Sierra-Beltrán, A. P.1, Lluch-Cota, D. B.2, Lluch-Cota, S. E.2 and Cortés-Altamirano, R.3, Mario Castillo-Chavez4, Carrillo, L.5, Luis Pacas5 and Roxana Viquez6
1Molecular Genetics Laboratory, CIBNOR. P. O. Box 128, La Paz, B. C. S., México. Tel (52) 112 53633 ext 3805, Fax (52) 112 53625 e-mail: asierra@cibnor.mx, 2Climatology Laboratory, CIBNOR. P. O. Box 128, La Paz, B. C. S., México. Tel (52) 112 53633 ext 3770, Fax (52) 112 53625 e-mail: dblluch@cibnor.mx & slluch@cinbor.mx, 3Plankton Laboratory, ICMyL-UNAM, P. O. Box 818, Mazatlán 82040 Sinaloa, México. Tel (52) 69 852845, Fax (52) 69 826133 e-mail: roberto@mar.icmyl.unam.mx, 4Environmental Health Direction, Mexican SSP, Health Ministry. Mariano Escobedo 366, C.P. 11590, D.F. México. Tel: (52) 52 034951 e-mail: castillochavez@hotmail.com, 5Center for Aquaculture Studies. University of Guatemala. Building T14, University City, Zone 12, Guatemala City. Guatemala. Tel: (50) 24 7654795 e-mail: pacas_luis@yahoo.com, 6Marine Biology. Escuela de Ciencias Biológicas. Universidad Nacional. P.O. Box 126-5400, Puntarenas, Costa Rica. Tel: (50) 66 613 022 Fax: (50) 66 613 635 e-mail: roxana@una.ac.cr
Abstract
The Pacific coast of Central and North America have been and still are impacted by the flourishing of microalgal populations known as Harmful Algal Blooms (HABs). The organisms that have caused recent HABs episodes in the region are among others Gymnodinium catenatum, Pyrodinium bahamense var. compressum, and recently Cochlodinium cf. catenatum. In spite of the piling of effects on the human health, the economic activities and the environment, there is still a lack of information available on the subject. The augmented use of coastal zones for human activities is also paralleled by increased awareness of global climate changes. Thus, discriminating whether, anthropogenic or natural phenomena, or both, are the major driving forces is not an easy task. The long-term data sets available for reduced regions, as well as some sporadic observations during notorious blooms, allowed us to make evident major changes in the biodiversity and biogeography of HAB organisms. The number of events, the area covered, the duration and frequency, the number of species blooming and the appearance of not previously reported harmful taxa are among the factors affected. The variable more clearly related to this dynamic phenomena, seems to be sea surface temperature while, up to date is not possible to weight its contribution. The participation of wind force and rain is not fully evaluated to date. The collaborative communication among small budget monitoring activities in the region allowed to "pass the voice" in due case of peaking concentrations of HAB organisms, diminishing the risk of poisoning.