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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Environmental Sciences

University of Nebraska - Lincoln

United States Department of Commerce: Staff Publications

Series

Climate

Publication Year

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Seasonal Zooplankton Dynamics In Lake Michigan: Disentangling Impacts Of Resource Limitation, Ecosystem Engineering, And Predation During A Critical Ecosystem Transition, Henry A. Vanderploeg, Steven A. Pothoven, Gary L. Fahnenstiel, Joann F. Cavaletto, James R. Liebig, Craig A. Stow, Thomas F. Nalepa, Charles P. Madenjian, David B. Bunnell Jan 2012

Seasonal Zooplankton Dynamics In Lake Michigan: Disentangling Impacts Of Resource Limitation, Ecosystem Engineering, And Predation During A Critical Ecosystem Transition, Henry A. Vanderploeg, Steven A. Pothoven, Gary L. Fahnenstiel, Joann F. Cavaletto, James R. Liebig, Craig A. Stow, Thomas F. Nalepa, Charles P. Madenjian, David B. Bunnell

United States Department of Commerce: Staff Publications

We examined seasonal dynamics of zooplankton at an offshore station in Lake Michigan from 1994 to 2003 and 2007 to 2008. This period saw variable weather, declines in planktivorous fish abundance, the introduction and expansion of dreissenid mussels, and a slow decline in total phosphorus concentrations. After the major expansion of mussels into deep water (2007–2008), chlorophyll in spring declined sharply, Secchi depth increased markedly in all seasons, and planktivorous fish biomass declined to record-low levels. Overlaying these dramatic ecosystem-level changes, the zooplankton community exhibited complex seasonal dynamics between 1994–2003 and 2007–2008. Phenology of the zooplankton maximum was affected by …


Multidecadal Otolith Growth Histories For Red And Gray Snapper (Lutjanus Spp.) In The Northern Gulf Of Mexico, Usa, Bryan A. Black, Robert J. Allman, Isaac D. Schroeder, Michael J. Schirripa Jan 2011

Multidecadal Otolith Growth Histories For Red And Gray Snapper (Lutjanus Spp.) In The Northern Gulf Of Mexico, Usa, Bryan A. Black, Robert J. Allman, Isaac D. Schroeder, Michael J. Schirripa

United States Department of Commerce: Staff Publications

Dendrochronology (tree-ring analysis) techniques were applied to develop chronologies from the annual growth-increment widths of red snapper (Lutjanus campechanus) and gray snapper (Lutjanus griseus) otoliths sampled from the northern Gulf of Mexico, USA. Growth increment widths showed considerable synchrony within and across species, indicating that some component of environmental variability influenced growth. The final, exactly dated red snapper chronology continuously spanned 1975 through 2003, while the gray snapper chronology continuously spanned 1975 through 2006. To determine baseline climategrowth relationships, chronologies were compared to monthly averages of sea surface temperatures, U winds (west to east), V winds …