There's a lot more to chumming than a load of ground-up or cut pieces of fish or shellfish tossed over the transom. In many ways it's an art.
by Bob Stearns
While it is true that there isn't a gamefish in the sea that won't respond to chumming, if you don't do it right, you very likely won't get the results you have in mind.
First, you need motion–something to take your chum to the fish. If you're fishing from a fixed location, like a pier, seawall, jetty, or an anchored boat, the key element in chumming is current. There must be enough water movement to carry the scent and food particles a good distance (except when you're trying to bring fish straight up from the bottom). If there is no current, you're better off chumming from a drifting boat, where a scent trail is left by the boat's motion.
Yum, Yum-Pick Your Chum
Chum comes in many forms, from fresh to frozen to dried. The most common ingredients include fish, shellfish, squid, and oil.
To attract fish from a distance or from deep water, fresh-cut chunksof chum are hard to beat. The process, called chunking, involves using a small amount of frozen or dried chum as a starter to attract baitfish, which are then caught, cut up, and immediately tossed overboard. This attracts even more baitfish, creating a mix of fresh-cut chum scent and a big school of baitfish. Reef and blue-water species simply cannot ignore the abundance of food. Chunking works especially well on the tunas, but I've also seen wahoo, king mackerel, sailfish, marlin, and dolphinfish lured by this technique.
With fresh chum, it's good to use a variety of ingredients. By-catch from commercial shrimp trawlers is a fine example. Usually the only way to get this is from a shrimp boat that's cleaning its nets; if you're willing to buy or barter, you're usually welcome. While you're checking out the shrimp boats, remember that even the heads from shrimp that have been cleaned dockside make great chum, although they spoil very rapidly if not kept on ice.
Live chum, including small baitfish partially crippled by bouncing them off the transom, works best when the gamefish you're after have already been attracted to the vicinity by other means–by the smell of dried or frozen chum, or by slow-trolling with a live baitfish until the first fish is hooked. It is important for the gamefish to be close enough to see the crippled baitfish hitting the water. This works best with aggressive species like bluefish, the mackerels, and billfish.
Frozen and Canned
Frozen chum typically consists of fish and shellfish that have been ground into small pieces and frozen in blocks weighing several pounds apiece. You can make your own or buy it in bait shops. Put the frozen block inside a nylon-mesh laundry bag, and hang it in the water. As the block thaws, the food particles drift away with the current. You can shake the bag to release chum a little faster. A block will usually last several hours, even in warm water. Some anglers add a little bunker oil to the mix to create a stronger scent trail.
You can even find chum on supermarket shelves. I often use cheap canned tuna or fish-flavored cat food, mixed with bread and bunker oil. Form the mixture into golf ballĖsized chunks, and toss them overboard at regular intervals. To make them sink faster, add a little sand to the mix. It's a great way to attract baitfish and gamefish.
When and Where
Essentially, you need to chum in a location where tide or current will broadcast the scent over the target zone where you expect to find fish. Anchor up-current from a channel, reef, or other structure where you think the fish may be holding–far enough away for the chum to be able to sink as deep as necessary by the time it gets there. The stronger the current, the farther upstream you need to be.
Current flow most frequently depends upon the tide. Be sure to use tides to your advantage. You may have to re-anchor as the current increases or decreases during the tidal cycle. Slack water is usually a poor choice because the chum doesn't spread far enough to attract fish.
Some species, like snappers, are easiest to attract at night, but as a general rule the morning is always a good time to chum. For others, like the mackerels, bluefish, and tunas, almost any time of the day is good if conditions are right.
You may be in the right place with the right chum, but if you don't dispense it efficiently, you're just wasting time. For example, use too much chum at once, and you'll send all the fish chasing a big mass of the stuff downcurrent. Or they will hang so far back that you'll never even know they are there. On the other hand, if you're too stingy with chum, fish may never show up at all.
The best approach is to start slowly. Gradually increase the flow until you start to get the desired results. When chunking, remember that as a rule the bigger the fish you want to catch, the bigger the edible pieces must be; scent alone may bring bait and panfish on the run, but the big boys usually want something they can chew on. In shallow water, like a bonefish flat, small pieces of fresh-cut shrimp, for example, serve as both scent and edible tidbits.
No matter which type of chum you use, it can unquestionably improve your success. Without using chum to bring them to your vicinity, catching pelagic species like the tunas, king mackerel, and other far-roaming fish on flies or lures would be an exhausting process with a huge number of casts per strike. And it's exciting to watch yellowfin tuna slow from their normal supersonic speed to a bare crawl when they get a taste of chum. Once big pelagic or reef species fall into a rhythm of taking chunks of fresh chum, the substitution of a fly or lure at some point almost always gets dramatic results.