Catholic pastoral workers play a crucial role in coming to the aid of "sea slaves" -- fishermen who are held in inhumane conditions on the high seas for what can be years, a US Department of State official said.

The church's longtime ministry with seafarers puts them in a unique position to be among the first to identify victims of trafficking and provide them needed services no one else may be offering, said Kari Johnstone, acting director of the State Department's Office to Monitor and Combat Trafficking in Persons.