Impact of artificial lagoons on seawater quality: evidence from 7 years of physicochemical seawater monitoring

Chlorophyll–Nutrient Relationships of an Artificial Inland Lagoon Equipped with Seawater Replenishment System in the Northern Red Sea (Gulf of Aqaba)

“…Ayla's UL experiences more widely varying temperatures (16.2-28.8 • C), as shown in Supplementary Files S1 and S2 and discussed by Manasrah [29], than the ambient conditions in the GoA water (22.7-27.7 • C) [18,27,29,[33][34][35][36]. In particular, the UL has much lower winter temperatures (16.2-21.8 • C) than the ambient GoA water conditions (21.9-23.8 • C); this is due to the UL's shallow depth (~2 m) and high surface area, which makes it more vulnerable to losing heat due to surface wind effects, therefore decreasing its temperature during the winter.…”

“…Such data are necessary to develop management plans capable of preserving the lagoons' natural chemical properties, productivity, and biodiversity [14][15][16][17]. A recent study by Rasheed et al [18] highlights the impact of two small artificial lagoons (marinas) on the water quality in the GoA and illustrates the importance of environmental design studies for lagoons before any construction begins. The two lagoons discussed by Rasheed et al [18] lacked a water circulation system, which rendered them subject to high levels of eutrophication that influenced the water quality inside the lagoons and in the adjacent GoA seawater.…”

“…A recent study by Rasheed et al [18] highlights the impact of two small artificial lagoons (marinas) on the water quality in the GoA and illustrates the importance of environmental design studies for lagoons before any construction begins. The two lagoons discussed by Rasheed et al [18] lacked a water circulation system, which rendered them subject to high levels of eutrophication that influenced the water quality inside the lagoons and in the adjacent GoA seawater. Ayla lagoon's design was subjected to different environmental models before the actual design was modeled and constructed, resulting in the design of a seawater pumping system which pumps ambient seawater from the GoA into the lagoons, in an attempt to minimize eutrophication and maintain "close to ambient" in-lagoon water quality, and thereafter minimal impact on the adjacent ambient water of the GoA.…”

“…Eutrophication is a state of an aquatic ecosystem exposed to an increase in nutrient concentrations from point and non-point sources, leading to increased phytoplankton and algal biomass in the water column, and causing decreased levels of dissolved oxygen in water, which all can lead to deterioration of water quality and negatively impacts the ecosystem functioning in general, and coral reefs in particular [19][20][21][22]. The eutrophication status of two artificial lagoons, Royal Yacht Club (RYC) and Tala Bay (TB), in the GoA (Figure 1b) has been discussed by Rasheed et al [18]. Briefly, the two lagoons were exposed to the adjacent "ambient" seawater through a single passageway, depending solely on natural exchange of water with the adjacent open seawater through the single lagoon opening.…”

“…Studies indicate that healthy water quality in lagoons can be maintained through the provisioning of adequate flushing conditions and minimal discharge or runoff of pollutants such as sewage and nutrients into the lagoons [11,14,[16][17][18]29]. In order to maintain reasonable water quality in the Ayla Oasis lagoons, international standards have been applied during the design, construction and operation, through engagement with marine experts who carefully developed a water quality model, recommended adequate water replenishment system before construction, and established a detailed water quality monitoring program during the operation.…”