Mercury content and consumption risk of 8 species threadfin bream (Nemipterus spp.) caught along the Gulf of Thailand

Abstract

Total mercury (T-Hg) was examined in 8 threadfin bream species (Nemipterus spp.) caught in the Gulf of Thailand (GoT). The T-Hg contents ranged from 11.3 to 374 μg kg⁻¹ wet weight, with the lowest in Nemipterus peronii and the highest in Nemipterus nemurus and Nemipterus tambuloides. Accumulation of T-Hg in fish tissue was found to be related to fish size, trophic levels, feeding habits and habitat. Threadfin bream caught in the upper GoT exhibited significantly (p < 0.05) lower T-Hg than those in the middle and lower parts of GoT, which possibly due to local mercury sources e.g., internal anthropogenic activities in the GoT and external from terrestrial input via river discharge. The estimated daily intakes were ranged from 0.03 to 0.07 μg kg⁻¹ bodyweight day⁻¹. All threadfin breams in the GoT have HQ <1. To prevent the associated potential risk, the maximum safe daily consumption is recommended at 95.3 g day⁻¹.