Abstract
Using satellite derived data from 1997–2010, sea surface temperature (SST), chlorophyll a (Chl) and primary productivity (PP) variations are described at different temporal and spatial scales in the Gulf of California. Interannual signals of El Niño (EN) and La Niña (LN) were more evident at the entrance to the gulf. Once EN or LN events were over, there was a delayed response of three to six months for the reestablishment of “normal” phytoplankton activity levels. Phytoplankton response to high concentrations of nutrients due to LN was not immediate. At regional scale, EN significantly decreased the Chl mean with regard to “normal” conditions at the entrance, central gulf, and Midriff Islands region (MIR); however, PP under EN conditions decreased significantly only at the entrance. The increase in Chl and PP due to LN relative to “normal” conditions was significant only at the entrance. SST, Chl, and PP annual signals are the main source of variation, particularly for the central gulf and entrance, but in the MIR, “winter” PP (1.96 g C m–2 d–1) was not significantly different from that of “summer” (1.62 g C m–2 d–1). Highest PP was found in the central gulf and MIR, where inferences of production attributable to new production were estimated at more than 60% of PP. At the gulf entrance, primary productivity was mainly attributable to regenerated production, particularly during summer and autumn.
Highlights
The Gulf of California is one of the most productive oceanic ecosystems ( 300 g C m–2 yr–1) with marked seasonal and interannual variation (Álvarez-Borrego and Lara-Lara 1991, Álvarez-Borrego 2010)
The mean chlorophyll a (Chl) and primary productivity (PP) values presented a gradient along the Gulf of California, with oligotrophic characteristics at the entrance (0.46 mg m–3, 0.92 g C m–2 d–1), mesotrophic conditions in the central gulf (0.83 mg m–3, 1.52 g C m–2 d–1), and eutrophic conditions in the Midriff Islands region (MIR) (1.44 mg m–3, 2.14 g C m–2 d–1)
Our findings indicate that the effects of La Niña (LN) on Chl and PP were more evident at the mouth
Summary
The Gulf of California is one of the most productive oceanic ecosystems ( 300 g C m–2 yr–1) with marked seasonal and interannual variation (Álvarez-Borrego and Lara-Lara 1991, Álvarez-Borrego 2010). La señal interanual más prominente en la región proviene de la secuencia de los fenómenos climatológicos El Niño (EN) y La Niña (LN) (Soto-Mardones et al 1999), los cuales impactan a la biomasa fitoplanctónica (Lara-Lara et al 1984, Valdez-Holguín y Lara-Lara 1987, Ciencias Marinas, Vol 39, No 2, 2013 sea surface temperature (SST) (Soto-Mardones et al 1999, Lavín et al 2003) associated with a decrease in nutrient and chlorophyll a (Chl) concentrations and primary productivity (PP) (Santamaría-del-Ángel et al 1994a, 1994b; EspinosaCarreón and Valdez-Holguín 2007). The decrease in SST, relatively low sea level, and rising of the thermocline associated with LN conditions increase nutrient and PP levels (Dajoz 2002)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
