Element concentrations in pelagic Sargassum along the Mexican Caribbean coast in 2018-2019

PeerJ

article

Rosa E. Rodríguez-Martínez¹  Priyadarsi D. Roy²  Nuria Torrescano-Valle³  Nancy Cabanillas-Terán³  Silvia Carrillo-Domínguez⁵  Ligia Collado-Vides⁶  Marta García-Sánchez¹  Brigitta I. van Tussenbroek¹ 

[1] Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México;Instituto de Geología, Universidad Nacional Autónoma de México;El Colegio de la Frontera Sur;CONACYT - El Colegio de la Frontera Sur;Departamento de Nutrición Animal, Instituto Nacional de Ciencias Médicas y Nutrición “Salvador Zubirán”;Department of Biological Sciences and Center for Coastal Oceans Research in the Institute of Environment, Florida International University;Instituto de Ingeniería, Universidad Nacional Autónoma de México

关键词: Sargassum fluitans;    S. natans;    Metal content;    Arsenic;    Caribbean Sea;   

DOI  :  10.7717/peerj.8667

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The massive influx of pelagic Sargassum spp. (sargasso) into the Mexican Caribbean Sea has caused major deterioration of the coastal environment and has affected the tourism industry as well as livelihoods since 2015. Species of Sargassum have high capacity to absorb metals; thus, leachates of sargasso may contribute to contamination by potentially toxic metals when they drain into the sea and into the groundwater when dumped in inadequate land deposits. Valorization of sargasso would contribute to sustainable management; therefore, knowledge on potentially toxic metal content is necessary to define possible uses of the algae. We present concentrations of 28 elements measured using a non-destructive X-ray fluorescence analyzer (XRF) in 63 samples of sargasso collected between August 2018 and June 2019 from eight localities along ∼370 km long coastline of the Mexican Caribbean Sea. The sargasso tissues contained detectable concentrations of Al, As, Ca, Cl, Cu, Fe, K, Mg, Mn, Mo, P, Pb, Rb, S, Si, Sr, Th, U, V, and Zn. The element concentration in sargasso varied on spatial and temporal scales, which likely depended on the previous trajectory of the pelagic masses, and whether these had (or had not) passed through contaminated areas. Total arsenic concentration varied between 24–172 ppm DW, exceeding the maximum limit for seaweed intended as animal fooder (40 ppm DW) in 86% of the samples. For valorization, we recommend analyses of metal contents as a mandatory practice or avoiding uses for nutritional purposes. The high arsenic content is also of concern for environmental contamination of the sea and aquifer.

【 授权许可】

CC BY