Experimenting with different variables in a controlled environment.
- Experiments on habitat (raising and lowering water temperature)
Problem-
Due to climate change, seawater temperatures will rise dramatically (especially at the current level of temperature increase). Consequently, this will not only result in the bleaching of coral reefs, and the death of many other ocean organisms, which not only reduce and possibly remove many habitats for countless species but will also decrease the biodiversity of ocean life. Specifically, and in regards to oysters, we will measure how these organisms react to rising and dropping sea temperatures (in order to mimic what may come in future years and what already occured in previous years).
Question & Methodology-
What will happen to the oysters in higher temperatures than they are used to? What will happen to them in temperatures lower than they are used to, and in comparison to Hong Kong’s natural ocean temperatures? Oysters prefer water to be around 7 degrees C (not the local Hong Kong Crassostrea hongkongensis and magallana hongkongensis, which are used to local water temperatures. And those are the ones we will be using), and preferably not higher than 10 degrees C. Using our oyster lab, we intend to raise and lower the temperature of the water in each of the oyster tanks to mimic the rise and fall of global temperatures (due to global warming and environmental recovery).
Experiment, Measurements, Observation And what we will evaluate-
Using an aquarium chiller/ heater, we will raise the temperature of Hong Kong seawater by 1.5 degrees gradually, which is the normal rise in ocean temperature over several decades, rising approximately 0.3 degrees every week. The oysters will remain in the same tank for the entire course of this experiment for 4 weeks. We will observe the oysters closely to monitor the thickness of their shells. The thinner the unhealthier and the thicker, the healthier, and more nutritious. We will also measure the amount of food the oysters need. If the ocean temperature rises and they require more food, that is counterproductive as increasing ocean temperatures decrease the amount of food present in the oysters’ habitat. Present in the oysters’ habitat. However, if they adapt to require less food with increasing ocean temperatures, then we know that they are capable of surviving as global warming gets more intense. In addition, by lowering ocean temperatures, we will also see if the oysters react positively to the change, as is expected since lower temperatures were their natural birth point.
- Experiment on habitat (raising and lowering pH values)
Problem-
Acidity levels are rising in Hong Kong waters, and oceans around the world as gases, rising temperatures, oil spills, and other chemicals are distributed into the sea. According to EPA, ocean acidification has increased by 25% from preindustrial times until the 21st century, a rate higher than ever recorded. Thus, sea creatures will experience a different breathing percentage than they are used to. Although some may adapt and thrive anyhow, we want to explore how oysters will react to lowering pH levels and measure their health (in order to mimic how they might react to an increase in ocean acidity).
Question & Methodology-
How will oysters react to lowering ph levels (increase in water acidity)? Will they adapt to higher levels of acidity in order to maintain their health and shell thickness? Will they filter the same amount of water, and with the same efficiency? Or will they react negatively and start dying? This is crucial to understanding the different effects acidity will have on the oysters’ health.
Experiment, Measurements, Observation and what we will evaluate-
Using carbon dioxide, we will lower ph levels in order to measure the health of the oysters as they respond and react to rising ph levels, we will use Hong Kong seawater. In order to increase ph levels, we can add ph to the water using kits we found in Mong Kok. Using a pH Meter to track the pH levels and adjust the pH. We will slowly introduce different levels of pH to see which is optimal for the peak of the oyster’s health and success. Generally, higher levels of ph show thicker oyster shells (healthier), whereas lower levels of ph tend to show thinner, less healthy shells in oysters and clams.
