Biomagnification of Tantalum through Diverse Aquatic Food Webs

Tantalum (Ta) is a technology-critical element (TCE) that is growing in global demand because of its use in electronic and medical devices, capacitors, aircraft, and hybrid cars. Despite its economic relevance, little is known about its environmental concentrations and the trophodynamics of Ta in aquatic food webs have not been studied. Invertebrates and fishes from coastal marine food webs representing different climatic zones in northwestern Chile, western Chilean Patagonia, and the Antarctic Peninsula were sampled and analyzed for Ta. The trophic level (TL) of species was assessed with nitrogen stable isotopes (delta N-15), and carbon stable isotopes (delta C-13) were used to trace energy flow in the food webs. Levels of T-a varied among taxa and sites, with the highest values found in fishes (0.53-44.48 ng g(-1) dry weight) and the lowest values found in invertebrates (0.11-7.80 n ng g(-1) dry weight). The values of (delta C-13) ranged from -11.79 to -25.66 parts per thousand. Ta biomagnified in all four aquatic food webs, with slopes of log Ta versus TL ranging from 0.16 to 0.60. This has important implications as little is known about its potential toxicity and there may be increased demand for TCEs such as Ta in the future.