The demand for shark fin is the main cause of shark mortality. The major shark fin consumer countries are China, Hong Kong, Japan, Malaysia, Singapore, Taiwan, and South Korea (Soest, 2016).
Shark fin soup can be detrimental to the health of humans. Since sharks are top predators, heavy metals biomagnify along the food chain and lead to high concentrations of contaminants in the species at the top of the food pyramid. Methylmercury (MeHg) is of particular concern because it is readily absorbed in animal and human bodies. MeHg accumulates in the body and can cause severe damage to the nervous system, reproductive and cardiovascular systems.
The main source of MeHg to humans is the consumption of seafood. The most famous example of MeHg exposure is the Minamata incident in Japan between 1932 and 1968, where 27 tons of mercury was discharged from a petrochemical plant into waterways. Consumption of contaminated fish led to severe mercury poisoning in the area, causing numbness in limbs, loss of vision, damage to speech, paralysis, limb deformities, and death. As of 2001, 2,265 victims have been recognized as having Minamata disease, and 1,784 have died. It is estimated that at least 50,000 people were affected, however only 2,265 cases have been certified as mercury poisoning (Kugler, 2019).
Mercury is the third most toxic element after lead and arsenic in the list of most toxic elements by the U.S. Agency for Toxic Substances and Disease Registry (ATSDR, 2020).
In a study done by Laura Garcia Barcia at Florida International University, nine of the most common shark species in the fin trade were sampled for mercury from Hong Kong and China. The species assessed were the Blue Shark, Silky Shark, Blacktip Shark, Scalloped Hammerhead, Smooth Hammerhead, Bull Shark, Shortfin Mako Shark, Great Hammerhead, and Oceanic Whitetip. 267 shark fin trimmings were tested (Barcia, 2020).
It was found that fins from all nine species exceeded mercury limits, with most of the mercury found being in the form of MeHg. Legal limits of mercury are 0.5 parts per million. The highest mercury concentration recorded was from a Great Hammerhead with 55.52 parts per million. According to Barcia, “the mercury levels are super high and, on average, 6 to 10 times higher than what a safe level of mercury would be considered in Hong Kong” (Márquez 2020).
The normal level of mercury in the human body is zero. The metal does not have a specific function in the human body. However, mercury naturally occurs in air, water and soil. All humans are exposed to some level of mercury, but health problems arise when mercury is transformed into methylmercury, where exposure mainly occurs through bioaccumulation of fish and shellfish (when an organism contains higher concentrations of a substance that the surrounding area).
Shark fin soup can be detrimental to the health of humans. Since sharks are top predators, heavy metals biomagnify along the food chain and lead to high concentrations of contaminants in the species at the top of the food pyramid. Methylmercury (MeHg) is of particular concern because it is readily absorbed in animal and human bodies. MeHg accumulates in the body and can cause severe damage to the nervous system, reproductive and cardiovascular systems.
The main source of MeHg to humans is the consumption of seafood. The most famous example of MeHg exposure is the Minamata incident in Japan between 1932 and 1968, where 27 tons of mercury was discharged from a petrochemical plant into waterways. Consumption of contaminated fish led to severe mercury poisoning in the area, causing numbness in limbs, loss of vision, damage to speech, paralysis, limb deformities, and death. As of 2001, 2,265 victims have been recognized as having Minamata disease, and 1,784 have died. It is estimated that at least 50,000 people were affected, however only 2,265 cases have been certified as mercury poisoning (Kugler, 2019).
Mercury is the third most toxic element after lead and arsenic in the list of most toxic elements by the U.S. Agency for Toxic Substances and Disease Registry (ATSDR, 2020).
In a study done by Laura Garcia Barcia at Florida International University, nine of the most common shark species in the fin trade were sampled for mercury from Hong Kong and China. The species assessed were the Blue Shark, Silky Shark, Blacktip Shark, Scalloped Hammerhead, Smooth Hammerhead, Bull Shark, Shortfin Mako Shark, Great Hammerhead, and Oceanic Whitetip. 267 shark fin trimmings were tested (Barcia, 2020).
It was found that fins from all nine species exceeded mercury limits, with most of the mercury found being in the form of MeHg. Legal limits of mercury are 0.5 parts per million. The highest mercury concentration recorded was from a Great Hammerhead with 55.52 parts per million. According to Barcia, “the mercury levels are super high and, on average, 6 to 10 times higher than what a safe level of mercury would be considered in Hong Kong” (Márquez 2020).
The normal level of mercury in the human body is zero. The metal does not have a specific function in the human body. However, mercury naturally occurs in air, water and soil. All humans are exposed to some level of mercury, but health problems arise when mercury is transformed into methylmercury, where exposure mainly occurs through bioaccumulation of fish and shellfish (when an organism contains higher concentrations of a substance that the surrounding area).
Factors that determine whether health effects occur include the type of mercury consumed, the dose, the age of person exposed, the duration of exposure, and the route of exposure.
Fetuses are particularly susceptible to negative developmental effects due to mercury. Exposure in the womb can result from the mother’s consumption of fish and shellfish. The primary health effect is impairment of the growing brain and nervous system (World Health Organization, 2020).
Because of the adverse effects that accompany the consumption of mercury, the United States Environmental Protection Agency (EPA) recommends eating 8 ounces of seafood a week based on a 2,000 calorie diet. Women who are pregnant or breastfeeding should consume around 8-12 ounces of seafood per week, from choices with low mercury content. Children should consume around 4 ounces per week.
Choices to avoid are King Mackerel, Marlin, Orange Roughy, Shark, Swordfish, Tilefish, and Bigeye Tuna (Environmental Protection Agency, 2019).