Foraminifera as indicators of marine pollutant contamination on the inner continental shelf of southern Brazil Patricia P.B. Eichler a,⇑ , Beatriz B. Eichler a , Barun Sen Gupta c , André Rösch Rodrigues b a Universidade Federal do Rio Grande do Norte, Centro de Ciências Exatas, Departamento de Geologia, Departamento de Geologia, Campus Universitário, Lagoa Nova, Caixa-Postal: 1596, 59072-970 Natal, RN, Brazil b Instituto Oceanográfico da Universidade de São Paulo, Praça do Oceanográfico, 191, Cidade Universitária, 05508-120 São Paulo, SP, Brazil c Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, United States article info Keywords: Foraminifera species diversity Environmental parameters Pollution indicators Sewage outfall Salinity Coliforms abstract Analyses of living foraminiferal and environmental parameters near an outfall at Mar Grosso Beach (Laguna, SC, Brazil) demonstrate its usefulness as indicators of domestic sewage pollution. The low spe- cies diversity may be due to sand accumulation in the central part. Higher diversity was noted closer to the mouth of Laguna estuarine system where reduced salinity and higher temperatures indicate freshwa- ter influence, suggesting a relationship between increased diversity and greater availability of terrestrial food. On the basis of foraminiferal diversity and average coliform count the higher values are closer to the mouth of the estuarine system and under the influence of the outfall. Due to the effect of local hydrody- namics, the particulate organic waste derived from the outfall does not settle down locally, and thus, do not accumulate nearby. Our hypothesis is that the fine material derived from the outfall is accumulating on the southwestern and northwestern parts of the beach. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction All over the world, the coastal zone is most seriously affected by alterations introduced by human activity. Scenic beauty and recre- ational opportunities attract people to the coastal zone and lead to marine pollution. The open sea can also be polluted by transport of continental material by wind and surface circulation, or by trans- port along the ocean bed from polluted coastal zones (Miranda et al., 1998). Domestic sewage is an inevitable consequence of hu- man settlement. The increasing human occupation of coastal re- gions and the growth of great coastal urban centers in the last three decades have resulted in a dramatic increase in the supply of nutrients and other deleterious material in the sewage, includ- ing pathogenic organisms. The continued growth in coastal popu- lation density, which has been observed in recent decades, calls for the establishment of adequate strategies to manage and reduce the impact of sewage pollution on the environment and on human health. Benthic communities are widely used in the monitoring of ef- fects of marine pollution as the organisms are slow-moving or ses- sile which render them more sensitive to local disturbances integrating effects of pollutants over time. Most benthic communi- ties comprise a large number of species and because of the varying sensitivities of species, it should be possible to identify subtle ef- fects of pollutants reflected in changes in community structure (Gray et al., 1990). In monitoring programs, the use of benthic organisms as indica- tors of environmental change in pollution-prone areas is reliable, be- cause the benthos, unlike the plankton or nekton, adapt to local conditions over a period of time instead of just reflecting the condi- tions prevailing at the moment of sampling. A second point is the close dependence of benthic organisms on the composition of the sediment in which contaminating substances accumulate. This is why the use of alternative biotic components in environmental monitoring is generally unnecessary (Warwick, 1993). The Forami- nifera, which constitute a class of unicellular organisms (Kingdom Protoctista, Phylum Granuloreticulosa; Sen Gupta, 1999), are among the more abundant eukaryotes in most marine and brackish water habitats; the large majority is benthic, but planktonic species are conspicuous in open-marine surface waters. A consensus exists that benthic Foraminifera should be used in routine long-term surveil- lance programs, hazard assessment at specific discharge sites, and monitoring of the effectiveness of remedial actions (Debenay et al., 2000). Foraminifers have a short life cycle, and react quickly to envi- ronmental shifts. This rapid response of their populations to impact- ing agents can be used as an early warning of human-induced environmental change, as defined by Kramer and Botterweg (1991). In particular, the well-known foraminiferal species of estu- aries and lagoons hold special promise as biological indicators of such changes (Boltovskoy and Wright, 1976). 0025-326X/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.marpolbul.2011.10.032 ⇑ Corresponding author. Tel.: +55 84 20106245. E-mail addresses: patriciaeichler@gmail.com (P.P.B. Eichler), glbarun@lsu.edu (B.S. Gupta), bbeichle@usp.br, andre.rosch.rodrigues@gmail.com (A.R. Rodrigues). Marine Pollution Bulletin 64 (2012) 22–30 Contents lists available at SciVerse ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul