded for both toxicants, in a monotonic dose-response curve, at very short-exposure times (2 h). The toxicity thresholds obtained with polychaetes were in line with the ones obtained with the SET, concluding that their sensitivity is similar. In conclusion, in vivo and in vitro bioassays developed with H. diversicolor are accurate toxicity screenings of pollutants that could be bounded to sediments or dissolved in the pore water, and may complement the SET outside the spawning period of the echinoderms. The bioassays herein developed could be applied not only to establish the toxicity thresholds of individual compounds or mixtures, but also to assess the toxicity of field collected sediments.

Health conditions of Guiana dolphins facing cumulative anthropogenic impacts

Coastal areas are associated with anthropogenic activities and stressors that can expose the marine fauna to negative cumulative impacts. Apex predators, such as dolphins, can flag the quality of their environment through health parameters such as cutaneous and body conditions. We examined the potential relationship between environmental conditions and health parameters of Guiana dolphins around a port and a conservation unit within the Paranaguá Estuarine Complex, southern Brazil. During boat surveys between July 2018 and April 2019 covering both areas, we measured environmental parameters, photographed dolphins to infer their health condition and the frequency of use of the estuary. In total, 204 individual Guiana dolphins were photo-identified, 52 of which were seen in both years. In general, dolphins showed poor body condition (76% classified as emaciated or thin in 2018, and 79% in 2019), diverse cutaneous conditions (four types of lesions suggestive of an infectious aetiology, two conditions suggestive of traumatic events of anthropogenic origin, and two anomalous pigmentation) and a high prevalence of such cutaneous conditions (85% in 2018, 70% in 2019). Most individuals maintained their body and cutaneous conditions between the two years. There were no clear differences between the port and the conservation areas in terms of environmental conditions, frequency of use and health conditions of individual dolphins, suggesting that dolphins inhabiting this estuarine complex are exposed to potential cumulative impacts, such as pollutants, noise and habitat degradation. This study provides baseline information on some health parameters of Guiana dolphins in southern Brazil and highlights the need for systematic, long-term health assessment of Guiana dolphin populations to guide conservation actions to safeguard this vulnerable species.

A 140-year record of environmental changes in São Sebastião, Brazil

Over the past two centuries, coastal and estuarine areas have experienced environmental stress due to rapid population growth, leading to higher demand, overexploitation, habitat transformation, and pollution, which have severe consequences on the overall ecosystem and human health. This work aims to understand historical perspectives of such environmental stress in a coastal area of São Sebastião city in the São Paulo State of Brazil, which has witnessed rapid changes in land use over the past 60-70 years. We collected eleven surface sediments and one 64 cm long core from the shallow water depth sector of the São Sebastião Channel (SSC), adjacent to the Araçá Bay region. Sediments were dominantly composed of terrestrial siliciclastic material carrying signatures of both local inputs (i.e., weathered granitic and gneissic rocks of Serra do Mar Mountain ranges) and Plata Plume sediments brought by Brazilian coastal currents. Low sediment accumulation (avg. = 0.10 cm yr^-1) between 1880 and 1947 showed a stable environment followed by an abrupt increase in sedimentation (avg. = 0.84 cm yr^-1) from 1947 to 2017. This approximate eight-fold increase in sedimentation after 1947 marked significant anthropogenic changes in the region, which is coincidental with major changes in land use through the construction of the port of São Sebastião (1930s) and BR-101 Highway (1980s). While recent surface sediments showed no pollution of heavy metals, anthropogenic Zn enrichment was found between 1880 and 2000. Zn enrichment was from the combined sources, e.g., agriculture activities, domestic sewage, and possibly Zn coated ship paints. Our study also indicates that planned future expansion of São Sebastião port may further increase the sedimentation rate in SSC and impact the ecosystem of Araçá Bay and SSC.

Univariate or multivariate approaches for histopathological biomarkers in the context of environmental quality assessments?

Although the simplification of multivariate histopathological data into univariate indices can be useful for the assessment of environmental quality, this implies a great loss of information. The objective of the present study was to evaluate the effectiveness, in the context of environmental quality assessment, of an approach that integrates individual histopathological responses in a discriminated manner with the results of contaminants by means of multivariate analyses. This analysis was compared to the diagnosis of environmental quality provided by the use of the univariate Bernet histopathological index. Contaminant loads (sediments and fish) and the liver histopathology of Cathorops spixii were integrated through multivariate analysis. Integrated individual histopathological responses allowed classifying environmental quality from more to less impacted sites, while the univariate index showed some inconsistencies with chemical loads and allowed identifying only the most impacted site.

Microscale Toxicity Identification Evaluation (TIE) for interstitial water of estuarine sediments affected by multiple sources of pollution

Estuaries in the world are affected by different contamination sources related to urbanisation and port/industrial activities. Identifying the substances responsible for the environmental toxicity in estuaries is challenging due to the multitude of stressors, both natural and anthropogenic. The Toxicity Identification and Evaluation (TIE) is a suitable way of determining causes of toxicity of sediments, but it poses difficulties since its application is labour intensive and time consuming. The aim of this study is to evaluate the diagnosis provided by a TIE based on microscale embryotoxicity tests with interstitial water (IW) to identify toxicants in estuarine sediments affected by multiple stressors. TIE showed toxicity due to different combinations of metals, apolar organic compounds, ammonia and sulphides, depending on the contamination source closest to the sampling station. The microscale TIE was able to discern different toxicants on sites subject to different contamination sources. There is good agreement between the results indicated in the TIE and the chemical analyses in whole sediment, although there are some disagreements, either due to the sensitivity of the test used, or due to the particularities of the use of interstitial water to assess the sediment toxicity. The improvement of TIE methods focused on identifying toxicants in multiple-stressed estuarine areas are crucial to discern contamination sources and subsidise management strategies.

M-Triad: An improvement of the sediment quality triad

The traditional sediment quality triad generally uses three lines of evidence (LOE) in the assessment, integrating environmental chemistry, ecology and ecotoxicology. However the assessment is performed without considering the multivariate structure within LOE. In order to improve the sediment quality assessment, the M-Triad is proposed. Instead of averaging the values within a LOE, the new approach is based on the Euclidean distance between each sampling station and the reference station (s) for each LOE. These distances are then plotted in a radar-chart to obtain the area of the triangle and the quality assessment is subsequently obtained from the difference between the triangle areas of the impacted and the reference station. Three studies were selected to test the applicability of the M-Triad. In two cases, the M-Triad returned a more realistic ranking of the stations as observed in the principal component analysis (PCA) from each LOE By including the Euclidean distance, the use of M-Triad is advantageous when multiple variables with negative or uncorrelated patterns within a LOE are analyzed simultaneously. The combination of the M-Triad and the results of the PCA allows one to identify multiple contamination gradients and how biota and bioassays respond to each of these gradients. In comparison to the traditional method, the M-Triad reduces the uncertainty of the final analysis, permitting a more comprehensive ecological assessment.

Trace metals in estuarine organisms from a port region in southern Brazil: consumption risk to the local population

Metal contamination is a threat to estuarine environments. They can accumulate in the food chain and cause toxic effects on aquatic organisms and human health. This study evaluated the concentrations of metals (Cd, Cr, Cu, Fe, Ni, Pb, and Zn) in aquatic organisms of Antonina Bay (southern Brazil) to analyze whether the metal concentrations were in accordance with Brazilian food legislation and estimate the human risk of local seafood consumption. All analyzed organisms (Centropomus parallelus, Mugil curema, Genidens genidens, Crassostrea brasiliana, and Xiphopenaeus kroyeri) showed traces of metals in their tissues with different metal concentrations among species. Metal concentrations were generally higher in oyster C. brasiliana, and biomagnification was not observed. Cr and Zn concentrations were above the limits established by legislation for all species in at least one sample. The concentrations of the other metals were within permitted levels. However, concentrations of Cd, Cr, Fe, and Zn posed a human consumption risk. In general, the C. brasiliana oyster presented the highest risk for human consumption, probably due to its filtering habit. Thus, the results indicated that metal concentrations in the tissues of the Antonina Bay seafood can pose a risk to human health, and this chronic exposure to metals also can cause toxic effects on local aquatic biota.

Marine protected areas in Latin America and Caribbean threatened by polycyclic aromatic hydrocarbons

The present study is a literature-based analysis investigating occurrence and the possible consequences of polycyclic aromatic hydrocarbons (PAH) in marine protected areas (MPAs) of Latin America and Caribbean. The approach using overlapping of georeferenced MPA polygons with data compiled from peer-reviewed literature, published during the last 15 years, showed 341 records of PAH in 9 countries. PAH was reported to occur within the boundaries of 36 MPAs located in Argentina, Brazil, Colombia, Mexico, Nicaragua and Uruguay. According to quality guidelines, low to moderate impacts are expected in MPAs categorized in different management classes. Considering sediment samples, 13% of the records presented concentrations enough to cause occasional toxicity. Such level of risk was also seen in Ramsar sites and in Amazonian MPAs. In addition, based on concentrations reported in biota, occasional deleterious effects on organisms from Biosphere Reserves might occur. Diagnostic ratios pointed out petrogenic and pyrolytic processes as PAH predominant sources, and were mainly attributed to the proximity to ports, industries and urban areas. MPAs located in the vicinity of impact-generating areas may be under threat and require government attention and action, mainly through implementation of contamination monitoring programs.

Integrating multiple lines of evidence of sediment quality in a tropical bay (Guanabara Bay, Brazil)

The present study evaluated the ecological risk of metal contamination in sediments of Guanabara Bay (GB) by combining multiple lines of evidence (LOEs). Chemical analysis and a set of whole-sediment toxicity assays were conducted with Tiburonella viscana, Kalliapseudes schubartii, Anomalocardia flexuosa, and Nitocra sp. Results were integrated by multivariate analysis and qualitative methods. Additionally, a whole-sediment Toxicity Identification Evaluation technique (TIE) was applied to identify the chemical groups responsible for the effects. Sediments from harbor and industrial areas exhibited toxicity linked to moderate to high concentrations of Zn, Pb, Cu and Cr. The TIE technique confirmed such effects, but it also indicates the contribution of ammonia and organic compounds to the observed toxicity. Our results demonstrate that the combination of multiple LOEs improves the effectiveness of environmental risk assessment of chemical stressors and management of coastal ecosystems in tropical regions.

Can shell alterations in limpets be used as alternative biomarkers of coastal contamination?

The present study evaluated the association among traditional biochemical biomarkers with biometric, morphometric, and elemental composition of Lottia subrugosa (patelliform gastropod) shells from three multi-impacted coastal areas in Brazil. The study was carried out in Todos os Santos Bay (TSB), Santos/São Vicente Estuarine System (SESS) and Paranaguá Estuarine Complex (CEP), using three sampling sites to seek contamination gradients in each area. Results showed that all biomarkers evaluated responded to environmental contamination, regardless the presence (SESS and CEP) or absence (TSB) of a gradient of contamination. The responses found using biometric and morphometric parameters were consistent with the traditional biomarkers of exposure and effects (lipid peroxidation and DNA damage). Indeed, changes in elemental composition of L. subrugosa shells suggest that exposure to contaminated environments is probably responsible for the alterations detected. Despite the simplicity and lower cost of biometric and morphometric analyzes, these parameters are influenced by natural environmental conditions from which biases may arise. Therefore, these tools should be evaluated through experimental studies before it can be used in future assessments. However, the findings from the present study were observed in three aquatic systems distributed over a wide range of latitudes, which indicates that gastropod shells reflect effects resulting from environmental contamination.

Assessment of metal contamination in fish from estuaries of southern and southeastern Brazil

Historically, the Brazilian coast has been impacted by urban, industrial, and port activities that have increased the input of chemical contaminants, such as heavy metals, to the ecosystem. The Paranaguá estuarine complex (PEC), Cananéia-Iguape estuarine-lagoon complex (CIELC), and Santos-São Vicente estuarine complex (SSVEC) (S-SE Brazil) are surrounded by urbanized cities and port areas characterized by various anthropogenic discharges comprising several potential pollutants, including heavy metals. Concerns about such contamination are paramount because these estuaries are important for traditional fishing communities and are categorized as World Heritage sites and biodiversity hotspots by UNESCO. In this study, metals (Cu, Cr, Ni, Pb, Zn, and Hg) and metalloids (As and Se) known to affect the health of marine life were evaluated in regional fishes. Muscle and liver tissues from three demersal teleosts (Stellifer rastrifer, Paralonchurus brasiliensis, and Isopisthus parvipinnis) were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES), with a coupled vapor generated accessory (VGA). Irrespective of species, metal bioconcentration was significantly greater in fishes from the PEC and CIELC, which had higher As, Cu, and Zn concentrations, while Se levels were higher in fish from the PEC and SSVEC estuaries. Seasonality, fish species and maturation stage affected the accumulation of metals. Some metal levels, including As, Cr, Pb, and Se in all species across all estuaries, and Zn in the PEC, exceeded the maximum permitted level for seafood and might present a risk for daily human consumption. The results provide reference points for existing chemical contamination and should be used to guide monitoring programs and the sustainable development of these coastal regions, within a broader objective of maintaining public health.

Pollution status of marine protected areas worldwide and the consequent toxic effects are unknown

Chemical pollution is considered a factor that may threaten marine protected areas (MPAs), and recent studies have found contamination and associated biological effects in some MPAs. However, organized data on this topic are lacking. This study reviewed the literature on pollution in MPAs in order to compile data, determine whether MPAs are influenced by pollution and, whenever possible, describe how they are being affected by contaminants. The results show that the pollution status is unknown in most MPAs worldwide. When any information is available, it is often insufficient to diagnose the threats to biodiversity or to support further actions. More robust and extensive information is available on a small number of MPAs, and much less information is available regarding the negative effects of pollution. More than 80% of the areas studied exhibited evidence of contamination at potentially toxic concentrations or were found to have a status that produced toxic effects on the biota. The scientific community is encouraged to study pollution in MPAs worldwide.

Use of Tisbe biminiensis nauplii in ecotoxicological tests and geochemical analyses to assess the sediment quality of a tropical urban estuary in northeastern Brazil

An approach pooling geochemical analyses and ecotoxicological tests has been applied to assess the sediment quality of the Capibaribe River Estuary, Brazil. Toxicity tests were performed to compare a well-established, labor-intensive protocol using ovigerous females to a new, easier and faster protocol using nauplii of the epibenthic marine copepod Tisbe biminiensis. The endpoints of the nauplii toxicity test were comparable to those of the female test. Nauplii proved to be more sensitive than females as a biological model for indicating sediment toxicity. All sediments collected had at least one contaminant above the threshold effects level (TEL) proposed in the literature. Furthermore, more than one-third of samples exhibited contaminants above the probable effects level (PEL). The PCA revealed that nauplii mortality was associated with metals in October 2014, which was confirmed by the Spearman correlation factor. In contrast, no strong association among contaminants and toxicological endpoints in May 2015 was found.

PAHs in Water, Sediment and Biota in an Area with Port Activities

The study reports concentration of 16 PAHs in sediment, water, plankton and in muscle and liver of sampled fishes from Paranagua Bay in Southern Brazil. According to the range of PAHs concentration found in sediments (ΣPAHs 15.33-133.61 µg g^-1) and water (ΣPAHs 51.20-162.37 µg L^-1), the area was characterized as slightly polluted. In contrast, significant concentration of PAHs was found in fish and plankton, ranging from 26.52 to 2055.00 µg g^-1 and 175.41 to 2096.10 µg g^-1, respectively. The concentrations were 15 times more than in sediments. Even though the concentration of PAHs in water and sediments are low, the concentration in fish tissues are alarmingly. The hypothesis of bioaccumulation is not discharged. Accumulation levels of PAHs in the biota were used to calculate biota-sediment accumulation factor (BSAF) and bioaccumulation factor (BAF). For example, fish sampled from site 11 had a BAF of 49 and BSAF of 2.3, whereas for plankton the BAF was 16.3 and BSAF 0.7. Mean values of BAF and BSAF were higher in plankton samples. It is known that PAHs are enzymatically metabolized by organisms, thus the lower BSAF in fish might have resulted from biochemical transformation. Statistical analysis indicates no significant correlation between total PAHs concentration in fish tissues and total lipid content in fishes (p > 0.1).Accumulation in tissues is controlled by lipid content, although factors, such as spatial distribution of compounds, trophic level, and behavior of each species in the environment, must be considered. Besides, size and nutritional conditions can affect both absorption as well as metabolic process and excretion. A positive and significant correlation was found between total PAHs and trophic positions obtained from FishBase data (r² = 0.784; p < 0.05). Thus, it seems that the area, with great influence of urban and industrial activities, and the bioaccumulation compounds, such as PAHs, depend on others factors, as well as resuspension of sediments and releasing of compounds for biota.

Occurrence of halogenated organic contaminants in estuarine sediments from a biosphere reserve in Southern Atlantic

The occurrence, distribution, and the total mass of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were studied in surficial sediments of the Paranaguá Estuarine System (PES), a subtropical estuary in Southern Atlantic. Altogether, concentrations and inventories of contaminants ranged from <0.06 to 4.78 ng g^-1 and < 0.13 to 10.47 ng cm^-2, respectively. OCPs presented the higher total mass (10.85 kg) and a decreasing trend from the inner estuary towards the adjoining shallow shelf. The occurrence of PCBs was restricted to sites nearby urban and industrial areas, which accumulated ~80% of the total mass of PCBs. Although the level of contamination is low, the results refer to recent years, which mean that the actual values could be greater if sediments from periods of higher usage were analyzed. This study provides the first estimates of POPs (persistent organic pollutants) total mass in the PES, contributing to data for the Southern American inventories.

Integrative assessment of sediment quality in lower basin affected by former mining in Brazil

The Ribeira de Iguape River (Southeast Brazil) is metal contaminated by mining activities. Despite it has been cataloged as "in via of restoration" by the literature, this basin is still a sink of pollution in some segments of the fluvial system. This study aimed to assess the sediment quality in the lower part of the RIR basin. The employed approach was based on biological responses of the freshwater clam Corbicula fluminea after 7-day exposure bioassays using as the reference site the Perequê Ecological Park. Toxic responses (burial activity and lethality) and biochemical biomarkers (GST, GR, GPx, LPO, MTs, AChE and DNA damage) were evaluated and then integrated with metal bioavailability and chemical concentrations to address the sediment quality in the area through the weight-of-evidence approach. A multivariate analysis identified linkages between biological responses and contamination. Results pointed that, despite being below the benchmarks of the US Environmental Protection Agency, there is slight metal contamination in the lower part of the basin which induces oxidative stress in C. fluminea; other toxic responses were sometimes attributed to As and Cr bioaccumulation. The sediment quality values (TEL-PEL values in mg/kg) were calculated for the current study for As (0.63-1.31), Cr (3.5-11.05), Cs (1.0-1.17), Cu (6.32-7.32), Ni (6.78-7.46), Ti (42.0-215), V (1.77-8.00). By comparison with other international guidelines, the sediment quality of the lower basin of the Vale de Ribeira does not identify a significant environmental risk.

Is the microcosm approach using meiofauna community descriptors a suitable tool for ecotoxicological studies?

The usual approaches used in ecological risk assessment have been based on individual and population level standard procedures. Although these have been important tools to assess adverse effects on ecosystems, they are generally simplified and therefore lack ecological realism. Microcosm studies using meiobenthic communities offer a good compromise between the complexity of the ecosystem and the often highly artificial settings of laboratory experiments. An experiment was designed to investigate the potential of the microcosm approach using meiofauna as a tool for ecotoxicological studies. The experiment tested the ecological effects of exposure to sewage-impacted pore water simultaneously at the community level using meiofauna microcosms and at the individual level using laboratory fecundity tests with the copepod Nitokra sp. Specifically, the experiment tested the toxicity of pore water from three sites according to a contamination gradient. Both approaches were efficient in detecting differences in toxicity between the less and more contaminated sites. However, only multivariate data from community analysis detected differences in the gradient of contamination. In addition to information about toxicity, the community level microcosm experiment gave indications about sensitive and tolerant species, indirect ecological effects, as well as raised hypothesis about contamination routes and bioavailability to be tested. Considering the importance of meiofauna for benthic ecosystems, the microcosm approach using natural meiobenthic communities might be a valuable addition as a higher tier approach in ecological risk assessment, providing highly relevant ecological information on the toxicity of contaminated sediments.

Trace elements in feathers and eggshells of brown booby Sula leucogaster in the Marine National Park of Currais Islands, Brazil

Levels of trace elements were investigated in feathers of 51 adults and 47 eggshells of brown boobies Sula leucogaster from one bird colony in the Marine National Park of Currais Islands, Brazil, between December 2013 and October 2014. Average concentrations (μg g^-1, dry weight) in feathers and eggshells, respectively, were Al 50.62-9.58, As 0.35-2.37, Cd 0.05-0.03, Co 0.38-2.1, Cu 15.12-0.99, Fe 47.47-22.92, Mg 815.71-1116.92, Ni 0.29-11.85, and Zn 94.16-1.98. In both arrays, the average concentration of Mg was the highest among all the elements analyzed, while the lowest was recorded for Cd. As and Ni presented levels at which biological impacts might occur. Zn concentrations were higher than those considered normal in other organs. Levels of Al, Fe, Cu, Zn, and Cd were higher in feathers, whereas higher contents of Mg, Co, Ni, and As occurred in eggshells. The comparison between the elements in eggshells collected at different seasons showed no significant difference (p > 0.05) due, probably, to the lack of temporal variation on foraging behavior and/or on bioavailability of trace elements. Metals and arsenic in feathers and eggshells were mostly not correlated. Future studies on Paraná coast should focus on the speciation of the elements, especially As, Ni, and Zn, which proved to be a possible problem for the environment and biota. It is necessary to investigate both matrices, shell and internal contents of the eggs, in order to verify if the differences previously reported in other studies also occur in eggs of brown boobies in the Marine National Park of Currais Islands.

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.

Characterization of quality of sediments from Paranaguá Bay (Brazil) by combined in vitro bioassays and chemical analyses

The present study characterizes the quality of sediments from the Paranaguá Estuarine Complex (South Brazil). Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were determined in sediment samples together with a series of different in vitro bioassays. The fish hepatoma cell line (PLHC-1) was used to determine the presence of cytotoxic compounds and CYP1A- and oxidative stress-inducing agents in sediment extracts. Ovarian microsomal fractions from sea bass (Dicentrarchus labrax) were used to detect the presence of endocrine disrupters that interfered with the synthesis of estrogens (ovarian CYP19). Despite the relatively low levels of pollutants and no evidence of negative effects based on guideline levels, sediments collected close to harbors were enriched with CYP1A-inducing agents and they showed higher cytotoxicity. In contrast, sediments from internal areas inhibited CYP19 activity, which suggests the presence of endocrine disrupters at these sites. Overall, the selected bioassays and the chemistry data led to the identification of potentially impacted areas along the Paranaguá Estuarine Complex that would require further action to improve their environmental quality. Environ Toxicol Chem 2017;36:1811-1819. © 2016 SETAC.

The use of a Weight-of-Evidence approach to address sediment quality in the Odiel River basin (SW, Spain)

The fluvial systems of the Iberian Pyrite Belt (SW Iberian Peninsula) are affected by acid mine drainage (a lixiviate residue product of mining activities derived from sulfide oxidation). The high acidity and high concentrations of sulfates and metal(loid)s are the main causes of the environmental degradation of the Odiel River basin. The use of weight of evidence approach in areas of the Odiel River basin implies the integration of different lines of evidence (chemistry, toxicity and bioaccumulation) using the freshwater clam Corbicula fluminea as target species. The integration of the results from the application of the different lines of evidence showed that the index of pollution was higher downvalley (Ptriad=12,312), moderate after mining effluent discharges (Ptriad=13.9) and very low where the Odiel River sources (Ptriad=6.31). The multivariate analysis indicated that variables and chemicals were associated with geochemical matrix and background levels (% of fines and toxic metal(loid) concentrations), toxic effects, and metal(loid) bioaccumulation reflecting the geographical distribution of the contamination towards the estuary. Metal(loid) thresholds were calculated for the study area as site-specific values of interim freshwater sediment quality values: As≥171; Cd≥0.48; Co≥8.82; Cr≥38.4; Cu≥451; Ni≥18.4; Pb≥377; Sb≥17.7; Zn≥221mg/kg of freshwater fluvial dry sediment. These results revealed the possibility of using the TEL values proposed by the USEPA and the NOAA for sediments from this site, and proposed lower PEL values for the Iberian Pyrite Belt as result of toxicity effects found in the Asian clam due to the combination of extreme acidity and high metal(loid) concentrations.

Are intertidal soft sediment assemblages affected by repeated oil spill events? A field-based experimental approach

This study investigates the impact of repeated diesel spills on the structure of intertidal macrofaunal assemblages of a subtropical estuary. Three frequencies of exposure events were compared against two dosages of oil in a factorial experiment with asymmetrical controls. Hypotheses were tested to distinguish between (i) the overall effect of oil spills, (ii) the effect of diesel dosage via different exposure regimes, and (iii) the effect of time since last spill. Repeated oil spills dramatically altered the overall structure of assemblages and reduced the total density of macrofauna and densities of dominant taxa. Increasing the frequency of oil spills negatively affected macrofauna. In general, frequent low-dosage oil spills were more deleterious than infrequent high-dosage ones. However, increases in densities of some taxa, mainly the gastropod Heleobia australis, were observed in response to infrequent spills. Our results highlight the importance of repeated exposure events in determining the extent of oil impacts.

Using an integrated approach to assess the sediment quality of an estuary from the semi-arid coast of Brazil

The Jundiaí-Potengi Estuary (JPE) on the semi-arid coast of Brazil is influenced by multiple sources of pollution. Sediment quality at 10 JPE sites was evaluated through an integrated approach. Rainy and dry seasons were considered. Collected sediments were analyzed for texture, metal, nitrogen, phosphorus concentrations, and toxicity to invertebrates. Geochemical and ecotoxicological data were integrated using qualitative approaches and multivariate techniques. We observed decreased sediment quality in both seasons, particularly in the mid-estuary. In the dry season, the contamination-toxicity relationship was clearer, as hydrological conditions favor contaminant retention within the estuary. Rainy season conditions were found to be worse, since stormwater drainage from agricultural and urban areas carries the contamination into the estuary. Because of the contamination sources and dissolved and particle-bound metal transport, contamination and toxicity did not correlate as clearly in the rainy season. The results suggest that unmeasured contaminants are contributing to JPE sediment degradation.

Assessing genotoxic effects in fish from a marine protected area influenced by former mining activities and other stressors

The goal of the current study was to evaluate different genotoxicity tools in order to assess a marine protected area (MPA) affected by former mining activities and urban settlements. A catfish (Cathorops spixii) was analyzed for genotoxic effects at the (i) molecular and at the (ii) chromosomal levels. Through factor analysis, genotoxicity was found to be linked to levels of metals bioaccumulated and PAH metabolites in the bile. Micronucleus and nuclear alteration were less vulnerable to the effects of confounding factors in mildly contaminated areas since they were more frequently associated with bioaccumulated metals than the DNA analysis. The different genotoxicity responses allowed for the identification of sources of pollution in the MPA. This approach was important for detecting environmental risks related to genotoxic contaminants in a mildly contaminated MPA.

Assessment by self-organizing maps of element release from sediments in contact with acidified seawater in laboratory leaching test conditions

Carbon capture and storage (CCS) is gaining interest as a significant global option to reduce emissions of CO2. CCS development requires an assessment of the potential risks associated with CO2 leakages from storage sites. Laboratory leaching tests have proved to be a useful tool to study the potential mobilization of metals from contaminated sediment in a decreased-pH environment that mimics such a leakage event. This work employs a self-organizing map (SOM) tool to interpret and analyze the release of dissolved organic carbon (DOC), As, Cd, Cr, Cu, Ni, Pb, and Zn from equilibrium, column, and pH-dependent leaching tests. In these tests, acidified seawater is used for simulating different CO2 leakage scenarios. Classification was carried out detailing the mobilization of contaminants for environments of varying pH, liquid-to-solid ratio, and type of contact of the laboratory leaching tests. Component planes in the SOMs allow visualization of the results and the determination of the worst case of element release. The pH-dependent leaching test with initial addition of either base or acid was found to mobilize the highest concentrations of metals.

Assessing pollution in marine protected areas: the role of a multi-biomarker and multi-organ approach

Marine protected areas (MPAs) are vulnerable to many pressures, including pollution. However, environmental quality monitoring in these areas traditionally relies on only water chemistry and microbiological parameters. The goal of the current study was to investigate the role of a set of biomarkers in different target organs (liver, kidney, and gills) of fish in order to assess the environmental quality of an MPA (MTs, GPx, GST, GSH, DNA damage, LPO, AChE, and condition index). Chemical analyses were also performed on liver and muscle tissues to evaluate metal body burdens, and PAHs were identified in bile. A demersal fish (Cathorops spixii) that is widely consumed by the local population was used as bioindicator species, and the results were integrated using multivariate analysis. The use of the biomarker approach allowed for the identification of both seasonal and spatial variations in pollution sources around the Environmental Protected Area of Cananéia-Iguape-Peruíbe (APA-CIP). Higher metal body burdens associated with biological responses were found in the sites under the influence of urban areas during the dry season, and they were found in the sites under the influence of the Ribeira de Iguape River (RIR) during the rainy season. The liver was found to be more responsive in terms of its antioxidant responses, whereas gills were found to be more responsive to biomarkers of effect. These results show that this set of biomarker analyses in different organs of fish is a useful tool for assessing chemical pollution in an MPA.

Cumulative influences of a small city and former mining activities on the sediment quality of a subtropical estuarine protected area

This study aimed to evaluate the sediment quality in the estuarine protected area known as Cananéia-Iguape-Peruíbe (CIP-PA), located on the southeastern coast of Brazil. The study was designed considering possible negative effects induced by the city of Cananéia on the sediment quality of surrounding areas. This evaluation was performed using chemical and ecotoxicological analyses. Sediments were predominantly sandy, with low CaCO3 contents. Amounts of organic matter varied, but higher contents occurred closer to the city, as well as did Fe and Total Recoverable Oils and Greases (TROGs) concentrations. Contamination by Cd and Cu was revealed in some samples, while concentrations of Zn were considered low. Chronic toxicity was detected in all tested sediments and acute toxicity occurred only in sediments collected near the city. The principal component analysis (PCA) revealed an association among Cd, Cu, Fe, TROG, fines, organic matter, CaCO3, and chronic toxicity, whereas acute toxicity was found to be associated with Zn and mud. However, because Zn levels were low, acute toxicity was likely due to a contaminant that was not measured. Results show that there is a broad area within the CIP-PA that is under the influence of mining activities (chronic toxicity, moderate contamination by metals), whereas poorer conditions occur closer to Cananéia (acute toxicity); thus, the urban area seems to constitute a relevant source of contaminants for the estuarine complex. These results show that contamination is already capable of producing risks for the local aquatic biota, which suggests that the CIP-PA effectiveness in protecting estuarine biota may be threatened.

First evaluation of the threat posed by antifouling biocides in the Southern Adriatic Sea

The CARISMA project (characterization and ecological risk analysis of antifouling biocides in the Southern Adriatic Sea) aims to appraise the quality of the Southern Adriatic Sea between Italy (Apulia region) and Albania and, in particular, the impact due to the use of biocidal antifouling coatings. Under this project, a preliminary survey at the main hot spots of contamination (e.g. ports and marinas) was conducted at the end of the nautical season in 2012. Chemical seawater analyses were complemented with ecotoxicological assays and the results were analyzed by principal component analysis (PCA). As expected, PCA splits the Albanian and Italian ports, according to the different degrees of contamination indicated for the two countries by the experimental data, highlighting the most critical situation in one port of Apulia. In addition, in order to assess the potential adverse ecological effects posed by antifouling agents (i.e. tributyltin (TBT)-irgarol-diuron) on non-target marine organisms, hazard quotients (HQ) were calculated. The results showed a low risk posed by irgarol and diuron whereas the probability of adverse effects was high in the case of TBT.

Ecological relevance of Sentinels' biomarker responses: a multi-level approach

In response to the need for more sensitive and rapid indicators of environmental quality, sublethal effects on the lowest levels of biological organization have been investigated. The ecological relevance of these responses assumes a prevailing role to assure effectiveness as indicator of ecological status. This study aimed to investigate the linkages between biomarker responses of caged bivalves and descriptive parameters of macrobenthic community structure. For this purpose a multi-level environmental assessment of marine and estuarine zones was performed in São Paulo coast, Brazil. Multivariate analysis was applied to identify linkages between biological responses and ecological indices, as well as to characterizing the studied stations. Individuals of the marine mussel Perna perna caged along Santos Bay showed signs of oxidative stress, lysosomal membrane destabilization, histological alterations and reduced embryonic development. The estuarine oyster Crassostrea rhizophorae caged along Santos Port Channel showed alterations on biotransformation enzymes and antioxidant system, DNA damage and lysosomal membrane destabilization. The benthic community analysis showed reduced richness and diversity in the same areas of the Santos bay and estuary where biomarker responses were altered. Our results revealed that xenobiotics are inducing physiological stress, which may lead to changes of the benthic community structure and deterioration of the ecological status over time. Integrating biomarker responses and ecological indexes improved certainty that alterations found at community level could be related to xenobiotic as stressors, which was very useful to improve the discriminatory power of the environmental assessment.

Arsenic and other trace elements in two catfish species from Paranaguá Estuarine Complex, Paraná, Brazil

Concentrations of arsenic and four additional trace elements (Cu, Cr, Ni, and Zn) were determined by inductively coupled plasma-optical emission spectrometry in the muscular tissue of the yellow catfish (Cathorops spixii) and the urutu catfish (Genidens genidens) from Paranaguá Estuarine Complex, Brazil (PEC). The PEC can be characterized by an environment of high ecological and economic importance in which preserved areas of rainforest and mangroves coexist with urban activities as ports and industries. The average concentrations (in milligram per kilogram dry weight) of elements in the muscle tissue of C. spixii are as follows: Zn (31), As (17), Cu (1.17), Cr (0.62), and Ni (0.28). Similar concentrations could be found in G. genidens with exception of As: Zn (36), As (4.78), Cu (1.14), Cr (0.51), and Ni (0.14). Fish from the geographic northern rural region (Guaraqueçaba-Benito) display higher As concentrations in the muscle tissues than fish found in the south-western (urban) part of the PEC. An international comparison of muscle tissue concentrations of trace elements in fish was made. Except for Ni in C. spixii, a tendency of decrease in element concentration with increasing size (age) of the fish could be observed. According to the National Health Surveillance Agency of Brazil, levels of Cr and As exceeded the permissible limits for seafood. An estimation of the provisional tolerable weekly intake of As was calculated with 109 % for C. spixii and with 29 % for G. genidens.

Is the distribution of the lancelet Branchiostoma caribaeum affected by sewage discharges? An analysis at multiple scales of variability

Spatial variation in the density and biomass of Branchiostoma caribaeum was analyzed along a sewage contamination gradient identified by fecal steroids in a subtropical estuary, southern Brazil. Sampling, repeated in the austral winter and summer, followed a hierarchical design nested at four spatial scales (sector>1 km; area>100 m; site>10 m; replicate<1 m). Density and biomass were significantly lower at sites characterized by high concentrations of fecal steroids. The best combinations of variables that explained the biological similarities among sites involved contamination indicators. Most of the variation of biological data was found at the smallest scales and could be related with the sediment texture. Our study highlighted the usefulness of a multi-scale perspective to evaluate distribution patterns of benthic invertebrates as a biological indication of environmental pollution. Gradient analyses at larger spatial scales may be invalidated by the patchy distribution of benthic fauna if they do not account for such small scale variability.

Environmental quality assessment combining sediment metal levels, biomarkers and macrobenthic communities: application to the Óbidos coastal lagoon (Portugal)

Macroinvertebrate benthic communities are one of the key biological components considered for the assessment of benthic integrity in the context of the Water Framework Directive (WFD). However, under moderate contamination scenarios, the assessment of macrobenthic alterations at community level alone could be insufficient to discriminate the environmental quality of coastal and transitional waters. Keeping this in view, sediment quality of moderately contaminated sites in a coastal lagoon (Óbidos lagoon, Portugal) was assessed by the combination of sediment metal levels, Carcinus maenas biomarkers (accumulated metals and oxidative stress responses) and macrobenthic communities. Two sites were selected in confined inner branches (BS and BB) and a third one in the middle lagoon (ML). The site BB presented slightly higher levels of metals in sediment but biological variables calculated for macrobenthic data were not significantly different between sites. The biotic index M-AMBI that is being applied to assess environmental quality of transitional waters in the scope of the WFD pointed either to high (site ML) or good quality status (BS and BB) in the selected sites. However, crabs from BB site presented significantly higher levels of Ni in hepatopancreas than those from ML and macrobenthic community structure was significantly different between BB and ML. Additionally, spatial differences were obtained for oxidative stress parameters suggesting that BB site presented stressors for crabs (higher GST and lower GSH(t) at BB site). Factor analysis (PCA) integrating sediment contamination, biomarkers in crabs and macrobenthic data also distinguished BB site as the most environmentally disturbed. On the other hand, at ML site, some macrobenthic variables (equitability and polychaetes' diversity) were found to be enhanced by current environmental conditions, suggesting the existence of a better sediment quality. Current results pointed to the usefulness of integrating macrobenthic community alterations with responses at organism level (bioaccumulation and biochemical endpoints) in order to increase the accuracy of environmental quality assessment in lagoon systems. Moreover, the application of different statistical methods was also found to be recommendable.

Bioaccumulation of Polycyclic Aromatic Hydrocarbons and Mercury in Oysters (Crassostrea rhizophorae) from Two Brazilian Estuarine Zones

Nowadays, organisms are increasingly being used in biomonitoring to assess bioavailability and bioaccumulation of contaminants. This approach can use both native and transplanted organisms in order to accomplish this task. In Brazil, most of the studies related to bioaccumulation of contaminants in oysters deal with metals. The present work employs this kind of test in Brazilian coastal estuaries (Santos and Paranaguá) to evaluate total mercury and polycyclic aromatic hydrocarbon contamination in sediments and oysters (native and caged Crassostrea rhizophorae). The methodologies employed were based on known USEPA methods. Results have shown a significant contamination in Santos sediments and consequent bioavailability of organisms. Paranaguá sediments presented lower contamination in sediments, but native oysters were able to accumulate total Hg. The experiments done with caged oysters did not show significant bioaccumulation of Hg and PAHs in the Paranaguá site, but proved to be an excellent tool to assess bioavailability in the Santos estuary since they were able to bioaccumulate up to 1,600% of total PAH in the samples from the inner part of this estuary when compared to control organisms. Multivariate statistical analyses employed to these results have separated the sites evaluated and the most contaminated samples from the least contaminated.

Contamination of port zone sediments by metals from Large Marine Ecosystems of Brazil

Sediment contamination by metals poses risks to coastal ecosystems and is considered to be problematic to dredging operations. In Brazil, there are differences in sedimentology along the Large Marine Ecosystems in relation to the metal distributions. We aimed to assess the extent of Al, Fe, Hg, Cd, Cr, Cu, Ni, Pb and Zn contamination in sediments from port zones in northeast (Mucuripe and Pecém) and southeast (Santos) Brazil through geochemical analyses and sediment quality ratings. The metal concentrations found in these port zones were higher than those observed in the continental shelf or the background values in both regions. In the northeast, metals were associated with carbonate, while in Santos, they were associated with mud. Geochemical analyses showed enrichments in Hg, Cd, Cu, Ni and Zn, and a simple application of international sediment quality guidelines failed to predict their impacts, whereas the use of site-specific values that were derived by geochemical and ecotoxicological approaches seemed to be more appropriate in the management of the dredged sediments.

Multi-molecular markers and metals as tracers of organic matter inputs and contamination status from an Environmental Protection Area in the SW Atlantic (Laranjeiras Bay, Brazil)

The sources and concentrations of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), faecal and biogenic sterols, and trace metals at 10 sampling sites located in Laranjeiras Bay, a large Environmental Protection Area in the southern Atlantic region of Brazil, were determined to assess the sources of organic matter and the contamination status of estuarine sediments. Organic compounds were determined by GC-FID and GC-MS, and ICP-OES was used to evaluate trace metals. The total AHs concentration ranged from 0.28 to 8.19 μg g(-1), and n-C(29) and n-C(31) alkanes were predominant, indicating significant inputs from higher terrestrial plants. Unresolved complex mixtures (UCM) were not detected at any site, suggesting that the study area was not significantly contaminated by fossil fuels. The total PAH concentration varied from 3.85 to 89.2 ng g(-1). The ratio between selected PAH isomers showed that combustion of biomass, coal, and petroleum is the main source of PAHs in the study area. The concentrations of the faecal sterols coprostanol and epicoprostanol were below the detection limits, suggesting that sewage was not a significant contributor to sedimentary organic matter. The concentrations of the trace metals (As, Cr, Cu, Ni, Pb and Zn) were low, except near sites located at the mouths of rivers that discharge into the study area and near urbanised regions (Paranaguá city and the adjoining harbour). In general, the concentrations of PAHs were below the threshold effect concentrations (TEL) levels. Although the As, Cr and Ni concentrations were above the TEL levels, the study area can be considered as preserved from human activities.

Lead hampers gill cell volume regulation in marine crabs: stronger effect in a weak osmoregulator than in an osmoconformer

Hepatus pudibundus is a strictly marine osmoconformer crab, while Callinectes ornatus inhabits estuarine areas, behaving as a weak hyper-osmoregulator in diluted seawater. Osmoconformers are expected to have higher capacity for cell volume regulation, but gill cells of a regulator are expected to display ion transporters to a higher degree. The influence of lead nitrate (10 μM) on the ability of isolated gill cells from both species to volume regulate under isosmotic and hyposmotic conditions were here evaluated. Without lead, under a 25% hyposmotic shock, the gill cells of both species were quite capable of cell volume maintenance. Cells of C. ornatus, however, had a little swelling (5%) during the hyposmotic shock of greater intensity (50%), while cells of H. pudibundus were still capable of volume regulation. In the presence of lead, even under isosmoticity, the gill cells of both species showed about 10% volume reduction, indicating that lead promotes the loss of water by the cells. When lead was associated with 25% and 50% hyposmotic shock, C. ornatus cells lost more volume (15%), when compared to isosmotic conditions, while H. pudibundus cells showed volume regulation. We then analyzed the possible ways of action of lead on the mechanisms of cell volume regulation in the two species. Verapamil (100 μM) was used to inhibit Ca²⁺ channels, ouabain (100 μM) to inhibit Na⁺/K⁺-ATPase, and HgCl₂ (100 μM) to inhibit aquaporins. Our results suggest that: (1) Ca²⁺ channels are candidates for lead entry into gill cells of H. pudibundus and C. ornatus, being the target of lead action in these cells; (2) aquaporins are much more relevant for water flux in H. pudibundus; and (3) the Na⁺/K⁺-ATPase is much more relevant for volume regulation in C. ornatus. Osmoregulators may be more susceptible to metal contamination than osmoconformers, especially in situations of reduced salinity, for two basic reasons: (1) lower capacity of volume regulation and (2) putative higher uptake of Pb²⁺ through ionic pathways that operate in salt absorption, such as, for example, the Na⁺/K⁺-ATPase.

High organochlorine accumulation in blubber of Guiana dolphin, Sotalia guianensis, from Brazilian coast and its use to establish geographical differences among populations

Blubber samples from 33 Guiana dolphins (Sotalia guianensis) from three estuaries (Guanabara, Sepetiba/Ilha Grande and Paranaguá Bays) of Southern and Southeastern Brazil were analyzed for organochlorine compounds (DDTs, PCBs and HCB). The sampled individuals were incidentally captured in gillnet fishery between 1995 and 2005. The concentrations (in ng/g lipids) varied from 652 to 23 555 for SigmaDDT; from 765 to 99 175 for SigmaPCB; and from <4.4 to 156 for HCB. The results have shown that cetaceans from Brazil present organochlorine concentrations that are comparable to those reported for highly industrialized regions of Northern Hemisphere. Using discriminant analysis it was possible to verify that the dolphin populations from the three bays present different organochlorine accumulation patterns. This feature allows the use of this set of pollutants as an auxiliary tool for identification of different populations of the species off Brazilian Coast.

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).

Molecular mechanisms of megakaryopoiesis

One function of bone marrow megakaryocytes (MKs) is the controlled release of platelets into the circulation. Over the past few years, molecular mechanisms that contribute to MK development and differentiation have begun to be elucidated. This review provides a brief overview of megakaryopoiesis and platelet function, and the importance of selected hematopoietic transcription factors (including GATA-1, FOG, Fli-1, AML1, and NF-E2) and target genes in this biological process. In addition, a discussion of human diseases affecting megakaryopoiesis and mouse models of thrombocytopenia are presented with emphasis on how these systems have and will continue to provide further insights into mechanisms that control the biological functions of the megakaryocytic cell lineage. Ultimately, such knowledge may provide the basis for novel therapeutic approaches for modulation of platelet number and function.