Eli5: If salt is used to cure and preserve food why is ocean water full of bacteria?

Question

Eli5: If salt is used to cure and preserve food why is ocean water full of bacteria?

In: Biology

Answer 1

There’s more salt, by percentage, in the food preserved via salting. 

Like, ten times more. Food preserved solely by wet salting is very salty almost inedible. Food often times is salted and dried (as a serendipitous byproduct of salting) which both work together to reduce the water activity of food. 

As in most things it is the amount of something that makes the poison.