Illegal migrants are increasingly turning toward California’s beaches as a pathway to enter the U.S., The Wall Street Journal reported on Saturday.

While illegal migrant crossings at the U.S.-Mexico border have surged under the Biden administration, the number of successful and failed attempts to enter via boat in California has also jumped from 308 in fiscal year 2020 to 736 in fiscal year 2023, according to the WSJ, which cited Customs and Border Protection (CBP). Most of the migrants come through the San Diego area, but many have made their way north to Santa Barbara County.

“The big concern for us is we have absolutely no idea who these people are,” San Diego County Supervisor Jim Desmond told the WSJ. “We have no idea what they are doing. They’re ghosts.”

Federal agents have already mounted over 220,000 arrests in the San Diego area since Oct. 1, as well as nearly 8,000 for illegal entry into the U.S. by sea since 2020, according to the WSJ.

Rafael Fernandez de Castro, director of the Center for U.S.-Mexican Studies at the University of California, San Diego, told the outlet that most of the migrants smuggled into the U.S. by boat are likely Mexicans who had previously been deported or have a criminal history.

“They risk that, if they are seen by police, they will be immediately thrown out or even serve some time in jail,” Fernandez de Castro told the WSJ.

Desmond argued that the blue state is “laying out the red carpet and welcome mat for illegal immigrants to cross the border,” citing a 2017 law that limits when local officers can cooperate with federal immigration partners, the outlet reported.

A spokesperson for Democratic Gov. Gavin Newsom countered that localities may still work with federal authorities relating to serious criminals, and told the WSJ that Congress should pass border security legislation and asylum reform.

Some of the boat smuggling attempts have been captured on video and posted to social media, showing migrants fleeing to awaiting vehicles, according to the outlet.

“It’s becoming more obvious that they don’t care if they are seen,” Britt Mayer, an independent journalist who covers the issue in the San Diego area, told the WSJ.