Related Experiment Videos
Sulfate reduction in Lake Agmon, Israel.
O Hadas1, R Pinkas, N Malinsky-Rushansky
1Israel Oceanographic & Limnological Research, Yigal Allon Kinneret Limnological Laboratory, Tiberias. orah@ocean.org.il
The Science of the Total Environment
|March 22, 2001
Summary
Microbial sulfate reduction in Lake Agmon is driven by organic matter from algal blooms, with rates varying seasonally and by sediment type. This process is key to mineralizing organic matter in the reflooded lake.
Area of Science:
- Environmental Microbiology
- Limnology
- Biogeochemistry
Background:
- Lake Agmon, a reflooded Hula Valley lake, exhibits distinct seasonal phases: clear winter waters and summer/autumn algal blooms.
- High primary production and chlorophyll-a levels are observed during warmer months, fueling subsequent decomposition.
Purpose of the Study:
- To investigate the rates and influencing factors of microbial sulfate reduction in Lake Agmon.
- To understand the role of sulfate reduction in the mineralization of organic matter within this ecosystem.
Main Methods:
- Analysis of sediment cores from peat and marl sites across different seasons in 1997.
- Measurement of microbial sulfate reduction rates (SRR) using incubation techniques.
- Quantification of sulfate concentrations and organic matter availability.
Main Results:
- Sulfate reduction rates varied significantly with season and sediment type, peaking in June (marl) and September (peat).
- Highest rates reached 2834 nmol SO(4)2- reduced ml(-1) day(-1), while lower rates (11 nmol SO(4)2- reduced ml(-1) day(-1)) were recorded in February.
- Rates were strongly correlated with the input of fresh organic matter from bloom degradation and high sulfate concentrations.
Conclusions:
- Microbial sulfate reduction is a major mineralization process in Lake Agmon.
- Organic matter supply and sulfate availability are critical limiting factors for sulfate reduction.
- Seasonal bloom dynamics directly influence the biogeochemical cycling of sulfur in the lake.