Lower trophic levels and alewife in Onondaga Lake 2011
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Lower trophic levels and alewife in Onondaga Lake 2011 Presentation for OLTAC meeting Halloween 2012
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Lower trophic levels and alewife in Onondaga Lake 2011 Presentation for OLTAC meeting Halloween 2012. Phytoplankton in 2011. Synedra. Cyclotella. Bluegreens 2011. Biovolume 1998-2011. Phytoplankton 1998-2011. N:P ratio. Zooplankton. Daphnia. Calanoids. Cladocerans. Copepods. Bosmina. - PowerPoint PPT Presentation
Transcript of Lower trophic levels and alewife in Onondaga Lake 2011
Lower trophic levels and alewifein Onondaga Lake 2011
Presentation for OLTAC meeting Halloween 2012
Phytoplankton in 2011
Cyclotella
Synedra
Bluegreens 2011
Biovolume 1998-2011
Phytoplankton 1998-2011
N:P ratio
Daphnia
Cyclopoid
Calanoids
Copepods
Zooplankton
Bosmina
Cladocerans
Zooplankton in 2011
Zooplankton size in 2009-11
Zooplankton average length
Alewife
Daphnia
Alewife
Cascading interactions in the food chain
Algae
Zooplankton
2010 – 60% from the 2009 year class2011 - 74% from the 2009 year class 26% from the 2010 year class 2012 28% 2009, 13% 2010, 52% 2012
Water Quality Effects
• Smaller zooplankton
• “Top-down” trophic cascades: increasing algae
Secchi 2008-20122008 2009 2010 2011 2012
Density # /m2
• Oneida 1995 – 2009: 6300 (3600 – 9400)
• Onondaga 2007 – 2011: 13000-18000
Comparison with lake-wide biomass Oneida - Onondaga
Comparison with lake-wide biomass Oneida - Onondaga
Alewife
Trophic Cascades 2008 - 2011
Algae and Water Clarity
Nutrients
Winter MortalityChamplain January 2008
Thank You
