Impacts of Seawater Desalination on Coastal Environments

Seawater reverse-osmosis desalination facilities discharge brine effluent with potential implications to the integrity of marine coastal environments. Typical desalination brine effluent consists of hypersaline seawater along with additional antiscalants and coagulants, which are often mixed with cooling water of adjacent power plants. The spatial distribution of the brine plume, namely, the perimeter, flow direction, and buoyancy, varies according to the volume and rate of discharge as well as the dispersion technology. In this chapter, we will present a comprehensive overview highlighting the environmental effects of brine effluent on various coastal species, including bacteria, zooplankton, seagrass, fish larvae, and corals. Recent studies have suggested that desalination brine effluent may alter the activity and diversity of bacteria and microalgae, reduce the abundance of meiofauna, as well as impact the physiology of seagrass meadows around the outfall site. Following this, we will discuss possible means and measures to monitor and minimize the interface of brine effluent with marine coastal biota.