Coastal ecosystems give humans the important service of maintaining water quality by filtering or reducing toxic pollutants, absorbing nutrients inputs, and helping to control pathogen populations. That is why we should know how to measure coastal condition by considering biological changes in coastal ecosystems as follow:
- Harmful Algal Blooms, growth rapidly in the populations of algae species will produce toxic compounds. They are responsible for at least six types of food poisoning for humans, including several that can be lethal.
- Oxygen depletion, also called as hypoxia. Hypoxia, which is often linked with more danger forms of eutrophication, can be harmful to marine organisms, especially sedentary organisms that live in the sea floor.
- Persistent Organic Pollutants (POPs), include a number of chemicals that do not able naturally in our environment. POPs encompasses polychlorinated biphenyls (PCBs), dioxins and furan, and pesticides such as chlordane, DDT, and heptachlor. POPs persist in the environment and can accumulate through the marine food or in coastal sediment to a level that is toxic can threat organism and humans live.