The meaty swimmers deliver a boat load of easily digested premium-quality protein and other nutrients. They provide added flavours during the process of cooking. Undoubtedly, water species give you laudable amounts of protein to keep your muscles well fed, but every fish is not safe to be eaten. The reasons include - they are from unsustainable, overfished, vulnerable and/or badly managed fisheries or they are thrown back dead into the sea when caught whilst trying to catch other fish.
Here are a few fishes that are harmful and dangerous to health
Atlantic Cod: These fishes are native to the stocks on the East Coast. Here, they have just not been managed as well as in Alaska and California. Also, they’re contaminated with mercury and come under the category of endangered species list. Pacific Cods are extremely plentiful. So, you may eat them until Atlantic Cod recovers its population and becomes safe to consume.
Orange Roughy: Orange Roughy lives in deep waters and can live as long as 150 years. They have many years to accumulate mercury and other toxins into their flesh. Regular consumption of these fishes can adversely affect your health. These fishes are not a good source of omega-3 as well if compared to other varieties. It’s wise not to consume them.
长寿鱼：长寿鱼生活在深水中，可以活150年。所以它们肉体内含有多年积累下来的汞和其他有害毒素。经常食用这些鱼类会对你的健康产生负面影响。与其他品种相比，这些鱼的omega - 3脂肪酸并不好。所以不食用长寿鱼是明智的。
Blue fish: There is a higher risk of contamination through dangerous toxins, including PCB’s, pesticides and mercury in this fish. It can also become inferior and toxic from storm run-off, agricultural chemicals and industrial wastes. Also, Blue fish is known to consume natural toxins of some varieties of bacteria and algae and some other types of contamination. It is absolutely unsafe to be consumed.
American Eel: This fish is highly contaminated from both mercury and PCB’s. Mercury can harm nervous system and brain development, especially in young children and developing foetuses. Although it is great in taste, it is often contaminated with water pollution and overharvesting. Choose Atlantic or Pacific caught squid instead of this poisonous and contaminated selection.
Sharks: Sharks eat many smaller fishes. It leads to accumulation of mercury in their body. The high levels of mercury make these fishes terribly dangerous to eat. If consumed regularly, it can lead to blindness, coordination loss and sometimes even death.