SPATIAL AND TEMPORAL VARIATIONS OF PHYTOPLANKTON CHLOROPHYLL-ALPHA AND SUSPENDED PARTICULATE MATTER IN MAYAGAUEZ-BAY, PUERTO-RICO

Monthly measurements of chlorophyll a (Chi-a), suspended particulate m atter (SPM), light penetration and salinity were taken from March 1990 to February 1991. These parameters were sampled at three different tr ansects with respect to the Anasco, Yaguez and Guanajibo river dischar ge in Mayaguez Bay, off the western coast of Puerto Rico. A reduction in salinities occurred at all stations from August to November, and co rresponded with high precipitation and large river discharge. Maximum Chi-a values were registered at inshore stations during the rainy seas on. Maximum values of SPM were recorded in October and November; the m inimum values were found from March to June. The spatial correlation b etween Chi-a and SPM was significantly positive for the entire study p eriod, but the temporal relationship was not significant. The relation ship between Chi-a and SPM may reflect the relationship between nutrie nts and SPM, and the physiological adaptations of phytoplankton to lig ht intensity.