Comparing the metallic elemental compositions of Kelp Gull Larus dominicanus eggs and eggshells from the Swartkops Estuary, Port Elizabeth, South Africa

A global-level assessment of gulls (Larus spp.) as bioindicators of trace elements in coastal ecosystems

“…The lowest V levels are reported in L. dominicanus liver (0.2 µg g -1 ) from Brazil and several tissues of L. crassirostris from Japan (all concentrations <0.13 µg g -1 ). The highest V levels have been found in L. dominicanus eggshells (170 µg g -1 ) from South Africa (Van Aswegen et al 2019) and L. michahellis eggshells (4.91 µg g -1 ) from Turkey (Durmaz et al 2016). Data showed no clear tendency about which gull tissue concentrates this metal.…”

“…Antimony (Sb): this is a metal of concern because it can potentially be a carcinogenic agent, although there is a huge gap in information on Sb bioaccumulation and bioavailability (Obiakor et al 2018). There are only some studies from Japan in L. crassirostris (Agusa et al 2005), from South Africa in L. dominicanus (Van Aswegen et al 2019), and Turkey in L. michahellis (Durmaz et al 2016). The results indicated that the order of levels of Sb in eggshells of Larus spp.…”

“…with 22 countries and territories where Hg has been monitored in 26 species (Table S1). The lowest Hg concentrations have been reported in L. dominicanus feathers from Brazil (Ebert et al 2020) and L. dominicanus eggshells from South Africa (Van Aswegen et al 2019). On the other hand, the highest Hg concentrations in gull feathers have been found in coastal areas of the northern Mediterranean Sea (Fig.…”

“…It is an essential element that participates in the biological process of nitrogen fixation in organisms, presenting relatively low toxicity to humans (Barceloux 1999). Studies from Brazil, South Africa, and Japan have reported the Mo burden in the liver (Henrique-Pedrobom et al 2021), eggs (Van Aswegen et al 2019), and several other tissues (Agusa et al 2005), respectively. The lowest Mo levels (0.025 μg g -1 ) have been found in L. crassirostris eggshells from Japan (Agusa et al 2005).…”

“…Silver (Ag): this metal has been used widely as an antimicrobial. Ag levels have been assessed in L. dominicanus from South Africa (0.5 µg g -1 , eggshells; 0.28 µg g -1 eggs; Van Aswegen et al 2019) and in L. crassirostris from Japan (0.005 µg g -1 eggshells, 0.008 µg g -1 eggs; Agusa et al 2005). In wildlife, there is no evidence showing Ag biomagnification from marine or freshwater ecosystems, although certain toxicity at low levels has been linked to Ag (Ratte 1999).…”