in the southern Gulf of Mexico (Veracruz and Coatzacoalcos) in May regularly traveled northward in late spring and early summer along the Texas coast arriving in Louisiana waters by mid-summer, only to return south in the fall as the cold fronts begin stacking up along with plummeting ocean water temperatures. A similar observation is made in Florida for tarpon that arrive en masse in the Florida Keys with the arrival of the 26 degree Celsius water temperature, usually in March-April. These fish are thought to spawn at the deep shelf edge in late April-May, then depart northward in late May, working northward through Boca Grande, to Apalachicola and then on to the plume of the Mississippi River by mid-July.
Over the past fifteen years, we’ve learned much about tarpon travels and migration. In fact, tarpon migrations can truly be impressive in terms of their physical length, with huge distances covered per day (> 30-50 miles), and as much as 1,500 miles in only a month. In light of that finding, what were once considered “foreign” tarpon populations and not relevant to our national discussion on fishery sustainability, are now believed to be clearly connected to the U.S. fishery. Cuba, Puerto Rico, Nicaragua, and even Trinidad and Columbia may share our domestic tarpon migrations.
Evidence of systemic historical overfishing is apparent in the size structure of tarpon we have tagged over the years. We note that today the average size of tarpon above sexual maturity has been greatly reduced. The relative rarity of tarpon over 200 pounds indicates a potential sustainability problem. Tarpon population declines certainly are at least partly due to over fishing and exploitation of the resource outside the United States is substantial.
But “local” changes in tarpon habitat quality and quantity are very important, too. There are critical, but little studied, principal nursery grounds like those in the Bay of Campeche, the northern Gulf, and even southern Florida. It is very likely that Cuba is very important here, too, and may be a central problem to tarpon declines because of netting and other harvest methods around that island.
Historical data indicates that many years ago tarpon fishing was absolutely excellent along the Texas coast, not far from Mexico. In fact, from the 1930s-1950s Port Aransas, Texas was considered “Tarpon Capital of the World”. While south of the border commercial fishing for tarpon likely is the most insidious culprit for that fishery’s decline, Texas tarpon have other problems, too. (continued next page)
May through July tarpon tagged in Florida showing an unusual southern spring migration. Presumably, the fish traveled south to the Boca Grande area and then offshore to spawn.