3 healthy fish to eat more often and 3 to avoid

The Albacore tuna has lower mercury levels compared to other tuna species, but only when it's troll- or pole-caught, as only young fish can be caught this way. When caught in cold northern waters, the Albacore tuna is also very rich in omega-3.

These mollusks aren’t just nutritional and super rich in protein but they are also great for the environment. Oysters can improve water quality by eating nutrients and algae found in water.

This fish is rich in omega-3, vitamin D, and phosphorus. The only con to this fish is that it spoils easily. Mackerels should be properly refrigerated to avoid this. A fresh mackerel should be eaten on the same day it's caught.

This tuna was put on the 10 for 2010 list of threatened species by the World Wildlife Fund back in December 2009. Despite this, one bluefin tuna can be sold for as much as $177,000. The Environmental Defense Fund doesn’t recommend eating this fish.

Bluefin tunas have high levels of mercury as well as high levels of polychlorinated biphenyls (PCB), which can cause developmental and neurological problems in babies and children.

This fish, also called the Patagonian toothfish, is known for its buttery meat. Trawlers and longlines are used to catch the Chilean sea bass, which is really bad for the environment. These methods lead to the damage of the ocean floor and can seriously hurt sea birds.

The Chilean sea bass also has high levels of mercury. Adults can only eat it no more than twice a month. Children aged 12 or younger can only eat it once a month.

The mahi-mahi is also known as the dolphinfish. The Environmental Defense Fund has rated it as one of the least eco-friendly fish. When people fish for mahi-mahi, they unintentionally catch other sea creatures such as sea turtles, sharks, and even sea birds. These animals get caught in the fishing gear.