And then, on the last full weekend of July (that's July 25-27 this year), the population booms as if people were seeking sunken treasure.
For all practical purposes, they are. After all, the waters surrounding Grand Isle are as bountiful as any in the "Sportsman's Paradise" of Louisiana.
And like no other event, the International Grand Isle Tarpon Rodeo brings the crowds to this edge of Jefferson Parish by the thousands each summer.
Just how many anglers and angling fans turn up is anyone's guess. Some say 10,000, some say 20,000, some even more. Regardless, it's significantly more than the average weekend on the island.
There's further speculation about exactly how many years the Grand Isle Tarpon Rodeo has been held. It's widely believed the event began in 1928, though in recent years, the number of rodeos that were claimed to have been held exceeded the number of calendar years since 1928.
It's all part of the mystique that makes the International Grand Isle Tarpon Rodeo what it is today.
The first rodeo is said to have included less than a dozen boats and to have been reserved primarily for wealthy New Orleanians. As the event and its competitors grew in diversity, so did the categories of fish eligible to be entered into the tournament.
Today, there are dozens of divisions to enter, including tag-and-release categories and children's divisions.
One thing that has not changed about the rodeo is the fun to be had. Fishing starts at dawn on July 25, 26 and 27. There are contests for the kids, music for all and more food and drink that one could imagine.
And of course, the weigh scales are open all day long, which leaves plenty of opportunity to witness the hoisting of a magnificent catch.
A complete listing of this year's activities is available on the International Grand Isle Tarpon Rodeo website, www.tarponrodeo.org.