Gschwend%20thesis.pdf

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varies with about a 0.6 meter tide. The bottom is sandy and covered
seasonally with an extensive algal and seagrass growth. The shore is
cobbled and backed by a mixed oak and pine forest band. The main road
in the region is greater than 0.5 km away and is separated from the
beach by this vegetation. Public beaches are located about i km to
ei ther side, and Woods Hole and Falmouth harbors are beyond these.
Ferries to Martha's Vineyard and Nantucket pass se~eral times per day
several kilometers offshore. A series of brackish water ponds discharge
into the Sound to the east of the sampling site. Groins are placed
along the shore and inhibit thë longshore drift which is in the net
eastward direction (Bumpus et ál., 1971).
Seawater was collected 20 cm below the surface with a I-liter round
bottom flask fastened to the end of an aluminum rod by a PVC bracket.
The flask was filled and emptied three times, and then three separate
additional aliquots were used to rinse a 5-liter round bottom flask.
Finally this larger flask was filled with 4 liters of seawater, spiked
with an internal standard solution (2 ~l of 20 ng each l-chloro-n-
decane, -dodecane, -tetradecaneliil acetone) ~ and swirled. The l..liter
flask was then used to acquire samples for salinity, nutrients, chloro-
phyll ~ and phytoplankton counts.
Stripping
Samples were immediately returned to the lab and analyzed. The 4-
liter seawater sample was stripped according to the methods of Grob and
Zürcher (l976). Briefly, a metal bellows pump forces air through a frit
into the bottom of the water sample (figure 3-2). The resultant column
of bubbles sweeps the sample of its volatile compounds, and the effluent
air carries this organic load through glass and stainless steel tubing