How to fix starburst?

Can anyone tell me how I could have taken a better shot,

and how to get the best out of this image in Photoshop?

The photo is from Rottnest Island, Western Australia, latitude 30 S,

temperate climate, visibility 30 feet, depth 30 feet. It is winter here.

This is a school of Silver Drummer (Western Buffalo Bream) Kyphosus cornelii.

They often 'stampede' but this kind of circling is unusual.

I only got one shot before my exhaled air hit them, and they defecated

en masse and scattered ....

Thanks

Adrian