Mystic — For the past 13 summers, explorer Bob Ballard and his team of scientists have worked in the Black and Mediterranean seas.

There, they’ve discovered more than 50 ancient shipwrecks and their cargo, explored undersea volcanoes, geological features and marine life, and even found a World War II Italian plane.

But this summer’s expedition aboard the E/V Nautilus, which began Thursday, will be his last in the region, as Ballard said he will now turn his attention to the Caribbean Sea next summer and then to the Pacific and Indian oceans.

“We’ve been very, very successful, but it’s time to move on,” he said. “We’re explorers.”

Ballard, who has found famed wrecks such as the Titanic, Bismarck and PT-109, made the announcement Thursday as he outlined his 65-day summer expedition during a press conference at the Mystic Aquarium, where he heads the Ocean Exploration Center.

Ballard said the main thing that attracted him to the Black Sea was that it is at the crossroads of civilization and it was theorized that the low oxygen content of the deep water there would preserve ancient wooden ships.

“We’ve proven that to be true,” he said, adding that his finds also showed that ancient mariners boldly ventured far out into the ocean and did not stay close to the shoreline, as some historians had thought. He said the expeditions also illustrated the large-scale damage that fish trawling causes to the ocean floor and ancient wrecks.

He said they also were able to alert the Turkish government to the grave danger posed by a massive underwater volcano not far offshore.

Ballard said that later this year in Miami, he will meet with a group of scientists and others to decide what to explore in the Caribbean next summer and fall.

He said some early possible targets are slave ships and ships that cruised the Spanish Main of Belize as well as undersea volcanoes and areas where natural gas seeps up through the ocean floor.

The first stop for the E/V Nautilus this summer was on Thursday, when it began exploring a 2,500-year-old ship that Ballard’s team found in the Black Sea off the coast of Turkey last year. It will then examine two other wrecks in the area before heading east to look for more. In total, Ballard has found 50 ancient wrecks and their cargo in the region. Many of them are well-preserved because of anoxic layers of water.

The ship will then head south into the Aegean and Mediterranean seas and in one area will explore a giant tabletop seamount where Ballard said there is an amazing collection of ancient artifacts. The area also served as a busy ancient trade route between the copper mines of Cyprus and the eastern Nile.

The expedition was delayed for several days as Ballard and his team were asked by the Turkish government to find the wreckage of a Turkish fighter jet shot down by Syria off its coast last month. Using the Nautilus and its remotely operated vehicles, they found the plane and the bodies of its two pilots last week.

Visitors to the aquarium will now be able to watch the expedition live on four large, high-definition screens and talk to scientists aboard the ships in the new Nautilus Live Theater.

That’s where Ballard was on Thursday talking to Chief Scientist Katherine L.C. Bell, who was aboard the Nautilus in the Black Sea.

Video from the ship and the underwater vehicles it uses are transmitted in real time via satellite to the Inner Space Center at the University of Rhode Island and is then transmitted via the Internet. The expedition can also be followed at www.nautiluslive.org.

In addition to the 100 scientists and engineers aboard the Nautilus, there are also teachers and students ranging from middle schoolers to graduate students.

“We’re not only here to do exploration but to turn kids on to science,” said Ballard, who will be aboard the ship this summer. “Our goal is not to sell kids on science but (on being) scientists.”

Some of the scientists who now work with the 70-year-old Ballard were once involved in his Jason Project, which beams interactive expeditions to large numbers of children across North America each year.

j.wojtas@theday.com