Effects of seasonal and interannual events on satellite-derived phytoplankton biomass and production in the southernmost part of the California Current System during 2003–2016

Impacts of the 2014–2015 Warm‐Water Anomalies on Nutrients, Chlorophyll‐a and Hydrographic Conditions in the Coastal Zone of Northern Baja California

“…Comparatively with the mean Chl-a levels recorded during 2008-2015, Chl-a anomalies reported here represent a decrease of 19%-23% (upwelling season) and 23%-55% (2014-HW -El Niño), indicating that phytoplankton community was significantly affected during the presence of anomalously warm waters that arrived at the coast of nBC (Table 1). These results are consistent and complement previous studies that have reported decreased Chl-a content in the coastal and open ocean of Southern California (Gómez-Ocampo et al, 2018;Kahru et al, 2018) and Baja California under the 2014-HW and El Niño conditions (Gonzalez-Silvera et al, 2020;Gómez-Ocampo et al, 2017;Jiménez-Quiroz et al, 2019;Mirabal-Gómez et al, 2017;Ortiz-Ahumada et al, 2018). Our analysis indicates that the reduction of Chl-a concentration over the 2014-2015 period, rather than being directly affected by the anomalously high temperatures, was closely linked to the strong stratification promoted by the warm waters during the 2014-HW and El Niño (Figures 4c, 5g, and 5h;Gómez-Ocampo et al, 2017, 2018Gonzalez-Silvera et al, 2020), as well as reduced upwelling in spring-summer of 2015 (Figure 4b; Jiménez-Quiroz et al, 2019;Robinson, 2016).…”