EFFECTS OF SHIP BALLAST WATER DISCHARGES ON THE PHYTOPLANKTONS IN CALABAR COASTAL WATERS

The composition, distribution and abundance of phytoplankton species in Calabar coastal water and Ship ballast water were investigated. Phytoplankton recorded in Coastal water included six (6) major taxa namely Bacillariophyceae (36.5%), Chlorophyceae (21.2%), Cyanophyceae (17.3%), Pyrrophyceae (9.6%), Chrysophyceae (7.7%) and Euglenophyceae (7.7%). In Ship ballast water seven (7) major taxa were observed namely Bacillariophyceae (41.2%), Chlorophyceae (19.1%), Dinophyceae (16.9%), Cyanophyceae (11%), Chrysophyceae (5.1%), Pyrrophyceae (3.7%) and Euglenophyceae (2.9%. Phytoplanktons occurrence was highest in the months of July, September, November and June (wet season) for ballast water and August, October (wet season), December and February (dry season) for Calabar coastal water. It was observed, that species were found in both coastal and ballast waters which were alien species likely introduced into the Calabar coastal water through the ship ballast water discharged.