Why do dolphins have mercury?

Studies have shown that dolphin meat actually contains very high levels of mercury.  Similar to other types of fish, many health organizations around the world caution people from consuming dolphin meat because of its toxicity.  It is said that the very high levels of mercury in dolphin meat could cause serious illnesses in people.  People’s immune systems will be disrupted and affected if they are exposed to high levels of mercury on a regular basis.  Serious conditions such as neurological effects, hearing and vision problems, and even mental degradation are all associated with mercury poisoning from dolphin meat and other means of exposure.

The basic cause of mercury contamination in dolphins is that they consume food that is already contaminated with this substance.  In terms of the food chain, dolphins are classified as being on the top of their cycle or chain.  This simply means that they are the classified eaters or predators of small- to medium-sized fish.  These fish will then eat smaller organisms and food items including plankton and seaweed, for example.  All these members of the food chain contain some levels of mercury in them, and so when the dolphin eats its regular fish meal, it will have already consumed high levels of mercury.  The plankton and fish themselves already have some mercury in their system, and when they are consumed by dolphins, the natural tendency is that the mercury content will accumulate in the dolphin’s body.  This explains why most dolphins tend to have as much as 5 to 10 times the normal level of mercury in their meat.  With this very high level of mercury poisoning in their meat, health experts usually warn about regular dolphin meat consumption.  This also applies to the meat of sharks and whales who also contain high mercury levels because of their position in the food chain or cycle.