Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Bioremediation Of Soils Contaminated By Petroleum And Its Derivatives [biorremediação De Solos Contaminados Por Petróleo E Seus Derivados]

In view of the proven efficiency of bioremediation in the degradation of compounds toxic to humans, such as benzene, toluene, ethylbenzene and xylenes (BTEX), several companies, especially those related to remediation and environmental monitoring, have shown enormous interest in the deployment of bioremediation as an option for the rehabilitation of contaminated areas. In developed countries such as the United States, Canada and several European countries, these biochemical remediation techniques have been widely used in work that is based, for example, on the treatment of soil contaminated by petroleum hydrocarbons. However, contrary to what has been done in these countries, in Brazil, bioremediation projects are still mainly theoretical, with few practical cases, but there is a real likelihood of expansion. The more important aim of this review is to indicate the advantages that this technique can offer when it is used for the degradation of compounds such as BTEX in typical Brazilian soils, whose physico-chemical characteristics contribute to the degradation of contaminants. Research shows that environmental factors (such as moisture and oxygen levels) and the availability of soil nutrients, in addition to the climatic conditions in Brazil, are quite suitable for the employment of this technique. They may pose, as an advantage, a favorable cost/benefit ratio and the opportunity for greater efficiency in the degradation of toxic and recalcitrant compounds compared to the majority of conventional remediation techniques. In summary, this review focuses on the state of the art of bioremediation techniques of contaminants in soils, presenting the most current and recent applications and innovations, as reported in the national and international media.3531743Acton, D.W., Barker, J.F., In situ biodegradation potential of aromatic hydrocarbons in anaerobic groundwaters (1992) J. Contam. Hydrol., 9, pp. 325-352Aelion, C.M., Bradley, P.M., Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer (1991) Appl. Environ. Microbiol., 57, pp. 57-63Aislabie, J., Saul, D.J., Foght, J.M., Bioremediation of hydrocarbon-contaminated polar soils (2006) Extremophiles, 10, pp. 171-179Aislabie, J.M., Balks, M.R., Foght, J.M., Waterhouse, E.J., Hydrocarbon spills on Antarctic soils: Effects and management (2004) Environ. Sci. Technol., 38, pp. 1265-1274Alexander, M., (1999) Biodegradation and Bioremediation, p. 453. , 2nd ed. San Diego, California, Academic PressAlexander, M., (1977) Introduction to Soil Microbiology, pp. 423-437. , 2nd ed. New York, John WileyAndrade, J.A., (2005) Otimização da Reação de Fenton Visando Aplicações Na Remediação In-situ e Ex-situ de Águas Subterrâneas. Campinas, p. 249. , Universidade Estadual de Campinas, (Dissertação de Mestrado)Bastiaens, L., Vos, J., Maesen, M., Simons, Q., Lookman, R., Hendrickx, B., Diels, L., Van Gestel, G., The influence of ORC® injection on in-situ BTEX biodegradation and on endogenous micro-organisms (2003) P. Int. In-situ and On-site Bioremediation, , Battelle PressBento, F.M., Camargo, F.A.O., Okeke, B., Frankenberger Jr., W.T., Bioremediation of soil contaminated by diesel oil (2003) Braz. J. Microbiol., 34, pp. 65-68Bernoth, L., Firth, I., McAllister, P., Rhodes, S., Biotechnologies for remediation and pollution control in the mining industry (2000) Miner. Metall. Proc., 17, pp. 105-111Betancur-Galvis, L.A., Bernal, D.A., Ramosvaldivia, A.C., Dendooven, L., Bioremediation of polycyclic aromatic hydrocarbon-contaminated salinealkaline soils of the former Lake Texcoco (2006) Chemosphere, 62, pp. 1749-1760Borole, A.P., Sublette, K.L., Raterman, K.T., Javanmardian, M., Fisher, J.B., The potential for intrinsic bioremediation of BTEX hydrocarbons in soil/ ground water contaminated with gas condensate (1997) Appl. Biochem. Biotech., 63-65, pp. 719-730Brown, R.A., (2003) In Situ Chemical Oxidation: Performance, Practice, and Pitfalls, , http://www.clu-in.org/techfocus/default.focus/sec/In_Situ_Oxidation/ download/techfocus/chemox/4_brown.pdf, AFCEE Technology Transfer Workshop, San Antonio, Texas,. Disponível Acesso em 06 mar. 2008(2007) Avaliação Do Uso de Produtos Biotecnológicos Para Tratamento de Efluentes Líquidos, Resíduos Sólidos e Remediação de Solos e Águas - L1.022, p. 21. , http://www.cetesb.sp.gov.br/, CETESB: COMPANHIA DE TECNOLOGIA DE SANEAMENTO AMBIENTAL Disponível .Acesso em 20 mar. 2008http://www.cetesb.sp.gov.br/, CETESB: COMPANHIA DE TECNOLOGIA DE SANEAMENTO AMBIENTAL. Decisão de Diretoria no 103/2007/C/E, de 22 de junho de 2007, 2007a. 40p. Disponívelem:. Acesso em 10 mar. 2008(2001) Manual de Gerenciamento de Áreas Contaminadas, p. 389. , CETESB: COMPANHIA DE TECNOLOGIA DE SANEAMENTO AMBIENTAL. 2.ed(2004) Manual de Gerenciamento de Áreas Contaminadas. Capítulo X - Investigação Para Biorremediação, p. 77. , CETESB: COMPANHIA DE TECNOLOGIA DE SANEAMENTO AMBIENTAL(2006) Relação de Áreas Contaminadas, , http://www.cetesb.sp.gov.br/, CETESB: COMPANHIA DE TECNOLOGIA DE SANEAMENTO AMBIENTAL. Disponível Acesso em 07 mar. 2008(2005) Relatório de Estabelecimento de Valores Orientadores Para Solos e Águas Subterrâneas No Estado de São Paulo, , http://www.cetesb.sp.gov.br/, CETESB: COMPANHIA DE TECNOLOGIA DE SANEAMENTO AMBIENTAL. Disponível Acesso em 19 mar. 2008Chen, K.F., Kao, C.M., Chen, T.Y., Weng, C.H., Tsai, C.T., Intrinsic bioremediation of MTBE-contaminated groundwater at a petroleum-hydrocarbon spill site (2006) Environ. Geol., 50, pp. 439-445(2006) Technology Practices Manual for Surfactants and Cosolvents, , http://clu-in.org/, CLU-IN: HAZARDOUS WASTE CLEAN-UP INFORMATION CH2MHILL,. Disponível Acesso em 13 mar. 2008Colvin, G.H., Biostimulation and bioaugmentation of recalcitrant VOCs in groundwater using Hydrogen Release Compound (HRC®) and bio-dechlor inoculum (BDI) (2005) P. Int. In-situ and On-site Bioremediation, , Battelle PressCoulon, F., Delille, D., Influence of substratum on the degradation processes in diesel polluted sub-Antarctic soils (Crozet Archipelago) (2006) Polar Biol., 29, pp. 806-812Custance, S.R., McCaw, P.A., Kopf, A.C., Sullivan, M.J., Environmental fate of the chemical mixtures: Crude oil, jp-5, mineral spirits, and diesel fuel (1992) J. Soil Contam., 1, pp. 379-386Delfino, J.J., Miles, C.J., Aerobic and anaerobic degradation of organic contaminants in Florida groundwater (1985) Soil Crop Sci. Soc. Fl. Proc., 44, pp. 9-14Digiulio, D.C., Varadhan, R., (2001) Development of Recommendations and Methods to Support Assessment of Soil Venting Performance and Closure, , U.S. EPA, ORD, EPA/600/R-01/070Dua, M., Singh, A., Sethunathan, N., Johri, A.K., Biotechnology and bioremediation: Successes and limitations (2002) Appl. Microbiol. Biot., 59, pp. 143-152Embar, K., Forgacs, C., Sivan, A., The role of indigenous bacterial and fungal soil populations in the biodegradation of crude oil in a desert soil (2006) Biodegradation, 17, pp. 369-377(1995) How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers. (EPA 510-B-95-007), , http://www.epa.gov/swerust1/pubs/tums.htm, ENVIRONMENTAL PROTECTION AGENCY - EPA. Disponível Acesso em 07 mar. 2008(2001) A Citizen's Guide to Chemical Oxidation, , EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES. EPA 542-F-01-013(2004) How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, p. 52. , EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES Chapter XIII - Chemical Oxidation, EPA 510-B-94-003EPA 510-B-95-007 and EPA 510-R-04-002(2004) How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, p. 77. , EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES Chapter IX - Monitored Natural Attenuation, EPA 510-B-94-003EPA 510-B-95-007 and EPA 510-R-04-002(2004) How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, p. 36. , EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES Chapter II - Soil Vapor Extraction, EPA 510-B-94-003EPA 510-B-95-007 and EPA 510-R-04-002(2004) How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, p. 73. , EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES Chapter XII - Enhanced Aerobic Bioremediation, EPA 510-B-94-003EPA510-B-95-007 and EPA 510-R-04-002(2004) How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, p. 30. , EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES Chapter IV - Biopiles, EPA 510-B-94-003EPA 510-B-95-007 and EPA 510-R-04-002(2003) Integrated Risk Information System: Benzene, , http://www.epa.gov/iris/subst/0276.htm, EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES Disponível Acesso em 22 mar. 2008. CASRN 71-43-2(2006) Method 8260C: Volatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS), , http://www.epa.gov/epaoswer/hazwaste/test/new-meth.htm, EPA: ENVIRONMENTAL PROTECTION AGENCY, UNITED STATES. Disponível Acesso em 24 mar. 2008(2001) A Citizen's Guide to Bioremediation, Soil Waste and Emergency Response, , http://www.epa.gov/, EPA: ENVIRONMENTAL PROTECTION AGENCY, EPA 542-F-01-001, Disponível Acesso em 15 mar. 2008(2003) Bioremediation in the Field, p. 39. , http://www.epa.gov/, EPA: ENVIRONMENTAL PROTECTION AGENCY Disponível. Acesso em 10 mar. 2008Fukada, S., Takagi, K., Enhanced bioremediation of soil and groundwater at a petrol release site in Japan (2003) P. Int. In-situ and On-site Bioremediation, , Battelle PressGarnier, P.M., Auria, R., Augur, C., Revah, S., Metabolic degradation of methyl tert-butyl ether by a soil consortium: Effect of components present in gasoline (2000) J. Gen. Appl. Microbiol., 46, pp. 79-84Hawrot, M., Nowak, A., Effects of different soil treatments on diesel fuel biodegradation (2006) Pol. J. Environ. Stud., 15, pp. 643-646Hutchinson, S.L., Schwab, A.P., Banks, M.K., (2003) Biodegradation of Petroleum Hydrocarbons in the Rhizosphere, pp. 355-386. , McCUTCHEON, S.C. & SCHNOOR, J.L., ed. Phytoremediation - Transformation and control of contaminants. Hoboken, New Jersey, John Wiley(2006) Carcinogenicity Evaluation of BTEX, 71, p. 829. , http://www.iarc.fr/, IARC: INTERNATIONAL AGENCY FOR RESEARCH ON CANCER. Disponível. Acesso em: 14 mar. 2008JARAMILLO I.R. Fundamentos teóricos-práticos de temas selectos de la ciência Del sueco. Parte 1, Universidad Autônoma Metropolitana, México. Apud: OLIVEIRA, F.R. & MILLIOLI, V.S. Utilização de técnica de bioestímulo, avaliando-se parâmetros como relação nutricional e umidade na biorremediação de solo contaminado com óleo cru. XIII J.I.C., CETEM, 1996Koennigsberg, S.S., Willett, A., Accelerated bioremediation with oxygen release compound advanced: Evolution of time-release electron acceptors (2005) P. Int. In-situ and On-site Bioremediation, , Battelle PressMaila, M.P., Cloete, T.E., The use of biological activities to monitor the removal of fuel contaminantsperspective for monitoring hydrocarbon contamination: A review (2005) Int. Biodeter. Biodegr., 55, pp. 1-8Margesin, R., Schinner, F., Biodegradation and bioremediation of hydrocarbons in extreme environments (2001) Appl. Microbiol. Biot., 56, pp. 650-663Marín, J.A., Moreno, J.L., Hernández, T., García, C., Bioremediation by composting of heavy oil refinery sludge in semiarid conditions (2006) Biodegradation, 17, pp. 251-261Morgan, R., Watkinson, R.J., Hydrocarbon degradation in soils and methods for soil treatment (1989) CRC Crit. Rev. Biotechnol., 8, pp. 305-333Nakagawa, L.E., Andréa, M.M., Efeito de alterações nas características do solo sobre a degradação de hexaclorobenzeno (2006) Rev. Bras. Ciên. Solo, 30, pp. 575-582Nano, G., Borroni, A., Rota, R., Combined slurry and solid phase bioremediations of diesel contaminated soil (2003) J. Hazard. Mater., B, 100, pp. 79-94(2006), http://0-www.cdc.gov.mill1.sjlibrary.org/niosh/homepage.html, NIOSH: NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH. NIOSH Carcinogen List,. Disponível. Acesso em 17 mar. 2008(1993) In Situ Bioremediation: When Does It Work?, , NRC: NATIONAL RESEARCH COUNCIL Washington, DC, National Academy PressO, U.Z., (2000) Separate and Combined Environmental Behaviour of Surfactants and Polycyclic Aromatic Hydrocarbons (PAHs), p. 272. , Technische Universität Munchen Institut fur Chemie Lehrstuhl fur Ökologische Chemie und Umweltanalytik (Tese de Doutorado)Peralta-Zamora, P., Tiburtius, E.R.L., Contaminação de águas por BTXs e processos utilizados na remediação de sítios contaminados (2004) Quím. Nova, 27, pp. 441-446Rahman, K.S.M., Banat, I.M., Thahira, J., Bioremediation of gasoline contaminated soil by a bacterial consortium amended with poultry litter, coir pith and rhamnolipid biosurfactant (2002) Bioresour. Technol., 81, pp. 25-32Reed, T.A., Bioremediation of total petroleum hydrocarbons at a DOD site in Tracy, California (2004) P. Int. In-situ and On-site Bioremediation, , Battelle PressRobb, J., Moyer, E., Natural attenuation of benzene and MTBE at four midwestern retail gasoline marketing outlets (2001) Contam. Soil Sed. Water, Spring, pp. 67-71Sánchez, O., Ferrera, I., Vigués, N., Oteyza, T.G., Grimalt, J.O., Mas, J., Presence of opportunistic oil-degrading microorganisms operating at the initial steps of oil extraction and handling (2006) Int. Microbiol., 9, pp. 119-124Saul, D.J., Aislabie, J., Brown, C.E., Harris, L., Oght, J.M., Hydrocarbon contamination changes the bacterial diversity of soil from around Scott Base (2005) Antarctica. FEMS Microbiol. Ecol., 53, pp. 141-155Schwarzenbach, R.P., Gschwend, P.M., Imboden, D.M., (1993) Environmental Organic Chemistry, p. 682. , New York John WileyShuhong, Y., Leichang, H., Li, Y.O., Ming, D., Yingying, H., Deween, D., Investigation on bioremediation of oil-polluted wetland at Liaodong Bay in northeast China (2006) Appl. Microbiol. Biot., 71, pp. 543-548Silva, E., Fialho, A.M., Sa-Correia, I., Burns, R.G., Shaw, L.J., Combined bioaugmentation and biostimulation to cleanup soil contaminated with high concentrations of atrazine (2004) Environ. Sci. Technol., 38, pp. 632-637Sims, J.L., Suflita, J.M., Russell, H.H., Ground water issue: In situ bioremediation of contaminated ground water (1992) Environmental Protection Agency Office of Solid Waste and Emergency Response, p. 11. , EPA/540/S-92/003, U.STate, R.L., (1995) Soil Microbiology, p. 107. , New York John WileyTop, E.M., Springael, D., The role of mobile genetic elements in bacterial adaptation to xenobiotic organic compounds (2003) Curr. Opin. Biotechnol., 14, pp. 262-269Troquest, J., Larroche, C., Dussap, C.G., Evidence for the occurrence of an oxygen limitation during soil bioremediation by solid-state fermentation (2003) Biochem. Eng. J., 13, pp. 103-112Tsao, C.W., Song, H.G., Bartha, R., Metabolism of benzene, toluene, and xylene hydrocarbons in soil (1998) Appl. Environ. Microbiol., 64, pp. 4924-4929(2003) Biopiles of POL (Petroleum, Oils, and Lubricants) Contaminated Soils. Restoration Technology, , http://aec.army.mil/usaec/, USAEC: U.S. ARMY ENVIRONMENTAL CENTER Disponível. Acesso em 14 mar. 2008(2003) Intrinsic Remediation of POL (Petroleum, Oils, and Lubricants) Contaminated Sites. Restoration Technology, , http://aec.army.mil/usaec/, USAEC: U.S. ARMY ENVIRONMENTAL CENTER. Disponível Acesso em 15 mar. 2008Van Der Hoek, J.P., Urlings, L.G.C.M., Grobben, C.M., Biological removal of polycyclic aromatic hydrocarbons, benzene, toluene, ethylbenzene, xylene and phenolic compounds from heavily contaminated ground water and soil (1989) Environ. Technol. Lett., 10, pp. 185-194Vidali, M., (2001) Bioremediation. An Overview. Pure Appl. Chem., 73, pp. 1163-1172VROM ministry of housing, spatial planning and environment. Premises for risk management: Annex to the Dutch environmental policy plan. The Hague: Lower house, DBO/07494013 (1994) Intervention Values and Target Values: Soil Quality Standards, p. 19Watts, R.J., Haller, D.R., Jones, A.P., Teel, A.L., A foundation for the risk-based treatment of gasolinecontaminated soils using modified Fenton's reactions (2000) J. Hazard. Mater., 76, pp. 73-89Wynm, J.L., Monitored natural attenuation with oxygen release material (2003) P. Int. In-situ and On-site Bioremediation, , Battelle Pres

ANÁLISE DO ESTADO DE CONSERVAÇÃO NA APA DO ESTUÁRIO DO RIO MUNDAÚ, TRAIRI-CE.

O presente estudo verificou o estado de conservação da APA do estuário do rio Mundaú, tendo como indicativo o mapeamento de uso e cobertura vegetal nos sistemas ambientais. O mapeamento de uso e cobertura auxiliou na dentificação de práticas como o desmatamento, para a implantação de carcinicultura e a diminuição de apicuns e salgados. Os dados foram tratados a partir das técnicas de geoprocessamento. A área localiza-se entre os municípios de Trairi e Itapipoca, no o Litoral Oeste do Ceará

Atividade alelopática de substâncias químicas isoladas do Capim-Marandu e suas variações em função do pH Allelopathic activity of chemical substances isolated from Brachiaria brizantha cv. Marandu and their variations in function of pH

Este trabalho teve por objetivos isolar, identificar e caracterizar a atividade alelopática de substâncias químicas produzidas pela Brachiaria brizantha cv. Marandu e determinar as variações na atividade dessas substâncias em função da variação do pH da solução. A atividade alelopática foi realizada em bioensaios de germinação e desenvolvimento da radícula e do hipocótilo, utilizando as plantas daninhas malícia (Mimosa pudica) e mata-pasto (Senna obtusifolia) como receptoras. Os efeitos do pH foram analisados na faixa de 3,0 a 9,0. Os triterpenos pentacíclicos friedelina e epifriedelinol isolados da parte aérea de B. brizantha apresentaram baixa atividade inibitória na germinação de sementes e no desenvolvimento da radícula e do hipocótilo das duas plantas daninhas. As duas substâncias apresentaram comportamento diferenciado em relação à variação do pH da solução, com inibições mais marcantes em relação à planta daninha mata-pasto.<br>This work aimed to isolate, identify and determine the allelopathic activity of the chemical substances produced by Brachiaria brizantha cv. Marandu and to verify the effects of the pH in the solution on the activity of these compounds. The allelopathic activity was evaluated based on germination bioassays and radicle and hypocotyl growth using the species 'malícia' (Mimosa pudica) and 'mata-pasto' (Senna obtusifolia) as receptors. The effect of pH was analyzed in a range from 3.0 to 9.0. The pentacyclic triterpenes friedelin and epifriefelinol isolated from the shoots of B. brizantha showed a low inhibitory activity against seed germination and radicle and hypocotyl growth of the two receptor plants evaluated. The pentacyclic triterpenes friedelin and epifrifelinol presented differentiated behaviors in relation to the pH variation in the solution, with stronger inhibition activity against the weed 'mata-pasto'

Microfitoplâncton de águas costeiras amazônicas: Ilha Canela (Bragança, PA, Brasil) Microphytoplankton of Amazon coastal waters: Canela Island (Bragança, Pará State, Brazil)

Variações sazonal e nictemeral do microfitoplâncton foram estudadas em uma estação fixa (00º46'37,2''S-046º43'24,5''W), localizada em uma área costeira próxima à ilha Canela (Norte do Brasil), durante os meses de setembro e dezembro/2004 (período seco) e março e junho/2005 (período chuvoso). As amostras destinadas à análise qualitativa do fitoplâncton foram obtidas a partir da filtragem de 400 L de água, através de uma rede planctônica (65 &#956;m de abertura de malha), durante marés de sizígia, em intervalos regulares de três horas, por um período de 24 horas. O material coletado foi fixado com formol neutro a 4%. Paralelamente a essas coletas foi medida a salinidade da superfície da água. A salinidade apresentou variação significativa ao longo do período de estudo, variando entre 26,1 (junho/2005) e 39,0 (dezembro/2004), caracterizando o ambiente como eualino-polialino. Foram identificados 130 táxons incluídos nas divisões Cyanophyta (dois táxons), Bacillariophyta (115 táxons) e Dinophyta (13 táxons). As diatomáceas dominaram o microfitoplâncton da área, sendo Asterionellopsis glacialis, Dimeregramma minor, Skeletonema sp. e Thalassiosira subtilis os táxons mais freqüentes e abundantes. Os altos valores de salinidade condicionaram a maior representatividade das espécies marinhas neríticas, polialóbias. Os processos de ressuspensão provocados pelos ventos e arrebentação das ondas promoveram intercâmbios entre as populações planctônicas e ticoplanctônicas, dentre as quais as espécies Dimeregramma minor, Triceratium biquadratum e T. pentacrinus representaram novas ocorrências para as águas costeiras do litoral amazônico.<br>Seasonal and nyctemeral variations of the microphytoplankton were studied at a fixed station (00º46'37.2''S-046º43'24.5''W) on Canela Island (North Brazil) in September and December/2004 (dry season) and in March and June/2005 (rainy season). Samples for qualitative phytoplankton studies were obtained by filtering 400 L of surface water in the surf zone of the island through plankton nets (65 &#956;m mesh size). Field work was carried out during spring tides and samples were collected every 3 hours during a 24-hour period. The collected material was fixed in neutral formaldehyde at 4%. Simultaneously, salinity of the water surface was also measured. Salinity showed significant variation throughout the study period, ranging from 26.1 (June/2005) to 39.0 (December/2004), characterizing the environment as euhaline-polyhaline. A total of 130 taxa were identified, belonging to Cyanophyta (two taxa), Bacillariophyta (115 taxa) and Dinophyta (13 taxa). Diatoms were the dominant group of microphytoplankton at Canela Island. Asterionellopsis glacialis, Dimeregramma minor, Skeletonema sp. and Thalassiosira subtilis were the most frequent and abundant taxa. High salinities favored the occurrence of polyhalobous neritic marine species. Resuspension processes caused by wind and wave surf zone were responsible for exchange between planktonic and ticoplanktonic populations, including species such as Dimeregramma minor, Triceratium biquadratum and T. pentacrinus which represented new occurrences for the Amazon coast