The Effects of Zebra and Quagga Mussels Introduced into a Freshwater Lake - Lab Report Example

Purpose The purpose of this experiment was to study the effects of the invasion of the Zebra and Quagga mussels on the species found in a new ecosystem.Introduction The introduction of Zebra mussels to the Great Lakes has been found to have drastic consequences on the ecosystem. The mussels filter feed on phytoplankton suspended in the water. The phytoplankton serves as food to the zooplankton that is a food source to various fish such as salmon and whitefish found in the lakes (National Wildlife Federation, 2014).

As the number of Zebra mussels rises, there is a corresponding reduction in the biomass of fish (Benson, Raikow, Larson, & Fusaro, 2012). The mussels produce pseudofecal matter composed of minute unpalatable material bound in mucus. This is deposited at the bottom of the lake bed and then undergoes decomposition, yielding nutrients such as phosphorus and nitrogen that then accelerate the growth of algae species (Vanderploeg, et al., 2001).Hypothesis If the population of the Lake Trout is related to the population of phytoplankton, then the introduction of Zebra and Quagga mussels to the Lake Trout’s ecosystem will lead to a drop in its population.

Method Using MUSE, the numbers of phytoplankton, zooplankton, Cladophara, Foraging fish and Lake Trout were recorded at intervals of 0, 4, 7, 10, 13, 16 and 20 years after the introduction of the Zebra and Quagga mussels to the ecosystem.Results The recorded results showed that the population of the Zebra and Quagga mussels, as well as the Cladophora biomass,  increased rapidly from 0-13 years. It then decreased in subsequent years (16-20). Conversely, the populations of phytoplankton, zooplankton, Foraging fish and the Lake Trout decreased from 0-13 years and then increased afterwards.

DiscussionThe population of the mussels rose up to the point where the available phytoplankton could not sustain their survival, resulting in a large number dying off. This led to a subsequent drop in the biomass of Cladophora algae because of the reduction in the number of nutrients available. As the population of the mussels dropped, there was a slight increase in the population of the phytoplankton. This lead to a subsequent rise in the population of the species dependent on it both directly and indirectly.