aquatic plants and animals obtain oxygen, carbon dioxide, and other gases directly from the water that surrounds them. Aquatic plants obtain carbon dioxide from the water and convert it into oxygen through photosynthesis. Aquatic animals, on the other hand, take in oxygen from their environment and release carbon dioxide. Additionally, aquatic animals and plants need water for a variety of other physiological processes, such as osmoregulation (the regulation of the water content of cells), digestion, and excretion.
Pollution in water and gases can have a range of effects on aquatic plants and animals, particularly those that rely on oxygen. Pollutants such as fertilizer runoff and industrial waste can increase the levels of nutrients in the water, resulting in algal blooms that can deplete the water of oxygen. This can lead to the death of aquatic organisms that require oxygen to survive. Pollutants such as heavy metals and oil can also cause toxicity in aquatic organisms, resulting in death or other health issues.