Belle Isle's koi fish are in the basement, waiting out a 75-year overdue renovation

Belle Isle's koi fish have been moved to the aquarium basement, Planet Detroit reported this week, displaced temporarily by a $10 million HVAC overhaul. The project is the first major infrastructure update to the Belle Isle Aquarium in 75 years.

Aquarium curator Paul Shuert and Belle Isle Conservancy CEO Meagan Elliot confirmed the koi will return to their outdoor pond before the end of 2026. Elliot said the conservancy would like to mark the return with a celebration, similar to the historic Koi Festival.

The koi have been through bigger disruptions. Originally housed at Belle Isle's now-closed zoo, the fish have lived on the island through the aquarium's full seven-year shutdown. The city closed the facility in 2005 due to budget constraints. A group of dedicated volunteers maintained the 1904 building through the closure. The aquarium reopened to the public on September 15, 2012 and has since been operated by the Belle Isle Conservancy, a nonprofit partner to the state park.

The renovation is not requiring the aquarium to close. The facility is expected to remain open to visitors through the construction, which covers the heating and cooling systems, site drainage, and accessibility improvements.

Since reopening in 2012, the conservancy has run the aquarium as a free public resource while managing a building that had not received significant systems work in decades. The $10 million HVAC project addresses that directly.

The Belle Isle Aquarium, at 3 Inselruhe Ave., is the oldest public aquarium in the continental United States. It was designed by Albert Kahn and opened August 18, 1904. The 10,000-square-foot gallery features an arched ceiling covered in green glass tiles, built to evoke the feel of being underwater. The aquarium displays freshwater fish, marine species, and corals.

Belle Isle is a 982-acre island park in the Detroit River, managed by the Michigan Department of Natural Resources. The island is accessible via the MacArthur Bridge from East Grand Boulevard.

The heating and cooling systems had not been substantially updated in 75 years. For a building that houses living fish, climate control is a basic operating requirement. The current project is the first significant investment in those systems since the facility operated under city management, before the 2005 closure.

The koi are in the basement. They have been through worse.