Influência de algas de deriva sobre a meiofauna em um estuário subtropical (sistema estuarino de Laguna, SC)

• Autor(a) principal: Candido, Higor Marcelino Candido
• Data de Publicação: 2019
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Universitário da Ânima (RUNA)
• Texto Completo: https://repositorio.animaeducacao.com.br/handle/ANIMA/12523
• topic: Algas de deriva; Meiofauna; Nematoda

The high productivity of the estuaries depends on local climatic and hydrodynamic parameters, the maintenance of nursery grounds, and their primary productivity. However, changes in these factors, both of natural and anthropogenic origin, have been observed in the last decades. These changes include a drastic reduction of vegetated habitats dominated by marine phanerogams and an increase in the abundance of drift macroalgae of rapid growth and opportunistic character. In addition to increasing the habitat structural complexity, the algae still help organisms in their dispersal process, allowing large displacements along the estuary and the colonization of new areas. This study has as general objective to evaluate the influence of drift algae on the structure of meiofauna in the Laguna Estuarine System, SC, Brazil. Data collection occurred monthly between September 2016 and February 2017, and September 2017 and February 2018. Two areas were defined in the Imaruí lagoon, one in the intertidal portion and one in an adjacent sublittoral area 5 m apart. In each of the areas fixed lines of about 150 m was defined. In each of these lines, 4 samples were taken for meiofauna, sediments and algal biomass. Eight meiofaunal taxonomic groups were identified, out of 4433 individuals. The Nematoda represented 57% of the collected meiofauna and was the numerically dominant to the other groups. Tardigrada followed as the second predominant group, representing 31% of the total of individuals collected. The other groups represented 10%. years. The analysis of the algal biomass indicates an increase of 5gDW between years, where the intertidal showed higher biomass in both years. The results of this study show that the accumulation of algal biomass exerts a strong influence on meiofauna. Significant changes were detected in both sampled areas, especially in the intertidal. Values of the environmental variables showed significant alterations, except the concentrations of chlorophyll a and phaeopigments.