Natural resources officials said that turtles for the first time were favoring new nesting sites instead of traditional locations such as the sister island of Culebra and the northeast coast, which became a protected area earlier this year.
"It's something we're investigating," Diez said.
The most popular spots this year were beaches in the northern town of Dorado and the southeastern town of Maunabo, with more than 630 nests alone reported there.
As a result, the Department of Natural Resources is pushing to designate those beaches as possible natural reserves or refuges to prohibit deforestation and coastal development and help keep Puerto Rico as a top turtle destination.
"Puerto Rico has the highest number of leatherback turtles in the U.S. and is second in the Caribbean after Trinidad and Tobago," said Carmen Guerrero, natural resources secretary.
The turtles arrive to nest every two years, coming as far away as Canada and northern Europe. They can weigh up to 2,000 pounds (900 kilograms) and can measure up to 7 feet (2 meters) long. An estimated 26,000 to 43,000 female turtles nest annually across the world, down from some 115,000 in 1980.