In the wake of an increase in Mexican immigrants discovered having drowned while trying to cross into South Texas, The U.S. Border Patrol has expanded its search-and-rescue teams to better monitor the area.

Last month four men and a woman were found floating dead near a muddy bank on the Mexican side of the river.

Raul L. Ortiz, deputy chief of the Rio Grande Valley sector, spoke of the immigrants choosing more dangerous methods of entering the U.S., saying, "The canals and areas of the river they are trying to traverse, they typically weren't trying to go across before."

Although illegal crossings into South Texas have decreased overall since from last summer, when there was a historic surge of immigrant women and children crossing into South Texas, the number of deaths due to drowning in the Rio Grande have increased. One 320-mile sector has seen at least 16 drownings in six months, just five short of the total from late 2013 to September of last year, when crossings were at their latest peak.

As more law enforcement officials are patrolling the border in order to stop a similar wave of immigrants, people are increasingly trying to cross in remote and dangerous sections of the river to avoid detection. A high number of the corpses have recently been discovered southwest of Mission, Texas.

The city's fire department dive-and-rescue team has, in the months of January and February alone, recovered at least six bodies from the canals.

As reported by The Associated Press, Mission Fire Chief Rene Lopez Jr. spoke about the frequency of finding corpses in the canals, saying that what used to be a once a month occurrence is now happening once a week.

In an effort to provide aide to the area, the Border Patrol has transferred eight members of an elite rescue unit of agents trained in swift-water rescues, emergency medicine, tracking and diving, from El Paso to the Rio Grande Valley.

This brings the total number of rescue unit agents on the scene to 30.

Regardless of the efforts, experts believe the extra resources can only do so much to prevent immigrant drownings in the Rio Grande.

Nestor Rodriguez, a University of Texas at Austin sociology professor who has published a study that found drowning was the most common cause of migrant deaths, says the kind of death that the immigrants are experiencing is “not like slow dying in the desert or in the prairies of South Texas."

Rodriguez cautions that a “drowning happens in a minute or two and it's much more difficult to save someone."