BALTIMORE — For more than two years, the National Aquarium’s seven bottlenose dolphins have been training for a drastic move in 2020 from their home in a Baltimore amphitheater to the nation’s first oceanside sanctuary in Florida or the Caribbean.

Aquarium staff members wear flip-flops and sunglasses around the Pier 4 Marine Mammal Pavilion in hopes of acclimating the highly intelligent mammals to warm-weather sights and sounds.

A 4-foot, fake blue heron named Douglas adorns the dolphins’ tank, mimicking new friends the pod might meet in a wildlife setting.

Some dolphins have even started eating their food directly from the water, instead of being fed by staff members.

However prepared the pod might be for the move, though, National Aquarium chief executive John Racanelli says they will probably have to wait beyond the 2020 target moving date to leave Baltimore, in part because of climate change.

Aquarium officials have reviewed — and vetoed — more than 50 potential sanctuary locations from consideration because of unclean water caused by human development or the threat posed by climate-change-related events such as sea-level rise, rapid seaweed blooms in warming waters and extreme storms.

“It’s all about resiliency and finding sites to withstand whatever is going to happen in terms of climate,” Racanelli said.

In 2016, Racanelli announced plans to build a protected, year-round, seaside refuge in a tropical or semitropical locale so the animals, all of which were born in captivity, could live in a habitat as similar as possible to the wild. The announcement came amid a national debate over the merits of keeping intellectually advanced marine species in captivity.

Racanelli said that he has set a new target move date for the end of 2021, but he added that the search for an appropriate location is still underway and might take longer.

In the Florida Keys, some sites were eliminated from consideration because nearby housing developments emptied septic systems into the waterways and saltwater ponds.

Other sites were too prone to severe blooms of sargassum seaweed, which are becoming increasingly problematic as the ocean warms, Racanelli said.

Islands in the Keys are also close to sea level, meaning buildings would need to be constructed at least one story above ground to withstand rising waters. And in the case of extreme weather, sanctuary staffers will need to have multiple levels of response to hurricanes, including the ability to hunker down on site, Racanelli said.

Climate change should not prevent the dolphins from being relocated, but it does pose challenges, said Janet Mann, director of the Potomac-Chesapeake Dolphin Project. The project studies wild bottlenose dolphins to better understand and protect the migratory species that spends six months a year in the region.

“We’re not going to protect dolphins by taking them all into captivity to protect them from climate change,” Mann said. “These are animals that don’t belong in captivity. They cannot be released into the wild; they would die. So a sanctuary is one possible alternative.”

One of the biggest challenges facing the dolphins is their compromised immune systems, a result of years spent living in a controlled environment. With warming waters, the risk of disease is higher, Mann said.

“It’s the small things in the water you have to worry about, bacteria, small organisms that cause disease, not so much the big ones like sharks,” she said.

With Florida proving to be a less hospitable region in the face of climate change, Racanelli is looking to more mountainous locales, such as Puerto Rico and the U.S. Virgin Islands, for possible sanctuary locations.

Both islands’ status as U.S. territories makes them ideal for maintaining the aquarium’s permit to care for dolphins, which is issued by the National Oceanic and Atmospheric Administration under the Marine Mammal Protection Act of 1972, Racanelli said.

“The primary driver is water quality and suitability of the site for the dolphins; will this provide them with a healthy, safe environment for the rest of their lives?” Racanelli said, adding that the aquarium’s youngest dolphin is about 10 years old and likely to live in the new sanctuary for decades.

The average life span for dolphins in human care is 35 to 40 years, according to aquarium spokeswoman Kimberly Lacomare. NOAA reports the average life span of dolphins in the wild to be 30 to 50 years.

Aquarium officials plan to spend $12 million to $15 million to construct the sanctuary, which will need to stand for 50 years, have a fully equipped veterinary hospital and room for proper food storage, and have the ability to house 20 dolphins. The officials hope the extra space will accommodate rescue dolphins.

“We’re talking about sites that are tens and hundreds of times larger than the tank they live in today,” Racanelli said. “The important thing is they’ll continue to receive the same quality of care.”

— Baltimore Sun