Study of the zooplankton productive processes in a subtropical reservoir: an exper...
| Grant number: | 11/07218-6 |
| Support type: | Regular Research Grants |
| Duration: | August 01, 2011 - July 31, 2013 |
| Field of knowledge: | Biological Sciences - Ecology |
| Principal Investigator: | Evaldo Luiz Gaeta Espindola |
| Grantee: | Evaldo Luiz Gaeta Espindola |
| Home Institution: | Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil |
Abstract
With the growth of industrialization in the twentieth century, the supply of metals in different environmental compartments increased significantly. In aquatic environments, organisms are exposed to both dissolved metals in the water and to metal present in the food chain. Studies aiming to assess the effects of metals on phytoplankton are necessary because, as the food chain base, any changes resulting from toxic effects of metals in these organisms may reflect on other components of the biota. Moreover, because the ability of algae to retain metals and make them available through a food route to their consumers, greater knowledge about possible routes of contamination of zooplankton is necessary. Considering the importance of metal contamination in aquatic ecosystems, as well as the need for understanding the interactions of these elements in the environment, the main objective of this research is to evaluate the effects of exposure to chromium in phytoplankton and zooplankton populations and trophic interactions in these organisms based on structural and physiological aspects. Therefore ecotoxicological tests will be conducted in a laboratory using the algal species Pseudokirchneriella subcapitata, Chlamydomonas reinhardtii and Microcystis aeruginosa as test organisms, where cell density is evaluated along with biovolume, dry weight, cell morphology, content of carbohydrates, lipids, proteins, pigments and phytochelatin of the forementioned organisms after exposure to chromium; in addition to tests with zooplankton exposed to different routes of contamination, such as contaminated water, contaminated food and the combination of both situations (food and water contaminated) with the cladoceran Ceriodaphnia silvestrii and Ceriodaphnia dubia being used as test organisms. Also the fertility rate, survival, population growth, body size, eating rate and content of carbohydrates, lipids and proteins will be assessed. It will also be a study in mesocosms scale, seeking a better understanding of plankton community in response to contamination by chromium, which will be assessed by analyzing the composition and density of phytoplankton and zooplankton. (AU)