Sewage pollution effects on mesozooplankton structure in a shallow temperate estuary

Abstract

The effects of a sewage effluent with no treatment on the mesozooplankton structure and the environmental quality were evaluated in the Bahía Blanca Estuary, during June to November 1995. The highest values of particulate organic matter, nutrients and specially phosphate, were observed in the effluent discharge zone. In addition, taxa richness, mesozooplankton abundance and Shannon diversity values were lower in the sewage discharge area compared with the less polluted area. Eurytemora americana and Acartia tonsa as well as larvae of Balanus glandula, Neohelice granulata and Spionidae were found in the discharge area with lower densities. These results highlight the importance of sewage effluent effects on mesozooplankton community providing background data to use in other monitoring programmes.

Correspondence between zooplankton assemblages and the Estuary Environment Classification system

“…Moreover, and in addition to the natural stress conditions, estuaries are very vulnerable to human pressures, in particular pollution. As such, both the highly variable physical environment and anthropogenic alterations make the estuarine environment a challenging habitat for biota (Rosenberg, 1976;Elliott and Whitfield, 2011;Almeida et al, 2012;Biancalana et al, 2012).…”

Global change effects on biogeochemical processes of Argentinian estuaries: An overview of vulnerabilities and ecohydrological adaptive outlooks

“…Despite this ecological importance, the system is strongly impacted by industrial activities and maritime traffic. The Bahía Blanca estuary is considered highly eutrophic (Freije et al, 2008) and is polluted by untreated sewage discharge (Lara et al, 1985;Biancalana et al, 2012;Dutto et al, 2014), hydrocarbons (Lara et al, 1995;Arias et al, 2010), heavy metals (Marcovecchio and Ferrer, 2005;Simonetti et al, 2012;Fernández-Severini et al, 2013), and organotin compounds (Delucchi et al, 2007). The invading species B. glandula and the copepod Eurytemora americana have caused changes in species richness and diversity (Hoffmeyer, 2004).…”

Efecto de los efluentes cloacales sobre el ensamble macrobentónico submareal en un estuario urbano de la Argentina

“…The Bahía Blanca estuary, is one of the most urbanized and industrialized coastal areas of Argentina (Arias et al 2010;Biancalana et al 2012). Over the last three decades the estuary has suffered severe perturbations as a result of strong demographic expansion accompanied by growing industrial activity and cumulative organic pollution due to the dumping of untreated sewage (Botté et al 2007(Botté et al , 2010Marcovecchio et al 2008;La Colla et al 2015).…”

“…Since the estuary is home to the most important deep-water port system of the country, it is also affected by the continuous need for maintenance and dredging operations to accommodate maritime traffic. The physical and chemical changes in sediments produced by sewage effluents have been addressed in several studies (Tombesi et al 2000;Marcovecchio et al 2008;Serra et al 2017) and their effects on the biota have been evaluated through bioindicators such as bacteria (Baldini et al 1999), planktonic communities (Barría de Cao et al 2003Biancalana et al 2012;Dutto et al 2012;Chazarreta et al 2015) and commercial fishes (La Colla et al 2017). Several studies have also been conducted on the concentration of metals in crabs and mollusks inhabiting the intertidal zone of Bahía Blanca estuary (Ferrer 2000;Ferrer et al 2003;Simonetti et al 2012;La Colla et al 2018).…”