3.1.
Experiment I – screening of macrophyte extracts
A three-way repeated measures ANOVA showed that the effects
of
treatment, time, algal species and their interactions were all significant
(P < 0.001). Examination of the effect of algal species by
ANOVA
revealed that there was a significant interaction between
treatment
and time in A. variabilis treatment (P < 0.001) but no significant
interaction was found in the S. quadricauda treatment it
was
not analysed further. Examination of time by ANOVA in the A.
variabilis
treatment revealed that the effect of treatment was significant
for all days except day 2 (day 4, P < 0.01, days 6, 8 and 10,
P
< 0.001).