Differences in Methylmercury and Inorganic Mercury Biomagnification in a Tropical Marine Food Web

Abstract

Methylmercury (MeHg), inorganic mercury (Hginorg) and their biomagnification factors (BMF) were evaluated along a non-degraded Brazilian bay food web. Highly significant differences (p < 0.0001) were found between MeHg and Hginorg concentrations among all organisms (microplankton, shrimp, fish and dolphin). MeHg increased with increasing trophic position while Hginorg did not present the same pattern. BMF values for MeHg were higher than 1 for all trophic interactions from source to consumer, indicating that MeHg was transferred more efficiently and biomagnified over the entire web. Only one BMF exceeding one was observed for Hginorg (27) between microplankton and their consumer, planktivorous fish. BMF values for Hginorg were significantly different than those found for MeHg (20) at the base of the food web.

A review of estuarine fish research in South America: what has been achieved and what is the future for sustainability and conservation?

“…In a series of studies in estuaries of Rio de Janeiro (mainly Ilha Grande, and also including Guanabara Bay and the Búzios coast), Seixas et al . () have investigated both selenium and organic methyl mercury accumulation in fishes. They found considerable natural variation ascribed to prevailing environmental conditions.…”

Mercury and selenium status of bottlenose dolphins ( Tursiops truncatus ): A study in stranded animals on the Canary Islands

“…MeHg is strongly neurotoxic , harmful to the kidneys, lungs, the thyroid gland, and the immune system De Guise et al, 1995); it is also teratogenic (Crespo-Lopez et al, 2009) and carcinogenic (Vos et al, 2003;Vos et al, 2000). In the marine environment, MeHg accumulates and biomagnifies along the food chain (Seixas et al, 2014) representing a serious threat, especially to top predators such as humans (Visnjevec et al, 2014) or cetaceans, which are exposed to this metal mainly via the diet (Bennett et al, 2001;Storelli et al, 2005).…”

Mercury and methyl mercury in fishes from Bacajá River (Brazilian Amazon): evidence for bioaccumulation and biomagnification

“…Mercury concentrations in aquatic organisms usually correspond to their position in the food chain (Schmitt et al ., ; Coelho et al ., ; Seixas et al ., ). Here, biomagnification was confirmed by F B results.…”