Estrutura da comunidade epibêntica e icitiofauna associada ao banco de nódulos calcários da Reserva Biológica Marinha do Arvoredo, SC

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Blooms of bryozoans and epibenthic diatoms in an urbanized sandy Beach (Balneário Camboriú - SC - Brazil): dynamics, possible causes and biomass characterization

Balneário Camboriú (SC - Brasil) é uma cidade turística, onde o crescimento desordenado da população urbana e a implementação de obras costeiras sem uma avaliação adequada tem gerado impactos ambientais e afetado severamenteou a qualidade sanitária da água e do sedimento do rio Camboriú e da área marinha adjacente. Um dos fenômenos mais recentes e alarmantes observados são as florações de briozoários invasivos (Arboscuspis bellula e Membraniporopsis tubigera) associados com as diatomáceas epibênticas (Amphitetras antediluviana e Biddulphia biddulphiana). Vários indícios associam esses fenômenos, iniciados em 2003, com o excesso de nutrientes e matéria orgânica na enseada Camboriú e com grandes obras costeiras locais, como dragagem, aterro e construção de molhes, levando a mudanças na estrutura ecológica bêntica. Sendo um problema de estético e ambiental, a preocupação da comunidade e órgãos governamentais gerou uma intensificação nos estudos, uma vez que as ocorrências se tornaram mais frequentes e persistentes. O presente trabalho aborda este problema através de estudos ambientais e experimentais. A coleta de material bêntico com embarcação e mergulhos e monitoramento florações junto a praia compuseram a abordagem ambiental. Os trabalhos de laboratório incluíram o isolamento e a cultura de algas e brioozários, bem como a avalição do crescimento desses organismos, além da análise e avaliação química biomassa. Os dados de monitoramento mostraram uma tendência sazonal nas florações, com eventos mais evidentes nos meses mais quentes. Diatomáceas aumentaram em abundância nos meses mais frios e briozoários nos mais quentes. A diatomácea A. antediluviana, predominante nas florações, cresceu de forma satisfatória em cultivo laboratorial, mostrando um melhor crescimento em meios com concentrações mais elevadas de silicato e fosfato. Os briozoários mostraram crescimento lento em condições de laboratório. O material depositado no ambiente mostrou baixas concentrações de ácidos graxos, predominantemente saturados, mas a elevada biomassa sugere um possível uso para a produção de biocombustíveis. Amostras de biomassa dominadas por briozoários apresentaram atividade antimicrobiana moderada contra Klebsiella pneumoniae. A explicação para a ocorrência destes eventos ainda são inconclusivas, mas há evidências consideráveis de que há um efeito sinérgico entre a alta concentração de bactérias e detritos orgânicos na água, relacionada com a poluição local, e a eliminação de competidores naturais pelos impactos das obras costeiras.Balneário Camboriu (SC - Brazil) is a touristic city where the disordered growth of the urban population and the implementation of coastal works without proper evaluation generated environmental impacts and affected the sanitary quality of water and sediment of Camboriu River and marine adjacent area. One of the most recent and alarming phenomena observed are the blooms of invasive bryozoans (Arboscuspis bellula and Membraniporopsis tubigera) associated with epibenthic diatoms (Amphitetras antediluviana and Biddulphia biddulphiana). Several clues associate these phenomena, started in 2003, with the excess of nutrients and organic matter in the Camboriú cove and large coastal works such as dredging, landfills and construction of jetties, leading to changes in benthic ecological structure. Being an aesthetic and environmental health problem, the concern of the scientific community and government agencies intensified as the occurrences become more frequent and persistent. This research addresses this issue through environmental and experimental studies. Samplings of the benthic material collected by boat and diving, and blooms monitoring were the environmental approach. The laboratory work included the algal isolation and culture, in addition to growth conditions assessment and chemical biomass analysis. Monitoring data showed a seasonal trend in the blooms, with more conspicuous events in warmer months. Diatoms increase in abundance in colder months and bryozoans in the warmer ones. The diatom A. antediluviana, predominant in the blooms, grew satisfactorily in laboratory cultivation, showing better growth in media with higher concentrations of silicate and phosphate. Bryozoans showed slow growth in laboratory conditions. The deposited material collected in the environment showed low concentrations of saturated fatty acids, but the high biomass suggest a possible use for biofuels production. Biomass samples dominated by bryozoans showed moderate antimicrobial activity against Klebsiella pneumoniae. The explanation for the occurrence of these blooms are still inconclusive, but there is considerable evidence that it is a synergistic effect between the high concentration of bacteria and organic debris in the water related to local pollution and the elimination of natural competitors by coastal works

Estrutura da comunidade epibêntica e icitiofauna associada ao banco de nódulos calcários da Reserva Biológica Marinha do Arvoredo, SC

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Secondary succession impairment in restored mangroves

In this work it was hypothesized that secondary succession on sites that have been managed by single planting of mangrove species is compromised by residual stressors, which could reduce the ecosystem's structural development and lower its functions. Forest structure and environmental characteristics of three planted mangrove stands are compared with reference sites. Structural attributes showed significant differences in the comparison of planted and reference stands. Avicennia schaueriana was the dominant species within both natural regeneration and old-growth stands in terms of basal area (99.2 and 99.4 %, 69.6 and 84.5 %, and 59.0 and 87.1 % for Itacorubi, Saco Grande, and Ratones, respectively). Restoration stands were dominated by Laguncularia racemosa (80.6 and 94.2 % for Saco Grande and Ratones, respectively), except at one site (Itacorubi), where A. schaueriana prevailed (99.7 %). Even though restoration and regeneration stands at Itacorubi showed similar species composition and dominance, cohort sorting revealed an inferior regeneration potential in the restoration stand. Multiple correlation analysis indicated that variables related to elevation disruptions (p (w) = 0.521) were the environmental drivers responsible for the differences observed in forest structure. At restoration sites an impaired pattern of secondary succession was observed, indicating that single species plantings may be ineffective if characteristics of the site, as well as of the area surrounding it, are not considered. The inadequate management of restoration sites can therefore have implications for both immediate and long-term large-scale ecosystem services.Coordination for the Improvement of Higher Level Personnel (CAPES)Coordination for the Improvement of Higher Level Personnel (CAPES)National Council for Scientific and Technological Development (CNPq)National Council for Scientific and Technological Development (CNPq

Blooms of bryozoans and epibenthic diatoms in an urbanized sandy Beach (Balneário Camboriú - SC - Brazil): dynamics, possible causes and biomass characterization

Abstract Balneário Camboriu (SC - Brazil) is a touristic city where the disordered growth of the urban population and the implementation of coastal works without proper evaluation generated environmental impacts and affected the sanitary quality of water and sediment of Camboriu River and marine adjacent area. One of the most recent and alarming phenomena observed are the blooms of invasive bryozoans (Arboscuspis bellula and Membraniporopsis tubigera) associated with epibenthic diatoms (Amphitetras antediluviana and Biddulphia biddulphiana). Several clues associate these phenomena, started in 2003, with the excess of nutrients and organic matter in the Camboriú cove and large coastal works such as dredging, landfills and construction of jetties, leading to changes in benthic ecological structure. Being an aesthetic and environmental health problem, the concern of the scientific community and government agencies intensified as the occurrences become more frequent and persistent. This research addresses this issue through environmental and experimental studies. Samplings of the benthic material collected by boat and diving, and blooms monitoring were the environmental approach. The laboratory work included the algal isolation and culture, in addition to growth conditions assessment and chemical biomass analysis. Monitoring data showed a seasonal trend in the blooms, with more conspicuous events in warmer months. Diatoms increase in abundance in colder months and bryozoans in the warmer ones. The diatom A. antediluviana, predominant in the blooms, grew satisfactorily in laboratory cultivation, showing better growth in media with higher concentrations of silicate and phosphate. Bryozoans showed slow growth in laboratory conditions. The deposited material collected in the environment showed low concentrations of saturated fatty acids, but the high biomass suggest a possible use for biofuels production. Biomass samples dominated by bryozoans showed moderate antimicrobial activity against Klebsiella pneumoniae. The explanation for the occurrence of these blooms are still inconclusive, but there is considerable evidence that it is a synergistic effect between the high concentration of bacteria and organic debris in the water related to local pollution and the elimination of natural competitors by coastal works