|Distribution on a NASA SeaWIFS image|
The Atlantic herring (Clupea harengus) is a kind of herring, a fish. It can be found on both sides of the Atlantic. It can grow up to 45cm in length, weighing more than half a kilogram. It is a swarm fish, meaning many fish come together and form a school (or swarm) of fish. Swarms of up to 4 cubic kilometers in size have been measured of atlantic herring, with an eastimated 4 billion individual fish. Like with so many other fishes though, commercial overfishing is posing a problem. Stocks of herring have been collapsing.
Their natural predators are seals, cod, other large fish as well as some kinds of whales. The current reason for the overfishing is the need of the Omega Fatty Acid, which helps increase memory, and brain functions.