Lead, chromium, nickel, copper and zinc levels in Sargassum species reached the coasts of Dominican Republic during 2019: A preliminary evaluation for the use of algal biomass as fertilizer and animal feeding

Resumen

The repetitive invasive episodes of Sargassum natans and Sargassum fluitans on the Caribbean coasts during the last years have become a first-order problem threatening tourism, fishing, and local fauna. New massive seaweed arrivals are nowadays expected and could be considered in the near future a normal event, with its associated problems. Appropriate solutions, taking advantage of algal biomass, are necessary to overcome this problem. Due to the well-known ability of these algae to accumulate heavy metals, applications related to animal feeding and agriculture must necessarily be preceded by chemical analysis that guarantees the harmlessness of the algal material. In this research, the contents of lead (Pb), chromium (Cr), nickel (Ni), copper (Cu), cadmium (Cd) and the less toxic zinc (Zn) in S. natans and S. fluitans arrived in the dominican coast during 2019 were analyzed, by using flame atomic absorption spectroscopy (FAAS). The results showed significant levels of copper, although the concentration of all detected metals were within the normal values, reflecting the safety of the algal material as far as these metals are concerned, for use as fertilizers and animal feed. No significant differences in the contents of these elements were found between both species.