Marine biotoxins and harmful algal blooms in Mexico’s Pacific littoral

Jose L. Ochoa, D.U. Hernández-Becerril, S. Lluch-Cota, B.O. Arredondo-Vega, E. NuñezVázquez, A. Heredia-Tapia, J. Pérez-Linares and R. Alonso-Rodríguez 1 Northwest Center for Biological Research (CIBNOR). Box 128, La Paz, BCS., Mexico 23000. E-mail: [email protected] 2 Institute of Marine Sciences and Limnology, UNAM, Box 70-305, México 04510. Introduction Figure 39 summarizes the locations of harmful algal bloom (HABs) events registered in Mexico during the last 25 years (Ochoa 2002). Despite our efforts, this reflects only part of the actual HAB episodes that occurred along the Mexican coastline in this period. The map was prepared using information collected from over 100 reports of various Mexican researchers describing their observations. These reports are found in different media, sometimes difficult to access (Table 20). Yet, one very important conclusion of the information is that only in a handful of cases has the nature of the toxins, the causative organisms, and/or the implicated ecological and socioeconomic impacts been studied in detail. In these records, very little information is provided about the conditions that triggered the sudden proliferation of noxious microalgal blooms along the Mexican coast. Analyzing the data displayed in Figure 39 and listed in Table 20 together, it can be observed that various reports correspond to the same location. This does not imply that a given “red tide” event was repeatedly reported, rather that such a location was hit several times within the studied period.