Rauquírio Marinho da Costa

Spatial and temporal distribution in density and biomass of two Pseudodiaptomus species (Copepoda: Calanoida) in the Caeté river estuary (Amazon region - North of Brazil)

Spatial and temporal density and biomass distribution of the planktonic copepods Pseudodiaptomus richardi and P. acutus along a salinity gradient were investigated in the Caeté River Estuary (North-Brazil) in June and December, 1998 (dry season) and in February and May, 1999 (rainy season). Copepod biomass was estimated using regression parameters based on the relation of dry weight and body length (prosome) of adult organisms. The Caeté River Estuary was characterized by high spatial and temporal variations in salinity (0.8-37.2). Exponential length-weight relationships were observed for both Pseudodiaptomus species. Density and biomass values oscillated between 0.28-46.18 ind. m-3 and 0.0022-0.3507 mg DW. m-3 for P. richardi; and between 0.01-17.02 ind. m-3 and 0.0005-0.7181 mg DW. m-3 for P. acutus. The results showed that the contribution of P. richardi for the secondary production in the Caeté River Estuary is more important in the limnetic zone than in other zones where euhaline-polyhaline regimes were predominant. However, it was not possible to observe a clear pattern of spatial and temporal distribution for P. acutus.

Seasonal variation in the copepod community structure from a tropical Amazon estuary, Northern Brazil

The main purpose of this study was to investigate the seasonal variation of copepod community structure during the months of July, September and November 2003 (dry season) and January, March and May 2004 (rainy season) in the Curuçá estuary, northern Brazil. Samples were collected during neap tides via gentle 200microm mesh net tows from a small powerboat. Measurements of surface water conductivity were accomplished in situ using an electronic conductivimeter and salinity was later obtained through the transformation of the conductivity values. Salinity varied seasonally from 7.2 +/- 0.1 to 39.2 +/- 1.8 (mean +/- standard deviation) and was influenced mainly by differences in the amount of rainfall between the studied sampling seasons. In total, 30 Copepoda taxa were identified and Acartia tonsa comprised the most representative species throughout the entire studied period followed by Acartia lilljeborgii, Subeucalanus pileatus and Paracalanus quasimodo. In the present study, the density values, ecological indexes and copepod species dominance presented a clear seasonal pattern, showing that the studied area may be considered seasonally heterogeneous in relation to the investigated parameters.

Seasonal effects of wastewater to the water quality of the Caeté river estuary, Brazilian Amazon

Braganças socioeconomic situation is highly dependent on estuarine and marine biological resources that are influenced by tidal cycles and climatology. Field measurements (hydrological, hydrodynamic and microbiological variables) were taken in the most urbanized zone from Caeté estuary to characterise the quality of the local environment. During the dry period, the estuary was more eutrophic and presented the highest temperature (30.5 degrees C in Oct./06), salinity (17 psu in Feb./07), pH (8.24 in Feb./07) and fecal coliform (> 1000 MPN/100 ml in Dec./06 and Feb./07) values. The phytoplankton Cyclotella meneghiniana, Coscinodiscus centralis and other r-strategist species were observed. The lack of basic hydric canalization was responsible for the local contamination, especially during the dry period when more concentrated wastewater from the city was emitted into the estuary, showing the human influence on the reduction of local estuarine water quality. In Bragança, the fishery is considered one of the main economic activities so, this contamination is worrisome because a large part of the local economy depends on biological resources and, thus, the contamination could negatively affect the environmental health of this Amazon ecosystem.

Oceanographic Conditions and Human Factors on the Water Quality at an Amazon Macrotidal Beach

Abstract Pereira, L.C.C.; Pinto, K.S.T.; Da Costa, K.G.; Vila-concejo, A., and Da Costa, R.M., 2012. Oceanographic conditions and human factors on the water quality at an Amazon macrotidal beach. Atalaia beach is situated in the NE of the Brazilian state of Pará and is one of the most popular with tourists and local beachgoers. This paper describes the seasonal variation in the meteorologic and oceanographic characteristics of the study area, as well as the effects of the lack of a public sanitation system on the quality of the water used by beachgoers. Oceanographic campaigns were carried out between November 2008 and September 2009. The study area is characterized by high rainfall rates (>1900 mm during the rainy season), NE winds with mean speeds of up to 4.36 m/s in the dry season and 3.06 m/s in rainy season, macrotidal conditions (tidal range >4.0 m), moderate tidal current speeds (up to 0.5 m/s), and significant wave heights up to 1.5 m. Water temperature was relatively homogeneous (27.6°C to 29.3°C). Salinity varied from 5.7 (June) to 37.4 psu (November). The water was well oxygenated (up to 9.17 mg/L), turbid (up to 118 nephelometric turbidity units), alkaline (up to 8.68), and eutrophic (maximum of 2.36 µmol/L for nitrite, 24.34 µmol/L for nitrate, 0.6 µmol/L for phosphate, and 329.7 µmol/L for silicate), and it presented high concentrations of chlorophyll a (up to 82 mg/m3). The natural conditions observed in the present study indicate the need for a review of the hydrologic criteria used for the evaluation of beaches by national and international agencies and their adaptation to the reality of the Amazon Coast. The lack of a public sanitation system has led to bacteriologic contamination and the loss of water quality. Resumen A praia de Atalaia está situada no nordeste do estado do Pará (Brasil), e é uma das mais turísticas e populares praias do litoral amazônico. O objetivo deste trabalho foi descrever as variações sazonais das condições meteorológicas e oceanográficas da área estudada, bem como conhecer os efeitos da falta de um sistema público de saneamento básico sobre a qualidade da água utilizada para banho pelos usuários desta praia. Campanhas oceanográficas foram realizadas entre novembro de 2008 e setembro de 2009 e dados meteorológicos foram fornecidos pelo Instituto Nacional de Meteorologia. Os resultados mostraram que a área de estudo é caracterizada por possuir altas precipitações (>1900 mm durante o período chuvoso), ventos de nordeste com velocidades médias de até 4,36 m/s no período seco e 3,06 m/s no período chuvoso, macromarés com alturas acima de 4,0 m, correntes de marés com velocidades médias de até 0.5 m/s, e altura de ondas significantes de até 1,5 m. A temperatura da água foi relativamente homogênea (27,6 a 29,3°C). A salinidade variou de 5,7 (junho) a 37,4 psu (novembro). A água foi bem oxigenada (até 9,17 mg/L), turva (até 118 NTU), alcalina (até 8.68), eutrófica (máximo de 2,36 µmol/L para nitrito, 24,34 µmol/L para nitrato, 0,6 µmol/L para fosfato e 329,7 µmol/L para silicato), e apresentou altas concentrações de clorofila a (até 82 mg/m3). As condições naturais observadas no presente estudo indicam a necessidade da revisão dos critérios de qualidade da água das praias amazônicas, estabelecidos por agencias nacionais e internacionais. Por outro lado, a falta de um sistema público de saneamento tem causado contaminação bacteriológica e comprometido a qualidade da água da praia de Atalaia.

Tourism carrying capacity on estuarine beaches in the Brazilian Amazon region

ABSTRACT Sousa, R.C., Pereira, L.C.C., Costa, R.M. and Jiménez, J.A., 2014. Tourism carrying capacity on estuarine beaches in the Brazilian Amazon region. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 545–550, ISSN 0749-0208. Tourism Carrying Capacity (TCC) can be defined as the level of human activity that an area can support without provoking deterioration of its physical and environmental characteristics. The present study aimed to estimate the maximum number of visitors that Colares, Marudá and Murubira beaches can receive during periods of peak visitation. The TCC was calculated considering the Physical Carrying Capacity (PCC), the Real Carrying Capacity (RCC), and the Effective Carrying Capacity (ECC) of each beach. In each survey, the number of visitors along a pre-established transect (central portion of each beach) was counted every hour (8 am until 6 pm). The maximum recommended ECC values indicated a maximum of 674 visitors per day at Colares, 812 visitors per day at Marudá and 97 visitors per day at Murubira. In comparison with these recommendations, the observed numbers of visitors were relatively high at Marudá (885 visitors) and Murubira beaches (297 visitors), while Colares was within the suggested limit (193 visitors). Peak visitation rates were recorded between 1 pm and 4 pm, and observed carrying values varied from 1.5 to over 5.000 m2 per visitor at Colares beach, 0.7–426 m2 per visitor at Marudá beach, and 1.7–42.9 m2 at Murubira. The results of the present study indicated that the density of visitors on the study beaches exceeded tolerable limits, and that coastal management measures are necessary to improve local tourist activities.

Tidal-Induced Changes in the Zooplankton Community of an Amazon Estuary

ABSTRACT Garboza Da Costa, K.; Cunha Monteiro, M.; Rabelo Bezerra, T.; Vallinoto, M.; Francisco Berrêdo, J.; Cajueiro Carneiro Pereira, L., and Marinho Da Costa, R., 2013. Tidal-induced changes in the zooplankton community of an Amazon estuary. Because variations in the zooplankton community are common in macrotidal estuaries, the composition and density of these organisms in the estuary of the Paracauari River, an equatorial macrotidal system of the Amazon coastal zone, was studied during spring and neap tides to evaluate fluctuations related to variations in the physical and chemical characteristics of the water. Significant differences between tidal periods were recorded for salinity, pH, and dissolved oxygen. Phosphate concentrations were significantly higher in the spring tide. In all, 34 taxa were identified, with the Cirripedia dominating in both tides. Total density was highest in the spring tide (1871.6 ± 1248.4 individuals m−3), whereas chlorophyll a was lowest (10.46 ± 3.48 mg m−3). Diversity was also higher in the spring tide. Multivariate analyses indicated the formation of two distinct groups representing the spring and neap tides. The zooplankton comprised mainly estuarine and coastal species. Oithona oswaldocruzi, Paracalanus quasimodo, and Acartia tonsa were the most common, and their density was related directly to tidal oscillations. Resumo Uma vez que as variações na comunidade zooplanctônica são comumente registradas em estuários de macromarés, a composição e a densidade destes organismos no estuário do rio Paracauari, um sistema equatorial de macromaré da zona costeira amazônica, foi estudada durante marés de sizígia e quadratura para avaliar as flutuações relacionadas aos parâmetros físicos e químicos da água. Diferenças significantes entre os períodos de maré foram registrados para salinidade, pH e oxigênio dissolvido. As concentrações de fosfato foram significativamente mais elevadas na maré de sizígia. No total, 34 táxons foram identificados, com Cirripedia dominando em ambas as marés. A densidade total foi maior na maré de sizígia (1871,6 ± 1248,4 ind m−3), enquanto que a clorofila-a foi menor (10,46 ± 3,48 mg m−3). A diversidade também foi maior na maré de sizígia. Análises multivariadas indicaram a formação de dois grupos distintos representando as marés de sizígia e quadratura. O zooplâncton foi constituído principalmente de espécies estuarinas e costeiras. Oithona oswaldocruzi, Paracalanus quasimodo e Acartia tonsa foram as espécies mais comuns, e suas densidades estiveram relacionadas diretamente com as oscilações da maré.

Occurrence of Cymbasoma longispinosum Bourne, 1890 (Copepoda: Monstrilloida) in the Curuçá River estuary (Amazon Littoral)

The present work was carried out to verify the occurrence and distribution of Cymbasoma longispinosum Bourne, 1890 in a tropical Amazon estuary from North Brazil. Samplings were performed bimonthly from July/2003 to July/2004 at two different transects (Muria and Curuca rivers) situated along the Curuca estuary (Para, North Brazil). Samples were collected during neap tides via gentle (1 to 1.5 knots) 200 μm-mesh net tows from a small boat. Additional subsurface water samples were collected for the determination of environmental parameters. Males and females of Cymbasoma longispinosum were only observed during September and November/2003. The highest number of organisms was found in September/2003 at the Muria River transect. The presence of C. longispinosum in samples obtained during September and November/2003 could probably be related to the reproductive period of this species in the studied estuary, which is directly related to the dry period in the region. The highest salinity values and the highest number of individuals observed in September/2003 corroborate with the previous assumption, since no C. longispinosum was found during the months comprising the rainy period (January to June).

Effect of coastline properties and wastewater on plankton composition and distribution in a stressed environment on the north coast of Olinda-PE (Brazil)

Foi realizado um estudo sobre a estrutura das comunidades planctonicas ao longo das praias de Casa Caiada e Rio Doce (Pernanbuco, Brasil). A area de estudo sofre grande influencia antropica onde as condicoes ambientais sao controladas pela presenca de estruturas costeiras, reduzindo a intensidade da circulacao neste ambiente; e pelos efluentes clandestinos de esgoto que aportam aguas poluidas para dentro do sistema protegido. Os resultados obtidos indicam que nas zonas protegidas as aguas apresentam alta turbidez, temperaturas elevadas, salinidades reduzidas e altas concentracoes de nutrientes e oxigenio. Estas condicoes sao responsaveis pela reducao da diversidade do plâncton e pelo aumento da biomassa das especies mais resistentes. As diferencas registradas com respeito a areas similares, porem nao impactadas, parecem indicar que a estrutura planctonica pode ser usada como um indicador da qualidade ambiental, sugerindo uma baixa qualidade das praias em estudo.

Caracterização quali-quantitativa do fitoplâncton da zona de arrebentação de uma praia amazônica

A estrutura da comunidade fitoplanctonica da praia da Princesa (Ilha de Maiandeua) foi estudada durante um ciclo nictemeral nos meses de novembro/08, marco/09, junho/09 e setembro/09, de modo a verificar os efeitos de algumas variaveis ambientais sobre esta comunidade. O microfitoplâncton da praia da Princesa esteve representado por 98 taxons, com predominio das diatomaceas, seguidas dos dinoflagelados e cianoficeas. Nas amostras qualitativas, Coscinodiscus perforatus Ehrenberg se destacou como abundante nos meses de marco (45,6%) e junho (45,1%), enquanto que a analise quantitativa revelou Dimeregramma minor (Gregory) Ralfs como dominante, principalmente, em novembro (82,0%) e setembro (83,0%). A biomassa fitoplanctonica (clorofila-a) foi significativamente mais elevada em marco (U= 0,0; p<0,05). Os valores medios de densidade fitoplanctonica total foram significativamente mais elevados no periodo chuvoso (F= 6,2; p<0,05), principalmente em junho (1223 ± 110 x 103 cels L-1). As curvas de K-dominância revelaram um declinio gradual na diversidade ao longo do periodo seco. A analise de ordenacao (MDS) evidenciou a formacao de tres grupos, enquanto que a analise de componentes principais (PCA) mostrou a salinidade e a turbidez como as principais variaveis que definiram os componentes. A praia da Princesa e um ambiente dinâmico, onde os processos de ressuspensao promovem o intercâmbio entre populacoes fitoplanctonicas e fitobenticas. A elevada precipitacao e o maior aporte fluvial, carreando elevadas concentracoes de nutrientes, favoreceram o maior desenvolvimento do fitoplâncton, principalmente, durante o periodo chuvoso.

Temporal variation of zooplankton on a tropical Amazonian beach

ABSTRACT Pinheiro, S.C.C., Magalhães, A., Costa, V.B. da, Pereira, L.C.C. and Costa, R.M. da, 2013. Temporal variation of zooplankton on a tropical Amazonian beach. To assess the spatial and temporal variation in zooplankton populations at Ajuruteua Beach, northern Brazil, monthly samples were taken between August, 2004, and July, 2005, at three fixed stations, during the spring (flood/ebb) tide. The zooplankton community was characterized by the absence of any significant spatial or seasonal variation in density, diversity or evenness. However, density was significantly higher during the ebb tides, with mean values ranging from 4,967±670.0 ind.m−3 in July (flood tide) to 38,213±15,157 ind.m−3 in April (ebb tide). A similar tidal pattern was recorded for the density of copepods. The dominant copepod species were Euterpina acutifrons (47.0±30.5 to 18,313±2,431 ind.m−3) and Paracalanus quasimodo (420.0±60.0 to 11,260±7,203 ind.m−3) and, together with Oithona hebes and O. oswaldocruzi, were responsible for the peaks in zooplankton density recorded in April. Monthly zooplankton diversity (1.8±0.2 to 3.0±0.1 bits.ind−1) was relatively high overall, whereas evenness varied from 0.4±0.0 to 0.8±0.0, with both indices presenting significantly lower values in November. The absence of any significant seasonal trend in total zooplankton during the present study may have been related to atypical precipitation patterns during the study period, when surface waters were abnormally warm (~1.5°C). Overall, zooplankton community structure at Ajuruteua Beach was indirectly related to the local rainfall regime, which affected the physical, chemical, and biological parameters of the water, influencing the temporal dynamics of these organisms.