The Sea Warriors

In the ocean’s war against the humans who have caused so much damage, Kimo Pohaku leads a corps of transformed hybrids who are part human and part sea creature. Calling themselves the Sea Warriors, they can command dangerous aquatic creatures against human activities in Hawaiian waters, creating a massive strike back against human abuses in the ocean. But when the government takes violent reaction against the demonstrations, the confrontation escalates into war.

Book 2 in The Ocean Cycle by Brian Herbert & Jan Herbert.