Taking cores in the fishpond

Hi everyone, I am so glad we set all our cages and no cages in the fishpond. Last week, we spreaded beads into certain cages and took sediment cores as well as bead cores from the cages and put them into the labelled bags.

In order to take a sediment core, we need a large plastic core and a cap used as a stopper. After we took a core, we need to set the sample core on a iron standing whose top part is a small rubber platform to push the sediment upward. As the sediment sample was pushed close to the edge of the core and all the water ran away, we put another 5-centimeter-high plastic ring on the upper edge of the core. When the sediment was pushed to the upper edge of the 5 cm ring, we use a small shuffle to cut through the space between the plastic ring and the core. Therefore, the top 5 centimeter sediment from the fishpond bottom was taken for lab analysis.

Another interesting experiment was the bead experiment. The bead is fine, white powder that is not dissolvible in the water. The purpose of this experiment is to test how deep infaunnas can burrow into the sediment. We take cores from the randomly selected position in the cages and take sediment samples from each centimeter and count the bead we can see. In order to minimize the inaccuracy, the bead must be spreaded evenly in each cage area. Later, we took cores just like we did for the sediment cores, and take samples from each centimeter depth and put them into labbeled bags. One thing about the sample is we have to measure the volume of the sediment by putting them into a plastic graduated cylinder. When all samples go to lab, we can count the bead under microscope.

It was a very productive and exciting week in the fishpond. I have learned how to design an experiment, how to layout different cages, and how to take cores from the fishpond.