The oceans of Earth represent a vast frontier for exploration, and we are only beginning to grasp the level of diversity they hold. Sadly, as we are coming to these revelations, a great portion of that frontier is at risk, under attack from many angles by human demands—overfishing, industry, and even the noise of our expansive movements. One area where our impact is dramatic is on the peculiar and often highly specific mating behaviors of creatures of the sea. In her book, Sex in the Sea, Marah J. Hardt tells the story of those behaviors and brings into focus our neighbors in the vast oceans around us.

It smells like sex. I couldn't shake that somewhat disturbing thought as I floated at the surface, watching the moonlight glisten off the ever-widening slick—the residue of the night's intimacy … That's the thing about sex in the sea. It is at once utterly foreign, yet there are hints of the familiar—but only just. (p. 1)

Sex in the Sea represents a broad exploration of the unique and fantastic mating rituals of ocean dwellers and a powerful call to recognize and take action to protect the oceans and the biodiversity therein. Our understanding of ocean life is being dramatically changed as we learn more about the complex nature of its inhabitants, organisms whose survival hangs in the balance and can be easily tipped by small human actions that interfere with reproductive behaviors. Yet in the telling, Sex in the Sea not only champions ocean conservation but is also delightfully irreverent, comically inappropriate, and so engaging you can hardly put it down. There is truly nothing off limits, as Hardt explores everything from courting behaviors to sex change to orgies of the ocean in this book. I can honestly say that you will never find yourself more engaged and captivated by a book on the sexual habits of ocean life.

The book itself is hilariously divided into acts, literally and figuratively, with segments based on levels of engagement—dating games, sealing the deal (sexual intercourse then sexual outercourse), and post-climax. Throughout each act are chapters filled with playlists to set the mood (representing everything from traditional tunes à la Barry White and Marvin Gaye to Monty Python's The Penis Song); fishy (and other) artwork such as a snapshot of the magazine “Marine Claire” advertising exclusives for “One fishes’ tale—from testes to ovaries and back again,” plus a quiz to determine if you are ready to change sex (p. 69); sea sex trivia questions (did you know snails can ditch and then regrow their penis? p. 99); poetry; and anthropomorphized vignettes about various sea creatures and the soap opera–like sex lives they lead (Mr. Johnson was completely blindsided on p. 84).

To be clear, this would not be a book appropriate in any way for the school-age classroom, but for anyone interested in oceans, fish, conservation, or even for inappropriate stories to share at your next party, this book is truly a joy. I have scarcely had this much fun learning about a topic this far outside my proverbial wheelhouse, but Hardt brings the love stories of the ocean to the reader with a perfect balance of science and hilarity that can't be beat.