6 the brightness can reach the bottom water, which indicates that the water
condition is very good to be used for the development of marine cultivation. Production of seaweed and pearl oyster increases in the dry season, and will
become less in rainy season.
2.1.1.2 Dissolved Oxygen
Dissolved oxygen DO is derived from the results of a photosynthesis process of water plant or diffusion of oxygen into water by aeration rapid movement as a
waste product of photosynthesis. Photosynthesis processes could occur in green plants and some chlorophyll-containing bacteria Utama, 2005. Oxygen is needed
by all sentient life in the water such as fish, shrimp, shellfish and other animals, including microorganisms such as bacteria. DO is the most important indicator of
the health of a water body and its capacity to support a balanced aquatic ecosystem of plants and animals. Waste water containing organic oxygen
consuming pollutants depletes the dissolved oxygen and may lead to the death of marine organisms. DO content in water provides a high level guidance to the
primary productivity of water. Oxygen molecules are contained in the physics of soluble water. Hence, solubility is strongly influenced by water temperature. DO
from the field measurements indicated highest from 2.6 - 4.7 mg I for seaweed and pearl oyster. In overall the observed water is suitable enough to support
aquatic life organisms Wiradisastra, 2004.
2.1.1.3 Temperature
The sea temperature is influenced by sunlight radiation to the earth. Sunlight heating the surface sea water in tropical regions will be different with the results
of the heating in the middle latitude regions, or poles. In the tropics the sun fell down almost perpendicular, whereas in the polar region generally receive sunlight
with a skew. Temperature decreases regularly according to the depth, more depth from surface the temperature will be lower. This is due to lack of intensity of the
sun into the waters. However, although in the tropics more heat from the poles, the tropics have a temperature lower than the temperature of sea water in the
7 subtropical regions Utama, 2005. This is because much cloudy cover in many
tropical areas compared with sub tropic. Temperature changes slowly from the coast towards offshore, temperature generally is higher in coastal areas because
the sea could absorb sunlight easier while for the sea it is not easy to change the temperature when the environmental temperature does not change, commonly the
temperature of the offshore is stable. Temperature is one of the most important factor for living organisms in the ocean, because temperature affects both
metabolism and proliferation activity of any organism. Average temperature between each measurement point does not differ significantly, which range from
21
o
C – 32
o
C for seaweed and 21
o
C – 32
o
C for pearl oyster, where the temperature was within the category is suitable for developing marine farming area. The range
of temperature is not large due to Indonesian waters have a uniform temperature pattern Wiradisastra, 2004.
2.1.1.4 Acidity
Acidity or Potential of Hydrogen pH measured concentration hydrogen ion in water, indicated the acid and alkalie degree of sea water. Generally, acidity scale
is from 0 to 14, the mean value is a neutral number 7. Measurement of acidity is very important because acidity values affect the solubility and availability of
various nutrition for the organism. Sea water has ability to sustain fluctuating changes in acidity. pH or water acidity is one of the factors affecting productivity.
pH is measured during the study which ranged from 7.2 - 7.9 ppm for seaweed and 7.2 – 7.9 ppm for pearl oyster. The pH ranges show that the open water is
productive. Changes in pH can have bad consequences for the life of sea biota, either directly or indirectly Wiradisastra, 2004.
2.1.1.5 Salinity
