Estudo de caracterização geoquímica e das associações de foraminíferos parálicos do sistema estuarino do rio Jequitinhonha, litoral sul da Bahia

Isabel Honorata de Souza Azevedo, Simone Souza de Moraes, Antônio Fernando de Souza Queiroz, Ana Carina Matos Silva, Narayana Flora Costa Escobar, Fabiany Cruz Gonzaga

Abstract


The associations of foraminifera, besides being abundant and presenting a wide geographical distribution, take advantage of the intrinsic peculiarities of these organisms to store in their tests characteristics of the places where they lived. In this context, the tests of these organisms were related to the trace-metal contents of the sediment of the estuarine system of the Jequitinhonha River, south coast of Bahia, aiming to evaluate whether the levels of these elements are affecting the microfauna. For the canal region, 281 foraminifera tests were obtained in the first campaign (4.98% of the specimens were collected alive, and none of the tests were malformed) belonging to 10 species, of which Trochammina inflata; Haplophragmoides wilberti and Ammonia beccarii as major species. In the second sampling, there was no record of foraminifera, due to the low salinities, making it impossible the survival of even the most resistant species. In the mangrove area, in the first campaign, 116 tests (5.1% alive, 0.0% anomalous) Among 10 species, 4 stand out: Haplophragmoides wilberti; Ammonia beccarii; Quinqueloculina fusca and Q. venusta. In the second campaign, only 143 specimens were registered (0.70% alive, 0.0% anomalous). Among10 species 3 were stand out: H. wilberti; Trochammina inflata and Q. fusca, and the increase in the number of tests is due to the increase in salinity. In addition, it was observed only in the first campaign of the Pardo river channel that only lead (points 2, 3, 4, 5 and 6) presented values above the limits established by the reference institutions (CONAMA - Brazil, 2012) and Canadian Council of Ministers of the Environment (CCME, 1998).


Keywords


Foraminifera; Estuaries; Heavy Metals; Mangrove; Brazil.



DOI: http://dx.doi.org/10.21715/GB2358-2812.2019332144

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