Lee Ehmke had impressive design credentials when he became director and CEO of the Minnesota Zoo in 2000. He had just finished designing the still-lauded Congo Gorilla Forest at the Bronx Zoo.

But he had never led a major zoo.

Fifteen years later, as Ehmke departs to become CEO of the Houston Zoo, colleagues in the industry and at the Minnesota Zoo are lauding his vision and commitment to conservation, state-of-the-art interactive exhibits and a plan that outlines the zoo's future for the next four or five years. His last day is Aug. 11.

"I think this zoo is on a great course," Ehmke said. "It's my baby. I'll be keeping my eye on it."

His tenure has had its trials, among them budget troubles and dolphin deaths, but visitors have been introduced to exotic species such as grizzly bears, penguins and endangered Hawaiian monk seals.

Peter Maritz, chairman of the zoo's board, said the search for a new leader for the 485-acre Apple Valley attraction is expected to begin shortly and he hopes to have someone in place by the start of 2016.

He would like someone with strong skills in fundraising and marketing, he said. But most important is someone who shares the zoo's mission of conservation and is in sync with its strategic plan.

"That's exactly how we keep the zoo relevant in the future," Maritz said. "We're not entertainment, we're not education. We do both of those things but we do [them] with the goal of saving wildlife."

The zoo doesn't plan to open any new permanent exhibits in 2016, but provided the Legislature is on board, there are proposals to launch a major renovation of the snow monkey exhibit and add a meerkat exhibit in 2017. Longer range, the zoo hopes to build an African savanna exhibit, complete with giraffes.

Pain, then turnaround

One of the most public challenges under Ehmke's tenure came with the deaths of six dolphins, including three calves (one stillborn), between 2006 and 2012.

By 2012, there were two left, both on loan from other institutions. The zoo planned to move the dolphins temporarily to other locations while their tanks were resealed because of saltwater damage.

But there was some controversy at the Legislature, which had just put $4 million into the bonding bill to fix those tanks, when Ehmke decided to permanently close the exhibit. He said then that the cost and availability of new dolphins was out of the zoo's reach.

Fewer institutions are keeping dolphins, whales and other marine mammals, Ehmke said last week. Those that do face pressure from animal rights activists and public opinion about whether the intelligent animals should be in captivity.

"That was not the driver for us," he said. "The plain reality is you can't just go out and say I'm going to go get a group of six or seven dolphins and bring them to our zoo. That is not possible now."

Conflict with the state flared again in late 2014 when the zoo faced a $1.5 million budget shortfall — the result of rising costs and declining attendance — and said some exhibits might have to close.

Zoo officials asked for and got a $1.35 million special appropriation from the Legislature. Gov. Mark Dayton said he supported the extra money but was worried zoo officials didn't do a better job budgeting.

"I am very concerned that the zoo board and managers arrived in this predicament, and I expect the Legislature will properly take a close look at its costs, funding and future plans during this session," the governor said in a statement issued at the time.

Seven zoo staff positions were eliminated and other open positions were not filled.

Since then, attendance has rebounded and surpassed projections every month, thanks to nice weather and targeted marketing. The zoo is on pace to attract 1.25 million visitors this year, said Beth Burns, vice president of external relations.

A renovated Discovery Bay reopened in May to showcase the Hawaiian monk seals, jellyfish and an octopus. On Friday, the zoo opened Hanifl Family Wild Woods, a nature-based play area.

"We're much healthier than we were at this time a year ago," Burns said. "That, too, is a testament to Lee's leadership."

Conservation and politics

Rick Barongi, who retired last month as director of the Houston Zoo, and Kevin Bell, president and CEO of Lincoln Park Zoo in Chicago, said zoos must prioritize conservation in order to survive.

Under Ehmke, the Minnesota Zoo has expanded its conservation work on species as varied as black rhinos and butterflies. The zoo helped reintroduce Asian wild horses and trumpeter swans to the wild. Next fall, the zoo and the state Department of Natural Resources plan to release a group of genetically pure bison into Minneopa State Park.

"That is my passion," said Ehmke, who is serving a two-year term as president of the World Association of Zoos and Aquariums.

Both Barongi and Bell praised Ehmke's skill at designing and building exhibits that mimic an animal's natural habitat and help spread the conservation message.

Ehmke said one of the biggest challenges for the new Minnesota Zoo director will be establishing connections at the state Legislature. About one-third of the zoo's $25 million annual budget comes from the state.

"Once [legislators] experience the zoo, once they hear about what we're giving back, they become supportive," he said. "Constant reinforcement is critical."

He's excited about the work ahead in Houston. The zoo there is smaller, but its urban location attracts about 2 million visitors each year and it has an annual budget of about $46 million. The Houston Zoo has also embraced conservation as a mission, he said.

"I think that's why zoos exist … to do what we can to help save animals broadly in nature," Ehmke said.