Also, when a Black or Striped Marlin is mildly interested in a slow trolled dead bait or trolled lure but just won’t commit itself, a small free bait thrown out can sometimes be enough to raise the fish’s arousal level and it will finally attack the hooked offering.

The epitome of a little bait going a long way is the case of a chummer on a commercial “lift pole” tuna boat. His job is so important in keeping the school around the boat and in a frenzy that he is the only crewman that is not fishing. Even the cook and engineer both get in the racks with the other fishermen when the action is on. The chummer usually gets an extra share of the profits at the end of the voyage as well because of his value. Again, there is no way the few baits doled out around these boats are feeding every tuna. But the chummer’s goal is to keep the waters active to stimulate that feeding urge we mentioned before. Crewmen will often thrash the water with long poles to add to the commotion. In Australia I saw them employ a large fire hose, spraying the surface water to further excite the fish. There is a deep-seated belief among professional fishermen that if you chum too little the fish will not stay around, and just as importantly, if you chum too much the school will become satisfied and move away. Another reason for not tossing more baits over at any one time is that they will tend to find each other and school up. That seems to lessen the effects over a wider area you are trying to cover.

Another way chum is used is to draw fish from some distance away to the boat. This is the purpose of buckets or bags of ground up fish parts or oils, which create a “slick” that streams out from the boat with the current. Chum buckets can be purchased ready to use or made up personally and kept in the freezer until needed. The slow thawing is another way to have a time-release action, extending the effective life of the bag’s contents. Mako and Thresher shark fishermen in California say that fish will come from more than a mile away when the slick has spread down current. It may take patience, but if you chum them, they will come.

We fished at Bermagui in Southeast Australia several years ago. There they call chum “burley”. A large can with a number of holes on the sides is tied on the swim step and filled with oily baitfish. A mortar-like plunger is pumped up and down occasionally by a crewman to mash some of the fish. The natural rocking of the boat splashes the step in and out of the water, keeping a steady stream of burley drifting astern.

Many times as the fish move closer following a slick, chunks of baitfish are dropped into the slick and then chunk bait on a hook is drifted along with those free-floating pieces. This is intended to arouse initially line-shy fish to be less cautious with the angler’s offerings. Again, the rate and amount of chumming is important because if there are only a few fish out there they can become more sated and turn much more discriminating. At the afore mentioned kelp beds, old, wise, and well fed home guard Yellowtail can be seen daily, swimming around the boat picking up free chum bait but avoiding anything on a hook. It is uncanny how they can tell the difference but when you pull the bait off the hook and throw it away, they are right on it.

And finally, at times certain fish are located by meter or suspected to lie at some depth or near the bottom between feeding cycles. Dropping a small bait down 100 to 300 feet takes a lot of weight, which renders the bait less attractive and more unnatural. With quantities of live chum brailed out, these fish can be aroused and enticed to the surface where lighter line and bait can be very effective.

Well, how much is enough chum to take on your trip? Of course it varies with the species of fish but a rule of thumb might be:

• Billfish
  8 to 10 pieces of hook size fish per angler.  
• Tuna, Sharks
  A five gallon bucket of chunks and one or two chum buckets to establish a slick  
• Tuna, Barracuda, Yellowtail, Bonito
  One scoop of live anchovies or sardine size bait per angler. (Each scoop might consist of 30 to 50 pieces. 
• Dorado
  One scoop per boat of small baits. They can be chunked into Small pieces for when fish are around the boat already. 
• Bottom Fish
  Usually limited to the chum bucket routine as anything live will quickly disperse.