Thursday, February 16, 2012

Juvenile Tarpon in Los Roques

Here is an interesting exchange between Doug Jeffries (an old friend who joined me in Los Roques last week) and Aaron Adams who is Director of Operations from the Bonefish and Tarpon Trust and a senior scientist at the Mote Marine Lab in St. James City, Florida.
I’ll be posting my Los Roques story and some photos this week, but in the meantime I thought blog members might find this interesting:
Hi Aaron,
Just got back from Los Roques.  We went into a lagoon in the interior of one of the islands and caught juvenile tarpon around 10 - 12 inches long.  Caught snook about the same length.  The guides told us they have seen tarpon up to 12 kilos in there.  Are these [10-12 inch fish] yearlings?  There is no obvious fresh water source into this lagoon.  I thought juvenile tarpon wanted the ability to travel into fresh / brackish water.  Can you tell me anything about these fish?   Thanks,  Doug

I'm not surprised that you found the juveniles. Although commonly in brackish water, it's not required. What is required is backwater - areas that have soft, mucky, out of the way mangrove or marsh habitats. I imagine the lagoon had some of that habitat around its edges. It might also be possible that there is a freshwater spring in there somewhere. I've seen that on some of the islands off the coast of Belize.
The 12" fish were less than1 year old (typically expect tarpon at 1 year to be about 16"), so they were probably spawned last year. If the lagoon is entirely closed off to the ocean, those 12 kilo tarpon are stuck for life. If the lagoon has a connection to the ocean, then I'm not surprised - larger fish often move into backwaters. Even at 12 kilos, still not an adult!  Aaron
Thanks for the quick reply.  The lagoon was exactly was you described - soft mucky bottom that stank of decomposition, especially around the edges.  The middle was firmer, more sandy.  Lots of downed trees and cover.  Floating grass beds along the shore.  There may have been a spring but we didn't see any sign of it.  Did feel cooler water along one channel and I suspect that's were the inlet/outlet comes from.  Scott Heywood hiked farther down that channel than I but the salt marsh mosquitos won that battle and drove him back to the main lagoon.
 So if these fish are less than a year old, their parents must spawn somewhere close to the island, right?  I used to catch similar sized fish as a kid living in the Panama Canal Zone.  We'd ride our bikes out to the drainage canals (muddy, brackish water and throw tiny lead head jigs).  Those canals went directly to Cristobal Bay or the ocean.  But they also got flushed regularly by the heavy rainfall. Doug

Tarpon larval stage can be weeks to months, so they can be local or could be coming from many hundreds of miles away. Aaron

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