By Nathaniel Hanna Holloway
The last two months of the summer have been action packed here at CIEE Research Station Bonaire. For the second time we offered our 8-week STEM intensive program and we were lucky enough to have six young, aspiring scientists sign up and make their way down to Bonaire to dive right in. In addition to our scientific diver bootcamp, which includes our Marine Ecology Field Research Methods and Advanced SCUBA courses, the STEM students participate in a Coral Reef Ecological Research course. The Ecological Research course, we call it ER for short (but not to be confused with a visit to the Emergency Room), is the heart of the STEM program; the course is project-based and exposes the students to real world collaborative research focused on important questions in coral reef ecology. This summer we had two projects and two groups of students led by instructors working on each project. One project investigated the impact of Artificial Light at Night, or ALAN, on plankton and marine benthic organisms, and another used large-scale photomosaics to assess the recovery of the reef after it was damaged, particularly looking at excavating (or boring) sponges.
The ALAN project looked at the impact of artificial light at night on plankton and marine benthic organisms like hermit crabs and sea anemones. The researchers were curious to see if certain organisms were attracted to the light or if they remained outside of the lit area. The project was completed off a pier that was isolated from artificial light, allowing the researchers to control the timing and location of the artificial light by setting up their own artificial light source.
The students performed several night dives to complete the benthic surveys using a really cool, and cutting edge, technology called fluorescence. Using fluorescence to identify and record hard to see critters that live in the shallow sandy area off the pier is achieved using a blue light and yellow filter worn over the observer’s mask. Through the yellow filter the researchers can see bright, neon colors that are emitted from the marine benthic organisms. They also performed several plankton tows to collect plankton. Once the plankton tows were completed the students spent numerous hours counting thousands of microscopic organisms in the lab. One interesting result from the project was a higher abundance of hermit crabs were found in the dark area, not in the artificial light section.
In August 2015 a large metal chain was dropped on a small portion of Bonaire’s coral reef that caused damage in the form of broken and dislodged corals. The photomosaic project investigated the impact of the damage to the coral reef, particularly looking at the effect on the excavating, or boring, sponge community. The researchers were curious to see if the damage to the reef would cause an increase in boring sponge abundance and if photomosaics are a good tool to assess the boring sponge community. Photomosaics are large-scale (covering 50-100 square meters of the reef), high resolution digital images that are created by stitching together thousands of individual digital images that were taken of the reef. To compare the damaged area to an undamaged area the students established a “reference” plot 15 meters away from the damaged plot and collected sponge data and photomosaic images for both areas.
The students performed several dives to survey for sponges and collect the photomosaic images and then spent hours upon hours in the lab tracing and identifying benthic components in the large-scale photomosaics. There were a few surprising results from the project; one being that photomosaics are a great tool for determining percent cover of different benthic components on the reef but they in fact are not a good tool for investigating boring sponges. The photomosaics don’t represent the areas where these particular sponges tend to live very well (usually on the under side or vertical faces of exposed coral reef) and therefore the sponges simply can’t be found in the large-scale photomosaics. However, the sponge surveys performed in the field did show a higher abundance of boring sponges in the damaged plot than in the undamaged reference plot and the photomosaics showed about 20% less living coral in the deeper part of the damaged plot compared to the undamaged reference plot.
In addition to all the grueling laboratory and field work both groups prepared a research paper and delivered two very well received presentations to the public. Both talks were well attended and thought provoking and everyone one was very impressed with the herculean effort and the quality of the student’s work. All of us here at CIEE know that each and every one of these STEM students will go on to do great things.