Aquatic biomonitoring is the

science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

of inferring the

ecological Ecology () is the natural science of the relationships among living organisms and their environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels. Ecology overlaps with the closely re ...

condition of

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

s, and

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

s by examining the

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

s (fish, invertebrates, insects, plants, and algae) that live there. While aquatic biomonitoring is the most common form of biomonitoring, any

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

can be studied in this manner.

Purpose

Vaches dans les champs -Cows in the fields

Aquatic biomonitoring is an important tool for assessing

aquatic life An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environm ...

forms and their habitats. It can reveal the overall health and status of the ecosystem, detect environmental trends and the impacts of different stressors, and can be used to evaluate the effect that various human activities have on the overall health of aquatic environments.

Water pollution Water pollution (or aquatic pollution) is the contamination of Body of water, water bodies, with a negative impact on their uses. It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and ...

and general stresses to aquatic life have a major impact on the environment. The main sources of pollution to oceans, rivers, and lakes are human caused events or activities, such as

sewage Sewage (or domestic sewage, domestic wastewater, municipal wastewater) is a type of wastewater that is produced by a community of people. It is typically transported through a sewerage, sewer system. Sewage consists of wastewater discharged fro ...

oil spill An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially the marine ecosystem, due to human activity, and is a form of pollution. The term is usually given to marine oil spills, where oil is released into th ...

surface runoff Surface runoff (also known as overland flow or terrestrial runoff) is the unconfined flow of water over the ground surface, in contrast to ''channel runoff'' (or ''stream flow''). It occurs when excess rainwater, stormwater, meltwater, or other ...

litter Litter consists of waste products that have been discarded incorrectly, without consent, at an unsuitable location. The waste is objects, often man-made, such as aluminum cans, paper cups, food wrappers, cardboard boxes or plastic bottles, but ...

ing, ocean mining, and

nuclear waste Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear ...

. Monitoring aquatic life can also be beneficial in monitoring and understanding adjacent land ecosystems. Rapid changes to an environment, like, pollution, can alter ecosystems and community assemblages, and endanger species that live in or close to water. Many aquatic species serve as food sources for terrestrial species, which are therefore impacted by the size and health of aquatic populations.

Indicator organisms

Aquatic invertebrates, most popularly the larvae of the caddis fly sp., are responsive to

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

, low levels of pollution and temperature change. As a result, they have the longest history of use in biomonitoring programs. Additionally, macroscopic species: frogs, fish, and some plant species, as well as, many forms of microscopic life, like bacteria and protozoa are used as indicator organisms in a variety of applications, storm water run-off among them. Many species of Macroalgae (including

Cyanobacteria Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...

, though not technically a true algae) are also used in biomonitoring for both aquatic and marine environments, as their short lifespan makes them very reactive to changes.

Common methods

A biomonitoring assessment requires a baseline dataset which, ideally, defines the environment in its natural or default state. This is then used for comparison against any subsequent measurements, in order to assess potential alterations or trends. In some cases, these datasets are used to create standardised tools for assessing water quality via biomonitoring data, such as the Specific Pollution Index (SPI) and South African Diatom Index (SADI).

Methods employed in aquatic biomonitoring

* monitoring and assessing aquatic species (incl. plants, animals, and bacteria) * monitoring the behavior of certain aquatic species and assessing any changes in species behavior * analyzing the biochemical make-up of the waterbody, and its potential influence on the species that depend on it.

Common tools of ecological and biological assessments

Bioassay A bioassay is an analytical method to determine the potency or effect of a substance by its effect on animal testing, living animals or plants (''in vivo''), or on living cells or tissues (''in vitro''). A bioassay can be either quantal or quantit ...

s. Test organisms are exposed to an environment and their response is measured. Typical organisms used in bioassays are certain species of plants, bacteria,

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, water fleas (

Daphnia ''Daphnia'' is a genus of small planktonic crustaceans, in length. ''Daphnia'' are members of the Order (biology), order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their Saltation (gait), ...

), and

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s. * Community assessments. Also called biosurveys. An entire

community A community is a social unit (a group of people) with a shared socially-significant characteristic, such as place, set of norms, culture, religion, values, customs, or identity. Communities may share a sense of place situated in a given g ...

of organisms is sampled to see what types of

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

remain. In

aquatic ecosystem An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environ ...

s, these assessments often focus on

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

macrophyte Aquatic plants, also referred to as hydrophytes, are vascular plants and non-vascular plants that have adapted to live in aquatic environments ( saltwater or freshwater). In lakes, rivers and wetlands, aquatic vegetations provide cover for aquat ...

s (aquatic plants), fish, or

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

s. Rarely, other large vertebrates (

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s, and

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s) may be considered. * Online biomonitoring devices. One example uses

chemoreceptor A chemoreceptor, also known as chemosensor, is a specialized sensory receptor which transduces a chemical substance ( endogenous or induced) to generate a biological signal. This signal may be in the form of an action potential, if the chemorece ...

cells of molluscs and similar animals to monitor their coastal and fresh water habitats. 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 Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...

' valves is an example of one possible way to monitor ''in-situ'' the quality of fresh and coastal waters.

Variables considered

Water quality

Water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

is graded both on appearance, for example: clear, cloudy, full of algae, and chemistry. Determining the specific levels of

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s, bacteria, metals, and minerals found in water is extremely important. 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.

Water temperature

Water body temperature is one of the most ubiquitous variables collected in aquatic biomonitoring. Temperatures at the water surface, through the

water column The (oceanic) water column is a concept used in oceanography to describe the physical (temperature, salinity, light penetration) and chemical ( pH, dissolved oxygen, nutrient salts) characteristics of seawater at different depths for a defined ...

, and in the lowest levels of the water body (

benthic zone The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

) can all provide insight into different aspects of an aquatic ecosystem. Water temperature is directly affected by climate change and can have negative affects on many aquatic species, such as salmon. Salmon spawning is temperature dependant: there is a heat accumulation threshold which must be reached before hatching can occur. Post-hatching, salmon live in water within a critical range in temperature, with exposure to temperatures outside of this being potentially lethal. This sensitivity makes them useful indicators of changes in water temperature, hence their use in climate change studies. Similarly, Daphnia populations have been evidenced as being negatively affected by climate change, as earlier springs have caused hatching periods to de-couple from the peak window of food availability.

Community make-up

Species community assemblages and changes therein can help researchers to infer changes in the health of an ecosystem. In typical unpolluted temperate streams of

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, certain insect taxa predominate. Mayflies ( Ephemeroptera), caddisflies (

Trichoptera The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

), and stoneflies (

Plecoptera Plecoptera is an order (biology), order of insects commonly known as stoneflies. Some 3,500 species are described worldwide, with new species still being discovered. Stoneflies are found worldwide, except Antarctica. Stoneflies are believed to b ...

) are the most common insects in these undisturbed streams. In contrast, in rivers disturbed by

urbanization Urbanization (or urbanisation in British English) is the population shift from Rural area, rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. ...

agriculture Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...

forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests and woodlands for associated resources for human and Natural environment, environmental benefits. Forestry is practiced in plantations and ...

, and other perturbations, flies (

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...

), and especially midges (family

Chironomidae Chironomidae , commonly known as non-biting midges or chironomids , are a family of Nematoceran flies with a global distribution. They are closely related to the families Ceratopogonidae, Simuliidae, and Thaumaleidae. Although many chironomid ...

) predominate.

Local geology

Surface water can be affected by local geology, as minerals leached from sub-surface rocks can enter surface water bodies and influence water chemistry. Examples of this are the Werii River (Tigray, Ethiopia), where elevated concentrations of heavy metals have been linked to the underlying slate, and drinking wells in Indigenous communities near Anchorage, Alaska, where high concentrations of arsenic have been linked to the underlying McHugh Complex rock formation.

Limitations

* Reliance on accurate species identification - When using visual identification in the field, there is the potential for species to be misidentified, which could lead to incorrect analysis and conclusions. To reduce the likelihood of such errors, many monitoring organisations utilise laboratory verification of sample specimens for quality control purposes. * Species specific - It can be difficult to draw comparisons between results unless the same indicator organism has been used in each study, as every species has an individual niche and associated ideal conditions. Even similar species (as defined by either taxonomy or niche) may have different reactions and different thresholds for change. * External influences - Changes in population size or health caused by external factors may be incorrectly interpreted as resulting from changes in the environment. For example, a reduction in population that occurs due to disease, but coincides with a change in environmental conditions, could be misconstrued as resulting from the latter change. * Misleading results - Survival of species usually regarded as 'sensitive' can lead to the conclusion that there has been little change or contamination of an environment, which may be incorrect. An example of this is amphibians, which have traditionally been considered a highly sensitive class in regards to environmental changes, however, some research indicates that this may only be true for

phenols In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (− O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds ar ...

, with amphibians having similar sensitivity to other contaminants (e.g. heavy metals) as other aquatic taxonomic groups, such as bivalves.

References

External links

Biological Assessment of Water Quality
– US EPA
US Bioassessment and Biocriteria Programs for Streams and Wadeable Rivers
- US EPA {{aquatic ecosystem topics Aquatic ecology Bioindicators Environmental science Measurement of biodiversity Water pollution