1.TemperatureTemperature is a measure of molecular motion energy. Temperature is one very important factor in regulating life processes and the spread of the organism. Metabolic process works only within a relatively narrow temperature range, usually between 0-40oC. but there are also organisms that can tolerate temperatures slightly above and slightly below those limits, such as blue-green algae that live on the temperature of 85oC in the hot springs. Increased metabolic process two times for every increase of 10 ° C temperature. Most marine organisms have undergone adaptation to live and breed in the temperature range that is narrower than the total range of 0-40oC (Nybakken, 1992).Rising water temperatures will lead to a result as follows:a.Menurunkan amount of oxygen dissolved in the water.b.Meningkatkan speed chemical reactions.c.Mengganggu kahidupan fish and other aquatic animals.d. If the lethal temperature limits are exceeded, fish and other aquatic animals might die (Kristanto, 2002).
2.SalinitasSalinity is the amount of solute. Dissolved solids include inorganic salts, organic compounds derived from living organisms, and dissolved gases (Nybakken, 1992).The most distinctive feature of the ocean water, known by everyone is that it tastes salty. This is because the sea water in dissolved salts, the main thing is natrum chloride (NaCl) is often called table salt. In addition to NaCl, in the sea water there are also MgCl2, potassium, calcium and so on. Salinity is the total weight of all the salts (in grams) are dissolved in one liter of water, usually expressed in units of 0 / 00 (permil, grams per liter) (Nontji, 1986)In coastal waters due to the dilution effect of the flow of rivers such as salinity can go down low. By contrast, in areas with a very strong evaporation, increasing salinity can be high. Brackish water is a general term used to denote water salinity between freshwater and seawater.Estuarine waters or the area around the estuary can affect the salinity structure of the complex, because in addition to a meeting between the relatively mild fresh water and sea water is heavier also largely determines the stirring water (Nontji, 1986).3.Derajat acidity (pH)Normal pH value of water is neutral, between pH 6 to pH 8 (Fardiaz, 1992). The water pH less than 7 is acidic, while a pH greater than 7 is alkaline. Acidic soil will result in leaching and excessive availability of heavy metals in soils (Darmono, 1995). Changes in pH is very acidic or alkaline will interfere with the survival of aquatic organisms by causing disruption of metabolism and respiration.4.Oksigen Dissolved (DO)Dissolved oxygen is a basic requirement for plant and animal life in the water. Living life in the water depends on the ability of water to maintain a minimum concentration of oxygen required for life (Fardiaz, 1992). Dissolved oxygen can be derived from the photosynthesis of aquatic plants, where the amount is not fixed depending on the number of plants, and from the atmosphere (air) into the water with speed limited (Fardiaz, 1992). Dissolved oxygen in marine waters utilized by organisms for respiration and the decomposition of organic substances by microorganisms. The concentration of dissolved oxygen in a state of saturation varies depending on the temperature and atmospheric pressure (Fardiaz, 1992).Oxygen is the limiting factor in determining the presence of living creatures in the water. concentration of dissolved oxygen depends on:a.Suhu.b.Kehadiran plant photosynthesis.c.Tingkat light penetration depends on the depth and turbidity of water.d.Tingkat kederasan water flow.e.Jumlah described organic materials in water such as garbage, dead algae or industrial waste (SASTRAWIJAYA, 2001).