170 likes | 387 Views
Green Lake Fayetteville, New York. Green Lake: General Characteristics. Morphometry Glaciated plunge-pool basin 0.3 km 2 SA 7.2E6 m 3 TotV D L = 1.58 Z max = 52m Hardwater & Very Oligotrophic Dimitic & Meromictic w/ Permanent Chemocline (~ 20m)
E N D
Green Lake: General Characteristics • Morphometry • Glaciated plunge-pool basin • 0.3 km2 SA 7.2E6 m3 TotV • DL = 1.58 Zmax = 52m • Hardwater & Very Oligotrophic • Dimitic & Meromictic w/ Permanent Chemocline (~ 20m) • Ca2+, SO42+ Concentrated Groundwater
Green Lake: General Characteristics • Dense/Narrow Layer of Purple Sulfur Bacteria (Chemocline) • Abundance of CaCO3 in Littoral (Chara) • Residence Time: Upper ~ 2 yrs. Mono 7-35 yrs. • Fauna: Red Calanoid Copepods and Freshwater Sponges
Green Lake: Study Objective • Measure Physical, Biological, and Chemical Properties To Understand Lake Ecology • Apply Basic Principles of Limnology • Present Findings in a Regional Context
Green Lake: Physical & Chemical Properties Temperature (where are the 5 distinct layers?) % Dissolved O2 (100% ~ 11 mg/l) Source: YSI Probe
Green Lake: Physical & Chemical Properties Conductivity pH Source: YSI Probe
Green Lake: Physical & Chemical Properties Ammonia Conc Nitrate Conc RedoxPotential Source: YSI Probe
Green Lake: Physical & Chemical Properties Chlorophyll Turbidity Source: YSI Probe
Green Lake: Physical & Chemical Properties Light Attenuation Kd ~ 0.174 m-1 Secchi Disk: 8 m Redox Potential Dissolved Oxygen
Green Lake: Physical & Chemical Properties cdom440 c440 c550 c676
Green Lake: Physical & Chemical Properties Silica Phosphorous TP
Green Lake: Biota (not much …) • Macrophytes • Chara (macroalgea) • - order Charales • - rooted, submersed • green algae • a.k.a. Stonewort
Green Lake: Biota, cont’d • Phytoplankton • Phacus • - Euglenophyta • - Hypolimnion Chemolayer > Countless Purple Sulfur Bacteria
Green Lake: Biota – Zooplankton Reasonable agreement between Schindler & ZooToNet (5.3 vs. 3.4)
Green Lake: Highlights • Upper region very much oligotrophic • Water Transparency • Large Secchi value • Small attenuation coefficient • Nutrient Poor • Very low levels of P, Chl, Si • N and O2 are not limiting • Low fauna and flora diversity/density • Catchment area small (input from Round Lake)
Green Lake: Highlights • Dramatic change at the chemocline layer • Extremely Dense Thin Layer of PSB • Essentially where most of the photosynthetic activity is occurring (utilizing H2S as electron donor) • Large density gradient from salinity causing entrapment below resulting in formation of stable monimolimnion • Further stabilization due to surrounding topography • Unique lake system: small w/ deep basin, very protected, meromictic, well suited for paleolimnology