Flow-Through Experimental Seawater System

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There's a lot of snow! But the tanks are holding up great!

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(Daniel Cojanu)

Location Map
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Location of system.

tank side view
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Tanks are supplied with seawater through redundant lines. Water flow can be controlled through the main pump and at each tank. The tanks can be subdivided to increase experimental replication.

water filters
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Water is sequentially filtered before being delivered to the experimental tanks.

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The flow-through seawater system is designed so that replicated experiments can be conducted under realistic environmental conditions. Because the outdoor system experiences ambient weather conditions the need to artificially manipulate light and temperature is eliminated (Figs. 1, 2). Filtered water is delivered to the system from Martha’s Vineyard Sound. The system can be open to the elements or enclosed with translucent sheeting depending on the experiment and season.


Water from Martha's Vineyard Sound is delivered to the tank system at up to 85 gpm (322 lpm) by a dedicated pump. Unfiltered seawater at ambient Martha's Vineyard Sound temperatures or water treated in Environmental Systems Lab can be delivered. At the system, water is filtered before it is delivered to the tanks. Flow rates are controlled at multiple points at each tank (Fig 3).

Filters. Water is sequentially filtered through 1 of 2 sets of redundant filters (Fig. 4).

Security. The dedicated pump is connected to the WHOI central station for alarm coverage. A backup water system is available.  The entire system is on emergency, back-up power.

12 large tanks are constructed of fiberglass, 9’ long x 4’ wide x 2.5’ deep.  The tanks can be subdivided to increase experimental replication. For instance, each large tank can hold 8, 210L tanks or 18, 19L tanks.

Facilities. Fresh and salt water hoses; sieving area; compressed air; climate controlled shed; loading dock; motion-sensitive exterior lights; radiant heat.

Electrical outlets (120V, 20 amp) are at each tank, the lab bench, and in the shed. Electrical boxes with 8 outlets are suspended above the tanks and can be moved along tension wires. This allows multiple small devices to run at once.

Data.Ethernet ports are at each tank, the lab bench, and in the shed. Data boxes at each tank can send information to or receive data from instruments. Each box has:
• 5-port ethernet switch
• 4-port USB to ethernet
• 4-port RS 232 to ethernet
• Network power controller
• Outlet multiplier
A Linux-based server records and stores data. A secure web interface allows conditions to be monitored and adjusted real-time.

Informative Audio Slide Show

Want to know more about specific capabilities at the Mesocosm Lab? Here is a short audio slide show!

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Contact Amanda Spivak at aspivak@whoi.edu or 508.289.4847


WHOI, L. Madin, J. Seewald; construction by R. Galat, S. Gagnon, E. Dougherty, CIS, and others; F. Sonnichsen and S. Lerner made the data boxes and communication system possible.


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Last updated July 3, 2014
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