In a new study published in the journal Toxins, our research team examined fins and muscle tissue samples from 10 shark species found in the Atlantic and Pacific Oceans for concentrations of two toxins—mercury and β-N-methylamino-L-alanine (BMAA). Recent studies have linked BMAA to neurodegenerative diseases such as Alzheimer’s disease and amyotrophic lateral sclerosis (ALS). We detected concentrations of both mercury and BMAA in the fins and muscles of all shark species at levels that may pose a threat to human health. While both mercury and BMAA by themselves pose a health risk, together they may also have synergistic toxic impacts. Accordingly, we suggest that restricting consumption of sharks can have positive health benefits for consumers and for shark conservation, since several of the sharks analyzed in the study are threatened with extinction due to overfishing. Fins and muscle tissue samples were collected from 10 shark species found in the Atlantic and Pacific Oceans for concentrations of two toxins—mercury and β-N-methylamino-L-alanine (BMAA).
Merly L, Lange L, Meÿer M, Hewitt AM, Koen P, Fischer C, Muller J, Schilack V, Wentzel M, Hammerschlag N. (2019). Blood plasma levels of heavy metals and trace elements in white sharks (Carcharodon carcharias) and potential health consequences. Marine Pollution Bulletin; 142: 85-92.
Matulik AG, Kerstetter DW, Hammerschlag N, Divoll T, Hammerschmidt CR, Evers DC. (2017). Bioaccumulation and biomagnification of mercury and methylmercury in four sympatric coastal sharks in a protected subtropical lagoon. Marine Pollution Bulletin; 116(1): 357-364.
Hammerschlag N, Davis DA, Mondo K, Seely MS, Murch SJ, Glover WB, Divoll T, Evers DC, Mash DC. (2016). Cyanobacterial Neurotoxin BMAA and Mercury in Sharks. Toxins 2016, 8, 238.
Rumbold D, Wasno B, Hammerschlag N, Volety A. (2014). Mercury accumulation in sharks from the coastal waters of Southwest Florida. Archives of Environmental Contamination and Toxicology; DOI 10.1007/s00244-014-0050-6
Mondo K, Hammerschlag N, Basile M, Pablo J, Banack SA, Mash DC. (2012). Cyanobacterial Neurotoxin Î²-N-Methylamino-L-alanine (BMAA) in Shark Fins, Marine Drugs, 10(2), 509-520; doi:10.3390/md10020509
Brand LE, Pablo J, Compton A, Hammerschlag N, Mash DC. (2010). Cyanobacterial Blooms and the Occurrence of the neurotoxin beta-N-methylamino-L-alanine (BMAA) in South Florida Aquatic Food Webs. Harmful Algae 9: 620–635
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