05/18/2026
The brain behind the fish!π§ π
Our tagging data shows some amazing migration behavior detailing where fish go, but what's more spectacular is how bluefin know where to go in what appears to us as a featureless environment - the open ocean. Theories abound for which mechanisms guide them, but for Atlantic bluefin tuna, the mystery remains. Depending on their location in the ocean, they might only be able to see 20 feet in front of them, yet they can traverse 4,000 miles of open water to enter the nine-mile-wide Straits of Gibraltar with the precision of a GPS. For such a large fish, you would think their brain would be larger than it actually is. In fact, the brain of most fish is about 0.05% of its total weight. For reference, the human brain, on average, is 2% relative to body size, which is 40 times more than bluefin. For a 600-pound bluefin, it's about the size of a U.S. dime!
The next time you see one of our bluefin maps, remember the size of the brain that's behind it. For all you fishermen, Walt likes to joke that this is the brain you are up against as you try to pick your tide, your spot, hide your line, and present your bait! Please note an intact brain might look slightly different to this extracted one.