Environmental properties of the southern Gulf of Aqaba, Red Sea, Egypt

Abstract

Environmental properties (temperature, dissolved oxygen, nutrients and chlorophyll a) of the epipelagic zone off Sharm El-Sheikh, Red Sea, Egypt were studied seasonally throughout a year from March 1995 to March 1996. Water samples were collected from five water depths (0, 25, 50, 75 & 100 m). The studied parameters exhibited clear seasonal variability along the water column. The vertical distribution of water temperature showed thermal homogeneity during most seasons, and thermal stratification in summer. Dissolved oxygen attained slightly high concentrations (5.3-7.8 mg l -1 ) in the whole water column, with slight seasonal variation. The concentrations of nutrients reflected dominant oligotrophic conditions in the epipelagic zone and occasional mesotrophic status at some depths. Phosphate fluctuated between 0-0.7 μM, ammonium (0-2.27 μM), nitrite (0-0.72 μM), nitrate (0-1.49 μM) and silicate (0-6.48 M). Phytoplankton biomass was generally low in the epipelagic zone throughout the study, whereas chlorophyll a was less than 0.5 μg l -1 , except relatively high concentration (0.7-1.12 μg l -1 ) in deep layers in spring. In comparison with previous studies on the Gulf of Aqaba all environmental parameters during present study showed pronouncedly different values.

Effect of climate change on the reproduction pattern of sea urchin Echinometra mathaei at the Gulf of Suez, Red Sea, Egypt.

“…Temperatures recorded during the current study for the second period (2015-2016) were in agreement with results of previous records at the Red Sea as Abdelmongy and El-Moselhy (2015), who recorded a summer temperature of 29.25 o C and a winter temperature of 17.96 o C, 28.2 o C at summer and 20.17 at winter (Madkour, 2013) and 30.5 o C at summer and 22.8 o C at winter (Dorgham et al, 2012).…”

Assessment of heavy metal contamination in water, sediments, and Mangrove plant of Al-Budhai region, Red Sea Coast, Kingdom of Saudi Arabia

“…DO in the study area is almost similar to the recorded DO in other regions of Red Sea [69,70]. DO concentration of south part of Gulf of Aqaba, Red Sea, Egypt is 6.6-7 mgL −1 which was reported the same as in the surface water [71]. The minor variations of physicochemical characteristics including salinity, pH, and DO were found by this study.…”

Phytoplankton and Primary Production in the Red Sea

“…In a study of bio-optics along the axis of the Gulf, Stambler (2005) found that the concentrations of Chl a remained consistently less than 0.4 µg L −1 . Dorgham et al (2012) determined the concentrations of Chl a down to 100 m at a coastal station (Sharm El-Sheikh) at the Strait of Tiran over an annual cycle and observed that the concentrations ranged from 0.1 to 0.33 µg L −1 . The only instance when they were high (up to 1.2 µg L −1 ) was in the spring at depths >70 m.…”