Phytoplankton fuels Delta food web
Populations of certain fishes and invertebrates in the Sacramento-San Joaquin Delta have declined in abundance in recent decades and there is evidence that food supply is partly responsible. While many sources of organic matter in the Delta could be supporting fish populat...
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University of California Agriculture and Natural Resources
2003-10-01
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doaj-881fd46b162e4237988c9600c11d7fa22020-11-25T00:50:08ZengUniversity of California Agriculture and Natural ResourcesCalifornia Agriculture0008-08452160-80912003-10-0157410410910.3733/ca.v057n04p10410.3733/cav057n04_7Phytoplankton fuels Delta food webAlan D. Jassby0James E. Cloern1Anke B. Müller-SolgerA.D. Jassby is Research Ecologist, Department of Environmental Science and Policy, UC DavisJ.E. Cloern is Research Biologist, Water Resources Division, U.S. Geological Survey (USGS)Populations of certain fishes and invertebrates in the Sacramento-San Joaquin Delta have declined in abundance in recent decades and there is evidence that food supply is partly responsible. While many sources of organic matter in the Delta could be supporting fish populations indirectly through the food web (including aquatic vegetation and decaying organic matter from agricultural drainage), a careful accounting shows that phytoplankton is the dominant food source. Phytoplankton, communities of microscopic free-floating algae, are the most important food source on a Delta-wide scale when both food quantity and quality are taken into account. These microscopic algae have declined since the late 1960s. Fertilizer and pesticide runoff do not appear to be playing a direct role in long-term phytoplankton changes; rather, species invasions, increasing water transparency and fluctuations in water transport are responsible. Although the potential toxicity of herbicides and pesticides to plankton in the Delta is well documented, the ecological significance remains speculative. Nutrient inputs from agricultural runoff at current levels, in combination with increasing transparency, could result in harmful algal blooms.http://calag.ucanr.edu/archive/?article=ca.v057n04p104 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Alan D. Jassby James E. Cloern Anke B. Müller-Solger |
spellingShingle |
Alan D. Jassby James E. Cloern Anke B. Müller-Solger Phytoplankton fuels Delta food web California Agriculture |
author_facet |
Alan D. Jassby James E. Cloern Anke B. Müller-Solger |
author_sort |
Alan D. Jassby |
title |
Phytoplankton fuels Delta food web |
title_short |
Phytoplankton fuels Delta food web |
title_full |
Phytoplankton fuels Delta food web |
title_fullStr |
Phytoplankton fuels Delta food web |
title_full_unstemmed |
Phytoplankton fuels Delta food web |
title_sort |
phytoplankton fuels delta food web |
publisher |
University of California Agriculture and Natural Resources |
series |
California Agriculture |
issn |
0008-0845 2160-8091 |
publishDate |
2003-10-01 |
description |
Populations of certain fishes and invertebrates in the Sacramento-San Joaquin Delta
have declined in abundance in recent decades and there is evidence that food supply
is partly responsible. While many sources of organic matter in the Delta could be
supporting fish populations indirectly through the food web (including aquatic vegetation
and decaying organic matter from agricultural drainage), a careful accounting shows
that phytoplankton is the dominant food source. Phytoplankton, communities of microscopic
free-floating algae, are the most important food source on a Delta-wide scale when
both food quantity and quality are taken into account. These microscopic algae have
declined since the late 1960s. Fertilizer and pesticide runoff do not appear to be
playing a direct role in long-term phytoplankton changes; rather, species invasions,
increasing water transparency and fluctuations in water transport are responsible.
Although the potential toxicity of herbicides and pesticides to plankton in the Delta
is well documented, the ecological significance remains speculative. Nutrient inputs
from agricultural runoff at current levels, in combination with increasing transparency,
could result in harmful algal blooms. |
url |
http://calag.ucanr.edu/archive/?article=ca.v057n04p104 |
work_keys_str_mv |
AT alandjassby phytoplanktonfuelsdeltafoodweb AT jamesecloern phytoplanktonfuelsdeltafoodweb AT ankebmullersolger phytoplanktonfuelsdeltafoodweb |
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