A Combined Approach Using Water Quality Indexes and Statistical Analyses to Assess the Urban Surface Runoff: a Case Study in São Paulo Coastal Zone, Brazil

Although the most conventional methods to determine the quality of an aquatic ecosystem are aimed to evaluate its physicochemical, microbiological and ecotoxicological characteristics, the monitoring of a large number of environmental variables can represent a high cost for developing countries like Brazil. However, a combined approach using water quality indexes and statistical analyses may help us to monitor water quality through a previous selection of a few key environmental variables. In this context, the objective of this study was to highlight the set of environmental variables most useful to assess the urban channels water quality of Guarujá, Brazil, whose diffuse loads flow continuously into four tourist beaches (Tombo, Enseada, Perequê and Iporanga). For this purpose, three different methods were applied: (i) an existent published large data set (30 environmental variables: 28 physicochemical/microbiological, plus 2 ecotoxicological) obtained during a previous monitoring of the urban drainage channels of these beaches; (ii) the potential risks for the aquatic local fauna and flora through established water quality indexes, such as IMPC, TSI and ALPI; and (iii) through statistical methods such as Cohen D test, Standardized Odds Ratio and Logistic Regression, the set of environmental variables with the greatest potential to cause acute and chronic toxicity in urban channels waters. This combined approach using water quality indexes and statistical analyses was effective to successfully reduce the number of environmental variables needed to assess the ecological status of this coastal area. Moreover, this combined approach was useful to gather intuitive and user-friendly environmental information that could help decision makers (i.e., public authorities and environmental agencies) to plan and perform low-cost and effective monitoring plans in different coastal zones worldwide, namely in developing countries such as Brazil

Early life history of the European conger eel (Conger conger) as revealed by otolith microstructure and microchemistry of leptocephali

Dissertação de Doutoramento em Ciências do Meio Aquático apresentada ao Instituto de Ciências Biomédicas de Abel Salazar da Universidade do Port

Otolith shape and elemental signatures provide insights into the connectivity of euryhaline chelon labrosus inhabiting two close estuaries with different burdens of xenoestrogens in the southern bay of biscay

Intersex gonads have been observed in thicklip grey mullet Chelon labrosus, inhabiting estuaries with high burdens of xenoestrogens in the Southeast Bay of Biscay, but knowledge of population connectivity among estuaries is lacking for this euryhaline fish species. This study investigates the population structure of C. labrosus using otolith shape and elemental signatures of 60 adults (overall length ~ 38 cm) from two estuaries 21 nautic miles apart, one with a high incidence of intersex condition (Gernika), and the other one pristine (Plentzia). Otolith shape analyses were performed using elliptical Fourier descriptors, while elemental signatures of whole sagittae were obtained by inductively coupled plasma mass spectrophotometry. Univariate and multivariate statistics were applied to determine if otolith signatures show patterns of homogeneity between estuaries. The data indicated significant differences in the otolith shape and elemental composition between mullets of Gernika and Plentzia. Elemental differences were mainly driven by Sr, Li (both higher in Plentzia) and Ba (higher in Gernika). The 98% re-classification success rate obtained from stepwise linear discriminant function analysis suggests that Gernika and Plentzia individuals form separated population units. The limited connectivity between these two close estuaries would indicate a different life history of exposure to chemicals, which might explain the high prevalence of intersex condition in Gernika and its absence in Plenztia.info:eu-repo/semantics/publishedVersio

Past and contemporaneous otolith fingerprints reveal potential anthropogenic interferences and allows refinement of the population structure of isopisthus parvipinnis in the south Brazil bight

In this study, otolith geochemical signatures (Element:Ca ratios) were used to investigate the long-term spatial shifts of the population structure of Isopisthus parvipinnis, Bigtooth corvina, an economically and ecologically important Brazilian fish species. Two-hundred and ninety-seven juvenile individuals from historical (1975) and contemporary (2018/2019) samples were collected in five subareas [São Paulo: North—NSP, Center—CSP and South—SSP; Paraná (PR) and Santa Catarina (SC)] of the shallow waters off the coast of the South Brazil Bight were analyzed. The main informative single elements were Co:Ca, Cu:Ca, Li:Ca, Mg:Ca, Mn:Ca, Ni:Ca, Na:Ca, and Rb:Ca. Multivariate analysis showed spatial differences in otolith chemical composition over the years. Samples from 1975 presented an overall low reclassification rate (58%), suggesting the existence of two population units: (1) SP + PR; and (2) SC. However, samples from 2018/2019 discriminated four distinct population units with a good overall reclassification (80%): (1) NSP; (2) CSP; (3) SSP + PR;and (4) SC. This spatial differentiation on the geochemical signatures probably reflects the effects of long-term temporal variability in oceanographic conditions, anthropogenic influence, and climate change on this coastal ecosystem. The data also corroborate and refines the population structure scenario of I. parvipinnis recently described using complementary phenotypic tags.info:eu-repo/semantics/publishedVersio

Assessment of paracetamol toxic effects under varying seawater pH conditions on the marine polychaete hediste diversicolor using biochemical endpoints

Increasing atmospheric carbon dioxide (CO2) levels are likely to lower ocean pH values, after its dissolution in seawater. Additionally, pharmaceuticals drugs are environmental stressors due to their intrinsic properties and worldwide occurrence. It is thus of the utmost importance to assess the combined effects of pH decreases and pharmaceutical contamination, considering that their absorption (and effects) are likely to be strongly affected by changes in oceanic pH. To attain this goal, individuals of the marine polychaete Hediste diversicolor were exposed to distinct pH levels (8.2, 7.9, and 7.6) and environmentally relevant concentrations of the acidic drug paracetamol (PAR: 0, 30, 60, and 120 µg/L). Biomarkers such as catalase (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as peroxidative damage (through thiobarbituric acid reactive substance (TBARS) quantification), were quantified to serve as ecotoxicological endpoints. Data showed a general increase in CAT and a decrease in GST activities (with significant fluctuations according to the tested conditions of PAR and pH). These changes are likely to be associated with alterations of the redox cycle driven by PAR exposure. In addition, pH levels seemed to condition the toxicity caused by PAR, suggesting that the toxic effects of this drug were in some cases enhanced by more acidic conditions. An inhibition of AChE was observed in animals exposed to the highest concentration of PAR, regardless of the pH value. Moreover, no lipid peroxidation was observed in most individuals, although a significant increase in TBARS levels was observed for polychaetes exposed to the lowest pH. Finally, no alterations of COX activities were recorded on polychaetes exposed to PAR, regardless of the pH level. The obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of acidic drugs, such as PAR. This work was crucial to evidence that ocean acidification, in the context of a global change scenario of increased levels of both atmospheric and oceanic CO2, is a key factor in understanding the putative enhanced toxicity of most pharmaceutical drugs that are of an acidic nature.info:eu-repo/semantics/publishedVersio

Population structure of the brazilian carapeba eugerres brasilianus in a complex of lagoon systems from southwest atlantic ocean Inferred from otolith elemental and shape signatures †

The Brazilian mojarra, Eugerres brasilianus, is an economically important species for the artisanal fisheries that exist in the estuarine environments along the Southwest Atlantic Ocean. Despite this, knowledge about its population structure is scarce, and no management strategies have been applied to ensure the sustainability of E. brasilianus fisheries in Brazil. Thus, the present study intended to understand the population structure of E. brasilianus in a complex system of lagoons in the Southwest Atlantic Ocean. A total of 90 individuals were collected in the lagoons of Piratininga-Itaipu (IP), Saquarema (SQ) and Araruama (AR) between December 2019 and March 2020. For the analyses, 30 individuals per location from the same age group (2 years old), following age estimation by counting the annual growth increments, were used. The contour of the shape of each otolith was evaluated using elliptical Fourier descriptors (EFD). Multi-elemental signatures (MES) of the whole otoliths were obtained using solution-based inductively coupled plasma mass spectrometry. Data were analyzed using univariate and multivariate statistics to assess the degree of separation between individuals from different lagoons. EFD data showed differences between regions. MES exhibited distinct regional patterns, mainly driven by differences in Sr/Ca, Mg/Ca, Mn/Ca, Li/Ca and Cu/Ca ratios. Reclassification accuracy rates obtained from linear discriminant function analyses using both EFD and MES of otoliths were 100% (IP), 90% (SQ) and 97% (AR). Therefore, a clear distinction between the population groups was observed, probably related to the inherent characteristics of each lagoon system, their semi-restricted connectivity with the adjacent coastal zone, as well as the estuarine-opportunistic behavior of the species. Thus, the results suggest that these fisheries should be managed as different population-units.info:eu-repo/semantics/publishedVersio

Use of otolith shape and elemental signatures to infer the population structure of the Thicklip Grey Mullet Chelon labrosus in the Southern Bay of Biscay

Xenoestrogenic effects have been reported in thicklip grey mullet, Chelon labrosus, used as pollution sentinel organisms in estuaries in the Southeast Bay of Biscay with intersex gonads described in populations from some contaminated estuaries. Despite evidence of reproductive stress in this catadromous fish species, knowledge of mullet reproductive movements and connectivity between estuaries is lacking. This study investigates the population structure of C. labrosus using otolith shape and elemental signatures of 60 adult individuals collected from two estuaries found in the Southeast Bay of Biscay (Gernika and Plentzia). All samples were collected in June–July 2020. Otolith shape analysis was determined using elliptical Fourier descriptors, while elemental signatures (Sr:Ca, Li:Ca, Mg:Ca, Mn:Ca, Co:Ca, Ni:Ca, Cu:Ca and Ba:Ca) of whole sagittae were determined by inductively coupled plasma mass spectrophotometry. Both natural tags were analyzed with univariate and multivariate statistics to determine whether these signatures are geographically distinct and can be used to assess the degree of separation between individuals. The data showed significant differences in the otolith shape and elemental analyses, with canonical analysis of principal coordinates plots identifying two different groups, each one belonging to each estuary of origin. Differences in whole otolith elemental signatures between locations were driven by Sr:Ca, Li:Ca, and Ba:Ca. Sr:Ca and Li:Ca ratios were higher in Plentzia than in Gernika, while Ba:Ca was higher in Gernika. The high re-classification success rate using both tools obtained from stepwise linear discriminant function analysis supports these findings and suggests that Gernika and Plentzia individuals passed enough time in separated water compartments and should be regarded as two different population units. This could suggest that the intersex condition in mullets from Gernika is due to life-long exposure to xenoestrogens after homing during early larval development in that estuary, without migrations to other estuaries.info:eu-repo/semantics/publishedVersio

Geographic variation in opisthonema oglinum (Lesueur, 1818) in the southeastern brazilian bight inferred from otolith shape and chemical signatures

The thread herring Opisthonema oglinum (Lesueur, 1818) is a small pelagic fish distributed in the western margin of the Atlantic Ocean from the United States to Argentina. It is a target species for diverse commercial fisheries, including the Brazilian industrial purse seine fleets that operate in the Southeastern Brazilian Bight. To investigate the geographic variation in the thread herring populations in this fishing ground, sagittal otoliths were collected from two areas: Rio de Janeiro (RJ: 23°04′ S, 44°03′ W) and Santa Catarina (SC: 26°05′ S, 48°18′ W). Otolith shape analyses and multi-elemental signatures were statistically evaluated using elliptical Fourier descriptors and elemental/Ca ratios. Remarkable differences in the thread herring otoliths between the two areas were found. The previous scenario in which the thread herring constitutes a single panmictic population in the Atlantic Ocean is now debatable. The implications of these results in terms of rational fisheries management for this species are highlighted.info:eu-repo/semantics/publishedVersio

Effects of cerium dioxide nanoparticles in Oncorhynchus mykiss gills after an acute exposure: assessment of oxidative stress, genotoxicity and histological alterations

Data about the toxicological effects of cerium dioxide nanoparticles (CeO2 NP) in fish are scarce. This work aimed to assess the CeO2 NP possible deleterious effects on the gills of Oncorhynchus mykiss. A semi-continuous acute test was conducted to expose the rainbow trout to a freshwater control, 0.25, 2.50 and 25.00 mg/L CeO2 NPs for up to 96 hours. Gills pathological index showed a dose-effect relationship for the individuals exposed to CeO2. Gills showed aneurisms, epithelial lifting and hyperplasia. Furthermore exposure to CeO2 NPs caused statistical differences in some biomarkers determinations, namely a significant increase in the catalase activity and genotoxicity the higher concentrations. No significant changes were however observed in thiobarbituric acid reactive substances content, Na+-K+ ATPase and glutathione s-transferase activities. This study suggests that CeO2 nanoparticles are toxic compounds that can lead to histological, biochemical and genotoxic alterations