Many marine organisms help naturally purify water of pollutants and harmful substances through biological processes they perform while feeding, respiring, or growing. The most important of these organisms are:<br /><br />1. Oysters and mussels (filter mollusks):<br />Filter water through their gills while feeding.<br /><br />Remove small particles such as algae, bacteria, and some harmful minerals from the water.<br /><br />A single oyster can purify dozens of liters of water per day.<br /><br />2. Algae and phytoplankton:<br />Absorb excess nutrients (such as nitrogen and phosphorus) that pollute the water.<br /><br />Perform photosynthesis, producing oxygen and helping maintain water balance.<br /><br />3. Marine bacteria:<br />Decompose organic matter and waste in the water.<br /><br />Some species are capable of breaking down dangerous pollutants such as oil and chemicals.<br /><br />4. Seagrasses and mangrove trees:<br />Absorb pollutants from water and soil.<br /><br />Their roots help stabilize the soil and prevent the transfer of pollutants.<br /><br />5. Some fish and crustaceans:<br />Feed on microorganisms and organic waste from the seabed.<br /><br />They contribute to cleaning the marine environment of harmful sediments.<br /><br />Al-Mustaqbal University is the first university in Iraq.<br />