Mohamed Zein Alabdein Nassar , Lamiaa Ismail Mohamedein , Mohamed A. El Sawy

National Institute of Oceanography and Fisheries, Suez Branch, B. O. 182, Suez, Egypt
Author    Correspondence author
International Journal of Marine Science, 2016, Vol. 6, No. 8   doi: 10.5376/ijms.2016.06.0008
Received: 13 Jan., 2016    Accepted: 19 Feb., 2016    Published: 19 Mar., 2016

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Surface water and phytoplankton samples were seasonally collected from different 18 stations covering about nine harbors along the Northern Red Sea during 2014-2015. The phytoplankton community was represented by 146 species belonging to 57 genera. These species are classified as 86 species of diatoms, 39 dinoflagellates, 15 cyanophytes, three of euglenophytes, two species of chlorophytes and one of silicoflagellates. The diatoms were the leading and most dominated group, forming about 81 % of the total phytoplankton abundance. The highest occurrence of phytoplankton was observed at the stations and harbors near the northern part of the Suez Gulf (Suez Bay), due to the partial treated sewage discharged from ABB Company, and low fractions of petroleum hydrocarbons derived from some petroleum companies. Whereas, other harbors located in the Gulf of Aqaba and eastern coast of Suez Gulf were the lowest productive sites. The highest abundance of phytoplankton during winter, 2015 was associated with highest values of dissolved oxygen (3.35-10.39 mgO₂/l) and dissolved nitrate (0.170 -1.262 µmole/l). The species diversity of phytoplankton (annual average of 2.47 nats) showed its minimum during spring at Adabiya inside harbor, which may reflect a relative high pollution state at this area. The stepwise multiple regression analysis revealed that mainly dissolved nitrate followed by water temperature and pH values were the most effective variables that controlled the seasonal fluctuations of phytoplankton at the different sites of the study area during 2014-2015. However, the existence of some toxic phytoplankton species in the present study suggests careful consumption of fisheries resources at the different harbors of the study area and frequent monitoring for Harmful Algal Blooms (HABs) is required.

phytoplankton; diversity; nutrients; Northern Harbors; Red Sea, Egypt