The SCCF Marine Lab is hosting two Sanibel School 8th-grade science projects this semester. The school asked 8^th graders to come up with projects that were relevant and possible to complete by the first of December. Two students chose to look at the effects of climate change on water quality and ecosystem changes. 

Yuan Bonhayag chose to look at seagrasses based upon information he was too often hearing at home from his dad, SCCF Research Associate Mark Thompson. Yuan is an avid surfer and he put together his dad’s talking with an observation that the water around Sanibel has gotten hotter every summer to the point that he sometimes has to get out of the water to cool down.

Could the water really be getting hotter, and could the hot water be frying the seagrass? He sat down with his dad, and they came up with a plan to address the proposed problem with an experiment.

Meanwhile, in another remote part of Sanibel, 8^th grader Grayson Goessling was concerned that algae blooms were becoming more widespread around Sanibel and people were saying the blooms could be harmful. SCCF’s Sanibel School representative Richard Finkel guided Grayson to the Marine Lab for the development of an experiment that could look at climate change influences on the increase in algae blooms.

“I have been analyzing water temperature data taken over the past 15 years in shallow areas where seagrass has disappeared,” said Thompson. “There has been an almost linear increase in the mean hourly water temperature in areas where seagrass was lost.”

While Yuan was wondering if seagrass was being harmed by increased water temperatures, Grayson found in the scientific literature that rising water temperatures caused by climate change may also be affecting the growth of algae. He developed a hypothesis that rising water temperatures may increase algae blooms.

After discussion with their host mentor, the students agreed to have three tanks: one control, one treatment with a water temperature of 91°F and one with a water temperature of 98°C. The control would simulate temperatures the seagrass experiences in a typical October-November season in Florida.

Thompson’s data showed that seagrass now typically experience greater than one week of temperatures continuously above 91°F at shallow water sites (Treatment 1). The data also show that temperatures often exceed 98°C for shorter periods (Treatment 2).

Both students settled on looking at one of climate change’s most noticeable effects on the environment — rising temperatures. Yuan would ask if rising temperature caused seagrass to go away while Grayson would ask if rising temperature would cause algae blooms to be more prevalent. Because both hypotheses involved having a temperature-constant bath, they set up one which they both could use. Yuan’s seagrass is growing within the same bath that Grayson’s containers of algae are resting in.

Grayson and Yuan will both analyze water quality data using YSI water quality sensors. The sensors are able to measure the concentration of chlorophyll a and phycoerythrin pigments in the water, which are good measures of how much algae is in the water, while an increase in either means more algae.

Yuan will also count seagrass shoots before and after the experiment and will weigh the biomass of seagrass in each treatment and compare differences.

“The design and implementation of this experiment will give the students a full dose of the thrill of science,” said Thompson. “Asking questions, posing problems, designing tests to answer the questions they pose, and then asking more questions. Through application, science can become a wonderous process for discovery.”