Variability in the Structure of Phytoplankton Assemblages in relation to Human Disturbance in Southern Coast of Tunisia

Figure 4

Diagram of canonical correspondence analysis (CCA) showing the effects of nutrient ratios on microalgae species ordination according to the first and second axes. Species associated with K (disturbed station) were the dinoflagellates 3: Amphidinium carterae, 19: Karlodinium veneficum, 8: Ceratium candelabrum, 6: Ceratium fusus, 38: Protoperidinium diabolum, 34: Protoperidinium divergens, 20: Karenia selliformis, and 41: Pyrophacus sp., the diatoms 51: Climacosphenia sp., 47: Biddulphia sp., 54: Licmophora sp., 49: Coscinodiscus sp., 50: Chaetoceros sp., and 45: Amphora sp., and the cyanobacteria 71: Thalassiosira sp. Species associated with M (control station) were the dinoflagellates 9: Coolia monotis, 11: Diplopsalopsis sp., 21: Ostreopsis ovata, 22: Peridinium sp., 28: Prorocentrum lima, 31: Protoperidinium sp., 29: Prorocentrum triestinum and the diatoms 45: Asterionellopsis glacialis, 58: Navicula sp. Species whose coverage and frequency were less than 40% were eliminated.