Permit 101

“In the mid-1960s if you arrived inside the Marquesas just at dawn it looked like picket fences here the dorsals of sleeping permit and tarpon dotted the quiet lagoon.” This image is from the vivid memory of Lefty Kreh. Every time I read this quote I can feel my blood pressure rise and my casting arm start to tighten, for while my favorite fish on fly is tarpon, permit have cost me many sleepless nights.

My fly fishing relationship with permit is as Don Quixote’s was to windmills. Countless times thought I had the upper hand on permit, only to be knocked off the horse. Call it persistence or thickheadedness, I keep getting back on the horse. Time wasted or time invested, depending on your perspective. Fortunately my other relationship with permit, as a fish ecologist, is a bit more respectable. Back when Lefty scanned the horizon and saw so many permit tails breaking the calm water surface, we knew nothing about permit ecology — where they spawned, where the juveniles live, what they eat, how long they live. In fact, we didn’t know much about their ecology until recently — the first scientific study on permit wasn’t published until 2002, and even now there are less than five scientific articles on permit. Many of you are probably saying so what, those scientific studies won’t help me catch permit, and don’t affect me. But I disagree — knowing your quarry will increase your chances when pursuing them on the water, and the more we know about permit ecology, the better chance we have of making sure they’re around for the next generation of anglers.

I spend much of my research time on the water working on the second item — gathering information that can be applied toward conservation. In this case, we’ve been able to define which habitats are essential to juvenile permit, and how old they are when they first appear. First, a summary of what we know: Permit spawn around reef promontories — either natural reef dropoffs (Caribbean) or artificial reefs (Florida) – near the full moon. In Florida, they spawn during summer months. In the Caribbean, they spawn all but a couple months during winter. They ‘broadcast spawn’ — gathered in large groups, the fish eject eggs and sperm into the open water where the eggs are fertilized. Within a day, the eggs hatch, and the resulting tiny larvae float in the open ocean as plankton. Once the larvae find the right coastal bottom habitat, they transform into miniature versions of their parents, and do their best to grow to adulthood.

Until recently, we didn’t know how long the larvae lived as plankton, or what habitats were required by the juveniles. Thanks to research funding from BTT, we now know this important information. Permit larvae live as plankton for about 15-18 days. We know this because we can examine growth rings in their ear bones (ear bones are called otoliths) that we extract from their inner ear. Fish less than 1 year old have daily rings, and older fish have annual rings — just like a tree. Although we think that many permit larvae that survive (more than 99% die) don’t travel very far, some certainly do. For example, permit larvae spawned in Belize could easily make it to the Florida Keys by traveling on the Loop Current, that starts near the Yucatan Peninsula, and loops through the Gulf of Mexico, ending in the Florida Keys. This type of connectedness is just as likely throughout the Caribbean, so no matter where you are, ‘your’ permit are also likely ‘their’ permit. During our research, we sampled a variety of shallow water habitats in the Florida Keys and Belize to figure out which were most important to juvenile permit. With more than 98% of juvenile permit caught in tne habitat, we can safely conclude that juvenile permit require medium energy sandy beaches — beaches with some wave action. Juveniles of other species seem able to use a variety of habitats, but for juvenile permit it’s very specific — sandy beaches, usually right up in the swash zone.

So why is this important to anglers? First, any conservation and management plan for permit has to become regional. Over-harvest of permit at one location may have negative effects on populations at other locations. Second, since loss and degradation of juvenile habitats can have profound negative effects on fish populations, we must be vigilant about ensuring clean and healthy beaches as juvenile permit habitats. Anglers can have a strong influence in this by becoming active in fish and habitat conservation issues, and by letting lodges know that you care.