Hi Kasey, We have discussed this many many times and I'm not sure of the answer but do have a theory. Firstly the biggest GT I have ever seen was in the Maldives about 3 years ago. I thought the fish was three GTs swimming together but it turned out to be one massive fish at a guestimate maybe 70kg+. It was huge and swam right under the boat in the middle of calm water next to one of the islands. I almost fell off the boat! But apart from that we have only caught a handful of 35kg+ GTs.
It is definitely not because of overfishing as I have fished places with big GTs and a lot of commercial and subsistence fishing, so there must be another reason. Something that I think might happen, and this is only a wild opinion, is that the Maldives in a big nursery of small resident GT. When the GTs get into the 30kg+ range they migrate up to Lakshadeep islands and then onto Oman and down towards the East Coast of Africa. In the Musandam Oman and Southern Oman we see a small population of resident GTs up to about 15kgs which we can usually find in the same place most trips they are there most of the season and then we get waves of massive GTs coming throughout the season. We will find them arriving at certain points and will move through the area and then disappear again. We can also see that the fishing arriving are new because sometimes they are either all fat or thin or even different colours sometimes.
So I think that the big GTs migrate long distances depending on the season, currents and water temperature but also they will arrive in certain places for fish spawns, turtle nesting, sardine runs etc. So the Maldives small GTs stay close to the safety of the shallow water, atolls and abundant food till they get big enough to cross an ocean and chase bigger prey and not be eaten on the way.
Only a theory! Cheers,
Nick
