This is a rating/review of the series overall. 
First of all, the artwork was the selling point for me on this series and still at the end it's my favourite part. It's really phenomenal and being a marine biologist I was sucked in by the depictions of marine creatures and ocean imagery. Highly recommend on that alone.
As for the story, I found it had a lot of depth and I really enjoyed the characters introduced along the way. I loved the weaving in of the marine science points. I think I didn't grasp all the ideas presented within the series but I appreciate the overall message of interconnectedness.
It's a really heartfelt and meaningful series, illustrated spectacularly.