A review by joarfish
Below the Edge of Darkness: Exploring Light and Life in the Deep Sea by Edith Widder

informative lighthearted medium-paced

3.5

Looking at the negative user reviews for this and other ocean related pop-science books, it seems rather difficult to write one that is appreciated by a wide audience. Most complain about boring and dry scientific explanations, some even claim these books are targeted at STEM graduates. Others feel the science is too shallow and doesn‘t go into enough detail.
I belong to the second camp— but I feel it‘s unfair to fault the book on this. Everyone expects something slightly different from such a book.
That being said, I think it‘s a major shortcoming of this book that it looses cohesion half way through. While in the first part the problems and questions surrounding bioluminescence and the light field are developed in a very fascinating way, the second half cannot keep up this quality. Widder takes us on one expedition after the other, telling anecdotes that are only loosely connected. This has neither heart nor brain, because you won‘t learn much more about bioluminescence or get a deeper sense of her personal and emotional journey— what you‘ll get is a good sense of her career. 
So, I‘ve enjoyed wide parts of this book, especially the first half. But I don‘t care for the mildly interesting anecdotes and would rather she‘d kept a cohesive story about the science of bioluminescence.