"This study, which took place during the winters of 2008 and 2009, surveyed Prymnesium parvum concentrations in the tidal portion of ten Texas rivers: the Sabine, Trinity, Brazos, Colorado, Lavaca, Guadalupe, Aransas, Nuecus, Arroyo Colorado, and Rio Grande. No P.parvum were found in 2008. That winter proved to be atypical, as the warm, wet weather my have prohibited large-scale inland blooms. In 2009, the typical large inland blooms returned and P.parvum were present at two intertidal locations along the Texas coast, the Arroyo Colorado and the Brazos River. Because the species is primarily an estuarine organism in other parts of the world, there is concern over the possibility of P.parvum entering and blooming in Texas estuaries."