Abstract
Coastal lagoons are among the most vulnerable and economically significant ecosystems on Earth. Songkhla Lake, connected with the Gulf of Thailand, is the second largest lake in Southeast Asia and supports the development of the fishery, transportation, and tourism industries in southern Thailand. With increasing anthropogenic disturbances, the lake is facing acute ecological problems and further research is needed. Here, we provide 55-year record of grain size, color reflectance, magnetic susceptibility, total organic carbon, total nitrogen, and trace element (As, Hg, Pb, Cr, Ni, Cu, and Zn) concentrations of sediment core SKL8-2 collected from Songkhla Lake. These records reveal a three-stage sedimentary and input history of trace metals under anthropogenic effects: 1) From 1964 to 1982, it was a natural terrigenous input period with a relative reduction environment when the channel connecting Songkhla Lake and the Gulf of Thailand was closed. 2) Trace metal concentrations, organic carbon content, b* value, and magnetic susceptibility changed abruptly in 1982. During 1982–2000, the sources of trace metals were more complex than during 1964–1982 and mainly came from urban wastewater, industrial effluent, and fishery discharge. 3) From 2000 to 2019, contamination signals of Pb, Hg, As, Zn, and Ni emerged in the first decade because of the rapid development and poor sewage treatment around nearby cities.
Highlights
Coastal lagoons rank among the most productive ecosystems on Earth because they provide a wide range of ecosystem services and resources (Newton et al, 2018; Velasco et al, 2018; Faremi et al, 2021)
From the surface to the bottom of core sediment SKL8-2, 210Pbex activity generally decreased in the pattern of a negative exponential curve, occasional anomalies fluctuated in certain layers (Figure 2)
We have provided a comprehensive record of the geochronology, lithology, and geochemistry of metal contamination in lake sediment core SKL8-2
Summary
Coastal lagoons rank among the most productive ecosystems on Earth because they provide a wide range of ecosystem services and resources (Newton et al, 2018; Velasco et al, 2018; Faremi et al, 2021). Coastal lagoons are highly exposed to various types of contaminants including trace metals, hydrocarbons, and plastics, which result from sources that include, but are not limited to, increased discharge of domestic, municipal, and industrial effluents (Pedro et al, 2016; Sogbanmu et al, 2016; Veiga et al, 2019; Wakkaf et al, 2020; El Zrelli et al, 2021) These contaminants persist for long periods and become bioavailable to living organisms because of their potential to bioaccumulate and biomagnify through the food chain (Bryan and Langston, 1992; Zhou et al, 2008; Bakshi et al, 2018), where sediments serve as their ultimate sink (Gadkar et al, 2019; Jung et al, 2019). Lagoon sediments can serve as archives of environmental changes through time (Aparecida Leite Silva and Eduardo Rezende, 2002; Liu et al, 2006; Laermanns et al, 2021)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
