Romance! Danger! Hope! And the wildest sex even you can imagine.

In her new book Sex in the Sea, coral reef ecologist Marah J. Hardt dishes on the swinging sex lives of sea creatures, the perils they face from pollution to overfishing, and new hope for keeping the ocean healthy and its residents randy.

For Valentine’s Day Hardt talked to National Geographic about gigantic sperm, courtly lobsters, and why sexually satisfied sea life is good for everyone.

I was at a party when [a woman] said, “I just wish I could be in the body of a guy and know what’s going in their heads!” I said, “Yes, if only we could be parrotfish.” The conversation stopped. I said,