Radioecological assessment and radiometric dating of sediment cores from dynamic sedimentary systems of Pra and Volta estuaries (Ghana) along the Equatorial Atlantic

A worldwide meta-analysis (1977–2020) of sediment core dating using fallout radionuclides including <sup>137</sup>Cs and <sup>210</sup>Pb<sub>xs</sub>

“…They only recorded fallout associated with the global bomb peak in 1963 (e.g., Hansen, 2012). A similar finding was made in Ghana where both fallout sources associated with Fukushima and Chernobyl accidents were recorded in the Amisa and Sakumo River estuaries (Mahu et al, 2016), whereas no single 137 Cs peak could be identified in sediment collected in the nearby Volta and Pra River estuaries (Klubi et al, 2017).…”

Reviews and syntheses: <sup>210</sup>Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems – setting the record straight

“…We performed a literature review of studies on sediment accumulation in vegetated coastal ecosystems in the Web of Science ™ (http://webofknowledge.com, last access: 23 August 2018) with the following keywords: mangrove sediment; salt marsh, saltmarsh or tidal marsh sediment; seagrass sediment AND (Boolean operator) 210 Pb, Pb-210 or lead-210. The search produced 86, 223 and 27 results, respectively, all of them using one or more of the three models described above, probably due to their simplicity, with some exceptions such as Klubi et al (2017) that additionally uses the TERESA model (Table 2). From the literature review, we identified the most common sedimentary processes that result in anomalous types of 210 Pb xs specific activity profiles with depth.…”

“…In addition, the detection of 137 Cs is more difficult in sediment cores from habitats located in the Southern Hemisphere and near the Equator. The low 137 Cs bombtest fallout and Chernobyl inputs in these regions (Kelley et al, 1999;Ruiz-Fernández and Hillaire-Marcel, 2009), the greater solubility of 137 Cs in seawater (K d = 10 2 to 10 3 , Bruland, 1983), and the presence of sands and carbonates, particularly in seagrass sediments (Koch, 2001), are conditions that do not favor the adsorption of 137 Cs (He and Walling, 1996a) and may lead to its mobility (Davis et al, 1984). This effect could be intensified in the intertidal zone, which is not permanently submerged due to periodic changes in the water table.…”

“…The percentage of living (e.g., roots) and recently formed organic material is greatest in the upper 10 cm and may be affected by varying inputs of detrital sediment within vegetated coastal ecosystems and by its relative rate of decomposition. While tidal marsh and mangrove sediments have relatively high organic matter content (on average 25 %) (Breithaupt et al, 2012;Cochran et al, 1998), mineral deposits account for the majority (> 85 %) of the accumulated substrate in seagrass sediments (Koch, 2001; (Table 1). 210 Pb has a strong affinity for fine sediments (Chanton et al, 1983;Cundy and Croudace, 1995;He and Walling, 1996a) and organic matter (Wan et al, 2005), and thus any changes in these parameters due to sediment redistribution processes or to natural heterogeneity may also result in unique types of 210 Pb specific activity profiles in sediment cores of vegetated coastal ecosystems, adding complexity to the determination of sediment model age and sedimentation rates.…”

“…b Seagrass (Duarte et al, 2013), mangroves (Breithaupt et al, 2012) and tidal marsh (Ouyang and Lee, 2014). c Seagrass (Koch, 2001); mangrove (Breithaupt et al, 2012); tidal marsh (Cochran et al, 1998;Ember et al, 1987). d Seagrass (Fourqurean et al, 2012); mangrove (Breithaupt et al, 2012); tidal marsh (Chmura et al, 2003).…”