Sea creatures have always survived eating other sea creatures long before Adam ,Eve and sin entered into the world.
Alll land animals were destroyed in the flood except what was preserved in the Ark.
The multitudes of life that existed in the oceans were never destroyed during the flood .They were not condemned.
What did God have against land animals that he wiped all of them out bar Ark survivors and never took any action against sea creatures ?
I hate to see animals suffer for any reason,I was devastated when I had to put my toy poodle dog of 16.5 years down as I was of putting my cat of about 15 years down ,I cried and was heartbroken over these deaths.
Why do they suffer cancer arthritis brain tumours etc.etc IF their was a God.
And for that matter why was Abels sacrifice more acceptable to God than Cains because Abel slaughtered an animal , in my mind Cains sacrifice was more acceptable because it was the fruit of his labour.a grain offering.