Marsh Mesocosm Design
The salt marsh mesocosm system is made of 12 hydrologically independent tanks (10’ diameter, 5’ tall) with paired tidal surge tanks (6’ diameter) capable of generating tidal ranges up to 60 cm. Water is moved within the system via air blowers to recreate natural tidal cycles, with an overall maximum water residence time of 45 days. Each mesocosm tank consists of (from bottom to top) a gravel layer with a French drain, geocloth, sand, soil collected from nearby natural salt marsh channels, and a top layer of marsh plants/roots/soil (which is dominated by Spartina alterniflora). To minimize variability between tanks, we planted a uniform community of salt marsh grass collected as intact sections from nearby natural salt marsh.
Background Data Collection
My lab started frequently collecting a comprehensive suite of background data on the tank environment and ecosystem characteristics in early 2019. In addition to continuous, automated monitoring of basic water properties, we routinely measure (in each tank):
If you want to learn more about the mesocosms or our engineering or monitoring methods, please contact me at broberts (at) lumcon.edu.
The salt marsh mesocosm system is made of 12 hydrologically independent tanks (10’ diameter, 5’ tall) with paired tidal surge tanks (6’ diameter) capable of generating tidal ranges up to 60 cm. Water is moved within the system via air blowers to recreate natural tidal cycles, with an overall maximum water residence time of 45 days. Each mesocosm tank consists of (from bottom to top) a gravel layer with a French drain, geocloth, sand, soil collected from nearby natural salt marsh channels, and a top layer of marsh plants/roots/soil (which is dominated by Spartina alterniflora). To minimize variability between tanks, we planted a uniform community of salt marsh grass collected as intact sections from nearby natural salt marsh.
Background Data Collection
My lab started frequently collecting a comprehensive suite of background data on the tank environment and ecosystem characteristics in early 2019. In addition to continuous, automated monitoring of basic water properties, we routinely measure (in each tank):
- soil biogeochemistry
- porewater chemistry
- microbial ecology
- belowground plant production
- aboveground plant and algae characteristics
- in-tank animal population dynamics
If you want to learn more about the mesocosms or our engineering or monitoring methods, please contact me at broberts (at) lumcon.edu.
Large-scale oiling experiment
On 8 July 2019, we applied oil to the mesocosms at high tide. Louisiana light sweet crude oil (supplied by the Placid Refining Company) was weathered (~25% by weight) prior the application date. Weathered oil was applied in one of three oil levels that scaled to the low, moderate, and heavy oil SCAT categories in replicated block design.
On 8 July 2019, we applied oil to the mesocosms at high tide. Louisiana light sweet crude oil (supplied by the Placid Refining Company) was weathered (~25% by weight) prior the application date. Weathered oil was applied in one of three oil levels that scaled to the low, moderate, and heavy oil SCAT categories in replicated block design.
Oil application images (8 July 2019)
1 month post oiling (7 August 2019) images of marsh mesocosms
Recent Talk by Dr. Roberts providing an overview of oil spill impacts on coastal wetlands that highlights the mesocosm experiment:
"Coastal ecosystem complexity and connectivity: What have we learned from the Deepwater Horizon Oil Spill?"
TALK DESCRIPTION: Ecosystems are complex with many components that directly and indirectly influence other organisms and processes of the whole system. In addition, many ecosystems are exposed to a multitude of stressors that can often make it different to identify the impact a specific disturbance has on the system. This is clearly the case for coastal wetlands of Louisiana that received extensive oiling following the Deepwater Horizon oil spill. In this talk, I will summarize some of the research conducted by our research team and others throughout the Gulf to provide a holistic overview of the impacts of the oil spill on coastal wetlands. I will highlight the use of large-scale manipulation experiments using marsh mesocosms to control for these multiple stressors, enabling the direct assessment of oil spill impacts on salt marshes of coastal Louisiana.ohe Deepwater Horizon Oil Spill?
"Coastal ecosystem complexity and connectivity: What have we learned from the Deepwater Horizon Oil Spill?"
TALK DESCRIPTION: Ecosystems are complex with many components that directly and indirectly influence other organisms and processes of the whole system. In addition, many ecosystems are exposed to a multitude of stressors that can often make it different to identify the impact a specific disturbance has on the system. This is clearly the case for coastal wetlands of Louisiana that received extensive oiling following the Deepwater Horizon oil spill. In this talk, I will summarize some of the research conducted by our research team and others throughout the Gulf to provide a holistic overview of the impacts of the oil spill on coastal wetlands. I will highlight the use of large-scale manipulation experiments using marsh mesocosms to control for these multiple stressors, enabling the direct assessment of oil spill impacts on salt marshes of coastal Louisiana.ohe Deepwater Horizon Oil Spill?