Of all the tunas we encounter here in Southern California, few are as hard to catch from a private boat as the bluefin tuna. This in one of the fish that sportboats have a serious advantage targeting, utilizing side scanning sonar and heaps of live bait capacity to chum with. Bluefin can be caught on the troll, but not nearly as easily as yellowfin, albacore or skipjack, so some special techniques must be used to maximize opportunities for these hard fighting exotics.
It all starts with some pre-planning. Sea Surface Temperature charts (SST’s) are vital in all offshore trip planning, and knowing what water your target species lives and feeds in helps. Bluefin like what we would consider the cooler water, from 64 to 68 degrees. Being able to regulate their body temperature allows them to tolerate even cooler waters, but catching them also means finding the bait they are feeding on. For that you’ll need edges or “current breaks.” Armed with a little intel on where bluefin have been caught in the last couple days and a good SST chart, a guy could find the break and have a starting point in mind.
Next and probably most important is bait. Research this ahead of time to find out what receivers have the best bait available. This year live squid has been working excellent, and is a hearty bait that lives well in almost all bait systems. When the fishing is good and near the weekends it may be hard to rely on the bait receiver, so catching your own is another option. A strong, healthy bait makes all the difference when fishing bluefin, and anything less seriously hinders your chances at success.
On a sportboat the trolling rotation is more of a routine than the necessity it is on a private boat. To improve your odds, use lighter leaders to elicit strikes and utilize plugs and spreader bars often not allowed on overnight boats. These trolling lures require some tuning and patience when deploying, but work better than your typical feather on heavy leader. The natural cedar plug works well for bluefin, but will need to be re-rigged on lighter fluorocarbon leader to really shine. Experiment with lure positions long and short to find where the tuna want to bite, and often bluefin will take a trolled jig way back. When a strike occurs be ready to get a live bait in the water as fast as possible, and toss a few baits over as chum.
Use a good pair of binoculars to find signs that the tuna are around and stay in areas with life and clues they are around. Slick spots on the surface of the water tell a tale of fish feeding deep and the oils rising to give away this action. Troll over these and watch the fish finder for tuna marks, and toss a few live baits as chum when you do see meter marks. Watch for birds giving signals of feeding tuna, and look under the birds for boils, splashes or breezing fish. If you see good meter marks or have tuna come up and boil on the chum you have thrown, stop and fish that prime live bait you have. Be patient and do long soaks, as bluefin prefer a bait far from the boat at times.
Finding a kelp can be a great way to catch bluefin. Wind in the trolling outfits and begin a drift up wind of the paddy, throwing chum as you slide by. You may catch yellowtail or dorado closer to the kelp, and maybe even get the tuna to bite. Most often the tuna will bite after you have drifted a ways past the kelp and the yellows have stopped biting. Continue chumming one’s and two’s and be patient. Make sure to have fresh baits on but at the same time leave your bait out as long as its swimming good. If you see boils and/or meter marks, consider starting the boat and just “bumping” it in and out of gear once. This will push the chum hiding under your boat out and to the waiting bluefin, possibly starting the bite you have been waiting for.
30# is a great all around starting point for live bait but don’t be afraid to drop down to 25# or even 20# if you know the fish are around and just can’t get them to bite. If they bite the 30# fine and are hard to land, move up to the 40#, 50# or 60# as needed. Bluefin pull hard, and quality tackle is a must for these bruisers. One secret used by great anglers is the use of small hooks. If a 3/0 hook matches the size of the bait but bites are hard to come by, try a #1 to see if it makes a difference. It usually makes a big difference, and with a quality hook you can still land a high percentage of the fish that bite.
If you are lucky enough to hook and land a bluefin on a private boat, special care should be taken to preserve your catch. Bleed bluefin right after gaffing but cutting the gills and making a cut on either side of the tail. This will drain the blood line along the body and yield more quality meat. You may want to gut the fish and stuff ice into the body cavity, but a good ice chest with plenty of ice mixed with salt water works wonders to cool these warm blooded tuna quickly. When one bite ends and you go looking for the next one, consider filleting your catch between stops and packaging it for the ice box. This will not only give you the absolute best quality table fare when you get home, but a chance to make some fresh sashimi on the way in. Just be sure to have some wasabi and soy sauce on the boat!