Captain Robert "RT" Trosset stared intently at his video sounder as we idled toward the stern of an anchored shrimp boat some 45 miles northwest of Key West in the Gulf of Mexico. The shrimpers had trawled all night and recently finished separating the harvested shrimp from the other critters scooped up in the giant nets - what scientists call "bycatch" but fishermen call "shrimp boat trash."
The shrimpers shovel the trash overboard around daybreak, and predators move in to feast upon the thousands of small fish and crustaceans that are thus disposed of. This creates an incredible fishing opportunity for blackfin tuna, little tunny (what we Floridians call "bonito") and cobia. The trash makes it all happen, and so each day starts with the purchase of a bag or two from an anchored boat. The shrimpers know that fishermen want the trash to attract tuna, so they save some to sell in the hopes of picking up an extra buck or two.
Trosset had purchased two large bags of trash from one of the shrimpers the day before, so now we searched for the fish. As we approached the stern of the first boat, a large red orb appeared on the video screen, and Trosset said, "We've got company." He turned off the engines on his 34-foot Yellowfin, Spindrift, and began throwing a few pieces of the trash overboard to see what might show up from below.
It didn't take long to find out. Hordes of little tunny swarmed around the boat, their telltale green backs flashing in the clear Gulf water. We only spent a few minutes there and ultimately decided that we needed to move; bonitos are fine sport on light tackle, but we had come in search of blackfin, and they simply weren't appearing beneath this particular shrimp boat.
Invest Bait Wisely
"We don't want to waste our bait here," Trosset said. "You don't want to invest all of your bait on bonitos. You need 60 to 70 pounds of trash for bait, and you can go through it quickly if you're not careful." Fortunately, seven more shrimp boats lay at anchor, spread out over several square miles of the Gulf. We moved to the closest one and repeated the process.
This time, our drift and Trosset's chumming produced bonitos at first, but then a large black shape came streaking through the chum. "That's what we're looking for," Trosset said, and we set up to fish. My wife, Poppy, and I each grabbed stout spinning rods rigged with 30-pound braided line and 30-pound fluorocarbon leader tied to circle hooks. We baited with dead fish, carefully selected from the bag of trash, and awaited instructions.
"The key to catching blackfins and not bonitos is to throw just enough trash to keep them interested without getting the bonitos too fired up," Trosset explained. "If the bonitos get into a feeding frenzy, they will crowd out the blackfins and you'll never get one." He went on to explain that as we drifted farther from the shrimp boat, we would draw the fish away with us as they followed the chummed trash. With just the right amount of trash tossed overboard, the bonitos would eventually fall off, and the blackfins would remain.
When we began seeing more black backs than green ones in the water, Poppy and I cast our baits and stared into the depths below to see what would come. I hooked up first, a large bonito that came streaking out from under the boat. My reflexes were too slow to get the bait away from the fish as I saw it coming, but the 15-pounder put up a great fight and was released quickly.
Poppy did better: A large black shape engulfed her bait and headed straight down as the rod bent over hard. "That's a nice fish," Trosset said, a fact made obvious by the amount of braid screaming off the reel. Blackfin put up a terrific fight, and Poppy strained to lift the fish from the depths, but she soon had it boat-side, where Trosset gaffed it and swung it aboard. Our first blackfin of the day, a beauty that weighed in at 31 pounds! Fifteen-pound bonito are fun, but a 31-pound blackfin is awesome, and tasty too.
We repeated the process again and again during a hard morning of fishing, working from one shrimp boat to another, and we ended up catching nine blackfin, the smallest of which weighed 24 pounds. We also caught and released a dozen or more bonitos, including a few on fly rods. This light-tackle action went on nonstop until shortly after noon, when the fish faded away and we could no longer raise them. Just as well: A morning of pulling on strong fighters like these is enough.
Shrimpers move to the southern Gulf in late winter, north of Key West, and spring finds the tunas following them. Find the anchored shrimpers in May, and you'll undoubtedly find plenty of light-tackle action.
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