Aquatic biomonitoring is the science of inferring the ecological condition of rivers, lakes, streams, and wetlands by examining the organisms that live there. While aquatic biomonitoring is the most common form of biomonitoring, any ecosystem can be studied in this manner.
Approaches and study organisms
Biomonitoring typically takes different approaches:
Bioassays, where test organisms are exposed to an environment to see if mutations or deaths occur. Typical organisms used in bioassays are fish, water fleas, and frogs.
Community assessments, also called biosurveys, where an entire community of organisms is sampled to see what types of taxa remain. In aquatic ecosystems, these assessments often focus on invertebrates, algae, macrophytes, fish, or amphibians. Rarely, other large vertebrates may be considered as well.
Online biomonitoring devices, using the ability of animals to permanently taste their environment. Different types of animals are used for this purpose either in the lab or in the field. The study of the opening and closing activity of clams' valves is an example of one possible way to monitor in-situ the quality of fresh and coastal waters.
Aquatic invertebrates have the longest history of use in biomonitoring programs. In typical unpolluted temperate streams of Europe and North America, certain insect taxa predominate. Mayflies, caddisflies, and stoneflies are the most common insects in these undisturbed streams. In contrast, in rivers disturbed by urbanization, agriculture, forestry, and other perturbations, flies, and especially midges predominate. Aquatic invertebrates are responsive to climate change.
Importance
Aquatic biomonitoring is important in assessing marine life forms and their ecosystems. Monitoring aquatic life, from which life on land evolved, can also be beneficial in understanding land ecosystems. Aquatic biomonitoring can reveal the overall health and status of the environment, can detect environmental trends and how different stressors will affect those trends, and can interpret the effect that various environmental activities will have on the overall health of the environment. Pollution and general stresses to aquatic life can have a major impact on the environment. The main sources of pollution to oceans, rivers, and lakes are sewage, oil spills, land runoff, littering, ocean mining, and nuclear waste. Pollution greatly upsets marine life and can endanger species that live in or close to water. Because many aquatic animals serve as a main food source for many land animals, when aquatic species are affected, it causes a ripple effect in land species. Biomonitoring can help mitigate such problems through monitoring all forms of life and conditions in different bodies of water, both fresh and salt water. A challenge in aquatic biomonitoring is to simplify data and make data easier for all to understand, especially investigators in the health and environmental fields.
Practice
Methods employed in aquatic biomonitoring are:
monitoring and assessing aquatic species and ecosystems,
monitoring the behavior of certain aquatic species and assessing any changes in species behavior, and
looking at contaminants in the water and their effect on marine life.
Water quality is graded both on appearance—for example: clear, cloudy, full of algae—and on its chemistry levels. Determining levels of enzymes and minerals found in water is extremely important. Changes in these factors can change the overall aquatic environment and can severely impact aquatic life. Some contaminants, such as metals and certain organic wastes, can be lethal to individual creatures and could thereby ultimately lead to extinction of certain species. This could affect both aquatic and land ecosystems and cause disruption in other biomes and ecosystems.
