User:Kentrae/Biomanipulation

= Biomanipulation = Biomanipulation is the deliberate alteration of an ecosystem by adding or removing species, especially predators. The addition or removal of a species from a particular environment effectively manipulates the food web of that environment, thus triggering a ripple effect in which all characteristics of its ecosystem are subjected to minor or even drastic changes.

History
The term Biomanipulation was first coined in 1975 by the limnologist Joseph Shapiro (1929-2017) during his experimental study to establish an alternative method of restoring overfertilized, alga laden lakes and reservoirs by manipulating fish populations. Today it is popularly used as a method to regulate or alter ecosystems and the food chains therein.

Terrestrial Ecosystems
Biomanipulation in terrestrial ecosystems is oftentimes conducted in the form of species reintroduction. A species is introduced to an ecosystem that it was once very prevalent in or is capable of successfully surviving as a conservation effort. The manners of which the newly reintroduced species affects the ecosystem both biologically and physically are then closely analyzed. This is popularly done with a predatory, threatened, or endangered species. The utilization of methods of biomanipulation on a terrestrial ecosystem can have extreme impacts on both that ecosystem’s food chain and terrain.

Case Studies
Case studies of the effects of biomanipulation on a particular ecosystem are conducted one or two decades after the initial introduction or population reduction of a species occurs. This allows time for the effects to concretely manifest themselves within that ecosystem. The effects are then carefully observed and analyzed usually by the same researchers who initiated the original manipulation of the ecosystem.

Wolf Reintroduction in Yellowstone Prompts Changes in River Flow.
The reintroduction of grey wolves to the Greater Yellowstone Ecosystem in 1995 drastically changed the environment. The presence of a strong predator such as the wolf affects every aspect of the ecosystem ranging from the behavior of other species to the physical characteristics of the park’s terrain. The reintroduction of wolves triggered a tri-trophic cascade involving wolves, elk, and plant species. The Elk population saw a decline or nearly 41% as the number of wolves present in Yellowstone increased from 0 to 98. Subsequently, plant species such as the woody browse and canopy grew taller in some places and both beaver (Caster canadensis) and bison (Bison bison) numbers increased. The increase of the beaver population led to more dam engineering which in turn altered the flow of the park’s rivers. The wolves also indirectly caused the flow of the river to become fixed as rivers adjusted their flow to the restoration and stabilization of forests thanks to wolves preying on grazing species. Erosion of rivers decreased and formation of river pools increased. The introduction of wolves to Yellowstone effectively altered the geography of the ecosystem. Marine life consequently increased along with other animals such as rabbits, mice, bears, and eagles.

Examining Methods of Biomanipulation to Control Cyanobacteria Blooms
Methods of Biomanipulation are reviewed through limnological literature in a 2015 experiment of reducing cyanobacteria through natural, chemical-free, and cost-efficient means in order to restore lake and pond ecosystems. The study is conducted by Triest Ludwig, Iris Stiers, and Stijn Van Onsem. A total of nine case studies and meta analyses were conducted to assess the consequences of biomanipulation through fish removal. Methods included piscivorous addition, daphnia addition, macrophyte reintroduction, bivalve stocking, fish removal, and the addition of filter-feeding fish. Fish removal resulted in weakened dominance of cyanobacteria in the ecosystem. The colonization of macrophytes resulted in the enhanced stability of a clear-water state. However, the competition for nutrients with phytoplankton coupled with provision of shelter for zooplankton and allelopathy make it unrealistic to apply biomanipulation methods on after the development of large beds of macrophytes. The addition of piscivorous fish proves to have some advantages compared to traditional fish removal, but is oftentimes less successful. Consumption of omni-planktivorous by filter-feeding fish species prove to have very little success. Daphnia addition proves successful in improving water quality of Lake Shirakawa in Japan and reducing alga abundance & microcystic blooms. Overall, the methods prove to have some success, even if only successful in certain areas of analysis. However, more detailed information on how to control cyanobacteria blooms and the ratio of cyanobacteria to phytoplankton is required.