Mediterranews (English) AUGUST 2016 | Page 9

TERRA NEWS 2 The impact on the marine environment can be negative when the brine discharge zones coincide with sensitive ecosystems like the San Quintín Bay. Photo: Enrique Alfaro. Waste water discharge into the 3 ocean near Laguna Figueroa, Baja California. Photo: Enrique Alfaro. areas close to desalination plants can be affected by the quantity and quality of the brine. The osmotic shock caused by the elevated difference in salinity inside and outside of the cells lead to massive mortality in organisms that are found near the discharge areas, sessile species or species of limited mobility like demersal fish, algae, plankton, larvae and eggs of different species; as a result jeopardizing the ecological processes and the transfer of energy in the different trophic levels (Arreguin & Martin, 2000). Seagrass beds in San Quintín Bay are especially vulnerable to salinity changes. Studies conducted in the southeast coast of Spain in Mediterranean seagrass beds (similar to San Quintín) demonstrate the significant effects on the health of seagrass with variations of barely 1-2 g/L and morality above of 50% with variations of above 5 g/L (Buceta et al., 2003; Sánchez-Lizaso et al., 2008). This not will only cause the reduction of primary productivity in the bay and capture dioxide carbon from the atmosphere (Arreguín & Martín, 2000), but it also has an impact on the productive activities within the bay, such as oyster farming, synergetic activities, sport and commercial fishing. All these activities depend on a healthy bay with feeding, protection, breeding, nesting and reproduction areas. Good management of wastewater (brine) should not have any consequence, but bad management has a significant negative effect that has to be taken into account in the decision-making process, especially regarding a semi-closed water body like San Quintín Bay. In the next months there is a potential increase of discharge locations on the bay and the surrounding areas; with the accumulation of brine discharges in the bay, the negative impact on water quality would be immediate. When brine is discharged on the 4 ground, it forms salt crusts that make any type of plant growth impossible. AUGUST 2016 07