Bloom of Cochlodinium polykrikoides (Dinophyceae: Gymnodiniales) in Bahía de La Paz, Gulf of California

► A bloom of Cochlodinium polykrikoides is described at the Bahía de La Paz. ► C. polykrikoides was mainly observed as single cells or chains of two or three cells. ► High densities of C. polykrikoides did not lead to fish die-offs in the bay. ► Summer blooms of C. polykrikoides are related to higher temperature and rainy days.