Some seas in Europe are in a very bad condition, according to a three year survey by more than 100 experts.
The scientists say that things like too much fishing and pollution created by farming are make the seas get worse as years go by.
The situation will increase unless action is taken to slow down pollution and things like putting lots of buildings near coastal areas.
Experts looked at four seas - Atlantic, Baltic, Black and Mediterranean.
They said that the north east Atlantic Ocean, which is west of Scotland, is home to less birds because there is too much fishing in the area.
The birds leave the seas or die because there is not enough fish for them to eat, say the scientists.
The four seas which experts studied