The very last week of our stay has started and time runs faster than ever... Why is there always so much to do during the last days of fieldtrips?
The last week we spent mostly in the lab, analysing nutrient and chlorophyll samples and incubating sediment and water. The results are quite interesting for understanding the role of bottom-up factors at our study site. At the moment we are sampling along a transect from the river to our former experimental plots. Transects along the beach showed that the river is the most important source of nutrients to the bay but it influences the whole reef by seeping through the sand on a wide area. Interestingly, nutrient and chlorophyll a values are slightly higher at the reef edge than on the shallower stations closer to the beach. Does it have something to do with special hydrodynamics when the sand-flats meet the reef or does the reef provide a reservoir for nutrients? We are planning a transect along the outer reef edge to find out if this phenomenon is reflected throughout the bay and if the differences in nutrient concentrations close to the beach are also visible further out.
On biodiversity day we had a night dive under the pier in Chaloklum. Next to trash and fish heads thrown in the water from the fishing boats we could observe octopus, cuttlefish, seahorses, segmented sea cucumbers, feeding anemones and sleeping fish. Many creatures looked like templates for trashy alien movies.
But the most exciting event this week was the arrival of the new CoreSea family member, a beautiful little boat called ‘Constantly Confused’. At least this was the original plan; due to a typical spelling mistake found in every menu and on every street sign in Thailand we miss an ‘n’ in the name. We all had a good laugh and think it is definitely a sign for good luck. After a christening celebration at sunrise we were eager to test the boat in the waves. Diving from the boat is adventurous but not uncomfortable; it will be a great help when we get our last cages out of the water and good fun for future students.
Tomorrow is the big day when we submerge our 60 kg concrete block for the first permanent buoyline at Sailrock. But this adventure can be told personally back in Bremen next week.
This was the last blog-post from Koh Phangan, Thailand - thank you for reading! At this point we also want to thank Christian Wild and the CORE working group for the interesting project and Eike and CoreSea for the great work in the field.
We loved it! Team Thailand: Pepe, Sou, Ines
The last week was very exciting for all of us…
After the problems with our set-ups due to strong constant wind and waves we decided to stop our caging and fertilizing experiment. Recovering the cages was much harder than expected due to a visibility of 1-2 m and the fact that several cages decided to have a nice little walk on the vast sand-flats west of the reef. Well, this gave us the opportunity to try out different search and recovery patterns, good fun.
Without praising ourselves we still think our cage constructions are quite stable and long-lasting, but apparently not suitable if the weather goes wild. Therefore we wanted to try different fixation methods for future experiments. One complete set-up was secured back on its original place with concrete weights and self-made pegs. Also good for camping underwater… This plot still serves for recording fish species feeding on the tiles and cages. Avoiding the inconvenience of lugging tons of weights into the water for future set-ups another fixation method we test includes blue-pipe pegs and flexible rubber bands.
But this was not the only thing we constructed the last days: the beautiful concrete anchor on the right will play an important role for conservation…
Dive schools need buoy-lines to practice ascents and descents with their students. Unfortunately the lines are often tied to corals and other sessile marine organisms. CoreSea was thinking about solutions and collected some money for the construction of a permanent student-buoy-line at Sail Rock by designing and selling fundraiser shirts. The idea is to keep as much activity away from the substrate as possible. If the plan works out the dive schools will hopefully sponsor more buoys to reduce the impact on the marine life. We are looking forward to submerge the weight at the rock next week.
What keeps us very busy at the moment is the question where the high concentrations of nutrients in our study bay Mae Haad originate from. A small river passing some bungalow resorts and seeping into the bay through the sand delivers water with phosphate concentrations ten times higher than in the reef. We are still investigating how the nutrients are distributed within the bay and if there are additional sources of waste water.
Due to unfortunate circumstances, our team of three future scientists decreased to two. We miss you Tong…
Our week started with high waves. Strong westerly winds normally occurring not before mid June lead to high water motion in our study bay Mae Haad. We noticed sampling is quite difficult when the surge tries to push you into the next coral block and you try hard not to get seasick. And due to the water motion at the reef crest some of our experimental setups were pulled out of the sediment again and moved. A closer look at the cages brought the conclusion that the nets where we fixed the settlement tiles take up the wave energy and transfer it to the pipe-constructions. As a result, the cages are step-by-step lifted out of the sediment. So the action plan for yesterday was to secure the nets with additional weights and fix them to the pipe frame. Just in time, because all our set-ups tried to escape and hide… We brought them back to their original spots. Unfortunately we noticed today during water collection for Chlorophyll analysis that the plan didn’t work out and our cages are all over the place again. Since this situation heavily biases our results we now have to decide if we can find another way of protecting the set-ups or if we have to finish the experiment altogether for the safety of the reef and thereby loose three dates of data collection.
One positive experience in the last days was a wonderful fun-dive at Samran Pinnacles, a scarcely visited dive site in the Gulf of Thailand. What we found there was astonishing: apart from the stunning marine life, the main pinnacle was covered in old fishing nets. We also found huge old fish traps from which schools of rabbitfish where eager to find their way out. We could help, and witnessed how heaps of fish left their prison…
Last week sediment sampling was a bit of an adventure due to an unexpected situation. Despite that, Ines and Pepe bravely managed to carry the entire dive and sampling equipment and themselves on our reliable Saleng to the beach and back. Easy, anytime!
Due to the persistent rough conditions and currents, our cages of plot 1 keep getting moved. The resulting space below the cage allows fishes to sneak inside and ravage the sediment surface. This is reflected in the Chlorophyll values, which will probably be removed from the dataset since the simulated exclusion of herbivore fishes isn’t fulfilled anymore.
Tile sampling on Saturday went pretty well but took quite a while, ending with blue lips and shivering divers since the water temperature decreased from the usual 32°C to 30°C in the past few days… Freezing! But this long and laborious day was rewarded with some big microalgaes’ waiting to be scraped from their tile. Happy about every diversification!
Honestly, we are a great group! Working together and dealing with problems for several months wasn’t a big issue here.
We can't believe 12 weeks passed that quickly. Last week we conducted the tenth sampling, five more weeks to go. We can see some responses to caging and nutrients in the algae biomass on the tiles and in the chlorophyll on the sediment, but they are less clear and stable than we hypothesized. Other factors, like individual location of the cages or a single hermit crab grazing a tile completely clean are influences that are not predictable but apparently manage to override our manipulated conditions in some cases.
The results are further biased by the fact that regular storms within the last weeks managed to lift some cages from the sediment. Although no material is lost and we can easily secure the set-up again, this allows animals to come in and graze on the sediment and the lower tiles.
We are curious what will happen the next weeks. Will the biomass increase further or is it stagnating? Will we have much more coral recruits due to the spawning in the beginning of April?
Life on the island gets more quiet in the meantime. Eike's and Janina's friends from home left last week after a nice Burger-BBQ-night in the centre. Helper Michael is off to Koh Tao to finish his Dive Master and was missed for scraping tiles Saturday night. Looking forward to his return for next week's sampling days.
Besides, low season starts and as the tourists leave so do the dive instructors which are only here in the busy time of the year. We have to say farewell to many friends we made the last months. Feels like we are the last pirates left behind on this island...
The last week started with a big splash. Songkran, the Thai New Year festival was celebrated with the throwing of water on every person passing. Traditionally originating from the cleaning of Buddhas and using this "blessed" water to give good fortune to elders and family by gently pouring it on the shoulder, this festival has evolved into huge water fights with water-guns. As it falls in the hottest time of the year the nice side effect is to release the heat.
On a more serious base we continued our sampling routine. The fouling of turf is accompanied by single individuals of macroalgae on some tiles now. Although visually different, the algae cover on the tiles and on the sediment does not show clear responses in respiration or photosynthetic O2-production. Coral spawning in this area was reported for last Tuesday, which might be visible on the recruitment tiles in the next couple of weeks.
On Monday we spent the day in our home bay estimating the abundance and biomass of important reef fish larger than 10 cm. The herbivorous species are dominated by Rabbit- and small Parrotfish, with some large individuals of the colourful Surf-Parrotfish and the red breasted Maori Wrasse. We still have to put some more effort in the identification and counting of small Damselfish, which occur in high numbers and somehow all look the same to us…
An astonishing amount of time also goes into the organisation and comparison of data. Former students and volunteers produced numbers for benthic cover and fish abundance which we now try to take into account to follow the progression of the reef and to compare different methods.
It has been a while since our last blog-entry. In the meantime we visited the dive site Sail Rock again to get a better overview about the different fish-communities at an isolated rock in the middle of the otherwise sand-dominated gulf of Thailand compared to our fringing reef in Mae Haad.
Due to complicated national laws in Thailand, we had to leave the country in order to renew our visa for the next two months. So, after several busy days of sampling and data collection we boarded the ferry to the mainland early in the morning. Late at night the same day we finally arrived at our destination: Penang Island, Malaysia. The coexistence of several cultures and ethnic groups on Penang has resulted in a heterogeneous population, stunning architecture, temples and churches, not forgetting the oversupply of all kinds of different delicious food. To satisfy our scientific interests, we hiked through the world´s smallest national park (2563 hectares), admiring plant- and animal live until reaching a beautiful sandy beach which houses a turtle hatchery.
This small holiday was soon over. After using several busses and the night ferry we finally arrived on Koh Phangan 17 hours later, where we went straight back to sampling. Beside our normal routine we assessed coral cover, biodiversity and rugosity (complexity of the reef surface) at our sample site. Our task for the last days was the comparison of the line-point-intersect and the grid-transect (with Coral Point Count analysis) –method. The preliminary results state a live coral cover of 20 ± 4.36 % in Mae Haad Bay with a rugosity value of 0.649. This coincides with last year’s values.
At Easter, the house and center suddenly filled with people. Friends from our hosts Eike and Janina are visiting, which resulted in a big and entertaining Easter-barbecue.
Today is our weekly water-sampling day for Chlorophyll analysis, which gives us the opportunity to escape the humid hot air and cool down for a while in 30°C seawater. We are looking forward to present you some more results on the state of the reef, until then we wish you all the best!
Time flies and another week passed already.
High waves and rough conditions resulting from strong westerly wind made it impossible to sample water for chlorophyll analyses last week because we were not able to find our plots in 5 m depth from the surface. Fortunately the wind calmed down the following days so we could conduct our sampling without major disturbances. Due to the high wave energy at the reef crest some of our cages were lifted from the bottom a few centimetres and tilted towards the sea. This resulted in unusually clean sediment under two of the cages but did not affect the tiles. We might think about further options like sand screws or additional weights to secure our set-ups if the weather gets worse.
Playing around with the nutrient analysis method revealed that the distilled water we can buy on the island is contaminated with phosphate in concentrations twice as high as in the seawater. For this it was quite handy to have a chemist around who quickly distilled some water on the gas stove. In the future we will have to make some additional effort and order the water from the mainland.
As part of the CoRe Sea research diver course we talked about self reliance and safety questions last week and played around with DSMBs, alternative air sources and liftbags. We also worked on our buoyancy skills by training different kicks and equipment removal under water. Good fun.
The last two days we spent with transect work counting the coral eating snail Drupella sp. in Haad Yao and herbivorous fish in Mae Haad. While it is quite easy to count the big parrot- and rabbitfish, we definitely have to practice identifying the many different damsels and estimating their size.
What else?! It’s getting hotter and hotter and the hour of pouring rain last night was pleasantly cooling, at least for some time. The water temperatures already reached 31 °C and will be even higher next month. Feels like working in a bathtub and we are almost jealous of the nice spring temperatures in Germany.
We already want to apologize for being a bit late with our blog next week. We have to go to Malaysia for a visa run and might get stuck in a border town for two days. Almost like holidays!
As already mentioned last week, we started gaining additional background information for our projects. First, we deployed the prepared clod cards in the field to measure water movement inside our experimental setups. By that we want to investigate if the conditions are affected by caging artefacts. To assess biotic parameters we started using line point intercept transects for coral cover and echinoderm (sea urchins and sea cucumbers) surveys. So far we can report a live coral cover of only 15 %. Further transect work will be conducted to reduce the standard deviation and increase the spatial resolution.
The weekly sampling and analysis program went as usual, with some promising chlorophyll patterns in the sediment samples and new coral recruits on the tiles.
We proudly present a new guest in the research centre, Michael, a molecular biologist from Germany who is doing the "CoRe research diver’s course" with Eike. It offers in-depth training on current marine research and sampling techniques. We have the great opportunity to participate in this course and integrate our project specific questions, which results in an interesting and productive dialogue. Furthermore it allows us to improve our performance under water by practicing advanced diving skills and various scientific methods.
Apart from that interesting work we spent a great Monday evening celebrating Pepe’s Birthday with heaps of friends, cake and ping-pong battles!
Besides our normal routine of sampling, incubations, chlorophyll measurements, nutrient sampling and cover analysis of the tiles we managed to squeeze in some fun stuff last week. This was probably also due to the perfect team work which enabled us not only to reduce the lab hours, but also to finish work in a better mood.
On Thursday we climbed the highest mountain of Koh Phangan – Khao Ra, 628 meters above sea level. The sweaty ascent was rewarded with a beautiful view over the bay of Chaloklum and the islands behind. The whole week we were treated with very loud Thai music played on the temple feast just across the street: spicy food, traditional dances, monks and praying Thais.
The last two nights we tried to observe a mass spawning event of the staghorn coral Acropora that was announced for this full moon. Unfortunately, we didn’t find spawning colonies, but there may be another chance in April, when Porites and other massive corals are predicted to release their eggs and sperm in the water. Quite close to our study site we run into the fellow in the picture. The crown-of-thorns seastar is a coral predator which can do serious harm to coral reefs when occurring in high numbers. This giant representative was a rarity and is not often seen in the waters around Koh Phan Ngan.
For next week we already prepared plaster clod cards to measure water movement in our bay. We also get ready to start benthic line-point-intercept transects on Thursday. Keeping up the good spirit…
Two very long days of sampling and data recording showed us again quite plainly that science is hard work and can be frustrating sometimes, although it takes place in a tropical paradise. Anyway, sampling of sediment and tiles was done in half of the time, the teamwork is good and we managed to overcome some problems in our respiration analyses. And we hope to reduce the long hours in the lab the more often we use the methods.
Pepe proudly presents the first settling coral recruit. We hope that the coral spawning which is announced for next week will result in many more recruits on the tiles and - even more important - in the reef that suffered mass bleaching in 2010. Besides the normal sampling we started with the determination of nitrate and phosphate in the water, to check whether our nutrient enrichment is detectable. Analyses of chlorophyll a resulted in values comparable to data from last year and will also be continued.
Today CoRe Sea organized a clean-up in the reef of Mae Haad. Together with a local dive school we were able to recover nets, fishing lines and further waste entrapped in corals. We also found settlement tiles from last year’s experiments which were lost during a big storm and are eager to see what organisms settled on the surface after 12 months. For us it is nice to see that lots of divers without a scientific background are aware of certain issues and willing to alleviate the problems resulting from increasing fishing and tourism.
We are quite proud of our cages, since observations during the last week showed our blue-yellow cubes to be safely secured to the sediment and widely accepted by fish. Although we informed all local dive schools about what we are doing in the reef and provided information sheets for their customers, one of our cages has been moved from its original plot. We are confident that this was an exceptional case, since the feedback we got from dive-instructors and other people is overall positive, although often a bit amused. We have been teased with names like algae-whisperer and crazy scientists.
On Friday we successfully conducted our first sampling. Even though we had to carry plenty of material back to shore, we safely brought 16 sediment samples, 32 tiles and 30 liters of seawater to our laboratory at CoRe Sea. The tiles have only been exposed to natural conditions for seven days and we are quite surprised how many different organisms seized the opportunity of new settlement space already. On the upper tiles we could observe small individual filamentous red and green algae; tiles facing downward were already sparsely populated by barnacles, spirorbid worms, as well as eggs and larvae of unknown invertebrates.
The sediment incubations taught us to improve and tightly organize the respiration experiments in the future, because we are short in space and material and the required temperature constancy is quite hard to achieve in a hot room with a small air condition.
The rest of the time we spent constructing a dry oven driven by solar energy and identifying fish and coral species at our study site to get an overview for upcoming surveys. Furthermore we helped surveying the snail Drupella sp., a coral predator that occurred in alarmingly high numbers last year but apparently decreased recently. This was also a good opportunity for us to practice underwater surveys.
Last night we were invited to celebrate the Russian Pancake Festival, the traditional ending of winter and beginning of spring. Feels kind of ironic at the moment…
Kho Pan Ngan, Gulf of Thailand
After travelling through time (+ 6 hours) and space (about 13.000 km from Bremen to Düsseldorf-Dubai-Bangkok-Koh Samui-Koh Phangan) we finally arrived in the village Chaloklum in the north of Koh Phangan almost 42 hours after we left Bremen. We were accompanied by an increase in temperature of more than 50 °C (from -20 to 32°C).
Warmly welcomed by Eike and Janina Schönig from our partner CoRe Sea we got settled in our new home for the next 4 months, an old Chinese brothel…keep up the spirit of the ancient pirate island! The wooden house has been renovated with love and effort and provides us with more luxury than we dreamed of. It is directly linked to the CoRe Sea research station where we find all necessary facilities for our projects’ analyses.
The purpose of our stay is to conduct research for our master theses in Marine Biology (Ines), Marine Environment and Resources (Soureya) and Ecology (Pepe). We will simulate overfishing and eutrophication in a coral reef environment by displaying herbivore exclusion cages, and nutrient diffusers. The effects on algae growth, invertebrate recruitment and the sediment will be investigated using biomass, respiration, isotopic signatures and other parameters.
During the last week we did several trips to our study site Mae Haad and checked out the best locations for our experimental set-up. We’ve also been very busy organising material and constructing the cages and racks for 480 settlement tiles.
Today was the big day! A traditional longtail boat brought dive equipment, all 16 set-ups and us to the previously marked sandflats within the reef. After a quite laborious back and forth, carrying cages and hammering them into the sediment we successfully completed the first step of our experiment: set-up submerged!
We are very happy that everything worked out well so far, although the Thai mentality tends to be more relaxed than back home: “you come back, come back next week!”.
We’ll keep you updated!
Ines Stuhldreier, Soureya Becker and Pepe Bastian, WG Coral Reef Ecology – CORE
(master students supervised by Prof. Dr. Christian Wild)