Kealia Pond California Bulrush Eradication Study

Kealia pond national wildlife refuge is one of over 500 refuges in the United States. This refuge is a home to endangered native water birds. The two endangered species that needs to be saved are the Hawaiian coot and Hawaiian stilt. The Hawaiian coot is endemic to the Hawaiian Islands. Its natural habitats are freshwater lakes, freshwater marshes, coastal saline lagoons, and water storage areas. This endangered species is threatened by habitat loss. The Hawaiian stilt is also endemic to the Hawaiian Islands. Its natural habitat is coastal ponds and fish ponds. This endangered species is also threatened by habitat loss. Some native plants that can be found in the Kealia Pond are saltgrass and sea purslane. They are very helpful to the animals in the Kealia Pond because they provide homes for them. However, the invasive plant that needs to be eradicated is the California Bulrush. They can be found typical in a clump of 10 feet x 100 yards in marshy areas. They grow to a height of 1-2 meters and their roots can grow to a minimum depth of 36cm. However, they have no tolerances for shade. This invasive plant is not providing homes for the animals in the Kealia pond. This directly affects the endangered species because they can’t find a good place to hide their eggs and themselves so their prey are finding them more easily and killing the endangered species and their eggs. This is a problem because their numbers are declining and if this keeps on happening there wouldn't be any Hawaiian coot or Hawaiian stilt.

The significance of this study is important for the tourism on Maui because some tourists come to this island for bird watching and if there are no birds to watch then, there might be less tourist coming to the island to watch birds which will impact Maui’s economy. It’s also important to the Kealia Pond because if the California Bulrush keeps on growing all around then that provides fewer homes for the animals. However, this study is extremely important to the endangered species because we are providing them more homes and preventing less from being taken away.

This is a picture of the Kealia Pond. ^

So as a class we separated into three different groups and each group was responsible of taking data on their specific study area which could have been either the spray area, the cut area, or the spray and cut area. We also had a control area and that data was collected by the group of students that got completed first with their data for their specific study area. The data that we had to collect was how big the study area was, salinity, water temperature, air temperature, plant height, pH, turbidity, weather condition, water depth and finally density. However, due to unexpected pond conditions some of the data was unable to be collected. Then, after 14 days we went back to Kealia pond to collect post data for each of the study areas. So that we could figure out what treatment was the best to eradicate the California bulrush.

This is a picture is of the spray area.^

This is a picture is of the cut area.^

This is a picture is of the spray and cut area.^

This is a picture is of the control area.^

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Graphs

This is a graph of the height of the Bulrush before the treatments.^

This is a graph of the density of the Bulrush before the treatments.^
This is a graph of the height of the Bulrush after the treatments. ^

This is a graph of the density of the Bulrush after the treatments.^

In conclusion the treatment that worked the best out of all the three treatments was the spray and cut. The reason why is because if you look at the results on my density post treatment graph you will see that there was a greater amount of dead bulrush than the other two treatments. I believe this treatment is the best because the bulrush was cut so low that it got exposed to shade and the spray also helped by speeding up the killing of the bulrush.