Harmful Elements in Estuarine and Coastal Systems

Abstract

Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities.

Juvenile Oblada melanura (L. 1758) otolith shape is impacted near recreational harbours or due to settlement position in nearby sites

“…Type B sites were small waterway mouths which are mainly natural sources of metals in the Mediterranean (Fukai et al 1975;Du Laing et al 2009;Khan et al 2014). Type C sites were near recreational harbours where pollution (Mestres et al 2010;McCoy and Johnson 2010) is mainly caused by fuel (Telli Karakoc et al 1997) and boat paints containing metals (Konstantinou and Albanis 2004;Damiens et al 2007).…”

Environmental risk assessment in a contaminated estuary: An integrated weight of evidence approach as a decision support tool

“…at low concentrations (Khan et al, 2014). The study of the speciation of arsenic in these vegetables should be conducted to confirm the levels of inorganic arsenic (see Table 3).…”

“…The study of the speciation of arsenic in these vegetables should be conducted to confirm the levels of inorganic arsenic (see Table 3). Several authors referred the occurrence of inorganic arsenic in raw vegetables and in feed mainly due to arsenic accumulated in soils and irrigated waters (Khan et al, 2014;Norton et al, 2013). This is particularly important since species interconversion did not occur across the food chain, including cooking processes, where magnification is described as inorganic arsenic is transferred from water used in the preparation of meals (Norton et al, 2013).…”

NanoSIMS Imaging of Bioaccumulation and Subcellular Distribution of Manganese During Oyster Gametogenesis

“…Over the past few decades, the use of Mn showed a sustained growing trend and recent yearly production is more than 15 billion tons, with larger amounts of Mn-containing compounds being released into the environments. Mn has been considered as an emerging contaminant in many coastal and estuarine environments , due to its high environmental concentration and potential threat to marine animals. , As an intermediate oxidant/reductant, reduced Mn can be released from the sediment into overlying water during hypoxic conditions, and the concentration of Mn in anoxic bottom water of marine coastal environments can be up to 3 orders of magnitude higher than those normally documented in seawater. , Thus, the potential risk of Mn to benthic organisms has attracted increasing attention recently. − …”