Microzooplankton grazing impact on the phytoplankton community at a coastal upwelling station off northern Baja California, Mexico

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Main Author: Lorena Linacre
Format: Artículo científico
Language:en
Published: Universidad Autónoma de Baja California 2017
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author Lorena Linacre
author_facet Lorena Linacre
contents Microzooplankton grazing impact on the phytoplankton community at a coastal upwelling station off northern Baja California, Mexico Lorena Linacre J. Rubén Lara-Lara Uriel Mirabal-Gómez Reginaldo Durazo Carmen Bazán-Guzmán Ciencias de la Tierra 2016 El Niño 2015 Baja California ENSENADA station microzooplankton grazing Experiments were carried out at a coastal upwelling site (ENSENADA station) off northern Baja California (México) during autumn 2015 (OCT-15) and spring 2016 (APR-16) to estimate phytoplankton daily growth (μo) and mortality (m) rates and to assess microzooplankton grazing impact (m:μo) on the phytoplankton community and specific autotrophic groups. In accordance with regional seasonality and under an environmental warming scenario due to the El Niño 2015–2016 event, significant differences in both hydrographic conditions and the growth–mortality dynamics of the phytoplankton community were observed between the 2 study periods. The μo and m estimates were, respectively, 0.120 ± 0.012 d–1 and 1.145 ± 0.049 d–1 for OCT-15 and 1.186 ± 0.002 d–1 and 0.409 ± 0.086 d–1 for APR-16. The results of this study suggest that the effects of the anomalous warming on the phytoplankton community were more evident in OCT-15. During that period, growth of the larger autotrophic components (diatoms) was severely controlled by the environmental limitation of nutrients caused by the sinking of the thermocline that resulted from the entrance of warm water to the region. Furthermore, microzooplankton exerted active grazing pressure on phytoplankton biomass (72% of chlorophyll a [Chla]) and primary production (PP = 0.20 μg Chla·L–1·d–1), with grazing impact >100% of PP. In APR-16, when the ecosystem apparently started returning to the spring conditions, a high value for PP (3.73 μg Chla·L–1·d–1) was estimated, with only one third of it being consumed by microzooplankton (34% of PP). The results of this research evidence the high dynamism of multivorous food webs coupled to the seasonal and interannual variability of coastal upwelling systems. 2017 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48052086003 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.2 Vol.43
format Artículo científico
id redalyc_48052086003
institution Redalyc
language en
publishDate 2017
publisher Universidad Autónoma de Baja California
spellingShingle Microzooplankton grazing impact on the phytoplankton community at a coastal upwelling station off northern Baja California, Mexico
Lorena Linacre
Ciencias de la Tierra
2016
El Niño 2015
Baja California
ENSENADA station
microzooplankton grazing
Microzooplankton grazing impact on the phytoplankton community at a coastal upwelling station off northern Baja California, Mexico Lorena Linacre J. Rubén Lara-Lara Uriel Mirabal-Gómez Reginaldo Durazo Carmen Bazán-Guzmán Ciencias de la Tierra 2016 El Niño 2015 Baja California ENSENADA station microzooplankton grazing Experiments were carried out at a coastal upwelling site (ENSENADA station) off northern Baja California (México) during autumn 2015 (OCT-15) and spring 2016 (APR-16) to estimate phytoplankton daily growth (μo) and mortality (m) rates and to assess microzooplankton grazing impact (m:μo) on the phytoplankton community and specific autotrophic groups. In accordance with regional seasonality and under an environmental warming scenario due to the El Niño 2015–2016 event, significant differences in both hydrographic conditions and the growth–mortality dynamics of the phytoplankton community were observed between the 2 study periods. The μo and m estimates were, respectively, 0.120 ± 0.012 d–1 and 1.145 ± 0.049 d–1 for OCT-15 and 1.186 ± 0.002 d–1 and 0.409 ± 0.086 d–1 for APR-16. The results of this study suggest that the effects of the anomalous warming on the phytoplankton community were more evident in OCT-15. During that period, growth of the larger autotrophic components (diatoms) was severely controlled by the environmental limitation of nutrients caused by the sinking of the thermocline that resulted from the entrance of warm water to the region. Furthermore, microzooplankton exerted active grazing pressure on phytoplankton biomass (72% of chlorophyll a [Chla]) and primary production (PP = 0.20 μg Chla·L–1·d–1), with grazing impact >100% of PP. In APR-16, when the ecosystem apparently started returning to the spring conditions, a high value for PP (3.73 μg Chla·L–1·d–1) was estimated, with only one third of it being consumed by microzooplankton (34% of PP). The results of this research evidence the high dynamism of multivorous food webs coupled to the seasonal and interannual variability of coastal upwelling systems. 2017 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48052086003 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.2 Vol.43
title Microzooplankton grazing impact on the phytoplankton community at a coastal upwelling station off northern Baja California, Mexico
topic Ciencias de la Tierra
2016
El Niño 2015
Baja California
ENSENADA station
microzooplankton grazing
url https://www.redalyc.org/articulo.oa?id=48052086003