Its original theme when the park opened was Treasure Island - that's what the shipwreck is doing there. It was kind of a playground - ala Tom Sawyer's Island.
No interest, so they turned it into kind of a zoo. Mostly birds. If you had a park hopper pass, it was a great place to spend an afternoon, but not necessarily worth paying for.
Most of what the provided is now at AK. But many of the birds stayed behind. My guess (although I don't know this) is that Disney is still feeding them. (I saw boats pull up early one morning, my guess is that's what they were doing. Letting the birds starve would be poor PR).
I would odd meant "not necessarily native to Florida."
I'd guess Disney won't develop this space. Its expensive to run anything on an island.