I See Golden Mussel! They are Everywhere! Environmental DNA Supports Widespread Dissemination of Limnoperna fortunei in Hydrographic Basins in the Paraná State, Brazil

Abstract The golden mussel is an aquatic invasive species that was introduced in South America in the '90s, including Brazil, and was firstly registered in 2001 in the Paraná state. This bivalve causes macrofouling issues because adhere in substrates and form dense aggregations, affecting especially hydroelectric power plants, and water treatment facilities, apart from the native biodiversity. The present research aimed to diagnose the distribution of Limnoperna fortunei in the Paraná state using environmental DNA (eDNA) from 174 sites from 12 basins, and scientific and technical previous records. L. fortunei eDNA was found in 90 sites from 11 hydrographic basins sampled. Most of the positive samples were detected in Iguaçu (42), Tibagi (15), and Ivaí (10) rivers basins. We also registered the first occurrence for five basins: Cinzas, Itararé, Ivaí, Pirapó e Ribeira rivers. Together, our and previous data recorded L. fortunei in 118 sites, between adult, larvae, and eDNA detection. Moreover, the results evidenced that eDNA is a low coast and reliable tool, and it may be very recommended for L. fortunei early detection and diagnosis. The present research was the greatest and most widespread survey for golden mussel prospection in a state in Brazil, supported a worrying scenario for Parana, with the urgent need for intense and continuous monitoring and prevention actions for controlling and mitigation of the L. fortunei impacts.

Evaluation of anti-biofouling potential of Viburnum opulus extracts / Evaluación del potencial anti bioincrustante de extractos de Viburnum opulus

In this study the in vitro investigation of the inhibitory effect of ethanol extract of Viburnum opulus L. bark sample on Streptococcus mutans planctonic cells and biofilm has been intended. A Scanning electron microscopy analysis has been performed in order to investigate the inhibitory effect of the extract on Streptococcus mutans biofilms. Furthermore, the Exopolysaccharide and dextran production of this bacteria have been identified in the presence of the extract. It has been found out that the bark extract with the concentration of 2,5 mg/mL is able to inhibit more than 50% of the cells in the different times development phases. According to this, the exopolymeric matrix on the biofilm surface disperses and the Exopolysaccharide and dextran production get lowered in the presence of bark extract compared to the control group. It is considered that this extract can be used as an alternative approach for the new chemotherapeutic strategies against tooth decay.

En este estudio se investigó el efecto inhibitorio in vitro del extracto de etanólico de una muestra de corteza de Viburnum opulus L. en biopelículas de células planctónicas de Streptococcus mutans. Se realizó un análisis de microscopía electrónica de barrido para investigar el efecto inhibitorio del extracto sobre las biopelículas de Streptococcus mutans. Además, se identificó la producción de exopolisacárido y dextrano de esta bacteria en presencia del extracto. Se descubrió que el extracto de corteza con una concentración de 2,5 mg/ml inhibió más del 50% de las células en las diferentes fases de desarrollo. Consecuentemente, la matriz exopolimérica en la superficie de la biopelícula se dispersa y la producción de exopolisacárido y dextrano se reduce en presencia de extracto de corteza en comparación con el grupo de control. Se sugiere que este extracto puede ser usado como un enfoque alternativo para las nuevas estrategias quimioterapéuticas contra la carie dental.

Marine bacteria from the Gulf of California with antimicrofouling activity against colonizing bacteria and microalgae / Bacterias marinas del Golfo de California con actividad antimicrobiana frente a bacterias colonizadoras y microalgas

Abstract One way of reducing the input of pollutants into the marine environment is to enforce the use of non-toxic antifouling paints in marine protected areas. Thus, the purpose of this study was to detect marine microorganisms that secrete inhibitory substances against bacteria and microalgae to avoid biofouling on manmade structures in La Paz bay, B.C.S., Mexico. The inhibitory potential of 125 bacteria was evaluated against biofilm-forming bacteria. Crude extracts were obtained with methanol and ethyl acetate from 16 bacterial strains that exhibited antagonistic and antibacterial activity in a preliminary screening. Antibacterial and antimicroalgal assays were performed using crude extracts, the minimum inhibitory concentration (MIC) was determined. The highest activity against bacteria and microalgae was found in two strains, Shewanella algae and Staphylococcus sp. The results of this study suggest that extracts of bacteria from the Gulf of California with antimicrobial properties against biofilm-forming bacteria can also prevent the adhesion of microalgae, which may control the development of biofilm formation and, as a consequence, biofouling.(AU)

Resumen Una alternativa para reducir la contaminación en el medio marino es el uso de pinturas anti-incrustantes no tóxicas en áreas marinas protegidas. En el presente estudio se propuso encontrar microorganismos marinos que secreten sustancias capaces de inhibir la adhesión de bacterias y microalgas, de esta manera evitar la bioincrustación en estructuras marinas en la bahía de La Paz, B.C.S., México. Un total de 125 bacterias fueron evaluadas por su capacidad para inhibir el desarrollo de bacterias formadoras de biopelículas. En una selección preliminar de actividad antagónica y antibacteriana, 16 cepas bacterianas mostraron potencial actividad inhibitoria, de las que se obtuvieron los extractos crudos con metanol y acetato de etilo. Se realizaron ensayos antibacterianos y anti-microalgales utilizando los extractos crudos, se determinó la concentración mínima inhibitoria (MIC). Dos cepas mostraron la mayor actividad contra bacterias y microalgas: Shewanella algae y Staphylococcus sp. Los resultados de este estudio sugieren que los extractos de bacterias aisladas en el Golfo de California que poseen propiedades antimicrobianas contra las bacterias formadoras de biofilm y también pueden prevenir la adhesión de microalgas, con lo que se podría controlar el desarrollo de la formación de biopelículas y como consecuencia, el biofouling.(AU)

Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria

Background: Marine ecosystems contain benthic microalgae and bacterial species that are capable of secreting extracellular polymeric substances (EPS), suggesting that settlement of these microorganisms can occur on submerged surfaces, a key part of the first stage of biofouling. Currently, anti-fouling treatments that help control this phenomenon involve the use of biocides or antifouling paints that contain heavy metals, which over a long period of exposure can spread to the environment. The bacterium Alteromonas sp. Ni1-LEM has an inhibitory effect on the adhesion of Nitzschia ovalis, an abundant diatom found on submerged surfaces. Results: We evaluated the effect of the bioactive compound secreted by this bacterium on the EPS of biofilms and associated epiphytic bacteria. Three methods of EPS extraction were evaluated to determine the most appropriate and efficient methodology based on the presence of soluble EPS and the total protein and carbohydrate concentrations. Microalgae were cultured with the bacterial compound to evaluate its effect on EPS secretion and variations in its protein and carbohydrate concentrations. An effect of the bacterial supernatant on EPS was observed by assessing biofilm formation and changes in the concentration of proteins and carbohydrates present in the biofilm. Conclusions: These results indicate that a possible mechanism for regulating biofouling could be through alteration of biofilm EPS and alteration of the epiphytic bacterial community associated with the microalga.

Early bacterial biofilm colonizers in the coastal waters of Mauritius

Background: The past years have witnessed a growing number of researches in biofilm forming communities due to their environmental and maritime industrial implications. To gain a better understanding of the early bacterial biofilm community, microfiber nets were used as artificial substrates and incubated for a period of 24 h in Mauritian coastal waters. Next-generation sequencing technologies were employed as a tool for identification of early bacterial communities. Different genes associated with quorum sensing and cell motility were further investigated. Results: Proteobacteria were identified as the predominant bacterial microorganisms in the biofilm within the 24 h incubation, of which members affiliated to Gammaproteobacteria, Alphaproteobacteria and Betaproteobacteria were among the most abundant classes. The biofilm community patterns were also driven by phyla such as Firmicutes, Bacteroidetes, Chloroflexi, Actinobacteria and Verrucomicrobia. The functional analysis based on KEGG classification indicated high activities in carbohydrate, lipid and amino acids metabolism. Different genes encoding for luxI, lasI, agrC, flhA, cheA and cheB showed the involvement of microbial members in quorum sensing and cell motility. Conclusion: This study provides both an insight on the early bacterial biofilm forming community and the genes involved in quorum sensing and bacterial cell motility.

Inhibition of marine biofouling by aquatic Actinobacteria and coral-associated marine bacteria

Aims: Biofouling is a common biology phenomenon occuring on ship surface. This phenomenon has become serious threat in marine industries because of great economic loss. Tributyltin has been used to prevent biofouling, but it turned to cause the environmental problem. Therefore, the discovery of alternative environment-friendly compound is necessarily needed. Methodology and results: Five Actinobacteria isolates and fourteen marine bacteria isolates were tested against the biofilm formation of eight biofouling bacteria isolates that isolated from boat surface and the attachment of three biofouling diatoms (Amphora, Navicula, Nitzschia). Actinobacteria CW17 supernatant showed the broad spectrum activity against all fouling bacteria, whereas BC 11-5 supernatant was the only marine bacteria that capable to inhibit biofilm formation of V. neocaledonicus. Moreover, three representative diatoms attachment could be inhibited by the bioactive compounds produced by Actinobacteria and marine bacteria. CW01 supernatant showed broad spectrum and high activity against all three representative diatoms which is very promising. Molecular identification based on 16S rDNA gene sequence showed eight fouling bacteria isolates were biofilm-forming bacteria. Conclusions, significance and impact of study: This research showed aquatic Actinobacteria and coral-associated marine bacteria have the potential to prevent biofouling formation. Further studies are needed to purify and characterize these antibiofouling compounds for environmental application.

Natural antifouling compound production by microbes associated with marine macroorganisms: A review

In the marine environment, all hard surfaces including marine macroorganims are colonized by microorganisms mainly from the surrounding environment. The microorganisms associated with marine macroorganisms offer tremendous potential for exploitation of bioactive metabolites. Biofouling is a continuous problem in marine sectors which needs huge economy for control and cleaning processes. Biotechnological way for searching natural product antifouling compounds gained momentum in recent years because of the environmental pollution associated with the use of toxic chemicals to control biofouling. While, natural product based antifoulants from marine organisms particularly sponges and corals attained significance due to their activities in field assays, collection of larger amount of organisms from the sea is not a viable one. The microorganisms associated with sponges, corals, ascidians, seaweeds and seagrasses showed strong antimicrobial and also antifouling activities. This review highlights the advances in natural product antifoulants research from microbes associated with marine organisms.

Influence of antifouling paint on freshwater invertebrates (Mytilidae, Chironomidae and Naididae): density, richness and composition / Influência de revestimentos antiincrustantes em invertebrados aquáticos (Mytilidae, Chironomidae and Naididae): densidade, riqueza e composição

Abstract We conducted a study about invertebrates on artificial substrates with different antifouling paints in order to answer the following questions 1) is there lower accumulation of organic matter on substrates with antifouling paints, 2) is invertebrate colonization influenced by the release of biocides from antifouling paints, 3) is the colonization of aquatic invertebrates positively influenced by the material accumulated upon the substrate surface and 4) is the assemblage composition of invertebrates similar among the different antifouling paints? To answer these questions, four structures were installed in the Baía River in February 1st, 2007. Each structure was composed of 7 wood boards: 5 boards painted with each type of antifouling paints (T1, T2, T3, T4 and T5), one painted only with the primer (Pr) and the other without any paint (Cn). After 365 days, we observed a greater accumulation of organic matter in the substrates with T2 and T3 paint coatings. Limnoperna fortunei was recorded in all tested paints, with higher densities in the control, primer, T2 and T3. The colonization of Chironomidae and Naididae on the substrate was positively influenced by L. fortunei density. The non-metric multidimensional scaling (NMDS) of the invertebrate community provided evidence of the clear distinction of invertebrate assemblages among the paints. Paints T2 and T3 were the most similar to the control and primer. Our results suggest that antifouling paints applied on substrates hinder invertebrate colonization by decreasing the density and richness of invertebrates.

Resumo O estudo dos invertebrados em substrato artificial com diferentes revestimentos antiincrustantes foi realizado com o intuito de responder as seguintes questões 1) Há menor acumulação de material orgânico nos substratos com revestimentos antiincrustantes? 2) A colonização de invertebrados é afetada pela liberação de biocidas dos revestimentos antiincrustantes? 3) A colonização dos invertebrados aquáticos é facilitada por material acumulado sobre a superfície do substrato? 4) A composição da assembléia é similar entre os diferentes revestimentos? Para realização deste estudo, quatro estruturas foram instaladas em 01 de fevereiro de 2007 no rio Baía. Em cada estrutura foram colocadas sete placas de madeira: cinco placas com aplicação de um tipo de revestimentos antiincrustantes (T1, T2, T3, T4 e T5), uma placa apenas com a aplicação do primer (Pr) e a outra placa permaneceu sem aplicação de nenhum revestimento (Cn). Ao final dos 365 dias em que os substratos ficaram submersos observou-se maior acumulação de material orgânico nos substratos dos revestimentos T2 e T3. Limnoperna fortunei foi registrada em todos os revestimentos testados, com maiores densidades encontradas no controle, primer, T2 e T3. A colonização de Chironomidae e Naididae sobre os substratos foi influenciada pela densidade de L. fortunei. A ordenação (NMDS) evidenciou a separação da assembléia de invertebrados entre os revestimentos. Os revestimentos T2 e T3 foram os mais similares ao controle e ao primer. Os resultados obtidos sugerem que revestimentos antiicrustantes aplicados sobre substratos dificultam a colonização de invertebrados, reduzindo a densidade e riqueza de invertebrados.

Influence of antifouling paint on freshwater invertebrates (Mytilidae, Chironomidae and Naididae): density, richness and composition

Abstract We conducted a study about invertebrates on artificial substrates with different antifouling paints in order to answer the following questions 1) is there lower accumulation of organic matter on substrates with antifouling paints, 2) is invertebrate colonization influenced by the release of biocides from antifouling paints, 3) is the colonization of aquatic invertebrates positively influenced by the material accumulated upon the substrate surface and 4) is the assemblage composition of invertebrates similar among the different antifouling paints? To answer these questions, four structures were installed in the Baía River in February 1st, 2007. Each structure was composed of 7 wood boards: 5 boards painted with each type of antifouling paints (T1, T2, T3, T4 and T5), one painted only with the primer (Pr) and the other without any paint (Cn). After 365 days, we observed a greater accumulation of organic matter in the substrates with T2 and T3 paint coatings. Limnoperna fortunei was recorded in all tested paints, with higher densities in the control, primer, T2 and T3. The colonization of Chironomidae and Naididae on the substrate was positively influenced by L. fortunei density. The non-metric multidimensional scaling (NMDS) of the invertebrate community provided evidence of the clear distinction of invertebrate assemblages among the paints. Paints T2 and T3 were the most similar to the control and primer. Our results suggest that antifouling paints applied on substrates hinder invertebrate colonization by decreasing the density and richness of invertebrates.

Resumo O estudo dos invertebrados em substrato artificial com diferentes revestimentos antiincrustantes foi realizado com o intuito de responder as seguintes questões 1) Há menor acumulação de material orgânico nos substratos com revestimentos antiincrustantes? 2) A colonização de invertebrados é afetada pela liberação de biocidas dos revestimentos antiincrustantes? 3) A colonização dos invertebrados aquáticos é facilitada por material acumulado sobre a superfície do substrato? 4) A composição da assembléia é similar entre os diferentes revestimentos? Para realização deste estudo, quatro estruturas foram instaladas em 01 de fevereiro de 2007 no rio Baía. Em cada estrutura foram colocadas sete placas de madeira: cinco placas com aplicação de um tipo de revestimentos antiincrustantes (T1, T2, T3, T4 e T5), uma placa apenas com a aplicação do primer (Pr) e a outra placa permaneceu sem aplicação de nenhum revestimento (Cn). Ao final dos 365 dias em que os substratos ficaram submersos observou-se maior acumulação de material orgânico nos substratos dos revestimentos T2 e T3. Limnoperna fortunei foi registrada em todos os revestimentos testados, com maiores densidades encontradas no controle, primer, T2 e T3. A colonização de Chironomidae e Naididae sobre os substratos foi influenciada pela densidade de L. fortunei. A ordenação (NMDS) evidenciou a separação da assembléia de invertebrados entre os revestimentos. Os revestimentos T2 e T3 foram os mais similares ao controle e ao primer. Os resultados obtidos sugerem que revestimentos antiicrustantes aplicados sobre substratos dificultam a colonização de invertebrados, reduzindo a densidade e riqueza de invertebrados.

Antifouling effect of bioactive compounds from marine sponge Acanthella elongata and different species of bacterial film on larval attachment of Balanus amphitrite (cirripedia, crustacea)

The antifouling activity of bioactive compounds from marine sponge Acanthella elongata (Dendy) and five species of bacterial biofilm were studied. Larvae of Balanus amphitrite (Cyprids and nauplii) were used to monitor the settlement inhibition and the extent to which inhibition was due to toxicity. The crude extract and partially purified fractions of A.elongata showed significant inhibition over the settlement individually, and with the interaction of bacterial species. No bacterial film stimulated the barnacle settlement. The high but variable levels of antifouling activity in combination with less amount of toxicity showed the potential of these metabolites in environmentally-friendly antifouling preparations.

Development of polyvinyl chloride biofilms for succession of selected marine bacterial populations.

Present investigation was made to bring out the pattern of biofilm formation by heterotrophic bacteria on nontoxic material, polyvinyl chloride (PVC) sheet fitted wooden rack that was immersed in seawater and the study was conducted in Tuticorin coast. Samplings were made over a period of 7 days with the following time period intervals: 30 min, 1, 2, 4, 24, 48, 72, 96, 120 and 144 hr. Bacterial enumeration was made by spread plate method on nutrient agar medium and characterization of bacterial isolates up to generic level was done. Gram-negative bacteria like Pseudomonas sp., Enterobacter sp., Aeromonas sp., Cytophaga sp. and Flavobacterium sp. were found to be the pioneer in colonizing the surface within 30 min and seven genera were represented in the biofilm. Among them two genera were found belonging to Gram-positive groups which included Micrococcus and Bacillus sp. The early stage biofilm i.e. up to 24th hr was wholly constituted by Gram-negative groups. However, the population density of Pseudomonas sp. was found to be higher (315 CFU) when compared to other Gram-negative forms. Occurrence of Gram-positive group was noted only at 48th hr old biofilm (28 to 150 CFU). The period between 48 and 96th hr was the transition where both the Gramnegative and Gram-positive groups co- existed. After 96th hr, the biofilm was found constituted only by Grampositive groups. The isolates of early stage biofilm were found to produce allelopathic substance like bacteriocin.

Sessile and sedentary macrofauna from the Pirapama Shipwreck, Pernambuco, Brazil / Macrofauna séssil e sedentária do Naufrágio Pirapama, Pernambuco, Brasil

Shipwrecks are considered artificial reef environments - structures immersed in aquatic environments (especially marine ones) that provide fauna with shelter, hard substrates, food and nursery areas. This study aimed to survey the benthic animal biodiversity of the Pirapama shipwreck, located 23 m deep and six miles off Recife harbor. From 2001 to 2007, species were observed, photographed and collected through scuba diving. The material was later sorted and identified in the laboratory. A total of 76 sessile and sedentary animal taxa were recorded belonging to the following phyla: Porifera (Demospongiae and Calcarea), Cnidaria (Hydrozoa and Anthozoa), Mollusca (Bivalvia and Gastropoda), Annelida (Polychaeta), Arthropoda (Cirripedia), Bryozoa (Gymnolaemata), Echinodermata (Asteroidea and Echinoidea), and Chordata (Ascidiacea). The greatest richness was for Porifera and Bryozoa - 13 listed species for each. Eleven new occurrences were recorded for the state of Pernambuco, the hydroid Halopteris polymorpha and ten bryozoan species, one of them being the first record for Brazil (Scrupocellaria curacaoensis). The Pirapama's biodiversity was considered typical when compared to other shipwrecks that have been studied around the world.

Naufrágios são classificados como ambientes recifais artificiais, estruturas imersas em ecossistemas aquáticos (principalmente marinhos) que fornecem abrigo, substratos consolidados, áreas de crescimento, alimentação e de berçário. Este estudo objetivou pesquisar a biodiversidade bentônica animal do Naufrágio Pirapama, localizado a 23 m de profundidade e a seis milhas do Porto de Recife. Entre 2001 e 2007 mergulhos autônomos foram realizados para coletar, observar e fotografar as espécies. No laboratório, o material foi posteriormente classificado e identificado. Um total de 76 táxons foi registrado para a fauna séssil e sedentária, pertencentes aos seguintes filos: Porifera (Demospongiae e Calcarea), Cnidaria (Hydrozoa e Anthozoa), Mollusca (Bivalvia e Gastropoda), Annelida (Polychaeta), Arthropoda (Cirripedia), Bryozoa (Gymnolaemata), Echinodermata (Asteroidea e Echinoidea), e Chordata (Ascidiacea). A maior quantidade de espécies foi de Porifera e Bryozoa, com 13 espécies listadas para cada um. Onze novas ocorrências foram registradas para o Estado de Pernambuco, o hidróide Halopteris polymorpha e dez espécies de briozoários, uma deles sendo o primeiro registro para o Brasil (Scrupocellaria curacaoensis). A biodiversidade do Pirapama foi considerada típica quando comparada com a de outros naufrágios que foram estudados no mundo.

Seasonal variation in larval density of Limnoperna fortunei (Bivalvia, Mytilidae) in the Iguaçu and Paraná rivers, in the region of Foz do Iguaçu, Paraná, Southern Brazil

The larval density of the invasive mussel Limnoperna fortunei (Bivalvia, Mytilidae) was monitored from January 2005 to February 2006 at two points along the Paraná and the Iguaçu Rivers, near Foz do Iguaçu, PR, Brazil. The results indicated two density peaks in the Paraná River: a lower peak between March and June and a higher peak in October. In the Iguaçu River, the values were much lower, yet they also showed a peak between September and October. A reduction in the reproductive activity was observed in both the rivers between July and August. The average larval density at the collection point in the Paraná reached 948.5 larvae/m³, with a peak of 2,999.5 larvae/m³ in October. The present study represented the first quantification of the larval density of L. fortunei in the lower reaches of the Iguaçu River, downstream of the Iguaçu falls.

A densidade larval do molusco invasor Limnoperna fortunei (Bivalvia, Mytilidae) foi monitorada entre janeiro de 2005 e fevereiro de 2006 em dois pontos dos rios Paraná e Iguaçu, na região de Foz do Iguaçu, PR. Os resultados registraram dois picos de densidade no rio Paraná: entre março e junho e um maior em outubro. No rio Iguaçu, os valores foram muito inferiores, mas também com um pico entre setembro-outubro. Em ambos os rios foi verificada uma pausa reprodutiva entre os meses de julho-agosto. A densidade média de larvas de L. fortunei no ponto amostrado no rio Paraná chegou a 948.5 larvas/m³, com pico de 2.999,5 larvas/m³ em outubro. O presente estudo representa a primeira quantificação da densidade larval de L. fortunei no rio Iguaçu, a jusante das Cataratas do Iguaçu.

Introduced and cryptogenic species and their management in Paranaguá Bay, Brazil

The aim of this work was to identify the introduced and cryptogenic species in encrusting and associated communities of hard substrates in Paranaguá Bay, Brazil, and to attempt to determine which of these species could negatively affect the local community to suggest management strategies for these species. At least four introduced species were found - a large number in comparison with other port surveys. These were the hydrozoan Garveia franciscana Torrey, 1902, the polychaete Polydora cornuta Bosc, 1902, the barnacles Amphibalanus reticulatus (Utinoni, 1967) and Striatobalanus amaryllis Darwin, 1854, all with potentially harmful impacts. Of the 33 cryptogenic species, four were also listed in the literature as causing negative effects. We propose the following management practices: periodic cleaning of all underwater structures, population monitoring of invasive species and potential substrates, an information database of potential sources of introduction.

Espécies marinhas exóticas (= não-nativas) podem afetar drasticamente as comunidades das regiões em que são introduzidas. Prever quais espécies possuem maiores chances de causar impactos negativos é extremamente importante. Neste estudo, identificamos espécies introduzidas e criptogênicas entre as espécies incrustantes e associadas das comunidades que ocorrem nos substratos consolidados da marina do Iate Clube de Paranaguá. Com base em literatura, verificamos quais destas espécies são capazes de afetar negativamente a comunidade local e sugerimos recomendações para seu manejo adequado. Quatro espécies introduzidas foram identificadas, o que é uma cifra elevada quando comparada a outros levantamentos de biotas portuárias: o hidrozoário Garveia franciscana Torrey, 1902, o poliqueta Polydora cornuta Bosc, 1902, e as cracas Amphibalanus reticulatus (Utinoni, 1967) e Striatobalanus amaryllis Darwin, 1854, todas com efeitos negativos já registrados em outros locais. Entre as 33 espécies criptogênicas, quatro também são relatadas na literatura pertinente como causadoras de impactos negativos. Ações de manejo propostas incluem limpeza periódica dos cascos das embarcações e estruturas da marina, monitoramento das populações de espécies com potencial invasor, monitoramento dos substratos naturais para detecção de espécies introduzidas, criação de um banco de dados com informações sobre as viagens dos barcos de recreio e possíveis rotas de dispersão das espécies.

STUDIES ON HARMFUL MICROBES IN RECIRCULATING WATER SYSTEM OF HEATING PIPELINE IN TAIYUAN / 微生物学通报

The microbial counts, type, as well as relationship between microbial counts and the temperature of water in reticulating water system of heating pipeline in Taiyuan were studied, which the main biofouling harmful microbes included slimeforming heterotrophic bacteria, sulfate reducing bacteria, iron bacteria and fungi, respectively. The results showed that the harmful microbes in water system were lower than that of control guideline during heating period, whereas the microbes were higher than that of control guideline, which would result in biofouling of water tube during non- heating period.