is because bioaccumulants are stored in the muscle tissues of fish, and when a predatory fish eats another fish, it assumes the entire body burden of bioaccumulants in the consumed fish. Thus species that are high on the food chain amass body burdens of bioaccumulants that can be ten times higher than the species they consume. This process is called biomagnification. Man-made disasters can cause localised hazards in seafood which may spread widely via piscine food chains. The first occurrence of widespread mercury poisoning in humans occurred this way in the 1950s in Minamata, Japan. Wastewater from a nearby chemical factory released methylmercury that accumulated in fish which were consumed by humans. Severe mercury poisoning is now known as Minamata disease. The 2011 Fukushima Daiichi Nuclear Power Plant disaster and 1947 - 1991 Marshall Islands nuclear bomb testing led to dangerous radionuclide contamination of local sea life which, in the latter case, remained as of 2008. A widely cited study in JAMA which synthesised government and MEDLINE reports, and meta-analyses to evaluate risks from methylmercury, dioxins, and polychlorinated biphenyls to cardiovascular health and links between fish consumption and neurologic outcomes concluded that: "The benefits of modest fish consumption (1-2 servings/wk) outweigh the risks among adults and, excepting a few selected fish species, among women of childbearing age. Avoidance of modest fish consumption due to confusion regarding risks and benefits could result in thousands of excess CHD [congenital heart disease] deaths annually and suboptimal neurodevelopment in children." Mislabelling Due to the wide array of options in the seafood marketplace, seafood is far more susceptible to mislabeling than terrestrial food. There are more than 1,700 species of seafood in the United States' consumer marketplace, 80 - 90% of which are imported and less than 1% of which is tested for fraud. However, more recent research into seafood imports and consumption patterns among consumers in the United States suggests 35%-38% of seafood products are of domestic origin. consumption suggests Estimates of mislabelled seafood in the United States range from 33% in general up to 86% for particular species. Byzantine supply chains, frequent bycatch, brand naming, species substitution, and inaccurate ecolabels all contribute to confusion for the consumer. A 2013 study by Oceana found that one third of seafood sampled from the United States was incorrectly labelled. Snapper and tuna were particularly susceptible to mislabelling, and seafood substitution was the most common type of