In the northern region of Peru (Tumbes), mangrove forests develop in Puerto Pizarro and in Santuario Nacional Manglares de Tumbes.1 The first site is a highly impacted area due to its high urban, commercial and touristic unregulated development, while the second one corresponds to a better-preserved area due to the regulation of anthropogenic activities. In both, extractive activities of native species like bivalves, fishes and crustaceans for human consumption take place daily.1
Previous research has shown that, thanks to the high retention capacity of fine sediments and organic matter that these ecosystems have, they can accumulate large quantities of heavy metals in such sediments. This accumulation could come from anthropogenic activities (e.g. urban expansion, extractive activities, etc.) and can be influenced by the natural conditions of the system (e.g. geomorphology, stationary hydric regime, etc.). Moreover, this accumulation can be harmful to native bivalve species that inhabit and depend on these sedimentary environments, we consider that metal accumulation capacity can vary depending on the species and habitat.1
In this presentation we review the results of the project1 aimed at determining if the sedimentary environment and seasonal hydric regime are factors controlling heavy metal accumulation in the soft tissue of Anadara commercial species (Anadara tuberculosa, A. similis, A. grandis) collected in ranges of comparable sizes to each other. The muscle and sediment samples are taken from the main “conchales” (high bivalve density extraction areas) located in Puerto Pizarro and Santuario Nacional Manglares de Tumbes during dry and wet seasons. The project is determining whether the hydric regime and sedimentary environment are controlling heavy metal accumulation of these bivalve species. Furthermore, it will provide useful information to acknowledge the “conchales” that present 5x higher metal accumulation inside the mangrove ecosystems. The results could be used to develop management, administration, and conservation plans of hydrobiological resources. In addition, information about total mercury in Penaeus sp., fish, and mangrove sediment from the same areas will be presented.2
References
1. García R., Álvaro Sebastian; Ramos Burga, Gabriel Ernesto. 2022. Acumulación de metales pesados en especies nativas del género Anadara sp. y en sedimentos de los manglares de Tumbes. Repositorio Institucional Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Urb. Ingeniería, S.M.P. Lima - Perú. https://hdl.handle.net/20.500.12866/11450.
2. Total mercury in bass (Centropomus sp), black conch (Anadara tuberculosa), mangrove crab (Ucides occidentales) and sediment in mangroves of Tumbes, Peru. 2024. Manuscript in preparation.