Doctors warn against eating too much fish because of the risk of ingesting mercury, but how does mercury get into fish in the first place?

How Does Mercury Get Into Fish?
http://www.scientificamerican.com/article/how-does-mercury-get-into/
“Mercury in the fish we like to eat is a big problem in the United States and increasingly around the world. Mercury itself is a naturally occurring element that is present throughout the environment and in plants and animals.“

Synthetic coral could remove toxic heavy metals from the ocean
http://www.eurekalert.org/pub_releases/2015-07/e-scc072315.php
“A new material that mimics coral could help remove toxic heavy metals like mercury from the ocean, according to a new study published in the Journal of Colloid and Interface Science.”

Mercury Levels in Commercial Fish and Shellfish
http://www.fda.gov/food/foodborneillnesscontaminants/metals/ucm115644.htm
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