Greetings from Heron Island, on Australia’s Great Barrier Reef! I am writing this blog entry from the top bunk of a bed in the Heron Island Research Station, located on a coral cay—a relatively small, unfixed pile of calcareous coral skeletons—60 kilometers off the Queensland coast. The best word I can use to describe Heron Island is ‘paradise.’ The consensus among us is pure happiness: we’re taking in sights that could rival a postcard, eating like royalty, snorkeling daily, and learning about the largest coral reef system in the world. Yet only two weeks remain of the Australia spring 2011 program, and most people are having a difficult time accepting that reality.
Heron Island is paradise, but it is not immune to bad weather. Queensland is experiencing the rainiest summer in over one hundred years, and we’re feeling the effects out here. It was pouring the entire afternoon yesterday, but we didn’t let the water interfere with our plans (more on that later). I am pleased to report the sky cleared up in the evening, and it was clear enough to view the sunset, and later, the arch of the Milky Way bend across the entire night sky.
Wednesday was quite a day! We began with a lecture by marine biologist/conservationist Tim Stevens on the ecology and identification of reef fish. There are 92 families of bony fish and 19 families of sharks and rays on the Great Barrier Reef. We learned key characteristics of only a few of the most common families of reef fish, including wrasses, parrotfish, butterfly fish, damselfish, groupers, and gobies. Then we immediately put what we learned in that lecture to practice, in a snorkel on the reef flat. The coral was spectacular. We saw colonies of branching coral that extended far past the eye could see, and brain corals the size of boulders. The current was incredibly powerful though, and grew increasingly more so throughout the course of the snorkel. Attempting to swim against the current in the direction we were supposed to head was futile, and most groups abandoned the cause after about 45 minutes.
An afternoon snorkel provided us with another chance to observe the reef ecosystem we’ve been learning about. This time we took a boat to the leeward side of the island for a drift-style snorkel to a spot on the reef edge called Blue Pools. Drift snorkeling took a lot of the stress and frantic fin flipping out of our snorkeling experience: the boat dropped us off and we simply let the current push us along the reef edge until we reached Blue Pools, a deep but protected inlet along the edge. The boat followed us from a distance and picked us up when the snorkel was over. While all this sounds quite pleasant and serene, I must stress that while we were suiting up and riding over to our snorkel spot, we were caught in a torrential downpour that changed the color of the water surrounding the island from crystal aquamarine to dreary shades of gray. The cold, ominous weather lowered the group morale a bit, but once we were in the water and snorkeling, I (and I’m assuming most people) forgot all about the miserable weather.
Jumping into the water and taking the first look at my surroundings took my breath away because the depth of the water and my inability to see the bottom shocked me. Once Melanie (my snorkel buddy) and I reached the walls of coral that compose the reef edge, we immediately observed that there were even more animals there than on the reef flat, and some were different from the usual suspects we saw on the flat. We saw a metre-long grouper on the sand, delicate orange anemone fish, various flashing rainbows of parrotfish whizzing past, and dazzlingly yellow butterfly fish pecking delicately at the coral. My personal favorite is a species of damselfish: they swim in very large schools that look like diffuse glittering blue clouds below. They’re only a few centimeters long and an electric sky blue color. These fish are not timid like most of the fish we observed, which gave me the opportunity to get a good look at them. Most people in the group were lucky enough to see a powerful reef shark swimming below. I was keen on the shark, but the highlight of my snorkel was the two loggerhead turtles I observed. Drew and Ryan have both informed our readers about the turtle hatching events we’ve had the privilege of witnessing this week. After seeing the vulnerable, four-centimetre long hatchlings scurry through the gauntlet of gulls and ghost crabs out to sea, seeing an adult turtle was quite gratifying: it was a reminder how beautiful, massive, and powerful those hatchlings will become if the 1/1000 odds of surviving past infancy weigh in their favor. The giants we observed moved so slowly and gracefully in the water, and were prehistoric looking, like dinosaurs. They had the entire group mesmerized, to say the least.
Later that night we had the privilege of hearing a lecture on sea turtles by Tim Harvey, the manager of the Heron Island Research Station and founder of the Sea Turtle Foundation. Before coming to Heron Island, I had no idea I would ever in my life be able to watch sea turtle hatchlings scurry to the sea. But apparently, North Queensland has some of the most robust sea turtle populations in the world; the beaches of Heron Island are the nesting grounds for thousands of sea turtles each year. Heron Island is home to three of the world’s seven sea turtle species: the Green, Loggerhead, and Hawksbill sea turtles.
While the sea turtle population on the island is stable compared to other places in the world, it has declined significantly over the past 90 years. From 1923 until 1932, Heron Island had a turtle soup cannery on it. Then, after the tourist resort was established in 1935, a popular holiday pastime here was turtle riding. I’m not joking: tourists used to wrangle nesting turtles on the beach, flip them over so they were incapacitated, and then come back the next morning to attach bridles around their necks that allowed people to literally surf on the turtles’ backs.
I’m happy to report the tourists on the other side of Heron Island (we’re on the research side!) don’t partake in such activities anymore, though turtles are still faced with numerous threats that extend far beyond the seagulls that pick them off at birth: many are struck by boats or caught as by-catch due to certain practices of the modern fishing industry, including the use of purse seines and trawlers. Others are injured or killed by renegade fishing line or ghost nets (old, unattached nets that float around and indiscriminately trap everything in their path). Rubbish and runoff are harmful to turtles too. Many turtles suffer from a disease called fibropapiloma, which is caused by pollution runoff from hog farms. Other sea turtles have been found with rubbish in their stomachs or caught around their necks. Sea turtles have existed for approximately 120 million years, but because of human impact on the marine environment, they are threatened by extinction.
Like Wednesday, Thursday was an academically and experientially stimulating day on the island. After brekkie Tim gave us a lecture on the life histories of reef fish. This lecture explored the varying reproduction strategies of different fish in the coral reef ecosystem. We learned that sharks and rays are gonochorisic, meaning they do not undergo sex change throughout their lifespan. In contrast, most bony reef fish are hermaphodites. Protogynous fish are born female but may become male when they reach sexual maturity. Protoandrous fish are the opposite, changing from male to female. One fascinating example of a hermaphodite reef fish is the wrasse, from the family Labridae. These fish have a complex social system in which one male lives with a harem of females. If the male dies or is removed from the group, the dominant female will undergo a sex change and replace the lost male. This transformation occurs incredibly rapidly: only a few hours after the male has been removed, the dominant female begins showing male colors. Within a few days she is a fully functional male.
During our time on Heron Island, students have been responsible for undertaking two field study research projects. Most of Thursday morning was dedicated to going into the field to gather data for our various research questions on reef fish. Then we presented our findings that afternoon. I was in a group with Melanie, Delaney, and Rebecca. We were interested in reef fish feeding frequency and how it relates to different species’ defensive strategies. In order to collect data, we went snorkeling on the reef flat and compared the feeding frequency of butterfly fish to that of damselfish. Our observations did not support our hypothesis, because we found that while the two species feed in quite different ways, they both feed more or less constantly. Our research question was interesting and relevant, but we had a difficult time collecting data. This project gave me renewed appreciation for marine biologists, because collecting data on fickle and/or timid fish while battling a strong current and keeping track of the tide schedule is not easy!
I was interested to see what other groups found in their field studies. Marni, John, Hanah, and Katy observed fish schooling behavior, and whether or not it was correlated to coral type. Their observations did not support their hypothesis; fish do not tend to school more on one coral type than another. Anna-Brooke, Ryan, Allison and Drew studied butterfly fish feeding strategies, and whether or not the fish prefer a certain type of coral. Their field observations supported their hypothesis; butterfly fish prefer branching coral, probably because the coral is small enough for their minute mouths. The research question for Dick, Jared, Kathryn and Sara’s group was similar, only regarding parrotfish. They wanted to know what type of coral parrotfish prefer to eat. They found overwhelmingly that parrotfish prefer branching coral. The parrotfishes’ preference—like that of the butterfly fish—may relate more to mouth shape and structure than anything else.
After the sunset and dinner came the highly anticipated night snorkel. This may sound like a dark and dangerous activity, but don’t worry readers, we were looked after very carefully. To prepare, we suited up, attached glow sticks to our snorkels, grabbed our underwater flashlights and made our way down to the jetty. From there we were dispatched in the harbour in groups of five or six, and led by an expert. Night snorkeling is completely different from snorkeling during the day (especially when it’s sunny). It’s difficult to explain what I mean, but it just feels different: instead of seeing a busy reef with countless species of fish swimming in all different directions, at night it is still. That does not by any means imply the reef is lifeless at night, but the fish that are typically darting about during the day are asleep. Also, the nocturnal fish are much better at hiding and making their presence unknown. The coral looks different too; it is an eerie, ghostly white at night, because the sunlight—which gives it so much of its color—is absent. The various snorkel groups all saw giant sleeping sea turtles. One person described them as small submarines on the sand bottom. Our presence woke some of the turtles, however. Drew and Dick had a special moment with a turtle that swam with them, and then came right up to them on the surface and looked them both in the eyes. At night one can observe coral polyps feeding (it looks like they’re blooming), plankton floating, and fish sleeping. Looking up at the crisp night sky and seeing the Milky Way, the Southern Cross, and the crescent moon, and then putting my face into the water and observing a huge puffer fish on the Great Barrier Reef, provided me with a reminder that 1) I am in Australia, and 2) I am a very small human being in a very large ocean, world, and universe.
Having moments like that make me love and value traveling so much. With only 11 days left in Australia, I have been reminiscing about our time spent learning about this spectacular country. We have seen so much beauty—from the orange and red hues of the outback, to the aquamarine shades of the Great Barrier Reef. I can only imagine the hues of green our eyes will take in during our time in the rainforest this coming week!
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