Outdoor Experimental Tanks at PNNL-Sequim
The Marine and Coastal Research Laboratory at PNNL-Sequim has coastal research mesocosm environments that allow for controlled and mid-scale research on shoreline, intertidal, and near-shore ecosystems.
Photo by Andrea Starr | Pacific Northwest National Laboratory
The coastal research mesocosm environments at PNNL-Sequim enable controlled and mid-scale research on shoreline, intertidal, and near-shore ecosystems. At the core of this capability are eight identical tanks measuring 1.8m long x 3m wide x 1.2m high. Pairs of tanks are connected to a head tank used for preconditioning of the water supply. This method gives researchers control over temperature, salinity, turbidity, and other conditions. The water supply options for the head tanks include unfiltered or filtered seawater and non-chlorinated fresh well water. Lighting can be from natural sunlight or variable intensity LED illumination. Water depth can be held constant, or varied to simulate tidal fluctuations.


In addition to the rectangular tanks, we have large circular tanks ranging from 1,390 L to 62,000 L. Three tanks, one holding 62,000 L and two holding 31,100 liters maintain active eelgrass (Zostera marina) communities. Paired with bench-scale laboratory research and field studies, the various mesocosm tanks complete the laboratory's capability to conduct research on biogeochemical processes across multiple scales. Furthermore, we have analytical tools for detailed analysis of:
- sediment and water geochemistry
- the water-atmosphere interface
- biochemistry
- the dynamics and behavior of microbial and macrobiotic populations and communities