Efeito da temperatura na produção de biomassa perifõtica em tanque de piscicultura.

Abstract

Periphyton is essential for the functioning of aquatic ecosystems, contributing mainly to primary productivity and acting at the base of the trophic web. Temperature is a determining factor in the development of periphytic algae, as it has an effect on the structuring of the community and the successional process. In this context, we evaluated the primary production of periphyton on artificial substrates (glass slides) for 60 days in temperature treatments at 28, 30 and 32ºC. The experiment took place in mesocosms in a fish pond. The biomass of the substrates was assessed using chlorophyll-A, and the environmental variables were checked using a multi-parameter probe. Repeated measures ANOVA was applied to verify the effect of temperature and colonization time on periphytic biomass. The highest biomass peak (0.6872 mg.m-3) was recorded in the 32ºC treatment, specifically at 20 days after the start of the experiment. In contrast, the lowest amount (0.0115 mg.m-3) was observed at 32 days in the 30ºC treatment. We conclude that the higher temperature of 32ºC determined a greater biomass of periphytic algae and accelerated successional evolution.