Coastal Research Lab: Seawater Service
Flowing seawater is available to investigators in the Coastal Research Lab (CRL). Keith Bradley oversees the seawater system in CRL 101 (GFD Lab) and can assist new users to gain access.
Replicate seawater intakes are in Vineyard Sound, approx. 200 yards from shore in about 12 to 15 feet of water depth. They are located directly offshore from the beach pump station and are plumbed to ESL via polyethylene pipe. The pump station is located at the end of the footpath from CRL to the bikepath (directly across the street from the CRL driveway). The actual seawater intake is sited approximately 2 feet off of the bottom and is protected by a grating which filters out fish and other large (>1 inch) material. Only one intake line is used at a time. The second one is allowed to "rest" to eliminate internal fouling growth; the lines are alternated approximately every 6 months.
The seawater system is plumbed to ESL, where it is sand-filtered. The large commercial sand filtration units (rated to 10 micron but not monitored) are back-flushed twice a day and are maintained by outside contract. CRL is plumbed with a single PVC feed line from ESL and receives ambient sand-filtered water. Running seawater in CRL is user selectable (10deg. - 25deg.C). Water in CRL can be user-filtered (either 1 micron or 10 micron), using felt-type single-sided polypropylene mesh bags inserted into large in-line canisters. Adding bags to filter the seawater slows the supply, especially as they become clogged (e.g., filling the 17 meter flume (33000 liters capacity) takes 1.5hrs but can take approx twice as long, depending on the state of filter clogging). Seawater treatment dramatically alters the oxygen content and aeration (or degassing) may be needed for some users. CRL has a degassing system but new users will need to ascertain it's current status.
Access to the CRL seawater can be found in the first floor labs. New users should get in touch with Keith Bradley.