The Colorado River Delta: A high primary productivity ecosystem

The Colorado River Delta: A high primary productivity ecosystem

The construction of major dams in the Colorado River has produced a drastic effect on the amount of fresh water entering the Colorado River Delta. After 1935 there was a dramatic decrease in fresh-water input, causing ecological impacts and a decrease of organisms in the natural habitat. We carried...

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主要な著者: Millán-Nuñez, R, Santamaría-del-Ángel, E, Cajal-Medrano, R, Barocio-León, OA
フォーマット: Online
言語:eng
出版事項: Iniversidad Autónoma de Baja California 1999
オンライン･アクセス:https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/729
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id oai:cienciasmarinas.com.mx:article-729
record_format ojs
institution Ciencias Marinas
collection OJS
language eng
format Online
author Millán-Nuñez, R
Santamaría-del-Ángel, E
Cajal-Medrano, R
Barocio-León, OA
spellingShingle Millán-Nuñez, R
Santamaría-del-Ángel, E
Cajal-Medrano, R
Barocio-León, OA
The Colorado River Delta: A high primary productivity ecosystem
author_facet Millán-Nuñez, R
Santamaría-del-Ángel, E
Cajal-Medrano, R
Barocio-León, OA
author_sort Millán-Nuñez, R
title The Colorado River Delta: A high primary productivity ecosystem
title_short The Colorado River Delta: A high primary productivity ecosystem
title_full The Colorado River Delta: A high primary productivity ecosystem
title_fullStr The Colorado River Delta: A high primary productivity ecosystem
title_full_unstemmed The Colorado River Delta: A high primary productivity ecosystem
title_sort colorado river delta: a high primary productivity ecosystem
description The construction of major dams in the Colorado River has produced a drastic effect on the amount of fresh water entering the Colorado River Delta. After 1935 there was a dramatic decrease in fresh-water input, causing ecological impacts and a decrease of organisms in the natural habitat. We carried out six spatial samplings during a period of no fresh-water inflow to the delta, in June, August and November 1989, and February, April and June 1990; during each sampling, a 24-hour time series was conducted at one station and seawater samples were taken every two hours. Also, in May 1991 we carried out an eight-day time series, taking samples of seawater at 08:00, 12:00 and 16:00 hours. The objective was to estimate phytoplankton abundance, chlorophyll concentration and primary productivity during a period of no fresh-water input. In the spatial distribution, the chlorophyll a concentrations and phytoplankton abundance were higher on the Baja California side than on the Sonora side, with concentrations of 2.6–18.2 mg m–3 and 1.8–12.7 mg m–3 and of 274 and 166 cells mL–1, respectively. In the time series, the dinoflagellates were more abundant than the diatoms. The primary production showed a tendency to decrease from August 1989 to June 1990, with values of 15.0 to 0.5 mgC m–1. The primary productivity values in the time series presented a tendency to increase during the tide transition, reaching values of 76 mgC m–1. The variations of chlorophyll concentration, phytoplankton abundance and primary productivity were strongly influenced by the effects caused by the tidal currents.
publisher Iniversidad Autónoma de Baja California
publishDate 1999
url https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/729
_version_ 1715724003761455104
spelling oai:cienciasmarinas.com.mx:article-7292019-05-16T20:07:48Z The Colorado River Delta: A high primary productivity ecosystem El delta del Río Colorado: Un ecosistema de alta productividad primaria Millán-Nuñez, R Santamaría-del-Ángel, E Cajal-Medrano, R Barocio-León, OA primary productivity phytoplankton chlorophyll Colorado River Delta productividad primaria fitoplancton clorofila delta del Río Colorado The construction of major dams in the Colorado River has produced a drastic effect on the amount of fresh water entering the Colorado River Delta. After 1935 there was a dramatic decrease in fresh-water input, causing ecological impacts and a decrease of organisms in the natural habitat. We carried out six spatial samplings during a period of no fresh-water inflow to the delta, in June, August and November 1989, and February, April and June 1990; during each sampling, a 24-hour time series was conducted at one station and seawater samples were taken every two hours. Also, in May 1991 we carried out an eight-day time series, taking samples of seawater at 08:00, 12:00 and 16:00 hours. The objective was to estimate phytoplankton abundance, chlorophyll concentration and primary productivity during a period of no fresh-water input. In the spatial distribution, the chlorophyll a concentrations and phytoplankton abundance were higher on the Baja California side than on the Sonora side, with concentrations of 2.6–18.2 mg m–3 and 1.8–12.7 mg m–3 and of 274 and 166 cells mL–1, respectively. In the time series, the dinoflagellates were more abundant than the diatoms. The primary production showed a tendency to decrease from August 1989 to June 1990, with values of 15.0 to 0.5 mgC m–1. The primary productivity values in the time series presented a tendency to increase during the tide transition, reaching values of 76 mgC m–1. The variations of chlorophyll concentration, phytoplankton abundance and primary productivity were strongly influenced by the effects caused by the tidal currents. La construcción de grandes presas en el Río Colorado ha producido un dramático efecto en la descarga de agua dulce hacia el delta. Posterior a 1935 se tuvo una dramática disminución de aporte de agua dulce que ha causado impactos ecológicos y una disminución de organismos en el hábitat natural. Durante un periodo sin descarga de agua dulce se llevaron a cabo seis muestreos espaciales durante junio, agosto y noviembre de 1989, y febrero, abril y junio de 1990; en cada muestreo se realizó en una estación una serie de tiempo de 24 horas con toma de muestras de agua de mar cada dos horas. Además, en mayo de 1991 se realizó un muestreo de serie de tiempo de ocho días consecutivos, con toma de muestras de agua de mar a las 08:00, 12:00 y 16:00 horas. El objetivo fue estimar la abundancia del fitoplancton, concentración de clorofila y productividad primaria durante una época sin aporte de agua dulce. Las concentraciones de clorofila a y la abundancia del fitoplancton fueron mayores en el lado de Baja California que en el lado de Sonora, con concentraciones de 2.6–18.2 mg m–3 y 1.8–12.7 mg m–3 y de 274 y 166 cel mL–1, respectivamente. En la serie de tiempo los dinoflagelados fueron más abundantes que las diatomeas. Los valores de producción primaria mostraron una tendencia a decrecer de agosto de 1989 a junio de 1990, de 15.0 a 0.5 mgC m–3 h–1, mientras que la productividad primaria en la serie de tiempo presentó una tendencia a incrementarse durante la transición de la marea, alcanzando valores de 76 mgC m–3 h–1. Las variaciones de la concentración de clorofila, abundancia del fitoplancton y productividad primaria estuvieron fuertemente regidas por los efectos ocasionados por las corrientes de marea. Iniversidad Autónoma de Baja California 1999-03-06 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article Artículo Arbitrado application/pdf https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/729 10.7773/cm.v25i4.729 Ciencias Marinas; Vol. 25 No. 4 (1999); 509-524 Ciencias Marinas; Vol. 25 Núm. 4 (1999); 509-524 2395-9053 0185-3880 eng https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/729/656

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