Dolphin... the flipper kind!

What does it mean when there is huge schools of porpoise around where you are Tuna fishing. Especially at night. It seems like there is always Tuna there but they are a little harder to catch like the porpoise might disrupt there feeding and they seem like it might scatter the bait obviously because they are being fed on. Just curious if its a good sign or not? Please give me your thoughts.



Also, I have this goal to catch my first blue marlin by the end of the year. Going this weekend overnight and feeling lucky!