Hoga Base, Hoga Base….Part 1

Another year, another field season complete. I’m now back in the UK after spending roughly 7 weeks on the island of Hoga in south east Sulawesi, Indonesia. My field season was split in to two parts this year as I had the unusual event of having to leave site to attend a conference (see a meeting of great minds) midway through the season. Therefore I had to be a bit savvy with my data collection. I decided that I’d go hard graft in the first two week, get the lab sorted and complete one whole experiment before leaving site in week 3. Now I wanted to replicate the exact experiments we conducted in the Seychelles, this had been particularly successful and I left site with a full data set nearly analyzed. However this was easier said than done. In the Seychelles I had the added help of both my supervisors, who helped collect the samples and process both algal cell counts and photosynthetic data. I now had to collect my own samples, and being limited to two dives a day with a 43 min bottom time this made it very difficult. First I needed to decide which species within the Acroporid family occurred across all of my sites. Now many of these Acroprids form very small colonies and can be very hard to tell apart. Therefore I had to find colonies which enabled me to take replicate samples from them. I also decided this year I would include different light environments within the colony. Therefore I had to measure light from above and below the coral and take samples from both high light and low light areas of the coral.

For the first experiment I decided to only work on one site and then do the second two sites after I returned. I planned to get 3 replicates for each coral and around 3-4 coral species, plus both high and low light samples, which gave me approximately 18-24 corals per tank. I then repeat these 3 times in order to ensure there are no effects of the tank plus run a treatment vs. control. So I end up with 18-24 corals per tank across 6 tanks, 3 controls and 3 treatment tanks, approximately 100-150 coral fragments, so quite a lot. People ask me how I can take so much coral, doesn’t it die. The way I explain it is that corals are a bit like trees, you can cut off a branch and it will survive independently, you can then ‘re-plant’ this fragment and it will grow in to a new coral similar to when you coppice fruit trees such as apples and pears. Now I’m not saying anyone can do this, the coral has to be cut cleanly and monitored as they can be particularly fragile so really it should be left to those with experience.

So my first experiment was largely a success, it was several late nights and I didn’t quite get all the replicates I wanted, but I got enough and managed to continue the experiment literally until the day I left to get as much data as possible. I also started to keep on top of the data processing and entry, however, as the international conference neared, I spent a lot of time on my presentation and sorting out travel arrangements so started to fall behind which was a shame. There is no better feeling then having a nice clean processed data set which is fresh in your mind to work with.

So part with part one of my field season complete I can reflect on some of thee positives. I had several great encounters while collecting data this year, in the second week I was diving on the home reef and had had my face in a coral for around 15 minutes, after taking light depth and collecting my fragments I turned around to see two giant eagle rays doing backflips around each other who then quickly swam off as soon as I disturbed them. They could have been there the whole time and I hadn’t noticed it’s amazing what you can miss while it’s all work and no play. Later on that week two of the dive staff had a whale shark swim right up to them while the monitoring team were stereo videoing on the reef completely oblivious. It’s the first time anyone has ever spotted these gentle giants during the summer season and it’s good to know that they are still out there and not been overfished.

The next part of my summer work was to travel to Australia for the International Coral Reef Symposium, check out how I got on here, and check out part two of my field season here.

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