How and why tar balls end up on Texas beaches

CORPUS CHRISTI, Texas (KXAN) -- A phenomenon is taking place on Texas' beaches: sticky, black balls of tar.According to the Texas General Land Office (GLO), the tar balls come ashore in the summer due to changes in ocean currents. The balls occur when petroleum, whether arising from naturally occurring oil seeps or from off-shore oil spills, combines with sea water and solids.Tar balls also occur near California, according to the National Oceanic and Atmospheric Administration's Office of Respon