I think the larger amount of damage is done to the marine mammals, sea turtles, and other animals that are sensitive to sound waves.

The real damage isn't from the actual explosion per se, but from the massive sound wave which propagates far from the site underwater[1]. That assessment is discussing explosions much smaller than the one the Navy just did (and is scheduled to do twice again).

I'd like to believe to do something to mitigate the damage, but I don't know what they could possibly do for something this violent.

[1] https://www.doi.gov/sites/doi.gov/files/migrated/deepwaterho...

Based on their lack of carefulness when doing hull cleaning I wouldn’t expect it

they drop pamphlets in the water, of course

Underrated comment.

Hopefully there's a way to scare the whales and other larger ones away prior too.

Yes, making loud noises. Dolphin savers do that by banging steel tubes in the water, so dolphins swim away from the Japanese kill squads.