VENICE, Italy (AP) - Joined by a video link, Pope John Paul II and the spiritual leader of Orthodox Christians signed a declaration Monday stating that protecting the environment is a "moral and spiritual" duty.

Both the pope and Ecumenical Patriarch Bartholomew I, who was in Venice, have described the declaration as another step in helping bridge the nearly 1,000-year-old rift between the two ancient branches of Christianity.

The signing ended a five-day voyage by Bartholomew around the Adriatic Sea — from poverty-stricken Albania to prosperous Italy.

The frail 82-year-old pope remained at the Vatican and signed the document during a video link-up with Bartholomew at the Palazzo Ducale in Venice.

"We are ... concerned about the negative consequences for humanity and for all creation resulting from the degradation of some basic natural resources such as water, air and land, brought about by an economic and technological progress which does not recognize and take into account its limits," the document said.

"Christians and all other believers have a specific role to play in proclaiming moral values and in educating people in ecological awareness, which is none other than responsibility toward self, toward others, toward creation," the text said.

The text, which does not out outline any binding action, was the first the two religious leaders have signed concerning the environment. However, common declarations between the two are not unusual.

The declaration invites "all men and women of good will" to consider ethical goals in the protection of the environment.

About 250 religious figures, scientists and environmentalists joined the patriarch on the Adriatic trip — his fourth crusade to point out ecological problems. Other trips have taken him to the Aegean and Black Seas and down the Danube River.

The Adriatic faces pollution from raw sewage, herbicides, pesticides and industrial waste which flow into the 420-mile Mediterranean offshoot, surrounded by Italy and the Balkans.

Coastal habitats such as wetlands are gradually being destroyed. "This is a serious and increasing problem with the further development of tourism," said a statement from marine biologists who accompanied Bartholomew.

The conference said the main source of pollution in the Adriatic was the most prosperous nation in the region — Italy.

Apart from pollution flowing from the Po River, a large petrochemical industry near Venice has contaminated seafood and there is no adequate monitoring program for the developing oil industry along the Italian coast, the scientists said.