Assessment of oil refinery waste on Rhizophora mangle L. seedling growth in mangroves of Todos os Santos Bay, Bahia, Brazil

Abstract

Seeds of Rhizophora mangle L. were pianted and comparatively assessed in six mangroves of Todos os Santos Bay, Bahia, Brazil. Five of the mangroves were on the north of the bay, an area under the influence of ou activities: two areas around the Landuipho Alves Reflnery in Mataripe, and in Madre de Deus lsland, Pati lsland, and Fontes lsiand. The control site was a mangrove located on the south of the bay at Jiribatuba on Itaparica lsland. In January and March, 1994, 1995 and 1998, sets of seeds were established and distributed in a pattern at regular intervals of 0.1, 0.5 and 1.0 m from one another. Every 3 months, the seedlings were assessed for fixation, height, number of lateral branches, surface arca and wet and dry weight of leaves. During 1998, five individual seedlings were removed for biomass determination every 6 months. Ali variabies were co-related with environmentai conditions. After 12 months, a significant growth pattern difference (p < 0.05) was noted between seedhngs from the mangrove around the refinery and those from Jiribatuba, mainly related to the rates offixation higher than 50% and growth of ieaves and precocious lateral branches to the two most impacted mangroves around the refinery, and Madre de Deus and Pati lslands. This branching was not observed on the seedlings grown in the mangroves of Fontes lsiand and Jiribatuba. The construction of an effluent emission channel into one of the mangrove arca from the refinery began in 1998. One hundred and twenty-five seediings 1 yr in age and other young plants died foiiowing direct contact with these effluents in February, 1999. Published by Elsevier Science Ltd on behaif of AEHMS.