The nation’s leading accrediting organization for zoos and aquariums has renewed Honolulu Zoo’s accreditation.

The new elephant exhibit that opened in December was a critical element, the city said. The new home for Mari and Vaigai is 1.5 acres, nine times larger than the previous exhibit. It also contains two 50,000-gallon swimming pools.

The city also increased staffing and improved signage, two areas the Association of Zoos and Aquariums pointed out as deficiencies in a previous inspection.

In March 2011, the organization deferred re-accreditation as inspectors raised concerns that include staff vacancies, exhibit upgrades and lack of directional signage and educational graphics.