Books

These are some of my personal favourite/recommended reads. 

Ocean-related:

Sea Change: A Message of the Oceans by Silvia Earle

The Secret Life of Lobsters by Trevor Corson

Behind the Dolphin Smile by Ric O'Barry

Blue Mind by Wallace J, Nichols

Coral Reefs by Peter Sale

Nature/Conservation:

We are the Weather Makers by Tim Flannery

Silent Spring by Rachel Carson

Fire Country by Victor Steffensen

Others:

The Most Good You Can Do by Peter Singer

Most Good, Least Harm by Zoe Weil

Animal Liberation by Peter Singer