Heavy metals in surface sediment and epibenthic macroinvertebrates from the coastal zone and continental slope of Kenya

• Published in: Marine Pollution Bulletin
• Main Authors: Everaarts, J.M., Nieuwenhuize, J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1995
• Subjects: North Atlantic
• Online Access: https://pure.knaw.nl/portal/en/publications/2e78fc75-8c9a-46e1-ae81-f31fc2baf53b; https://doi.org/10.1016/0025-326X(95)00190-X; https://hdl.handle.net/20.500.11755/2e78fc75-8c9a-46e1-ae81-f31fc2baf53b

In surface sediments, a statistically significant increase was measured in the concentration of copper and cadmium along all transects, and of zinc along only the most southern (Gazi) transect, radiating into the Indian Ocean perpendicular to the Kenyan coast, Mean copper and cadmium increased from 5 to 30 mu g g(-1) dry wt and from 0.01 to 0.34 mu g g(-1) dry wt in shallow coastal (+/-20 m depth) to deep-sea stations (+/-2000 m depth), respectively. These gradients were found both during the south-east monsoon and north-east monsoon period, The shallow estuarine zone of the Sabaki river mouth showed significantly enhanced levels of total organic carbon and nitrogen and all metals analysed, except cadmium. In crustaceans, the concentration of copper and particularly cadmium was significantly above baseline levels, varying from 45 to 90 mu g g(-1) dry wt and 1.0 to 8.5 mu g g(-1) dry wt, respectively. Zinc levels (49-102 mu g g(-1) dry wt) were at about baseline levels or a little elevated. On the contrary, lead showed very low concentrations, varying from 0.1 to 0.6 mu g g(-1) dry wt. Other species generally showed the same pattern. [KEYWORDS: North-atlantic; trace-metals; indian-ocean; east java; hongkong; cu; zn; cd; cadmium; copper] In surface sediments, a statistically significant increase was measured in the concentration of copper and cadmium along all transects, and of zinc along only the most southern (Gazi) transect, radiating into the Indian Ocean perpendicular to the Kenyan coast, Mean copper and cadmium increased from 5 to 30 mu g g(-1) dry wt and from 0.01 to 0.34 mu g g(-1) dry wt in shallow coastal (+/-20 m depth) to deep-sea stations (+/-2000 m depth), respectively. These gradients were found both during the south-east monsoon and north-east monsoon period, The shallow estuarine zone of the Sabaki river mouth showed significantly enhanced levels of total organic carbon and nitrogen and all metals analysed, except cadmium. In crustaceans, the concentration of copper and particularly cadmium was ...