U.S. Coast Guard crews interdicted a lancha and detained four Mexican fishermen allegedly engaged in illegal fishing activity in federal waters off the southern Texas coast, the agency said.

A boat crew from Coast Guard Station South Padre Island, working in coordination with an aircraft from Coast Guard Air Station Corpus Christi, located and stopped the fishing vessel north of the Maritime Boundary Line in the Gulf of Mexico, according to a Coast Guard press release.

The fishermen were detained and transported to Coast Guard Station South Padre Island. Approximately 450 pounds of red snapper, along with fishing gear and equipment, were seized. The individuals were transferred to U.S. Homeland Security Investigations for further processing.

The Coast Guard, which has been cracking down on illegal fishing in the Gulf of Mexico, said it has referred the case to the Department of Justice.

"The Coast Guard will continue to defend our maritime borders, uphold our nation's sovereignty, and ensure that those who threaten the sustainability of our resources are held accountable," the Coast Guard said in a press release.

The interdicted vessel, known as a lancha, is a type of fishing boat commonly used by Mexican fishermen. Measuring 20 to 30 feet in length with a slender design and a single outboard motor, lanchas are capable of high speeds and are often used for illegal fishing in the U.S. Exclusive Economic Zone, according to the Coast Guard.

“The arrest and prosecution of Mexican commercial fisherman [sic] marks a change in policy concerning the protection of U.S. marine resources,” the U.S. Attorney's Office for the Southern District of Texas said in a May press release. “In past instances, authorities would seize the catch and destroy the vessel but release violators back to Mexico. Any commercial fisherman now apprehended in U.S. waters caught violating the Lacey Act face potential fines and imprisonment.”