Articles published for Earthzine’s Water Availability theme (Sept. 23-Dec. 21, 2011) address current issues, techniques…
Education Around Earth – Andros Island, Bahamas Coral Reef Ecosystem is Living Laboratory for Students
- Published on Saturday, 26 September 2009 00:01
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Earthzine: Why study Andros Island in the Bahamas?
Wiedman: It is one of the most remarkable and least explored places in North America—and it is a very pleasant place to be! Andros Island is the largest, yet least densely populated of all the inhabited Bahamian islands, and it is home to the world’s third largest barrier reef complex. And, as far as our students are concerned, even though it is a mere 140 miles from Miami, it is an ocean away! The proximity of the Bahamas to the U.S. allows students to participate in an international research project two or three times per year. Typically the trips occur during our Christmas break and our annual spring break in March, and, as possible, over the summer.
Earthzine: In any international research project, mutually beneficial relationships and cooperation are obviously cornerstones for success. What is required for your team to conduct research on Andros Island in the Bahamas?
Wiedman: Our research requires a permit from the Bahamian government. It stipulates that schools in the Bahamas be involved in the project. We have had the pleasure of working with several terrific students and biology teachers from local Androsian high schools. They collected data along with high school students and college students from the University of Saint Francis, as well as other Midwestern colleges in the U.S. Some of the schools that have been involved in the project include DePauw University (Greencastle, Indiana), Miami University (Oxford, Ohio), Hocking College (Nelsonville, Ohio), Wright State University (Dayton, Ohio), and Monmouth College (Monmouth, Illinois). We have also had strong involvement from Cody High School in Cody, Wyoming, and we work closely with representatives from the Bahamas National Trust, which is the non-governmental organization that oversees the national park system.
Earthzine: Why study reefs specifically?
Wiedman: Reefs are constantly changing. They have undergone stress historically and prehistorically that has shaped them into what we know today. For example, the Great Barrier Reef complex of Australia was not always there and certainly has waxed and waned through time. The Androsian reef, part of which has been designated as a national park in the Bahamas, seems to be increasing in reef-builder diversity. Our team was challenged to study this dynamic without influencing the natural progression of the change by establishing a multifaceted protocol that:
• would provide meaningful, testable, and quantifiable data
• could be passed “seamlessly” from one student generation to the next
• must be unobtrusive to the reef inhabitants, and
• leave no short term or permanent traces or scars in the newly designated protected areas.
Earthzine: How did you and your students ultimately design a research project to observe environmental changes without influencing them by your presence?
Wiedman: After several iterations, a plan using underwater, digital photography was selected using six to ten patch reef sites in shallow water (<4 meters depth) for repeated observation and documentation. Two sites were on artificial reefs that have sprung up on wrecked ships from the 1950s and 1970s. These provided nearly flat sampling sites in the mix. This eliminated the need for the entire team to be on scuba, allowed for maximum light, and saved training and site costs. It also allowed for a broader base from which to select student participants.
The reefs selected were each between 30 – 50 meters long with height limited by the water depth along the eastern coastline of Andros Island within easy travel of Forfar Field Station, Big Pond Settlement, which is our base location. The idea was to create photo montages from 70-100 images taken along uniform lines from a vantage point along a line two to three meters along the reef face. The single images were reconstructed using Photoshop II software. We used a bowling ball painted with wedges of blue, red, and yellow of known spectral values for scale and color control. When the images were reconstituted, the colors were set on the ball to the known values and all other parts of the image were dragged along proportionally in a way that the effect of the water depth was mostly nullified.
A shareware program, Image J, allows for unlimited sided polygons to be created around coral colonies or other features, such as areas of strong herbivory. The software provides surface area data for the enclosed forms. The areas will then be followed through time, with additional ones added through the research duration, which is expected to be 15-20 years. Current sites include patch reefs where no Diadema have returned thus far and those where Diadema seem to be on the way to being well established. Diadema are nocturnal feeders so it is only the results of theirs and other less voracious algal feeder herbivory that, in effect, are being documented. In the future, we plan to add remote sensing analysis to our study as well.
Earthzine: That is an interesting research methodology. Have you encountered any problems?
Wiedman: Yes, we discovered that observing the reef means observing the skies above the reef. Weather significantly impacts underwater photography! Lighting is not adequate when observations are not taken near high noon, and the weather sometimes does not allow for safe site visits. Water clarity is also critically important. Due to these challenges, some locations along the reef don’t have continuous, equally spaced temporal records. Also we have discovered that using a diver on scuba taking the photos with one support scuba diver and surface snorkelers works best because it keeps the water from becoming turbid. The photographer also has to be heavily weighted to maintain control while moving along the photo line. The current data are being analyzed now, but it appears that the protocol is proving successful.
Earthzine: So, what have your students discovered?
Wiedman: Let me preface my answer by pointing out that there has been significant change on Andros Island. Even before our team started studying in the Bahamas, both humans and nature significantly altered the island. From clear cutting of indigenous Bahamian pine trees for cardboard pulp in the 1950s through 1970s to the apparent natural mass mortality of the greatest “cow of the reef,” the long-spined urchin, Diadema antilarrium, in the early 1980s, the island has seen its share of changes. The good news all around is that the local folks and the Bahamian government have recognized the need to preserve this precious jewel from additional anthropogenic changes as much as possible. Multiple, large tracts of what are perceived to be the most threatened areas of the island were designated in the late 1990s as a land/sea park. The government of the Bahamas is trying to preserve at least the island’s most endangered land and offshore inhabitants, which include the Andros Island iguana (which is the largest in North America), the land crab, flamingos, and the reef inhabitants, especially the spiny lobsters and the Nassau groupers.
But, to answer your question specifically, our students are documenting the effects on the reef as Diadema has started a natural reintroduction from up current sources near Jamaica, where small pockets of the creatures were missed by the virus or bacterial infection that wiped out over 98 percent of the Diadema population. Lionfish, through inadvertent introduction associated with Hurricane Andrew in 1993 and suspected unwanted pet releases since then, have created a viable, rapidly expanding population of ambush predators in populations where the prey are unaccustomed to a new threat and nothing seems too interested in using them as a food source. All the while, local sea temperatures are following regional trends in heating slightly. One might assume that this is yet another doomsday scenario waiting to happen, but perhaps not. We think the removal of marine macro algae from the reefal patches by the returning urchins has opened up niche space and habitats for the reef-building hard and soft corals and sponges.
Earthzine: So, what have been the most significant learning outcomes for the students?
Wiedman: I would say that introducing research into the curriculum in high schools and in bachelor’s degree programs is one of the most important aspects of student learning. It is important that students have the opportunity to be actively involved in studying changes in the planet that impact people through systematic scientific methodologies that are not premised on supposition, but instead support data-driven decision making. The project has shown all involved that science is frequently done through collaboration–and that includes diligent folks at all educational levels. For University of Saint Francis’ students, it also allows them to be actively involved in finding the point at which faith and science meet. The university is founded on Franciscan values, one of which is to respect creation, and that is what this project is about. We are documenting changes on Andros Island unobtrusively because we respect the island, and we want others to have respect for it as well. It also has allowed more than 20 University of Saint Francis students to publish and present their results at international and domestic conferences and in peer reviewed journals. That is a great empowerment tool for those interested in graduate or professional studies! Before they became involvement in the project, many of these students had never been outside the U.S., seen saltwater, or flown in a small plane! There are so many additional benefits, they are too numerous to list.