Red tides along the coasts of Baja California Sur, México (1984 to 2001)

Thirty red tide spots were observed from 1984 to 2001 on both coasts of Baja California Sur. The involved species were: Gonyaulax polygramma, Noctiluca scintillans, Mesodinium rubrum, Akashiwo sanguinea, Scrippsiella trochoidea, Ceratium furca, Prorocentrum mexicanum, and Cylindrotheca closterium. The most frequent species were N. scintillans and M. rubrum. The seawater discolorations by N. scintillans were seen mainly in Bahia Conceptión during Autumn-Winter. The blooms of M. rubrum were recorded in Bahia de La Paz and off Isla Cerralvo during Spring-Summer. The highest concentration of this species was 23,000 cells ml^-1 during April 1994. Toxic species, producers of Paralytic Shellfish Poisoning (PSP) such as Alexandrium catenella, A. molinatum, and Gymnodinium catenatum, and a producer of haemolytic toxin P. mexicanum, were identified for Bahia Concepción and the west coast of the peninsula. However, most proliferations caused no PSP or other officially known public health problems. In this study, only three cases of fish, lobster, and marine bird mortality has been recorded for a coastal lagoon of Baja California Sur. The first was at Laguna San Ignacio and was caused by C. closterium and A. sanguinea. The second fish mortality occured in la Ensenada de La Paz and was related to G. polygramma. The third (jellyfish mortality) was observed during a red tide of M. rubrum occurred in the southern part of the Gulf of California.