User:Yesseniaml/Aquatic biodiversity research

Anthropogenic influence

Anthropogenic influences, those caused by human activities, will be discussed, beginning with climate change and how it affects aquatic biodiversity. Earth's temperature is rising at an alarming rate which in turn is causing sea levels to rise, increasing coastal erosion, ocean acidification, and higher evaporation rate of water resources. This affects aquatic biodiversity via increasing water temperature, increasing intensity of drought and precipitation events, shifts in species distribution range, changes in seasonal timing of reproductive and migration activities, genetic adaptation, and an increase of invasive species that affect natural habitats. These disturbances are increasing globally resulting in a direct impact and threat to aquatic biodiversity. For example, phytoplankton communities may suffer changes in their taxonomic composition and functional activities should temperatures continue to rise, which would influence food webs by resulting in species substitution and disrupting community dynamics at multiple trophic levels.

Aquatic biodiversity is believed to be decreasing at a higher rate than terrestrial biodiversity, an occurrence observed worldwide. An estimated 1/3 of all available freshwater is exposed to agricultural, industrial, or urban infrastructure, which presents a higher risk of poorer water quality and reduced biodiversity. An increase in nitrogen availability, due to industrial and agricultural activities, has a direct impact on aquatic systems. A circumstance that leads to soil and water acidification and eutrophication, which causes increased growth of particular species which in turn limit light penetration, reducing nutrient availability for other species, thus declining biodiversity. Urbanized areas experience a faster increase in stream and river temperatures, due to greater local surface temperature, increased thermal discharges, and heated runoff from paved areas, which contribute to the wide variability of urban stream temperatures influencing eutrophication, ecosystem productivity, stream metabolism, and aquatic biodiversity loss. Biological indicators, or bioindicators, can be useful when monitoring and assessing pollution and environmental degradation. Macroinvertebrate communities are good bioindicators because they are affected by disturbances in the physical, chemical, and biological conditions of a stream. Macroinvertebrates are commonly used in research to assess the health of aquatic systems. A variety of South African rivers were suspected of being affected by runoff from an adjacent wastewater treatment facility. This hypothesis was confirmed by observing drastic changes in macroinvertebrate communities upstream and downstream of the water treatment facility. Additionally, macroinvertebrates also serve to monitor pesticide contamination caused by agricultural runoff .

Management practices can also influence aquatic biodiversity. River restoration strategies focused on riparian vegetation restoration has been found to provide shade mitigating water temperature rise and promoting land-water interactions. Additionally, ongoing wetland conservation efforts include the construction of urban wetlands. For example, urban wetlands were being drained annually in an effort to control invasive fish populations with the goal of providing a threatened frog species with a habitat viable for its reproduction. However, these practices were also provoking aquatic biodiversity loss, as proved by bioindicators, when an increase in mosquito larvae which was considered a potential public health risk. Cultural traditions may also influence management practices, as is the case with the Abono Village and Lake Bosomtwe, where domestic, industrial, agricultural, and overfishing activities resulted in detrimental impacts on aquatic biodiversity. It is important to consider, however, that these activities are all influenced by their way of life which is based around indigenous, religious, and cultural beliefs, management practices have to act within a complex arena balancing management priorities and traditional environmental practices of local peoples.

The susceptibility of aquatic biodiversity to anthropogenic influences are likely to be reduced with the development of further research, mitigation strategies, and policies. A global disparity in freshwater biodiversity focus exists, as was mentioned with the South African example. There is a significant lack of research and literature regarding freshwater biodiversity in the South African area when compared to other countries. Developing comprehensive policy recommendations at a local, regional, national, and international level, which focuses on aquatic habitats across natural boundaries and climate zones can optimize aquatic biodiversity conservation efforts.