There are plenty of birds out there in the sea, like the Seagull, The Little Auk, Shags, Razorbills, and the Osprey. All are fish eaters, and great hunters. They don't really seem to care about their eggs, as they can always lay some more.
But, these are the most fascinating sea birds of all time: Puffins. With their striped bill, and the number of fish they can carry in one go, these birds are simply fascinating animals. They can carry about 10 fish in their tremendous bills, and can also eat 1 of them in a single gulp. But here is the weirdest part: Unlike other birds, they nest underground. More like a rabbit. The ground on where they nest is usually undermined with Puffin Burrows.
Another famous, yet common sea bird is the Seagull. They dive into the water, along with Shearwaters, Ospreys, and Little Auks. They drop there eggs carelessly without noticing.
The Osprey doesn't just dive into the water though. It has some of the most incredible eyesight in the Animal World. It can see the fish from above water, then will swoop down and collect it's meal.