Bioaccumulation and biomagnification of mercury and methylmercury in four sympatric coastal sharks in a protected subtropical lagoon

Elevated accumulation of the toxic metal mercury in the Critically Endangered oceanic whitetip shark Carcharhinus longimanus from the northwestern Atlantic Ocean

“…As demonstrated by this study and previous research (Rumbold et al 2014, Matulik et al 2017, O'Bryhim et al 2017, muscle biopsies provide an effective, non-lethal approach for assessing Hg exposure and uptake in sharks and their relatives.…”

“…As Hg accumulation is affected by trophic activity, it may appear surprising that we found no significant relationship between muscle THg concentrations and δ 15 N in Cat Island oceanic whitetip sharks. However, it is important to note that this observation is common in the literature; in fact, out of the sizeable number of studies that have examined intraspecific relationships between Hg accumulation and δ 15 N-derived trophic position in chondrichthyans, only a third (20 out of 60) of these associations were found to be significantly correlated (Domi et al 2005, Endo et al 2009, 2015, Pethybridge et al 2010, Newman et al 2011, Rumbold et al 2014, Teffer et al 2014, Kiszka et al 2015, Kim et al 2016, Matulik et al 2017, Le Bourg et al 2019. No studies to date have presented explanations for the conflicting results observed in these studies (other than low sample size; Pethybridge et al 2010); however, Teffer et al (2014) suggested that a lack of significant relationships between Hg concentrations and δ 15 N in single species (referring specifically to dolphinfish Cory phaena hippurus, yellowfin tuna Thunnus albacares, and albacore tuna T. alalunga) could result from sampling a narrow size range.…”

“…However, whether this is possible remains questionable because many shark species have been shown to accumulate Hg at levels well above the LOAEL without any apparent effects on health or reproduction (e.g. Matulik et al 2017). Given this, it is likely that sharks exhibit higher thresholds for Hg-associated effects than other fishes, especially considering that the LOAEL is largely based on studies of Hg effects in freshwater teleosts.…”

Spatial Variation in Mercury Bioaccumulation and Magnification in a Temperate Estuarine Food Web

“…Trophic magnification factors (TMF) have been increasingly used to quantify the biomagnification of chemicals in the environment, from legacy-type contaminants (e.g., organochlorines) to emerging chemicals of concern, such as pharmaceutical compounds (e.g., Houde et al, 2008;Liu et al, 2017;Matulik et al, 2017). TMF refers to the average rate of change in contaminant concentrations from diet-to consumer along the trophic web, which differs from classic bioaccumulation assessments based on single predator-prey relationships (Borga et al, 2012).…”

Species and correlations between selenium and mercury in fishpond ecosystems

“…However, high aquaculture density, excessive fertilization of fish feed, and weak environmental protection consciousness can easily lead to the deterioration of water quality in ponds, lakes, and neritic mudflats. Although selenium and mercury usually exist at trace or ultratrace levels in most environments, they can still lead to undesirable effects on organisms and human health resulting from their bioaccumulation and biomagnification properties (Arcagni et al., ; Matulik et al., ; Okelsrud, Lydersen, & Fjeld, ). Therefore, the studies on the existing forms, contents, distributions, and correlations between selenium and mercury in aquaculture ecosystems are of great significance.…”