Lionfish, which are native to the Indo-Pacific, started popping up along the Florida coast in the 1980s. Their appearance can be mostly attributed to aquarium releases, and they have only multiplied.

The city-owned aquarium in Gardner’s Basin finally reopened this week after five years of renovations and repairs.

The festival opens the aquarium up to nighttime visitors, offering sampling from culinary partners and a lionfish filleting demonstration. The event is the culmination of the three-month-long ...