Humpbacks don't feed in Hawaiian waters and the young whales feed on their mother's milk from fat laid down thousands of miles from Hawaii.   
The fish that died on Niihau were on the backside of the island, away from Lehua.  Unless there is an undiscovered water "jet" current from Lehua to this part of Niihau, we would need tens or hundreds of tons of  anticoagulant to diffuse away from Lehua in large enough concentrations to have an effect. And the bait wasn't dropped near the shore on Lehua and the helicopter followed a tight GPS guided grid pattern, hardly a "napalm in the morning" approach.

Bosch is entitled to his opinions but he has no facts.  How many young seabirds have died because of rats gnawing them to death since 2009 following his decision to prevent application of diphacione within 100 feet  of the shore. How many deaths will it take until we accept that too many have died? Lehua is a jewel of the aina. Protect it!