Gschwend%20thesis.pdf

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algal samples from the present work, would take many months to empty the
reservoir of pentadecane in these algae. Therefore, these release rates
appear reasonable.
These investigators have also reported somewhat lower levels of penta-
decane in the green alga, Enteromorpha, of i ~g/gm. The higher rate of
release of pentadecane from the sample of Enteromorpha examined in this
study may indicate a greater "leakiness" of this alga. This plant shows
a high surface-to-volume ratio relative to its brown counterpart, Fucus.
Even if handling of this fragile form caused the observed production,
similar damage is to be expected in the environment. This alga lives in
the shallowest waters and suffers breaking waves and occasional exposure.
Simple calculations
may be made to see if the release rates indicated
by these experiments may be responsible for the observed levels of penta-
decane in CD seawater. A typical benthic algal biomass for this region is
2
given by Conover (1958) as ranging between 1.5 and 4 kg wet weight/m .
Assuming these plants are 80% water, this converts to 300 to 800 gm dry
2
weight algae/m. At a production and release rate of 30 ng/gm dry weight/
day and assuming the average residence time of water at CD is 2 days (ch 3&4),
2
a standing stock of pentadecane as much as l8 to 48 pg/m may be expected.
For a 2- mete;r water column, this corresponds to IO to 20 ng nCl5/liter
seawater. Nearly all of the seawater samples assessed in the year-round
study at CD were in this concentration range (figure 3-16). On three
occasions (June and September, 1977 and May-June, 1978) pentadecane levels
in seawater rose dramatically. These incidents may reflect particularly
strong storm activity destroying algal structural integrity and releasing
pentadecane to the seawater. On the other hand, algal physiology, which
is closely aligned with environmental parameters such as light and tempera-
ture, may be responsible. Since these parameters are changing rapidly in