Wild Brown Trout Affected by Historical Mining in the Cévennes National Park, France

Abstract

In the protected area of the Cévennes National Park (Southern France), 114 wild brown trout (Salmo trutta fario) were captured at six locations affected to different extents by historical mining and metallurgy dating from the Iron Age to Modern Times. Cadmium and lead in trout livers and muscles reflect high sediment contamination, although an age-related effect was also detected for hepatic metal concentrations. Lead isotope signatures confirm exposure to drainage from mining and metallurgical waste. Developmental instability, assessed by fluctuating asymmetry, is significantly correlated with cadmium and lead concentrations in trout tissues, suggesting that local contamination may have affected fish development. Nowadays, the area is among the least industrialized in France. However, our results show that 60% of the specimens at one site exceed EU maximum allowed cadmium or lead concentration in foodstuffs. The mining heritage should not be neglected when establishing strategies for long-term environmental management.

Impact of trace metals from past mining on the aquatic ecosystem: A multi-proxy approach in the Morvan (France)

“…Cu and Zn) remain quite comparable. In the Morvan, TM concentrations in sediments do not reach levels reported in a similar study undertaken in the Cévennes (Monna et al, 2011). There, the impact of past mining on wild brown trout was visible in terms of developmental stability and liver metal concentrations.…”

“…This widespread predatory fish is situated at the top of the food web. Studies have already been undertaken on its tissues, providing a basis for comparison (Has-Schön et al, 2008;Monna et al, 2011). Fish liver is generally considered to be one of the best indicators of chronic exposure to TMs, because of its role in the accumulation, transformation and excretion of contaminants .…”

“…Fluctuating asymmetry (FA) was measured on four bilateral traits, and used to quantify stress in wild brown trout (e.g. Sanchez-Galan et al, 1998;Monna et al, 2011). Higher degrees of asymmetry are expected in cases of strong environmental stress during early development (Allenbach, 2011).…”

Regional patterns of heavy metal exposure and contamination in the fish fauna of the Kharaa River basin (Mongolia)

“…It was reported that metal bioaccumulation in fish was only weakly related to metal concentrations in the environment (water and sediment), although nonessential elements (Cd, Hg, Pb) were generally more consistent with environmental peaks than biologically essential ones, with the exception of Cu (Monroy et al 2014). Additionally in France, 60 % of brown trout (Salmo trutta fario) sampled from an historical mining region in the Cévennes National Park exceeded the maximum allowed concentrations for human consumption of Pb and Cd in fish tissue (Monna et al 2011). The heavy metals detected in trout from this study reflected the high content in the river sediment, although age-related effects were also identified as an influential factor determining contamination in fish (Monna et al 2011).…”

“…Additionally in France, 60 % of brown trout (Salmo trutta fario) sampled from an historical mining region in the Cévennes National Park exceeded the maximum allowed concentrations for human consumption of Pb and Cd in fish tissue (Monna et al 2011). The heavy metals detected in trout from this study reflected the high content in the river sediment, although age-related effects were also identified as an influential factor determining contamination in fish (Monna et al 2011). These results highlight the capacity of various heavy metals originating from mining operations to contaminate locally consumed freshwater fish stocks to the point where they potentially pose a health risk to people consuming them, even if the contamination occurred in the past.…”