Ecology Of Rivers And Coasts

Trophic cascades in rivers by Doctor Mary Power, PhD
The presentation chapter analyzes the various trophic feeding levels among aquatic animals. It explores how the interaction of herbivores, omnivores, and carnivores influence the habitats they live in. The presentation further explains how the animals naturally control their environment, for instance, animals influence the level of barrenness or plant cover on the soil. When there is a large population of animals, especially the herbivores, they feed more on vegetation along the trophic level which increases barrenness on land (Power N.p). On the other hand, other animals in the food chain influence their habitat and prey. Natural vegetation is also known to be influenced by many other factors including the climate and soil micro-organisms. Predation and hunger are also among the factors that controlled population.
River ecosystems
Water creatures such as fish, crabs feed on various foodstuffs in their habitats such as algae which grow on microscopic substances in water. Fish normally compete and move deep into the water to feed on algae which are extremely nutritious. The algae grow in abundance and faster in sunny pools as compared to shaded streams which not only have direct access to sunlight but also with plenty of nutrients. Therefore, to adapt to this phenomenon, water creatures such as cut fish are concentrated in sunny pools for feeding.
Trophic cascades in rivers can be maintained by taking care of water shades which are the primary source of water and habitat for most creatures.

A lot of biomass in most food chains is normally concentrated on lower levels of the food chain. For instance, in aquatic habitats, algae grows faster than in sunny pools thus feeding most grazer cut fish which are concentrated at such points. Therefore, algae can concentrate a lot of biomass enough to sustain small insects and fish in aquatic cascades. In clean water pools, a reversal can be made on any particular trophic pyramid. Research across various locations in the United States indicated that on average, algae grows faster and are feed on more quickly by fish.
In water masses, there can be a dense growth of algae bacteria underneath and above water surfaces with the production of cyanobacteria which is normally toxic as it depletes and prevents oxygen supply in water pools thus causing suffocation and death in trophic cascades. In the case of inverted biomass trophic pyramids, there can exist an imbalance in nature (Power N.p). In the event of an event when zero trophic levels exist, there will be plenty of nitrate concentration in water wells which might result in bearing blue babies. Algae can take on the excess nitrates and assimilate them into their nutrients for continued growth although failure to control the phenomenon would lead to eutrophication. This occurs when a lot of nutrients are carried through runoff thus causing the death of some animals living on land. The harmful effect of algae excessive growth can, however, be controlled through application of aquatic insect larvae which takes on the nutrients at two trophic levels although a problem of pesticides might arise.
To sum up, food chains should be maintained at many trophic levels to have cleaner watersheds. An apparent relationship is evident when minnows are added to a pool of one trophic level food chain in an aquatic cascade. Algae can grow taller and thicker in the absence of many grazers and predators.

Works Cited
Power, Mary. “2016 Holiday Lectures on Science”. YouTube. N.p., 2016. Web. 10 Nov. 2016.