THE world’s oldest aquarium is building new tanks as part of a major refurbishment and big surprises are promised for customers.

Sea Life Brighton will spend £2.6 million on renovating the 146-year-old building with new developments to be unveiled at a grand opening in the spring.

Max Leviston, general manager at the aquarium, said: “Being the oldest operating aquarium in the world, with Grade II listed heritage, we have a responsibility to the building and the safety of our visitors, staff and creatures to ensure structural integrity is maintained.”

This latest development is the fourth phase of refurbishment at the attraction.

It will include a remodelling of the venue’s ocean display and the building of new quarantine tanks.

When this phase is complete, the building will have had £7.5 million spent on it since 2012.

Some areas of the aquarium will be closed as these works are completed.

Mr Leviston said: “Although the auditorium and ocean display are currently closed there is still plenty to see and enjoy with over 55 displays and 3,500 creatures.

“By way of apology for the minor disruption, we are currently offering everyone that visits between now and the grand opening the chance to return free of charge next year when we reopen.”

The building was designed and engineered by architect Eugenius Birch, who also designed Brighton’s West Pier, between 1869 and 1872.

It has been used for many different activities during its history.

It has previously played host to penguins, chimpanzees and bears as well as being used as a car museum, ballroom and, most recently, a dolphinarium.

The aquarium contained the dolphinarium from 1968 but Misty and her friends were released back into the wild when Sea Life took over in 1991.

Mr Leviston said: “The final phase will provide us the opportunity to re-theme our ocean display that many of our previous visitors may remember as the dolphinarium prior to 1990.

“Although we are not creating any new displays we will be keeping you in suspense until next year before we announce some magical new additions to the Sea Life experience that we know will be enjoyed by everyone when we open for Easter 2019.”