Trace elements in oceanic pelagic communities in the western Indian Ocean

Abstract

The mineral composition of target and non-target pelagic fish caught by purse-seiners and longliners in the western-central Indian Ocean was determined. From the ten essential elements analysed, selenium and zinc showed the highest concentrations in swordfish and blue marlin while Indian mackerel appeared as a good source of copper, iron and chrome. All catch had levels of lead and cadmium, two toxic elements, below the maximum sanitary limits. Although some concerns were raised regarding mercury concentrations in the largest species (wahoo, swordfish and blue marlin), molar ratios of mercury and selenium indicate that all oceanic pelagic fish from the western-central Indian Ocean are safe for human consumption. This study also gives insights on the relationships between the levels of essential and toxic elements in fish muscle and the size, trophic position and diet sources of the studied pelagic species.

Trace element concentrations in the apex predator swordfish (Xiphias gladius) from a Mediterranean fishery and risk assessment for consumers

“…However, cadmium levels observed are similar to other studies worldwide (e.g. 0.059 mg kg − 1 , Bodin et al, 2016). Mean values of copper found in swordfish (0.349 mg kg − 1 ) were similar to concentrations recorded in the muscle from Indian Ocean, which reached a mean of 0.342 mg kg − 1 (Bodin et al, 2016).…”

“…In comparison with data reported by other authors, mean levels of iron (4.808 mg kg − 1) were similar to those reported by Kojadinovic et al, 2007 andBodin et al, 2016 in the same species (5.90 and 4.124 mg kg − 1, respectively). The detected chrome and selenium levels (0.043 and 0.552 mg kg were reported in swordfish from Atlantic Ocean and Indian Ocean (Olmedo et al, 2013;Bodin et al, 2016). Zinc values in this study were high (from 30.275 mg kg − 1 ), exceeding by far those reported in the Atlantic Ocean and the Indian Ocean (5.637and 7.480 mg kg − 1 respectively (Olmedo et al, 2013;Bodin et al, 2016).…”

“…0.059 mg kg − 1 , Bodin et al, 2016). Mean values of copper found in swordfish (0.349 mg kg − 1 ) were similar to concentrations recorded in the muscle from Indian Ocean, which reached a mean of 0.342 mg kg − 1 (Bodin et al, 2016). But these results were slightly higher than those observed in swordfish in the Indian Ocean and Atlantic Ocean (both 0.200 mg kg − 1 , Kojadinovic et al, 2007;Olmedo et al, 2013).…”

“…But these results were slightly higher than those observed in swordfish in the Indian Ocean and Atlantic Ocean (both 0.200 mg kg − 1 , Kojadinovic et al, 2007;Olmedo et al, 2013). In comparison with data reported by other authors, mean levels of iron (4.808 mg kg − 1) were similar to those reported by Kojadinovic et al, 2007 andBodin et al, 2016 in the same species (5.90 and 4.124 mg kg − 1, respectively). The detected chrome and selenium levels (0.043 and 0.552 mg kg were reported in swordfish from Atlantic Ocean and Indian Ocean (Olmedo et al, 2013;Bodin et al, 2016).…”

“…The detected chrome and selenium levels (0.043 and 0.552 mg kg were reported in swordfish from Atlantic Ocean and Indian Ocean (Olmedo et al, 2013;Bodin et al, 2016). Zinc values in this study were high (from 30.275 mg kg − 1 ), exceeding by far those reported in the Atlantic Ocean and the Indian Ocean (5.637and 7.480 mg kg − 1 respectively (Olmedo et al, 2013;Bodin et al, 2016). But these values were comparable with those reported by Kojadinovic et al (2007) (22.9 mg kg − 1 ).…”