Climatic Warming and the Decline of Zooplankton in the California Current

  title={Climatic Warming and the Decline of Zooplankton in the California Current},
  author={D. Roemmich and John F. McGowan},
  pages={1324 - 1326}
Since 1951, the biomass of macrozooplankton in waters off southern California has decreased by 80 percent. During the same period, the surface layer warmed—by more than 1.5�C in some places—and the temperature difference across the thermocline increased. Increased stratification resulted in less lifting of the thermocline by wind-driven upwelling. A shallower source of upwelled waters provided less inorganic nutrient for new biological production and hence supported a smaller zooplankton… Expand
Planktonic Foraminifera of the California Current Reflect 20th-Century Warming
Variations in planktonic foraminifera from varved sediments off southern California spanning the past 1400 years imply that 20th-century warming, apparently anthropogenic, has already affected lower trophic levels of the California Current. Expand
The biological response to the 1977 regime shift in the California Current
It is shown that a deepening of the thermocline accompanied the warming and increased the stratification of the water column, leading to a decrease in the supply of plant nutrients to the upper layers, which is the most likely mechanism for the observed plankton decline, and subsequent ecosystem changes. Expand
Reorganization of North Atlantic Marine Copepod Biodiversity and Climate
Evidence is provided of large-scale changes in the biogeography of calanoid copepod crustaceans in the eastern North Atlantic Ocean and European shelf seas related to both the increasing trend in Northern Hemisphere temperature and the North Atlantic Oscillation. Expand
recorded in marine sediments Recent increase in surface-water stability during warming off California as
Warming of surface waters in the California Current since the 1950s has coincided with a significant decline in zooplankton volume. This has been attributed to reduced upwelling of nutrient-richExpand
Did the Thermocline Deepen in the California Current after the 1976/77 Climate Regime Shift?
Abstract The 55-yr California Cooperative Oceanic Fisheries Investigations (CalCOFI) dataset in the southern California Current reveals a significant surface-intensified warming and stratificationExpand
Climate Impact on Plankton Ecosystems in the Northeast Atlantic
Future warming is likely to alter the spatial distribution of primary and secondary pelagic production, affecting ecosystem services and placing additional stress on already-depleted fish and mammal populations. Expand
Climate-Ocean Variability and Ecosystem Response in the Northeast Pacific
It is shown that there have been large interannual and interdecadal sea-surface temperature changes off the West Coast of North America during the past 80 years. Expand
Increased Stratification and Decreased Lower Trophic Level Productivity in the Oyashio Region of the North Pacific: A 30-Year Retrospective Study
An analysis of the time series data sets collected from the 1960s to 1990s in the Oyashio Water revealed signs of alteration in the physical, chemical and biological properties of the water column inExpand
Human activities, climate changes affect marine populations
Upwelling of nutrient-rich waters makes California's coastal ocean one of the most productive in the world and weekly changes in upwelling winds cause coastal currents to deliver planktonic larvae to the coast in spatial patterns. Expand
Last Century Patterns of Sea Surface Temperature and Diatom Variability in the Southern California Current
Abstract A time series reconstruction for the last 100 years of the variability of diatoms (> 38 μm) from laminated sediments off the southern Baja California margin shows the susceptibility of thisExpand


Global Climate Change and Intensification of Coastal Ocean Upwelling
  • A. Bakun
  • Environmental Science, Medicine
  • Science
  • 1990
Evidence from several different regions suggests that the major coastal up welling systems of the world have been growing in upwelling intensity as greenhouse gases have accumulated in the earth's atmosphere, and the cool foggy summer conditions that typify the coastlands of northern California and other similar upwelled regions might become even more pronounced. Expand
Climate and Chlorophyll a: Long-Term Trends in the Central North Pacific Ocean
Since 1968 a significant increase in total chlorophyll a in the water column during the summer in the central North Pacific Ocean has been observed. A concomitant increase in winter winds and aExpand
Ocean Warming and Sea Level Rise Along the Southwest U.S. Coast
Hydrographic time-series data recorded during the past 42 years in the upper 500 meters off the coast of southern California indicate that temperatures have increased by 0.8�C uniformly in the upperExpand
Decadal-scale climate variability in the tropical and North Pacific during the 1970s and 1980s: observations and model results
An abrupt change in the large-scale boreal winter circulation pattern over the North Pacific was observed during the mid-1970s. Most notably, this change was marked by a southward shift andExpand
Monthly Mean Sea-Level Variability Along the West Coast of North America
Abstract Linear statistical estimators are used to examine 29 years of nonseasonal, monthly-mean, tide-gauge sea-level data along the west coast of North America. The objective is exploration of theExpand
Atmosphere-Ocean Dynamics
How the Ocean--Atmosphere System Is Driven. Transfer of Properties between Atmosphere and Ocean. Properties of a Fluid at Rest. Equations Satisfied by a Moving Fluid. Adjustment under Gravity in aExpand
We are grateful to the scientists and technicians responsible for the existence and high quality of the CalCOFI data