Ecowar — Richard P. Henrick

The Star of Linshu - As it dumps toxic wastes in the waters off Hokkaido, Japan, a monstrous manta ray rises from the depths, rams it amid ship and sinks it to the bottom of the sea. The devilfish has struck again.
The USS Chicago - Dr. Peter Kraft, renowned expert in dolphin communication and training, boards the Los Angeles class attack vessel with orders to investigate strange reports of a marauding sea monster in the depths of the Kuril Trench.
Ecowar - A sleek submarine of stunningly advanced design, it plies the Pacific at speeds that defy pursuit and confound detection. Embarked on an impassioned mission to save sea-life from destruction, Ecowar stands ready to challenge the world's most sophisticated attack subs.