Akademik Veri Yönetim Sistemi
11th International Ecology Symposium (Ecology 2024), Sinop, Türkiye, 29 - 31 Mayıs 2024, ss.144-160
Göksu river estuary was studied seasonally to reveal impact of contrasting water masses
with varying trophicity on the phytoplankton distribution. Samples were collected from
total 51 stations representing nutrient-rich Göksu river estuary, productive coastal,
mesotrophic shelf and oligotrophic offshore waters. Total number of 246 phytoplankton
species belonging to Bacillariophyceae (79 species), Pyrrophyceae (146),
Prymnesiophyceae (16), Cryptophyceae, Chrysophycea, Euglenophycea, Ebriophyceae
and Chlorophyceae were identified with a persistent diatom dominancy observed
throughout. Community was found most diverse during spring followed by winter,
summer and fall. Summer population abundances exceeded much the winter, spring and
lastly fall population densities. Population was always found most species diverse and
abundant in shallow coastal areas fed by nutrient-rich freshwater from the Göksu river
and nearby Lamas creek. Maximum population densities were also retained in Taşucu
Bay receiving direct freshwater inputs from the nearby Göksu river. Significant positive
correlation between surface phytoplankton abundance and ambient temperature and
negative correlation with surface salinity whereas almost no correlation with any of
nutrient species were observed in fall. In contrast, highly significant positive correlations
were only present with nitrate, nitrite and silicate in winter. Despite a highly significant
negative correlation with salinity, highly significant positive correlations with phosphate,
nitrate, nitrite were observed in spring. Lastly, in summer, a highly significant negative
correlation between phytoplankton abundance and salinity & temperature and a
significant positive correlation with phosphate were observed. Similar to Pielous’ index
values, Shannon diversity index values were found maximal during spring followed in
decreasing order by fall, winter and summer. Multivariate analyses have displayed
numerous patchy aggregations in fall (10 patches), winter (8) and few in spring (2) and
summer (3). Despite the very complex affinities observed within various minor patches
observed in fall and winter, surface flora has split into two majors, namely coastal -
offshore, and east - west subpopulations in spring and summer.