Your sentence is mostly clear, but it can be improved for better grammar and flow. Here's a corrected version:
Seabirds eat fish and always follow fish schools around the sea. You can also find them on land, where they group together to nest and better defend their babies from predators.
Explanation:
- Added "and" between "eat fish" and "always follow" to connect the two actions clearly.
- Inserted a comma after "land" to separate the clause describing where they group.
- Added "together" after "group" to make the meaning clearer.
- Kept the rest of your sentence because it explains well why seabirds gather on land.
This small correction helps your sentence sound natural and easy to understand.