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Ocean and Coastal Research, Volume: 70, Published: 2022
  • Seasonal variation of estuarine birds from Trapandé Bay, Cananéia, Brazil Original Article

    Roselli, Larissa Yoshida; Barbieri, Edison

    Abstract in English:

    Abstract Estuaries are important environments for birds as resting and foraging sites. Therefore, information about the abundance, distribution, and biology of bird populations are necessary for preservation of such ecosystems. In this work, we studied the dynamic population of birds at Baixio do Arrozal, Trapandé Bay, Cananéia Estuary on the southern coast of São Paulo state, Brazil. As an original hypothesis, we expected that the species abundances would display differences across months and seasons. Using the point count method, bird data were collected monthly between April and December 2013. For comparing the assemblages, a bar chart of the total abundance as a function of the monthly frequency was used along with boxplot graph of this index as a function of the seasons. We also investigated variations in the abundance of some specific bird populations. The results obtained for the total abundance indicated a seasonal pattern, peaking during the warmer months. The population analyses showed a greater abundance occurring in spring/summer, and a decrease of resident species populations in the winter. Migratory birds were recorded in the autumn and spring, following the migratory movements. This demonstrated that bird assemblages varied according to seasons due to the life cycle and the population sizes. Therefore, Baixio do Arrozal is an important environment for avifauna, which use the area throughout the year and need to be preserved.
  • The mysterious oil spill in the northeastern coast of Brazil: tracking offshore seawater and the need for improved vessel facilities Original Article

    Carreira, Renato S; Zanardi-Lamardo, Eliete; Massone, Carlos G; Araujo, Moacyr; Nobre, Paulo; Yogui, Gilvan T

    Abstract in English:

    Abstract A scientific cruise between November 15 and December 18, 2019 aboard R/V Vital de Oliveira collected offshore seawater samples at 59 stations between the states of Ceará and Bahia. The objective was to identify hydrocarbon levels potentially associated with the mysterious oil spill that reached the northeastern coast of Brazil. Median concentrations of aliphatic hydrocarbons (AHs, 0.79 µg L-1) and polycyclic aromatic hydrocarbons (PAHs, 5.39 ng L-1) do not indicate contamination by crude oil and are comparable to baseline levels previously found in other areas of the Brazilian continental margin. The detailed composition of both groups of hydrocarbons revealed that some samples were contaminated during sampling and/or handling on-board. The data set presented herein highlights the difficulty in tracking small oil patches spread over a huge ocean area and, more importantly, the need for improving protocols of national research vessels used to collect seawater samples for trace organic analyses.
  • Trophic analysis of female mangrove crabs at two sites from Southeastern Brazil (Rio de Janeiro) Original Article

    Almeida, Eduardo Vianna de; Kütter, Vinicius Tavares; Silva-Filho, Emmanoel Vieira

    Abstract in English:

    Abstract The mangrove crab Ucides cordatus (Linnaeus, 1763) is a burrowing crab with an important role in mangrove nutrient cycling. The species holds major socioeconomic importance, generating yield for traditional and low-income populations. Despite its ecological and economic importance, there are few experiments in Brazil applying stable isotope tools to trophic crab classification, and even fewer considering females in the reproductive period. Females have different energy demands than males; studies examining C and N can reveal details regarding the differences. Hence, the present study is the first analysis of the δ 13C, δ 15N, and the C/N ratio in ovigerous females of two populations from Southeastern Brazil (Caceribu River - Guanabara Bay and Gargaú mangrove - Paraiba do Sul River secondary estuary). The Caceribu mangrove is larger and is located in one of the most impacted bays in the world. In the Paraiba do Sul River region, the mangrove swamp is about ten times smaller, has a substantially lower population in the surrounding area, and is more influenced by agricultural activities. The δ 13C analysis confirmed mangrove leaves as their main food source. The significant δ 13C variation between the Guanabara and Paraiba do Sul estuary populations can be related to differences in food availability and nutritional value. However, the δ 15N values can be related to the ingestion of other food items during the breeding season as well as the influence of anthropogenic mangrove degradation. At both study sites, the δ15N values were higher than those observed in other mangrove crab populations and other herbivorous species. Significant (p < 0.05) isotopic differences were found among populations, suggesting variations in biogeochemical cycles that may be related to different environmental conditions between the sites.
  • Diversity of benthic fauna of rhodoliths and sediments deposited on sandstone reefs in Southeast Brazil Original Article

    Neves, Sabrina Brahim; Costa, Karla Gonçalves

    Abstract in English:

    Abstract Sandstone reefs play an important role in sheltering a great diversity of organisms. In the north sector of the state of Espírito Santo, southeastern Brazil, the beaches are characterized by ferruginous sandstone reefs in the intertidal zones. These structures have unconsolidated sediment deposited over the reefs, mainly composed of bioclastic fragments of shells and seaweed, like the rhodolith. Rhodoliths are free-living calcareous algae with three-dimensional structures. By modifying the environment's physical characteristics, they create new microhabitats capable of being inhabited by several organisms, such as meio- and macrobenthonic invertebrates. This study sought to investigate the diversity of benthic fauna (macro- and meiofauna) on different substrates (rhodoliths vs. unconsolidated sediment) in the sandstone reef and investigate whether there are differences in benthic community structure between reef zones on Gramuté Beach in the Costa das Algas Environmental Protection Area in Aracruz, Espírito Santo, Brazil. Uni and multifactor analyses showed significant differences in the composition of the benthic fauna between the substrates (p < 0.05). Meiofauna and macrofauna had higher numbers of taxa and diversity associated with rhodoliths compared to with sediments. A multivariate analysis corroborates the results of the univariate, showing variations between substrates and beach zones. The presence of rhodoliths at Gramuté Beach contributes to the heterogeneity of the ecosystem and increases the richness and diversity of the benthos. The character of the benthic community and its dynamic aspects are discussed herein and are extremely important for conservation actions.
  • Short Period Baited Remote Underwater Video as a cost-benefit tool to evaluate effectiveness of Marine No-take Zones Original Article

    Tomasi, Marcos F; Waters, Linda G; Cruz, Igor C. S; Güth, Arthur Z; Turra, Alexander

    Abstract in English:

    Abstract Evaluating effectiveness of marine No-take Zones (NTZ) can be cost or labor prohibitive, thus comparisons to nearby unprotected areas are typically lacking. Two NTZs were evaluated, the waters surrounding Ilha Anchieta State Park and Palmas Island in Ubatuba, São Paulo, Brazil, for species richness, diversity, and abundance of ichthyofauna, comparing them with two nearby unprotected “Take” Zones. From 23 deployments using Baited Remote Underwater Video (BRUV), 737 individuals from 51 species of fish were recorded. The NTZ community composition was significantly different from Take Zones, with higher average species richness, abundance, and diversity but similar evenness. Seven species, accounting for more than 72% of the composition differences between Take and NTZs, were more abundant in NTZs. Comparisons of individual sites within each zone showed high variability for the Mar Virado Take Zone, with one site grouped with NTZs at 30% similarity. In parallel, BRUV deployed over a short period was assessed as a potential rapid, low-cost method for analyzing the effectiveness of a marine protected area, important for management of sites in low- and middle-income countries with patchy resource availability. BRUV distinguished significant community structure differences between Take and NTZs, with no difference between sites within each classification. Comparing with BRUV conducted for a longer period at two of the four study sites (MV and PA), our rapid study recorded 44.3% of total species using 28% of the survey effort. Compared with a multi-method survey as a proxy for a record of all potential species present at a third site (AI), BRUV recorded 30% of total species using 4.2% of the survey effort. BRUV showed bias towards size classes >15cm and certain feeding strategies, important to note if assessing a single target species. Overall, this rapid implementation of BRUV showed a clear difference between sites that differed in fishing protection level.
  • Recreational angling and related conflicts in a disturbed estuarine environment of the Southwest Atlantic Original Article

    Belruss, Carlos Gonçalves; Tutui, Sergio Luis dos Santos; Tomás, Acácio Ribeiro Gomes

    Abstract in English:

    Abstract We assessed the angling conducted in the Santos estuarine area (southeastern Brazil) between September 2012 and November 2013. The results, based on 189 interviews conducted in 38 different fishing locations, showed that shore-based anglers were predominantly residents (78%) and spent US$23 per fishing day. However, 61% of the onboard anglers were from the São Paulo metropolitan area and spent around US$100 per fishing day, generating a potentially important economic impact. Only two of the 15 variables analyzed showed no significant differences between the anglers' categories. According to the anglers' perception the possible pressure on the fishery resources and conflicts regarding resource use and areas in the face of port and industrial activities, urbanization, lack of security, as well as the anglers' time of experience, should be considered in any management measures to be proposed.
  • Population structure of the seahorse Hippocampus reidi in two Brazilian estuaries Original Article

    Carmo, Tatiane Fernández do; Santos, Luciano Neves dos; Bertoncini, Áthila Andrade; Freret-Meurer, Natalie Villar

    Abstract in English:

    Abstract This study aimed to evaluate and compare seasonal variations of Hippocampus reidi population structures in two Brazilian coastal areas. Samples were collected from the rocky shores of Urca and Duas Irmãs Island by freediving along fixed transects. All seahorses observed in the study were recorded, measured, and identified by sex and reproductive stage. Seahorse behavior and fish depth were also registered. All individuals were photo-identified to estimate recapture rates. Holdfast used by seahorses was also recorded. Results showed low densities at both sites; sex ratio and juvenile/adult proportion did not appear to vary with season. The seahorse height differed between the two areas but did not vary with season nor sex. Seahorses in both sites were found in shallow waters (i.e. up to 4 meters), and the depth did not vary by season nor sex. Males were more frequently recaptured than females in both areas. All seahorses were reproductively active year-round, peaking at rainy periods in both areas. The seahorses were more often recorded while resting and seemed to anchor on seaweed. Though in different bays, seahorse population structure and seasonality appeared similar. These data provide useful baseline data for future population assessments.
  • Effect of iron speciation on growth and heat resistance of Symbiodiniaceae Original Article

    Romero, Jose Miguel Diaz; Botana, Marina Tonetti; Elias, Aline de Carvalho; Nomura, Cassiana Seimi; Saldanha-Corrêa, Flávia; Espósito, Breno Pannia

    Abstract in English:

    Abstract Iron is a limiting nutrient for Symbiodiniaceae (colloquially known as zooxanthellae), with low solubility in seawater. The use of stable, soluble, and chemically defined iron complexes is proposed as a strategy to control the supply of this metal to target organisms. In this work, we investigated the effect of iron(II) and derivatives of iron(III) (desferrioxamine, deferiprone, deferasirox, and HBED) over the growth and metal loading of five Symbiodiniaceae species. Iron supplementation did not affect growth or metal load in species with high iron stocks. In contrast, for species with low iron stocks, hydrophobic Fe(DFX)2 was very efficient in inducing growth and iron loading. Also, the desferrioxamine derivative of iron Fe(DFO) appeared as an interesting, ecologically friendly source of the nutrient. The effect of iron supplementation on the growth of Breviolum minutum submitted to heat shock was also studied. Iron supplementation prior to the heat shock episode increased the heat tolerance of B. minutum. Such findings provide new insights for the strategy of iron supplementation to improve the fitness of Symbiodiniaceae, both in vitro and in the environment.
  • Conversion factor for size structure reconstruction and growth of Lophius gastrophysus Miranda Ribeiro, 1915 catches in the South Atlantic Ocean Original Article

    Silva, Arthur Tavares da; Tubino, Rafael de Almeida; Martins, Raquel Rennó Mascarenhas; Monteiro-Neto, Cassiano; Costa, Marcus Rodrigues da

    Abstract in English:

    Abstract Lophius gastrophysus is an exploited deep-sea demersal fishing resource in the Southeast-South region of Brazil, a capture target for the twin trawl multi-specific bottom trawling fleet. Considered a prized fish, it is commonly processed on board, retaining commercial cuts of the tail called colas. Thus it is difficult to recognize the original length of the specimens and, consequently, to assess the dynamics of sources and the impacts of catches. Individual length and weight data were used to generate body predictive models correlated to the monkfish cola. The parameters of growth, mortality and exploitation rate were also estimated from the size structure of Lophius gastrophysus captured by the industrial bottom trawling fleet in Southeast Brazil between May 2013 and April 2015, assessing monkfish stock based on indirect estimates of life history information. All predictive models of body size showed coefficients of determination above 0.9 (P <0.001), indicating good data adjustments. The growth parameters were determined by the minimum residual variance methodology, being: L∞ = 92.4 cm and k = 0.158/year. The size structure tended to increase with depth in the spring. Individuals under the age of sexual maturity contributed significantly to catches. The length of first sexual maturation was estimated at 48.6 cm and the recruitment age was between 6 and 7 years. The coefficients of total, natural, fishing and exploitation rates were estimated at: Z = 0.676; M = 0.241; F = 0.436 and E = 0.644. The fishing mortality rate was higher than the reference value (E > 0.50) indicating a state of overexploitation of the southeast most part of stock. A review of the current Brazilian legislation established for the species on the southeast coast is recommended.
  • Assessment of water quality with emphasis on trophic status in bathing areas from the central-southern coast of Cuba Original Article

    Losa, Mabel Seisdedo; González, Angel R. Moreira; Hurtado, Diamela Carles

    Abstract in English:

    Abstract Bathing water quality has become a matter of concern due to health risks. This study sought to assess water quality in bathing areas from the southeastern coast of the Cienfuegos province, Cuba. Certain physical, chemical, and biological parameters (salinity, temperature, pH, oxygen saturation, N-NH4+, N-NO2-, N-NO3-, P-PO43-, COD, BOD5, fats and oils, chlorophyll-a, thermotolerant and total coliforms, and phytoplankton) were measured on five beaches during 2019-2020 in both rainy and dry seasons. A water quality index (WQI) was calculated using the the results of an eutrophication index (EI) and subsequently analyzed. Cluster analysis (CA) and principal components analysis (PCA) were conducted to interpret water quality variations. The WQI values ranged between fair and good, with significant differences between seasons. Multivariate analyses demonstrated the influence of river contributions on water quality indicators based on the results of the CA and the first principal component (PC1) correlated with Sal, DO, total and thermotolerant coliforms, and certain nutrients. PCA also reflected the increase in BOD5 levels during the summer based on PC2, while the PC3 correlated with COD and response parameters (chlorophyll-a and phytoplankton) were linked to the trophic status. The assessment of trophic status showed non-eutrophic conditions. The abundance and diversity of phytoplankton in these beaches was low (128.5 x 103 cells L-1, total mean value), following the normative definitions of the water framework directive. Harmful algal species occurred in low numbers (1.88 x 103 cells L-1, total mean value), but certain species could represent a risk of dermatitis to bathers. The application of different classification schemes allowed for a comprehensive assessment of water quality in this coastal zone, helping to identify the need for monitoring and further ecological study on harmful algae species.
  • Continental influence on the fertilization of marine waters during the late quaternary in the south of the Brazilian continental margin Original Article

    Bottezini, Silvia Regina; Diniz, Débora; Ávila, Andréia Souza Pereira de; Leonhardt, Adriana

    Abstract in English:

    Abstract This study sought to understand the role of continental influence on ocean productivity along the late Quaternary based on the comparison between continental palynomorphs and paleoproductivity proxies from the marine sediment core SIS188. Retrieved from the slope of the Pelotas Basin at a depth of 1,514 m, the core documents the time interval between 47.8 and 7.4 cal ka BP, including the Marine Isotope Stages (MIS) 3, 2 and 1. The palynological content found in the core SIS188 indicates a typical flora of the southern Brazil highlands, which is at the same latitude as the core. Thus, continental input sources, such as wind-borne dust and discharges from the Mampituba and Araranguá rivers, would more likely account for the palynological content than the Brazilian Coastal Current (BCC). During the glacial intervals (MIS 3 and MIS 2), paleoproductivity (indicated by the proxies coccolith numbers, N Ratio, and TOC content) suggest the intensification of upwelling and transport of wind dust, the latter of which may have transported pollen grains to the core region. There is a concentration decrease of continental palynomorphs at the end of MIS 2, which is accentuated during MIS 1 when the sea level is higher. Paleoproductivity was high during MIS 1, especially from the Holocene onwards, although the concentration of continental-derived palynomorphs decreases sharply, showing that the rise in sea level interferes with the fertilization of marine waters far from the coast by continental input.
  • Spreading and accumulation of river-borne sediments in the coastal ocean after the environmental disaster at the Doce River in Brazil Original Article

    Lemos, Angelo T.; Osadchiev, Alexander; Mazzini, Piero L. F.; Mill, Guilherme N.; Fonseca, Sabrina A. R.; Ghisolfi, Renato D.

    Abstract in English:

    Abstract This study is focused on the fate of a large volume of mine slurry discharged from the Doce River (DR) to the coastal ocean after the worst environmental disaster in Brazilian which occurred in November 2015. We used Eulerian (ROMS) and Lagrangian (STRiPE) numerical models, as well as satellite remote sensing data, to study the spreading and seafloor accumulation of fine river-borne sediments during the initial six months following the disaster. We show that the regions of intense sediment accumulation were determined by spreading patterns of the surface-advected DR plume. The river discharge rate governed the plume surface area, while its position depended on local wind forcing conditions. The spreading of sediments carried by the DR plume was dominated by southward transport caused by prevailing upwelling-favorable northeasterly winds during the study period. Under high discharge conditions, river-borne sediments were transported over 100 km southward from the DR mouth and reached the outer shelf. In contrast, sediments were arrested near the mouth during drought periods and remained on the inner shelf. As a result, fine river-borne sediments accumulated on the seafloor, mainly in the large shallow shelf area southward from the DR mouth. Conversely, only a small fraction of residue was deposited northward. Thus, the Environmental Protection Area (EPA) of Costa das Algas, located 40 km southward from the DR, potentially exhibited more susceptibility to sediment arrival. On the other hand, their influence on Abrolhos Marine National Park, located 200 km northeastward from the DR mouth, was presumably minimal.
  • Environmental factors associated with southern brown shrimp (Penaeus subtilis) yield at Brazilian Amazon coast Original Article

    Aragão, José Augusto Negreiros; Cintra, Israel Hidenburgo Aniceto; Silva, Kátia Cristina De Araújo; Martins, Déborah Elena Galvão; Petrere Junior, Miguel

    Abstract in English:

    Abstract We evaluated the relationship between southern brown shrimp Penaeus subtilis (Pérez Farfante, 1967) yield and environmental parameters on the Amazon continental shelf. We analysed monthly fishing effort data (number of days spent at sea) and yield (kg of tails) collected between 1978 and 2009. A causal relationship had been expected between Amazon River discharge during the main period of shrimp occurrence in estuarine waters (considering post larval settlement and juvenile recruitment in second semester of each year) and adult abundance (represented by fishery yield in the first semester of the following year). We detected significant correlations between monthly river discharge and yield with a negative lag of four months, and between river discharge during the dry season (June to November) and yield in the following year. In general, low and high discharges during a given year were associated with high and low fishery yields, respectively, during the following year.
  • Wave climate and extremes on a mesotidal atoll lagoon Original Article

    Costa, Mirella B.; Siegle, Eduardo

    Abstract in English:

    Abstract Processes on atolls and coral reef lagoons are defined by local wave and tide climates. Based on the reconstruction of lagoon wave climate by downscaling offshore historical wave information, this study aims to assess the wave climate and wave extremes on a mesotidal atoll lagoon (Rocas Atoll, Brazil). Results show that the transformation of offshore waves, when propagating into the lagoon, results in a different and far more homogeneous wave climate. Atoll morphology and tides play a key role in controlling the directional and energy characteristics of the lagoon wave climate. Refraction processes and the reef passage make the side protected from the dominant SE waves the most energetic zone for lagoon wave propagation. Lagoon waves tend to propagate in opposite directions to offshore wind waves, showing the refraction effect of approaching waves when crossing the atoll rim and the channel. The tidal effect on the dissipation process is also a filter for extreme wave conditions. We highlight the dependence of the resulting lagoon wave climate on atoll morphology, thereby addressing its implications to geomorphological process inside the atoll.
  • Petroleum hydrocarbons in Brazilian Northeast continental shelf waters: baseline values Brief Communication

    Zanardi-Lamardo, Eliete; Schettini, Carlos A.F

    Abstract in English:

    ABSTRACT Water quality on the continental shelf off the eastern Brazilian Northeast region was investigated in two oceanographic campaigns during winter and summer, when vertical profiles of salinity, temperature, turbidity, chlorophyll and dissolved oxygen were recorded. Dissolved / dispersed petroleum hydrocarbons (DDPH) were also analyzed in sub-superficial water samples using fixed wavelength fluorescence spectroscopy methods. Shelf waters are dominated by Tropical Waters, with high salinity (> 36.5 g kg-1) and temperature (> 26 °C) and little continental influence. Turbidity was higher during winter, which may be due to the higher continental contribution and/or higher wave action. Chlorophyll was mostly < 1 µg L-1 and dissolved oxygen saturation was predominantly high (> 90%), but innermost costal stations were influenced by the Capibaribe estuary. Median DDPH concentrations were as low as 0.07 and 0.04 µg L-1 Carmópolis oil equivalents during winter and summer respectively, and 0.02 µg L-1 chrysene equivalent for both periods. An exception was observed off Suape Harbor (0.35 µg L-1 Carmópolis oil equiv. and 0.13 µg L-1 chysene equiv.), suggesting navigation activities as the main local source. The overall DDPH median of 0.06 μg L-1 Carmópolis oil equivalents and 0.02 μg L-1 chrysene equivalents are proposed as the baseline concentration for non-polluted coastal water for the tropical western Atlantic Ocean margin.
  • First report on the occurrence of Avicennia marina (Forssk.) Vierh. (Acanthaceae) in the Nicobar archipelago Brief Communication

    Thirumurugan, Vedagiri; Singh, Anoop Raj; Prabakaran, Nehru

    Abstract in English:

    Abstract The 2004 Sumatra-Andaman earthquake (9.2 Mw) and tsunami that followed it resulted in uplift and subsidence across the Andaman and Nicobar archipelago. This unusual natural event severely affected the mangrove and coastal ecosystems across the Andaman and Nicobar Islands. The tsunami and land drowning of 1.1-2.85 m resulted in considerable loss of mangrove habitats in the Nicobar archipelago. Meanwhile, the land drowning also created new intertidal habitats in the earlier terrestrial zones that are now providing suitable conditions for the colonization of mangroves. During the long-term monitoring of mangrove colonization in these new inter-tidal zones, we identified the first occurrence of the Avicennia marina (Forssk.) Vierh. in the Nicobar archipelago. The distribution of A. marina and the characteristics of its colonizing sites are discussed herein.
  • Farming Pacific oysters using the spat-on-shell system in a shallow area in the subtropical coast of Brazil Brief Communication

    Suplicy, Felipe Matarazzo; Souza, Robson Ventura de

    Abstract in English:

    Abstract The Santa Catarina Island Bay (SCIB) contributes with the largest production of cultivated oysters in Brazil, which is almost entirely based on hatchery produced cultchless oyster spat, whose metamorphosis is induced by an epinephrine solution. A production scale experiment was carried out to analyze the technical feasibility of the spat-on-shell system in SCIB. The experiment was carried out for 47 weeks, involving an internal phase, the larval settlement, and an external phase, encompassing nursery and growth. Nursery periods varied according to the experimental treatments: T3W - 3 weeks; T5W - 5 weeks; and T12W - 12 weeks. T3W and T5W showed lower survival during the two-week period shortly after transfer of the cultch from the nursery to the grow-out phase, likely linked to premature exposure of the spat in the cultch strings to predators such as fish. The 12-week nursery period showed the best results with clusters with a median of 6 animals and 11.4 g of meat per oyster at the end of the experimental period. Future studies could verify whether longer nursery periods or alternative methods to avoid exposure to predators can outperform these results.
  • Potential control of invasive species of orange cup coral Tubastrea coccinea Lesson, 1829 using a synthetic natural compound Brief Communication

    Costa, Rafaela dos Santos; Batista, Daniela; Batista, William Romão; Neves, Maria Helena Baeta; Lopes, Cláudio Cerqueira; Lopes, Rosangela Sabattini Capella; Braga, Esther Faria; Nascimento, Thiana Santiago; Dobretsov, Sergey; Coutinho, Ricardo

    Abstract in English:

    Abstract Non-toxic defence against marine biofouling species including invasive species is urgently required. The effect of a synthetic natural compound “1-hydroxy-2-O-acyl-sn-glycero-3-phosphocholine” was tested against larvae of the invasive orange cup coral T. coccinea Lesson, 1829. The larvae were placed in 24-well microtiter plates immediately after their release and subjected to the compound at concentrations of 0.5, 5, 10, 50, and 100 μg mL-1 and three treatments (copper sulfate, solvents, and seawater). Larval mortality ranged from 35% (100 μg mL-1) to 3% (5 μg mL-1), and their average of lethal concentration (LC50) was 142.2 μg mL-1. The results of this study show that compound is a potential option to be applied in the management and control of T. coccinea on artificial structures.
  • Fuzzy Logic: adding natural uncertainties into environmental assessment Case Report

    Gripp, Leonardo; Massone, Carlos German; Carreira, Renato da Silva; Wagener, Angela de Luca Rebello

    Abstract in English:

    Abstract This research study sought to evaluate aimed at evaluating the possible advantages of using Fuzzy Logic as opposed to Boolean Logic to assess environmental contamination and source appraisal for polycyclic aromatic hydrocarbons (PAH). Results obtained through traditional assessment tools for two different tropical coastal areas through using traditional clustering and principal components analysis were compared with those derived from the Fuzzy Logic, using the by Fuzzy C-means algorithm. The feedings achieved through Fuzzy Logic showed a greater qualitative detail than those derived from traditional tools. The abrupt and unnatural changes obtained from the usual classification methods were avoided by having membership values varying continuously in space, providing a more accurate picture of environmental contamination in complex and multiple sources environments. Furthermore, by not depending on statistic suppositions distribution of data like other methods, becomes more suitable for environmental data. Although Fuzzy Logic does not produce quantitative interpretations, its application generates adequate the data needed to avoid environmental management bias in the inference of contamination sources.
Instituto Oceanográfico da Universidade de São Paulo Praça do Oceanográfico 191, CEP: 05508-120, São Paulo, SP - Brasil, Tel.: (11) 3091-6501 - São Paulo - SP - Brazil
E-mail: diretoria.io@usp.br