I am attempting to find a childhood favorite for my brother. We were both born in the mid 60s so I suspect his book is from the early 70s. I don’t remember the title but it was an illustrated book about sea creatures. It was very ‘Boys Life’ in its design: realistic illustrations and high drama. The only specific memory I have is an illustration of a fisherman stepping on a deadly stone fish and being supported and carried away by his fishing buddies. I know it’s not much to go on. Good luck!
Could it be Animals of the Sea by Millicent Selsam?