Heavy metal accumulation in and food safety of shark meat from Jeju island, Republic of Korea

Sang Wha Kim,Jeong Woo Kang,Jehyun Cha,Byung Yeop Kim,Yonggab Kim,Hyoun Joong Kim,Saekil Yun,Jin Woo Jun,Taesung Park,Se Chang Park,Byeong Chun Lee,Se Jin Han,Sib Sankar Giri,Cheng Chi,Sang Guen Kim,Jun Kwon,Woo Taek Oh,Seunghee Han,Yi Hu

doi:10.1371/journal.pone.0212410

Abstract

Shark meat is consumed as a food source worldwide, especially in Asian countries. However, since sharks are apex predators in the ocean food chain, they are prone to bioaccumulation of heavy metals. More than 100 million sharks are caught annually for human consumption, and the safety of shark meat cannot be overemphasized. Here, we examined heavy metal concentration in the muscle tissue of 6 shark species including 3 migratory species (Carcharhinus brachyurus, Carcharhinus obscurus, and Isurus oxyrinchus) and 3 local species (Triakis scyllium, Mustelus manazo, and Cephaloscyllium umbratile) from fish markets in Jeju Island, Republic of Korea. The concentrations of 11 heavy metals (Cr, Fe, Cu, Zn, As, Se, Cd, Sn, Sb, Pb, and Hg) and MeHg were analyzed. The result showed that the average concentrations of all metals, except for that of As, were below the regulatory maximum limits of many organizations, including the Codex standard. Hg and MeHg were significantly correlated with body length, body weight, and age, and the concentration of Hg was expected to exceed the limit in C. brachyurus with a body length or weight of over 130 cm or 25 kg, respectively. Our results indicate that shark meat can expose consumers to a high level of As and that copper sharks bigger than the predicted size should be avoided for excessive Hg. Considering these findings, a detailed guideline on consumption of meat of different shark species should be suggested based on further investigation.

Highlights

Shark meat has been used as a food source since the fourth century, and there was a drastic increase in its usage after World War I [1]
In this study, we evaluated the concentrations of heavy metals (Cr, Fe, Cu, Zn, As, Se, Cd, Sn, Sb, Pb, Hg, and MeHg) in six shark species including C. brachyurus captured at Jeju island (C. brachyurus, Carcharhinus obscurus, Isurus oxyrinchus, Triakis scyllium, Mustelus manazo, and Cephaloscyllium umbratile)
Five shark species showed As concentrations that exceeded the regulatory maximum limit, whereas almost all Hg and MeHg concentrations were below the regulatory limits

Summary

Introduction

Shark meat has been used as a food source since the fourth century, and there was a drastic increase in its usage after World War I [1]. World shark capture production and shark meat trade amounts have increased continuously since 1950s, reaching the highest values on records in 2011 [2, 3]. Shark population has decreased due to unregulated shark fishing worldwide [4]. The capture amount has decreased since 2011, the reason is still unclear whether there has been a decrease in demand or a decrease in population [6]. Asian countries accounted for 59% of the global shark trade from 1976 to 2015; this percentage has increased to 63% in the last 15 years [3]

Methods

Results

Discussion

Conclusion