Not just any ol bunker chum... Not the stuff that comes out of the holds of big boats that have been out for a couple days. Reason? Bunkers start to break down almost immediately after dying... You want them twitching when they hit the grinder then blast frozen quick to stop any of that breakdown...
Now... why bunker? Makos in the north east are comming inshore to suppliment certin facets of their diet. High concentrations of these essential oils are found in bunker. Higher yet is the concentration in bluefish that eat the bunker. Bingo! Theres the food of choice.
Now that being food a slick made up of blues isn't natural. But following the scent of what blues are feeding on being bunker is... Now heres where you insert the blues for bait. Looks like they were killed by other sharks or even other blues to keep that natural presentation...
Up much farther north if the bluefish food is macks or even herring that would be my choice but hard to beat bunker...
Bunker chum is my first choice, especially when it is fresh caught with a net and super oily, next comes mackeral chum. The most important thing is fresh chum as opposed to frozen when available, it makes a difference in how it creates a slick. Flash frozen is just as good as fresh, the flash freeze retains the oils that are essential to having a good slick. If you cannot get fresh, you can add bunker oil from a drip tube to help, but make sure it isn't dripping on the boat, it can get really messy and is a pita to get off if it drys. We also use fresh caught bluefish since if we are catching them they are often the fish the sharks are feeding on for the day, but I have done better with them as bait then grinding them up as chum personally.
We also collect and freeze bags of fish blood from our striper trips since we bleed stripers, that blood has worked wonders, and the scales when they flutter in the slick adds a lot of attraction, and what is better then free blood for chum. If we keep bluefish, that blood is added and the fish are scaled as well. We can usually get atleast a 1 gal freezer bag filled, and often 3-5 bags on good days of fishing.