Семинар 2005 Красное море

JBL Workshop 2005 Red Sea

JBL Workshop 2005 Red Sea

Water analyses

Water samples were taken at different locations and at different depths. To do so neutral plastic bottles were filled with water at the surface, opened at the corresponding depth, inverted and filled with air, then again inverted and filled with the surrounding water to be tested.

The samples were analysed one hour later at the most using both JBL water tests as well as electronic measuring devices from WTW (oxygen, conductivity and pH). The density was measured with a JBL precision hydrometer and the water temperatures were taken using diving computers and JBL thermometers. The mean values of all the results were calculated (81 participants).

Evaluation of the samples from differing depths showed that the water values do not vary to a depth of 25 meters in a vertical direction.

The evaluation of the water values within one section of the reef (Marsa), out on the fringing reef and on a reef distant from the coast (Dolphinhouse) showed that the water values hardly vary. Only the calcium and magnesium levels, the water temperature and the oxygen content differ.

Here the measured values

Carbonate hardness: 7-8 °dKH
Conductivity: 60.2 mS
Density: above1.028. Measuring problem: the hydrometer was at its measuring limit.
pH: 8.1

Here the water values which differ depending on sampling site

Oxygen content:
Marsa inside: 7.8 mg/l
Fringing reef: 7.9 mg/l Reef distant from
coast: 8.3 mg/l

Calcium content: Marsa inside: 447 mg/l
Fringing reef: 467 mg/l Reef distant from
coast: 456 mg/l

Magnesium content:
Marsa inside: 1360 mg/l
Fringing reef: 1280 mg/l Reef distant from
coast: 1276 mg/l

Water temperature (14 – 19 Nov, 2005)
Marsa inside: 25.3 °C
Fringing reef: 24.8 °C
Reef distant from coast: 24.6 °C