I’m a meat eater but draw the line at whales and Dolphins, and I guess apes and monkeys too. My, probably highly flawed, logic is that they have the intelligence to comprehend and understand what’s going on around them so you can’t kill them humanely. I’m all for eating meat, but I do try as best as reasonably possible to only eat meat that’s been well looked after and humanely slaughtered. I don’t believe you could ever do that with Dolphins. Cattle and fish don’t have that level of intelligence and can be easily fooled and slaughtered without stressing them, they act more on instinct.
Having said that I love octopus and squid and they are supposed to be pretty darn clever.