In this study, variance analysis technique on unbalanced data was examined, and in this sense, Type II (fitting constants) methods were studied. The aim of this study was to show that meaningful evaluations can be performed even in unbalanced conditions and to contribute to the present investigations in biological area. In the implementation part of the study, the juvenile leaf densities of Posidonia oceanica-which is a sea grass that grows in Izmir Bay, and has very important ecological effects-in various regions and in various depths were determined. The results revealed that depth affect number of juvenile leaf (d.f. = 3, F = 523.90, R (2) = 0.998, p < 0,01). There were significant differences among region (d.f. = 3, F = 41.53, p < 0.01), site (d.f. = 1, F = 19.65, p < 0.01). As a result of Tukey ANOVA test it can be said that there were significant differences among Urla-Gulbah double dagger e (p < 0.001), Urla-Fo double dagger a (p < 0.001), Karaburun-Gulbah double dagger e (p < 0.001), Karaburun-Fo double dagger a (p < 0.001). It was found that Fo double dagger a had the highest juvenile leaf counts (782.15 +/- 435.71) whereas Urla had the lowest juvenile leaf counts (231.46 +/- 175.67). The mean juvenile leaf counts in Izmir was (496.23 +/- 377.61). it can be said that juvenile leaf counts in Karaburun(Island) had (448.13 +/- 250.85), and Fo double dagger a(Island) had (888.65 +/- 497.39).