Impact of “The Blob” and “El Niño” in the SW Baja California Peninsula: Plankton and Environmental Variability of Bahia Magdalena

Abstract

Warming Effects on a Mexican Coastal Lagoon diatoms. Algal blooms were composed by species adapted to high temperatures and nutrients depletion in 2015, while in 2016 and 2017 were composed by ruderalstrategist species and they were boosted by the nutrient pulses associated with the spring upwellings. The fall algal bloom, typical of subtropical coastal lagoons, was observed only in 2016 and it was confined to the interior of the lagoon where there are local inputs of nutrients. In 2015 and 2016 there was a succession of diatoms and dinoflagellates related to the rising of temperature while in 2017 this pattern changed because of the strong upwellings. The relationships of water temperature and silicate with a ratio of diatoms' cell abundance, was analyzed using generalized additive models (GAMs), showing significant correlations but different trends in some years. The species richness of diatom blooms was high; on the other hand, species diversity increased at the end of spring and early summer. The seasonal pattern of zooplankton biomass showed changes along the 3 years, but the most noticeable was an increase during winter and early spring 2015 and the lack of the usual high values of June-July in 2017. The seasonal pattern of the phytoplankton abundance was different in comparison with the 1982-1983 El Niño while the zooplankton was similar among the three strongest El Niño. The changes we observed strongly suggest that the warming caused by those phenomena highly affected the upwelling strength, the length of the temperate and warm seasons and the hydrology. Phenology of phytoplankton and zooplankton changed after the strong perturbation under the El Niño, and possibly The Blob. The recovery of phytoplankton biomass began in 2017, but its taxonomic composition was not adequate to support the zooplankton recovery.

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

“…Our hydrographic analysis for nearshore waters in nBC clearly shows that, after removing the mean annual cycle, SST anomalies were approximately 2.0°C warmer under the 2014‐HW conditions, decreased through the 2015 upwelling season, and finally, reached values > 2.5°C when El Niño was already present in the coastal zone (Figures 5a and 5b; Table 1). These results are comparable to those previously reported for the southern section of the CCS (e.g., Durazo et al., 2017; Jiménez‐Quiroz et al., 2019; Kahru et al., 2018; Rudnick et al., 2017; Zaba & Rudnick, 2016). Zaba and Rudnick (2016) and Gentemann et al.…”

“…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). Both conditions inhibited the regular upward flux of nutrients to the euphotic zone (Figures 4d, 5e, and 5f; Gonzalez- Silvera et al, 2020;Jacox & Edwards, 2011;Jacox et al, , 2018Marañon et al, 2014Marañon et al, , 2018.…”

“…By the end of 2015, a strong El Niño developed in the eastern equatorial Pacific and a pulse of warm water moved along the coast in the northeastern Pacific, producing extremely high SSTs along the coast of the CCS (Di Lorenzo & Mantua, 2016; Jacox et al., 2016; Rudnick et al., 2017). The highest positive temperature anomalies in the Baja California coast were observed in September 2015, followed by a steep decline to neutral conditions in spring 2016 (Durazo et al., 2017; Gómez‐Ocampo et al., 2017; Jiménez‐Quiroz et al., 2019), raising thus great uncertainty on the potential impacts on the chemical, biological, and oceanographic conditions of coastal waters in the southern boundary of the CCS. Here, we describe and discuss the changes in hydrographic conditions, nutrient concentrations, total chlorophyll‐ a (Chl‐ a ) and size‐structure of the phytoplankton community associated with warmer waters brought to the coastal zone of northern Baja California (nBC) during the sequential occurrence of the 2014‐HW and El Niño over the 2014–2015 period.…”

The Effect of Cold and Warm Anomalies on Phytoplankton Pigment Composition in Waters off the Northern Baja California Peninsula (México): 2007–2016

“…Many of these investigations [14,25,26,28] reported the effect of these warm anomalies on sea surface temperature and phytoplankton biomass from the SCC southern region using information obtained from remote sensors. However, off the Baja California Peninsula, only the work of Linacre et al [30] and Jiménez-Quiróz et al [31] reported results regarding phytoplankton biomass and its taxonomic composition in consideration of field data from the entire water column; however, their work was based on a reduced number of cruises and a short period of time.…”

Fine-tuning heat stress algorithms to optimise global predictions of mass coral bleaching

“…Anthropocene marine heatwaves are becoming increasingly intense, more frequent and longer lasting due to climate change (Oliver et al 2018;Holbrook et al 2019). These anomalous heat stress events can have severe implications for a range of marine biota, e.g., influencing shifts in zooplankton communities, declines in key groups such as krill (Jiménez-Quiroz et al 2019;Evans et al 2020;Işkın et al 2020), die-offs and reproductive failures of sea-birds (Cavole et al 2016;Jones et al 2018;Piatt et al 2020), marine mammal strandings (Cavole et al 2016), and mass coral bleaching and mortality events (Hughes et al 2018). While surveying in situ ecosystem responses to climate change disturbances are essential to assess impact, it is also very costly.…”