This is the tomalley or tamali, which functions like the liver, pancreas and intestines in the lobster. Many find it delicious to eat. Recently there have been concerns about finding dioxin in tomalley.
According to the Advanced Seafood Handbook “there are no known safety considerations when it comes to eating lobster meat. However, consumers are advised not to eat the tomalley, the light green substance found in the lobster’s carapace.
This is the liver and pancreas, which are thought to accumulate contaminants from the environment.” Much like the liver of other animals, the lobster’s tomalley is the natural filter for contaminants, like dioxins, from entering the system. Finding dioxins in the lobster tomalley is regrettable. However, it is also a reassuring indication of the lobster’s natural defense system at work, keeping the lobster meat wholesome, nutritious and delicious.