Solange Andrade Pereira

Pathological findings in Crassostrea rhizophorae from Todos os Santos Bay, Bahia, Brazil

Abstract Types and frequencies of pathologies were investigated in Crassostrea rhizophorae before and following heavy oyster mortality in Todos os Santos Bay, Bahia, Brazil. The sporozoan Nematopsis sp. was the only parasite present in sufficient numbers to be an important mortality factor, but the intensity of Nematopsis infections remained low until after the major die-off. Pathologies such as ceroidosis, reduction or loss of stored glycogen, decreased gametogenesis, edema, and metaplasia of the digestive diverticula were consistent with the hypothesis of an external environmental stress factor that may have caused feeding to cease, the resultant weakness contributing to high mortalities.

Integration of varying responses of different organisms to water and sediment quality at sites impacted and not impacted by the petroleum industry

Abstract The toxicity of surface waters and interstitial waters from sediments were determined at six study sites in Todos os Santos Bay, Bahia, Brazil, to evaluate the possibility of chronic environmental impact induced by 40 years of exposure to the local petroleum industry. Samples collected from four sites associated with the extraction, transportation and refinement of petroleum, and from two control sites, were tested at seven three-month intervals. Toxicological assays using acute mortality of brine shrimp (Artemia salina) nauplii and chronic abnormalities of sea urchin (Echinometra lucunter) and mangrove oyster (Crassostrea rhizophorae) larvae were employed. Friedman non-parametric analyses of variance integrated seasonal variations in species response patterns and revealed significant differences among the study sites. Ranging the among-site variations for each organism in each sampling period, on a scale from 0.00 (minimum response) to 1.00 (maximum response), permitted the calculation of a sing...

Toxicity of water‐soluble fractions of biodiesel fuels derived from castor oil, palm oil, and waste cooking oil

Concerns over the sustained availability of fossil fuels and their impact on global warming and pollution have led to the search for fuels from renewable sources to address worldwide rising energy demands. Biodiesel is emerging as one of the possible solutions for the transport sector. It shows comparable engine performance to that of conventional diesel fuel, while reducing greenhouse gas emissions. However, the toxicity of products and effluents from the biodiesel industry has not yet been sufficiently investigated. Brazil has a very high potential as a biodiesel producer, in view of its climatic conditions and vast areas for cropland, with consequent environmental risks because of possible accidental biodiesel spillages into water bodies and runoff to coastal areas. This research determined the toxicity to two marine organisms of the water-soluble fractions (WSF) of three different biodiesel fuels obtained by methanol transesterification of castor oil (CO), palm oil (PO), and waste cooking oil (WCO). Microalgae and sea urchins were used as the test organisms, respectively, for culture-growth-inhibition and early-life-stage-toxicity tests. The toxicity levels of the analyzed biodiesel WSF showed the highest toxicity for the CO, followed by WCO and the PO. Methanol was the most prominent contaminant; concentrations increased over time in WSF samples stored up to 120 d.

Stress protein accumulation as an indicator of impact by the petroleum industry in Todos os Santos Bay, Brazil

The relative concentrations of stress proteins in juvenile mangrove oysters (Crassostrea rhizophorae), from six study sites in Todos os Santos Bay, Bahia, Brazil, were used to evaluate the possibility of chronic environmental impact induced by 40 years of exposure to the local petroleum industry. Replicated tissue samples from oysters at four sites associated with the extraction, transport and refinement of petroleum, and from two control sites, were used for stress protein (60 kDa) determination. The relative levels of stress proteins were statistically compared by standard methods. Friedman nonparametric analysis of variance, followed by multiple comparisons among samples, revealed significant differences in stress protein levels. Oysters from sites associated with the extraction and transport of petroleum had the highest relative concentrations of stress proteins, while the control areas revealed minimum concentrations. Samples from the refinery site, where oyster populations were severely reduced, did not differ from the control sites. Comparisons with parallel studies on the toxicity of aquatic substrates at the same sites revealed that stress protein analyses were useful in evaluating chronic environmental impact, within the tolerance limits of C. rhizophorae, but that the stress response diminished significantly when conditions approached the lethal limits for this species. The stress protein response appears to serve as a valid biomonitoring method under chronic, sublethal exposures, before biological responses become evident at the organismic or population levels, but may not serve well when the stressor intensity is at or near the lethal tolerance level.

Changes in the condition index for mangrove oysters (Crassostrea rhizophorae) from Todos os Santos Bay, Salvador, Brazil

Abstract The condition index was calculated for two samples of 600 C. rhizophorae taken from Jacuruna farm in September–October 1977 (spawning period) and December 1977–January 1978 (post-spawning period). There was a significant difference ( P ≤ 0.05). Over the size range 2.1 to 10.0 cm (height) the condition index ranged from 59.0 ± 16.2 to 71.8 ± 30.5 for the spawning period, but was only 27.1 ± 10.2 to 43.9 ± 33.0 for the post-spawning period. The size class 4.1 to 6.0 cm gave the best commercial yields and was considered more suitable for the shucked oyster than the fresh oyster market.

Determination of the optimum commercial size for the mangrove oyster (Crassostrea rhizophorae) in Todos os Santos Bay, Brazil

Abstract Pilot studies were conducted in 1977–1978 on the cultivation of mangrove oysters in the Jacuruna River estuary at Todos os Santos Bay, Salvador, Brazil. Growth characteristics were studied by comparing the relationships between total live weight, volume of the shell cavity fluid and yield of meat, and dry body weight to size (height). The most economically feasible proposition was production of approximately 7 cm high oysters for the shucked oyster market rather than for the fresh oyster market. The harvesting of oysters less than 4 cm high was not considered desirable because it might reduce reproductive capacity. In oysters higher than 7 cm, growth rate and meat production decreased and did not warrant further cultivation.

Ecotoxicological diagnosis of Aratu Bay, Bahia, Brazil: a new approach to validate a reactive short-term toxicity end-point by comparison with intertidal benthic activity

Abstract The Aratu Bay ecosystem (12°48′S; 38°28′W), located in an industrialized area, was compared with a similar but undisturbed ecosystem, Iguape Bay, in order to determine the impact of industry on water quality during the last forty years. Comparison was based on simple and low cost methodologies using bioassays on oyster embryos, validated by a survey of a benthic activity index. A bioassay method based on oyster embryo development was used to compare water quality from the study areas. A high percentage (93.2 and 97.3) of abnormal oyster embryo development was observed in water samples from one area (south and southeast) of the bay where, besides receiving heavy discharges of industrial effluents, water circulation is restricted. At the north end of the bay where the area is shallow, and some industrial discharges are present, water quality data indicated that the area was stressed. Little effect of industrial impact has been noted around the Cotegipe channel, a deep area where the water circulati...

Coleção de microalgas de ambientes dulciaquícolas naturais da Bahia, Brasil, como potencial fonte para a produção de biocombustíveis: uma abordagem taxonômica

O presente trabalho envolveu a identificacao taxonomica de especies nativas de microalgas (isoladas de ecossistemas dulciaquicolas localizados nos arredores de Salvador, Bahia) integrantes da Colecao de Microalgas dulciaquicolas do LABIOMAR/IB/UFBA, visando estudos taxonomicos mais aprofundados (ultraestruturais e moleculares) e experimentos que possam avaliar sua capacidade para suprir cadeias produtivas de biocombustiveis. As coletas foram realizadas nos arredores de Salvador, Bahia, Brasil. A identificacao das especies foi efetuada com base em caracteres morfologicos. Foram identificados 19 taxons, 12 em nivel de especie e nove em nivel de genero, sendo 14 Chlorophyceae (Chlamydomonas sp1, Chlamydomonas sp2, Chlamydomonas sp3, Chlamydocapsa bacillus (Teiling) Fott, Chlorococcum sp1, Chlorococcum sp2), Coelastrum indicum Turn.. Coelastrum microporum Nageli, Desmodesmus brasiliensis (Bohl.) Hegew, Scenedesmum obliquus (Turpin) Kutz, Ankistrodesmus falcatus (Corda) Ralfs, Ankistrodesmus fusiformis Corda, Kirchneriella lunaris (Kirchner.) Mobius, Pseudokirchneriella subcapitata (Korshikov) F. Hindak), tres Trebouxiophyceae (Botryococcus braunii Kutz., Botryococcus terribilis Komarek et Marvan e Chlorella vulgaris Beijerinck), uma Bacillariophyceae (Nitzschia sp.) e uma Cyanobacteria (Synechocystis sp.).