The Tuna weighed 620-650ish It had about 75 herring in it's stomach. They weigh about 1# ea. The core which is no head, no entrals, the tail removed at the 4th finlet(weighed it at 37# before I removed the pendicle to mount) and finally all fins weighed 509# which is what you would be paid for. This fish was sold or the domestic market andwas less than the worst price you will see in the Wicked Tuna show (it doesn't work like they try to promote on that show)
I would think you have a bait that is prefered like shad or sunfish or even eels. These fish were all caught at night. Although all were between 35 and 41# we had quite afew that went well over that with 52# being biggest landed of my season. These were caught on eels the largest were caught on mackeral and haddock in the first 2 days of the commercial bass season. I usually catch big bass meaning well over 50# while tuna fishing but they are off limits due to regulations in federal waters.
If you have cold water springs that hold bait would be good to explore. Also look at how the dominant wind blows. Picture how the water is being moved. Bait will be pushed that way. Now picture what direction the water gets pushed in a storm out of the NW or NE Look for areas where the water is pushed up a bank or high spot. That will be a key area as the blow starts and will die out as some as the normal conditions return. Prettymuch the same as a hunting situation. Things I notice and talk about in my seminars in this realm. When you have a northerly blow you get a clean and bright sky after. In each and every lunar phase we have this happen. In every case it is a signal to the wildlife as a change in the light. In mid to late July every year we have a northerly right around a particular tournament. The seas are friggin bad to you should have stayed home. This northerly is when the herring that spawned in the spring's fry drop out into the ocean in my area. By being able to identify that change in the light I know that the biggest bass will be in one of 2 areas. Also the largest tuna of the year will also be within a mile of both of those 2 areas as well. It was one of these areas where my 4 largest bass came from this year.
In Mid August the northerly is the day that mature bucks will rub of the velvet up around Mom's house in NH. If I have time and that's a huge if due to fishing I will hit some areas that have big sign post rubs to see if the bucks I know about made it or if some new bucks have matured.
The following northerlies in September signal tuna changing from halfbeaks to herring and mackeral. It is also when the color pink works better than the green or black that has been so dominant during the summer.
You see deer eating in the fields then all of the sudden they switch to something and it takes a week ti figure it out. The food changed because the light changed.
The reason the light changes is this The angle of the sun coming through the atmosphere changes every day. How it works in your area takes some time logging what you see when you have storms that are from a different direction. It might take a couple of seasons however the reward of knowing not guessing what to do has a satisfaction that is hard to put a price on.
Hope that helps