Gschwend%20thesis.pdf

-191-
Also, wave action is frequently very strong in the shallow near-
shore region and may be expected to break up algal structures. It
was hoped that by restricting the period of incubation to only one
day and by controlling the flask temperature at that of the ambient
environment, the chemistry of the enclosed seawater would not dras-
tically change and cause unnatural release of organic compounds.
The stripping process may also alter algal production and re-
lease of the volatiles. Warming the samples and agitating the algae
with vigorous bubbling may influence the release of these substances.
The efficiency of stripping a water sample with a large algal sur-
face area included is unknown, but might be expected to be lower
than that containing only water due to competition between the sur-
face and the compound in solution (Le., a "strippable" state).
Despite these reservations, the data do indicate that hydro
bons and halocarbons are released at significant rates by various
marine algae into seawater.
car-
The purpose behind the biochemical synthesis of the halo-compounds
is unknoiYn. Fenical (1975) suggests that they. may be utilized as
anti-microbial or anti-herbivore agents. Thus a topical location
of these materials would be most useful and their consequent release
to the seawater would be expected to be easier than for hydrocarbons.
If competitive advantages exist, it would also be useful for a
higher marine plant such as Zostera to accumulate these compounds
from seawater. Also it may be particularly advantageous to maximize
production in the summer to protect plants during this period of
intense grazing by animals.
~ -
f
(
r