An international conference on balancing cruise ship visits with quality of life in historic port cities ended Friday without a breakthrough in Charleston’s ongoing debate but with plenty of ideas about what to do next.

The three-day event brought together more than 150 people from port cities across the globe to discuss air pollution, congestion and other ill effects that ever-larger cruise ships can bring — and what can be done to address them.

The World Monuments Fund and the National Trust for Historic Preservation have expressed their concern about cruise ships’ effects in Charleston, and they helped stage the conference with the Preservation Society of Charleston.

One central theme was that those who are concerned about cruise ships should make more allies.

Author Tony Hiss, whose remarks closed the symposium, said, “To me, it is disquieting and a bit disheartening that the only person of color who has been with us is from Aruba.”

Port cities also were urged to create a network to share information on cruise ships, to lobby high levels of government and the industry itself and to prevent the industry from playing one port city against another at the negotiating table.

Many attendees, including Joseph Geldhof, an Alaska lawyer who authored a cruise ordinance in Juneau, offered encouraging words.

“Your cause is right,” he said, urging Charleston residents to embrace their inner Francis Marion — a Revolutionary War fighter and namesake of the hotel where the symposium was held.

“You all need to get over the fact that you’re characterized as elitist. I would encourage you to embrace it, adopt it,” Geldhof added. “Nobody likes to be called an elitist, but don’t let other folks characterize what you’re doing.”

The S.C. State Ports Authority — which wasn’t invited to speak at the conference and whose officials didn’t attend — released a statement shortly afterward saying its plan to build a new cruise terminal at Charleston’s Union Pier strikes a balance.

Some are pushing to have that terminal located farther up the Cooper River, or at least have a fresh, public study of possible terminal sites.

Charleston Mayor Joe Riley, who has defended the Ports Authority, also was not invited, and a widespread rumor said that Riley also urged the mayor of Mobile, Ala., to cancel his planned appearance here. Mobile is home to a new cruise terminal that’s largely unused.

Charleston spokeswoman Barbara Vaughn denied that, and Barbara Drummond, spokeswoman for Mobile Mayor Sam Jones, said Jones canceled his trip to meet with suppliers to that city’s new Airbus manufacturing plant.

Meanwhile, three separate legal challenges that Charleston residents and preservationists have filed against the Ports Authority, Carnival Cruise Lines and others will continue to wind through the courts.

In the end, Hiss noted, “Communities that argue tend to solve their problems. Silent ones don’t, so you’re well on your way to solving your problems.”

Preservation Society of Charleston Director Evan Thompson added, “The conversation has just started, but it’s our responsibility to keep the conversation going.”

Reach Robert Behre at 937-5771.