There are two major trophic cascades that scientist use. One is called bottom-up and the other is top-down. The controller of top-down would be the top predator or the apex predator (Wallach and O’Neill, 2009). The apex predator can also be known as the keystone species in that ecosystem. Top-down control is when the apex predator regulates the structure and population of the ecosystem (Wallach and O’Neill, 2009). The apex predators will prey on the consumers, which keeps the consumers population in control so that the producers can survive. This way top-down control keeps the consumers from over populating and destroying the structure of the ecosystem. Bottom-up control is basically the opposite of top-down control. In bottom-up, it is the
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In California, the top-down control for oysters is being destroyed by invasive species. With a normal top-down controlled environment, the top predator mostly consumes the intermediate consumer (Kimbro et al., 2009). Without the top predator, the intermediate consumers would eat all of the basal species (Kimbro et al., 2009). This is why top-down control is needed, to stop the intermediate consumers. Invasive whelks are starting to incorporate themselves in the California bay area. The normal ecosystem functions with native crabs consuming native whelks, which then consumes the oysters (Kimbro et al., 2009). Except now the area has invasive whelks. The native crabs are the natural top predators in the ecosystem but the invasive whelks have a protection against the native crabs (Kimbro et al., 2009). This causes the crabs to not be able to hunt the invasive whelks. The invasive whelks then have complete control in this ecosystem and over consume the oyster population. With the top predator not able to consume the intermediate consumer, the top-down control is lost. The intermediate species now has complete control and consumes all of the basal species, since there is nothing to stop them. The ecosystem is then lost to the invasive species, which now has the power to control it. Invasive species are able to completely disrupt the top-down control by breaking the order of top consumer to intermediate consumer to basal species. With invasive species, any control in the ecosystem is completely
In California, the top-down control for oysters is being destroyed by invasive species. With a normal top-down controlled environment, the top predator mostly consumes the intermediate consumer (Kimbro et al., 2009). Without the top predator, the intermediate consumers would eat all of the basal species (Kimbro et al., 2009). This is why top-down control is needed, to stop the intermediate consumers. Invasive whelks are starting to incorporate themselves in the California bay area. The normal ecosystem functions with native crabs consuming native whelks, which then consumes the oysters (Kimbro et al., 2009). Except now the area has invasive whelks. The native crabs are the natural top predators in the ecosystem but the invasive whelks have a protection against the native crabs (Kimbro et al., 2009). This causes the crabs to not be able to hunt the invasive whelks. The invasive whelks then have complete control in this ecosystem and over consume the oyster population. With the top predator not able to consume the intermediate consumer, the top-down control is lost. The intermediate species now has complete control and consumes all of the basal species, since there is nothing to stop them. The ecosystem is then lost to the invasive species, which now has the power to control it. Invasive species are able to completely disrupt the top-down control by breaking the order of top consumer to intermediate consumer to basal species. With invasive species, any control in the ecosystem is completely