Here we go again - another media hit on the dangers of fish consumption due to the possible threat that mercury may have on pregnant women.

A segment on the Dec. 30 "NBC Nightly News" warned viewers to exercise caution when consuming fish because of the potential side effects it may have on newborn children.

"There's no question that fish is healthy," NBC chief science correspondent Robert Bazell said. "But toxic mercury, mostly from coal-fired power plants makes it way into the ocean, where it can end up in the meat of certain fish."

Bazell's report even singled out certain fish that were deemed unsafe and those that were considered safe for viewers.

"So the key is knowing which fish is safest," Bazell said. "Those with high levels of mercury include swordfish, king mackerel and tile fish. Seafood with low levels of mercury include salmon, cod, shrimp, trout and most small fish."