Chemical elements in sediments and in bivalve mollusks from estuarine regions in the south of Bahia State, northeast Brazil

Abstract

Estuaries receive daily inputs of chemical elements which can impact the quality of water and sediment, as well as the health of biota. In addition to the sediment, bivalve mollusks have been used in the chemical monitoring of these systems. This study investigated the presence and contents of As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in superficial sediment and in bivalves (Crassostrea gasar, C. rhizophorae and Mytella guyanensis) from estuaries in the south / extreme south of Bahia State, northeast Brazil. The samples were evaluated with inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 710). Except for Cd, all other elements were found in the samples, being that Co was exclusive in the sediment. The estuaries equivalent to sampling stations #1 - Valença, #2 - Taperoá, #3 - Ilhéus and #4 - Belmonte showed levels of metals compatibles with those established by the Brazilian legislation, however, the #5 - Santa Cruz Cabrália, in addition to the presence of As, presented a high level of Pb and Cu in C. gasar, which was attributed to the impacts of nautical activities in that locality.

Nonessential elements (Al, As, Cd, & Pb) in shrimps and mussels from southeastern Brazil

“…The higher elemental concentration in the tissues of bivalve mollusks concerning other marine organisms (invertebrates and vertebrates) that share the environment is well documented elsewhere (e.g., Wang et al 2013; Suami Catry et al 2021). The higher concentrations are explained by the suspension-feeding habit of bivalves, with intense filtering activity, the elements are transferred to the tissues through phytoplankton, which is at the base of the marine food chains (Santos & Boehs 2023).…”

Mangrove forests transition between land and ocean, bioremediation areas, refuge and conservation of species

“…Pollutant molecules are usually associated with suspended particulate matter, where they become bioavailable to aquatic invertebrates, causing bioaccumulation when their detoxification levels are exceeded. For this reason, the study of metallic contaminants in sediments and biological matrices is recommended (Santos et al, 2021).…”