This book is giving The Meg 2 and Jaws but with a very depressing and emotionally dispondant main character who finally pulls herself together 60% of the way through the story. There's enough marine biology and deep sea intrigue to get your interest peaked and then throw in some conspiracy, but we don't even get that, sadly, until over half way through the book. It was a good story (minus all the dramatics of the main character) but I wanted more! Give me more of the deep sea, more marine biology, more of the conspiracy! 
The book is good, but gives "made for TV movie" vibes... there's a good story it just needs more