Rano Kao Expedition 2008 (RKE08)
Rapa Nui
March 17-29
Summary

It had been almost exactly three years since my last visit to Rapa Nui, and Rano Kao specifically. But in 2005 it was very different on the lake than what we found this time. I will discuss the findings later in this summary. Meanwhile, I organized a new expedition that included myself, Ki Istre from Seattle, Washington, Rosanne Hawarden, from Christchurch, New Zealand and Michael Osborne from Stanford, California. We are otherwise known as the Rano Kao Expedition of 2008.

In 2005, I along with the help of John Flenley, David Meek, Rob Dunbar, Yan Araki and Francisco Rapu obtained 3 sediment cores from Rano Kao. These cores were taken at various points around the lake while another attempt rendered over 20 meters of water and obtained no core. The one near to center of lake, called KAO3, is the one that I have chosen to work on for this PhD. KAO3 consisted of 2 meters of floating Totora/Polygonum mat that were collected from the surface of the lake with a D-Section corer. Below this mat we found 10.5 meters of water and 9 meters of sediment below til we maxed out the Livingstone corer.

Chart One. Radiocarbon dates of KAO3, Rano Kao, Rapa Nui March 2005.

These 9 meters were radiocarbon dated by using Scirpus seeds to give a very good linear chronology ranging from 1,000 years BP at top of sediment to 15,000 years BP at bottom of core. (see chart one above) It seemed the modern to 1,000BP was trapped in the floating mat. This same conclusion was also found by John Flenley in his KAO2 core taken in 1983. (see chart two below)

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  Chart Two. Comparative Radiocarbon dating between Gossen’s KAO3 pollen and macrofossil dating and John Flenley’s core dates. (For more information on the radiocarbon dating of KAO3 and the above charts, see the article “The Mystery Lies in the Scirpus” printed in the Rapa Nui Journal October 2007.)
  
  If I were to reconstruct the ecology of the lake over the entire 15,000 years it would be necessary to use both the floating mat as well as the sediment cores. What I have been able to do thus far with the lake sediment samples is reconstruct the ecology of the lake from 1,000BP to 15,000 BP that includes pre-Holocene, inter-glacial information. Very exciting stuff from a climate perspective. Various samples were taken once the cores were archived at the Limnological Research Center in Minneapolis, Minnesota. These samples were sent to Brent Wolfe at Wilfred Laurier University for Carbon/Nitrogen ratios and isotope analysis of the cellulose of the aquatic plants that grew and thrived on the rainfall that entered the lake. Meanwhile I processed the same interval samples for pollen, macrofossil and ecological assessment at Massey University with John Flenley and University of Minnesota with Ed Cushing. What I have been looking for is a connection between rainfall, changes in the lake water levels and the plants that thrive on this ecosystem. This will tell us climate change on the island, particularly rainfall patterns and changes, plant adaptation and introduction of species by humans, as well as the presence of humans and the changes in pollen types.
  
  Once the lab work was mostly completed on the lake sediment portion of the core we decided to date the mat to find out if it indeed was the missing 1,000 years not found at the top of the core. Massey University took samples and sent them on to me to pull seeds from the samples. Of which we found and dated also perfectly linear from top of mat to bottom. The top sample contained modern carbon, very nice, and the bottom of the mat dated to 1200BP C14 which calibrated was about 1000BP. Still there were about 400 years unaccounted for between the bottom of the mat and the top of the sediment core. Various things could have happened: bottom of mat lost, top of sediment core lost in the coring attempts; perhaps the decomposition rate of the mat left some of these dates suspended in the water column and unable to retrieve in the coring at all. Perhaps there was some manipulation at the bottom of the lake that is suspected once I began to thoroughly compare all of my cores. The answer was unknown and still is.
  
  The unfortunate turn of events that have led to this expedition is in the transport of mat portion of this core. Massey University was storing the two meters of mat core over the past two years, and once radiocarbon dates were obtained I requested the cores be sent to the LRC for further sampling. Once the cores arrived and were opened I was devastated. Much of the cores had either consolidated, or were missing. But they were very different than what we had obtained in the field and no linear chronology could be depended upon. We had great dates on a core we could do nothing with. If I wanted to look at the human impact story of the island, and at Rano Kao, I didn’t have a core that would tell me. The information was in the mat that floated above the sediment. If I wanted to connect the questions of whether the ancient people of Rapa Nui cut down their forests and caused drought, it would be in the mat.
  
  At this point Chris Stevenson and I had written a grant with Aviva/Earthwatch for the analysis of the mat to find out these answers. I had little money but enough to conduct the tests. Without a core I was faced with no other direction than to obtain another core of the mat so that the grant obligation could be fulfilled, but even bigger was filling in the last 1,000 years of information that everyone seemed to be interested in.
  
  Hence the Rano Kao Expedition was created. And on March 17 I flew down to Rapa Nui, for my third visit to this island and was very glad to have landed on the little spec of land in the middle of the great ocean that I missed very much.
  
  The People of RKE2008
  First I want to tell you about the people that were both very critical to this expedition and helped me on this great adventure. We are a varied lot of folks (see group photo below):
  o Ki Istre, all of 19 years old and a culinary student in Seattle, Washington is also a lake ecologist, witty and my son. He is always a joy to have around, and this time he was actually part of the expedition, which made me feel like Thor Heyerdahl taking his son Thor, Jr. on their first expedition to the island in 1958. Ki was to be our camp cook and water quality expert.
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  o Rosanne Hawarden, of Christchurch, New Zealand. As Mike called her “she was a hoot to have around!” Rosanne was the energy of the team. She came with a mission to learn and that she did. She is currently working on her PhD thru Massey University in business, but volunteers her time as a research analyst for Gavin Menzies, who is looking for Chinese voyages and connections around the world, of which some were thought to be on Easter. Rosanne, beyond what her husband and men in her profession thought had not one thought that she would not make it trekking down to the depths of Rano Kao, thru the totora and water holes and falling thru the mat over and over again.
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  o Mike Osborne, is a student of Rob Dunbar’s at Stanford University. Rob has focused his work on the corals of the island by analyzing oxygen isotopes and sea-surface temperatures. Mike is a new addition to the team that has inquiries into caves and lakes. This was his first coring attempt and he was very much the braun of the coring that was very appreciated!
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  o Alejandro Naoa, helped us for three days coring on the lake, both when we were inundated with rain (Ua in Rapa Nui) on the lake, and days when it was clear. He was very instrumental to me understanding native plants along the way, as well as what he remembers growing up around the lake.

Rano Kao Expedition 2008 Group Photo – (left to right) Michael Osborne,
Candace Gossen, Ki Istre and Rosanne Hawarden.



Michael and Alejandro at core site 1



Objectives of This Research Travel (stated in proposal January 2008):

1. Core floating mat that ranges from 2-3 meters in thickness. Obtain a minimum of 5 cores.
Near to lake sediment core location from 2005 KAO3, as well as interesting parts of mat that may be dead, or have unique features.

2. Lake bottom survey. Using original core location, set up at least one transect line across lake in as many depth points as possible.
To confirm mysterious trenching found in core.

3. Plant specimens. Collect inflorescence of totora, and polygonum. Rhizomes and plant matter of both. Also other plants growing on mat including moss, fungi, and small plants. Photograph, collect seed, and some plant matter. Conduct walking survey around crater to locate plants types, collect seed and photograph.

4. Photograph coring adventure, plant collection, survey, and all pertaining to research to compile a documentary both for dissertation and education.

5. Sample Palm Root cast. Take soil sample in root cast to identify pollen, and whatever else may be located within the casts.

6. Petroglyph photograph and identify known areas that have plant relation. (Conversation and advice from Georgia Lee)

7. Mineral collection in crater to help identify minerals in lake sediment core.

Remaining work and analysis once cores return to USA

o Ship cores to LRC = $75? depends on weight
o Archive and identify and scan the cores at LRC – Candace Labor and time while in Minn.
o Sample and pick seeds for RC dating 4 locations = $2400 or use dating of existing dated mat?
o Sample for isotope analysis (10 samples at 20cm intervals = $1200 or 20 samples at 10cm intervals = $2400)
o Sample similar for pollen samples and process at UMN – Candace labor and time
o Sample similar for raw sediment macrofossils at UMN – Candace labor and time


Course of Events:

Upon landing on Rapa Nui I was faced with many challenges, which is expected, but it set the course of time for getting done all that was needed.

First one on the island was Rosanne, who greeted me at the airport. We looked around for our person we were to meet that Sonia had set us up with for stay at the Farmhouse. Noone showed so we proceeded to my friend Niko Haoa and the Hotel Otai for advice. We ended up in a much more suitable location to stay, with Selma Tuki and her little house next to the Otai. The stay with Selmas was wonderful and we all quickly became great friends.

The next day 3 days I spent visiting CONAF to obtain a permit to work on the island. I had been writing to Enrique Pakarati as I had been advised but quickly realized he was the wrong person to talk with about working on the island. CONAF representative Ricardo Crisostomo and Enrique Tuki and I met finally on Friday and typed up a permit and exactly what I was going to do on the island. 4 stamped copies and I was on my way to begin the coring once the guys arrived tomorrow.

Saturday Mike and Ki were on the same flight from Santiago, and quickly I saw Ki come off the plane with a great big smile. Rosanne, Ki and I waited outside the airport as every last one of the tourists departed and we stopped and looked at each other “where’s Mike?” There he came, delayed but he had arrived.Tired and weary, we walked a bit, got settled, ate, and planned our course for the next day.

Sunday, was Easter on the Island. How appropriate we should be there on the European namesake, but it came and went without much affair. Those that did care celebrated, those that used the occasion of holiday spent the time with their families camping and on the beach as it was 29C.

Sunday was also our first work day. We decided to survey the lake and take the water samples and be prepared for our Monday first day of coring. Everyone was quite surprised at the enormity of the lake and ominously looking down saying

“we are going down there?”       

as we proceeded to walk down 250 meters to the lake surface,

thru the Acacia and Avocado trees on a steep incline of some 60 degrees.        

We proceeded to walk out of the forest that had been planted in the 1970s to help soil erosion, and looked up totora as tall as the trees, over 4 meters tall. This was the first adventure for the others to “walk on water” or at least trek thru the water, on matted roots of polygonum and totora.

For about 20 meters we walked thru the stands of totora, falling in a few holes along the way, saving the camera! We arrived onto a hardened mat surface of ferns that gave us strength to walk on the mat. We came about within another 10 meters 3 trees that had firmly rooted themselves about 30 meters from the lake edge onto the inwashed sediments and water. It was quite a site. We proceed to try to find a path thru the totora, on the ferns towards the center of the lake.
Quickly we realized a pattern, dark mat with moss was soft and one plunged thru to mid-calf, stay on the ferns they kept it firm, and they were very abundant. It was truly a wet winter to have so many, much more than I had noticed from the very dry mat 3 years before in 2005.

We walked and took waypoints and depth readings whenever we could, and it became an arduous task to get around the water holes and be able to see thru the totora. As it was quite surprising to be walking thru the totora and fall in knee deep. So we obtained 5 waypoints noted on the GPS, and took depth readings with a sonar depth reader (fish finder) that also told air and water temperature. We stopped at waypoint 5 near a 12 meter hole in the mat for the water samples. (see waypoints and coring points on google earth map below)

This time I brought a water sampler that allowed me to take water samples at varying vertical depths of the lake and the chemical analysis was conducted partially on lake and completed at the house back at camp. Results below:



Waypoint Information (reference photo above for locations):

Stop1    27.18218 S lat., 109.43793 W long. NE edge of Lake

Totora very tall over 3 meters. Thick and triangulated, culms on top but not sure of maturity of seed within. Novembers culms were too young and had immature seeds. We will find out at camp what these contain. Walking thru Acacia, fern and avocado trees. Lots of ants on the trees, that climb onto you instantly but don’t seem to bite. If you touched a limb they would be all over you. But the thorns on the trees coming were down were like daggers of up to 1” long, so you must keep your balance or be bludgeoned.
Mosquitofish were abundant in the lake, many on the edges that were minnow (bait) size of 5cm long. The slopes in the forest had many ferns and long grasses that drapped over the side like hair. A few snal shells were found along with obsidian pieces on the paths.

    


Stop 2    27.18253 S lat., 109.43795 W long. approximately 30 meters from the NE edge of lake

From edge of lake approximately 30 meters to the south of entry point from path. Tall totora on the lake edge measuring 4 meters tall and thick triangulation of 5-6cm. Deep water of a meter to the top of the root surface, tripping and falling until up on the mat surface about 20 meters out. Distinctly different from the edge of the lake which had polygonum and other plants to be identified growing in the shallow waters. This is approximately where the 3 trees were growing.


Stop 3    27.18343 S lat., 109.43866 W long.    First open water probe

    Water Temp: 25C
    Depth: 5.2 m (sonar)
    Rope: 7m (weight rope)
    Black clear water
    No smell

Polygonum taking over a dead patch on the mat surface

Stop 4    27.18432 S lat., 109. 43815 W long.

    Water Temp: 25C
    Depth: 1.5m
    Rope: 1.5m
    Black clear water
    Smell of sulfur? or some strong odor

It seems some of the water pools that we see from above are really shallow water collecting on top of the mat from the very wet winter. Therefor the 1.5 meters of water we are measuring is the rainfall for the winter that has collected on top of the mat.
Collected sample here of dead matter from mat surface.   
                                                                                        variety in the mat, dead dry patches, patches with new growth, dark                                                                                          brown wet patches with moss on surface, and totora patches between.



Stop 4b    27.18437 S lat., 109.43812 W lat.     

Water Temp: 25.5C
Water Depth: 7.9m
Rope: 8.2m
Black clear water
No smell

   
Stop 5    27.18465 S lat., 109.43820 W lat.

    Water Temp: 25C
    Water Depth: 12.2m
    Rope: 12.4m try one, 12.4 try two, 13.2 try three (rope tends to slide down slope which may add additional length as we discovered the mats have shallow shelves at they slowly decompose into the water.

 





Water Quality Testing: Location:    Stop 5    27.18465 S lat., 109.43820

                               
    no fecal coliform test conducted, as did not want to contaminate water or island with foreign bacteria to test                            

Water Temps collected on site in water sampler and then placed into 3 different colored Nalgene Lexan bottles for further testing that was conducted within 2hours of retrieval.

Testing procedures:
1. pH was tested with dissolved tabs
2. phosphates with dissolved tabs
3. dissolved oxygen with dissolved tabs
4. BOD water in tube, wrapped in alum foil for 5 days then tested the same as for dissolved oxygen with dissolved tabs
5. nitrates with dissolved tabs
6. temperature in field with fish finder in collection tube (1.5litre)
7. when all tests were completed, remaining water was poured into white container with turbidity secchi disk.

 


Weather and Climate Information:

When we got to the island we discovered that there had been a drought for the past 5 months. Noone was having problems with water as yet, as the people of Rapa Nui get their drinking water from the aquifer under the island which I have been told contains millions of liters of rainwater.

The drought though had a bad consequence on the trees and plants though, as there was a plaque of insects that were devouring all of the leaf matter in search for fluids. These little buggers were no local and not wanted, but the plight of importation of food. Invisible little eggs that come along on the skin of oranges and in the wood of crates, and amongst the hundreds of tourists that land on the island every day. CONAF was working really hard with sticky cards dated in all of the places they had observed these insects. I walked quite a bit in the Rano Kao area as well as Hanga Roa, the little town and noted the trees and plants that had these cards. All of the cards had been hung within 7 days of my landing on the island, so there was a diligent watch on these bugs.

Although quite interesting where all the water is in the lake, I saw no insects such as I had seen on the trees in the town. I was glad for that.

Previous to this drought, there was a very wet winter. Wetter than most I was told. And I verfied that observation by noting small pools of water 1.5 meters thick on the floating mat of the lake. I had not seen so much water present from above as I first thought looking down, and then once on the mat I realized that these were not open water holes between the mats, but collected water on the top.

This wet winter, heavy rains made everything green at Rano Kao. The totora flourished and covered the entire lake. What had been an open middle in 2005 was now covered with thick ferns and totora growing to the middle of the lake. I came across new rhizomes of totora that were just branching outward with their typical two-finger size rhizome thickness and running 7-10 stems per rhizome ranging from tall to new emergents. The rhizomes were about 20 cm below the surface in a wet, brown mossy like mixture, a perfect peat.

The totora was also taller than I have ever seen on the edges of the, while the polygonum grew vertical at the edges, it was also spreading horizontal into the open pools with its suspended reaching into the open water. I could see how the mat was forming, it was taking advantage of the dying patches by invading and using the nutrients while expanding its thick roots outward and interlocking to branch across the lake. I put myself back in time and imagined the same thing happening when the mat was forming for the first time, or maybe many times in the ancient past.

Linking Weather Patterns:

This weather event of a really wet winter and then drought on Rapa Nui, also followed patterns that I had seen in Minnesota and Portland this past year. While in Minneapolis fall of 2007, rain came in September which was unusual for this area, and snow started at Thanksgiving and hasn’t let up yet and it is April 2008. The talk around here is that there are record snowfalls, and it is late in the spring for snow to be falling, but it came yesterday, only 3 days after feeling 76 degrees and sun here. They say this is Minnesota weather and I hear the farmers talking about a trend, that happened 10 years ago all the same, a really wet year. And planting that could not happen before Memorial Day as it would be freezing again soon.

Meanwhile in Portland it has not stopped raining, and it has hailed with snow a few times in the city. Mt. Hood is not closing for the spring whereas it is common for the past years to be closed in Mid-March. There is a 222” base and growing still of snow. Its wet, there is moss growing everywhere and all are waiting for spring, including the trees that have all bloomed.

But is there a connection between the wet winter that fell on Rapa Nui, that then followed by Portland and then Minneapolis? Yes it is the same, and also if one looks back when I arrived in Portland in 1996, it was the year of great rainfall and an almost overflowing Willamette River. 12 year cycle? La Nina? Could the El Nino and La Nina cycles also affect the planet the same whether it be 27deg South or 45 deg North of the equator? Can we find clues on Rapa Nui that are linked to already known observations in North America? These are good questions. But for me I experienced them all, I am the observation tool and overtime and the older one becomes the patterns emerge that we see and remember about change.

Coring the Lake:

DAY 1
Sunday, the day we surveyed the lake and took water sample was the last day of the drought, because come Monday it rained very hard and messed up the plans for the first day of coring.
THAT is why one must allow extra time on an adventure, rain, and getting permits!

DAY 2
Tuesday March 25, Rosanne, Ki, Mike, Alejandro and me hiked down into the crater into what looked like ominous clouds folding over the crater rim. By the time we reached the bottom we could see it coming in over the rim and sinking down to the lake very fast, then the rain, lluvia and Ua in all three languages, English, Spanish and Rapa Nui came and fell. It came with torrents of rain. We hung out in the trees for an hour and waited and hoped we could get out on the lake, but to no avail it was not leaving.

So we left the gear in the trees hidden well, and hiked out soaking wet.

The day was not wasted though, as we later went to Rano Raraku and collected totora samples at the lake so that Heather at UC Davis could conduct DNA identification on both stem and seeds samples from Rano Raraku and Rano Kao. We also had fun walking around the place as my three friends had never seen the Moai Quarry.

DAY 3
Core 1    27.18442 S lat., 109.43832 W. long
Water Depth: 12m

Finally Wednesday was a sunny day. Rosanne off to New Zealand didn’t join us. Ki was the plant collector, so Mike, Alejandro and me started off in the direction of the water sample stop 5 but focusing more inward to the center of the lake if we could. The totora is tall, the water is high and we stopped a core spot 1 that was firm on a bed of ferns in a totora patch.

We began taking 50cm sections, and ended with a total length of 4 meters. This was unexpected as the KAO3 mat core only had 2 meters and John Flenley’s mat cores were also 2 meters. So were we in a place where there was deeper mat, would be able to recover the missing 400 years between the bottom of the KAO3 mat and the lake sediment cores? or was this a spot with in-washed sediments that made the appearance of a thicker mat? We maxed the coring rods that I brought so we had to stop. Not sure if we could have collected core deeper but it seemed the bottom 4th meter was watery which is a sign of the barrel not closing correctly due to a lack of resistence, no core.

The core was fibrous, good and linear 2 meters long. Not many gaps. Core identification has already begun on this core and I have archived the cores, scanned for magnetic susceptibility, and described the sections. I have noted in the smear slides for this core that there is charcoal in all of the sections, as well as what appears to be tehpra, and glass particles in the bottom section at meter 4. There is definitely human presence in this core.

This core was easy to get, cutting thru the mat was not difficult as it was very wet. In comparison to 3 years ago it was dry and very hard. The biggest challenge was getting a contiguous core with no gaps or missing parts. This core seems the best of the 4 collected on this expedition.

We collected a 2.5 meter core, but then could not get the rods apart. We radioed Ki to ask CONAF at Orongo for some help with the Park rangers, but noone had wrenches nearby. So we were stuck on the mat, some 200 meters out with a 4.5 meter long corer that was stuck together. We couldn’t walk up with it, nor core again as we couldn’t turn the small diameter tubes enough to collect more core.

So this very nice sunny day, was cut short and we had to return another day to finish more cores
It has now begun to rain everyday so it is very unpredictable on this Wednesday, what Thursday or Friday may be like. But we have to come, we cannot leave with having one core.

So we stashed the corer in the totora thanks to Alejandro, hid the bag in the trees and hiked out. Ki made two trips up and down, but little did we know he had 101 fever and was soon to get real sick.

DAY 4
Cores 2 and 3    27.18365 S lat., 109.43653 W long.
Elevation: 110m,
Water Depth: 12.2 m (12.7 with rope),
Water Temp: 23.0C
Today weather is holding. Clouds are forming and moving over the island. It rained hard overnight and everything was wet upon waking. We decided to go rain or shine.

It was good on the lake, cool while we found out later it was raining really hard at Hanga Roa. Strange this island has pockets where it rains and stays dry in other locations. The island is only 14 miles at its longest and it seems so small to have varying weather patterns but it does. But today we had Kon Tiki, the Sun God with us. Alejandro, Mike and me. Ki sick in bed with cipro and a 101 fever.

We tried to take a trek heading off towards the east rather than the path we had taken before. This time we tried to find the water path we had seen above. We ended up stopping near a large water hold with 12.7 meters of water.

Tried several places but couldn’t get good consistent cores. Polygonum was growing on the edges of the hold with ferns. Inside it was dark brown moss. We took core 2 and moved a little farther away for core 3. No problem with the corer and the wrenches we brought with us, 3 of them!



Core 4    27.18403 S lat., 109.43675 W lat.
Elevation: 108.5m
Depth: 12.2m
Water Temp: 23.0C

This core was the last. We reached the end of the tubes that we had brought.
We again searched out a placed near to another water hole towards the center of the lake.

The core was 3.5 m deep. Mike thought at 2 meters he was at the water because of little resistance but came up with a full core and continued down to 3.5 meters. The next 50 cm after that was mostly water as the cover didn’t close. Usually a sign there is no resistance and below mat.

We secured the cores then I told Mike I was going in for a swim. He got to it first and took a dive in. The water had a distinct thermocline in this hole. it was very warm at top, but only a meter below it was very cold. We swam across and took a depth reading with the waterproof sonar at 11.5 meters. Then came back and tried to get a vertical profile of the mat, and realized that the mats sink on the edges and provide a shallow ledge as it folds into the lake.

I also realized that since it was so difficult to get to the center of this lake and take a proper profile of the bottom, I would have to swim thru the holes to get it done next time!

Serendipity also was with us on the walk about. As Mike was walking around to find a new path he yelled at me to say there was obsidian in the mat where he was. I was trapped on another floating island and said he remind me when we leave to head that way, but by the time we wrapped up, soaking wet in that black clear water, I forgot. So somewhere on the lake is an ancient pile of obsidian, large enough he said that definitely looked flaked. and it was in as dead brown patch, not the grey dried up stuff, but the brown decomposing stuff.

Alejandro called this lake, Lago de Antigua, Aqua Dulce. It truly is the sweet water of the ancients.




Objectives Achieved:

1. Core floating mat that ranges from 2-3 meters in thickness. Obtain a minimum of 5 cores

Photo above: Profile view of coring spots in relation to the mirador at the rim. Directly ahead on the edge of the rim and to the left of the marker is the site of Orongo. Photo below: lake surface view of coring points.

LRC Archive Data Sheet

2. Lake bottom survey. Using original core location, Set up at least one transect line across lake in as many depth points as possible. To confirm mysterious trenching found in core.

As stated above, “I also realized that since it was so difficult to get to the center of this lake and take a proper profile of the bottom, I would have to swim thru the holes to get it done next time!”

This objective was not completed. With the new growth of Totora over the lake, and the amounts of water pools and holes, it was very difficulty to maneuver. It would take swimming from hole to hole to actually run a transect line across. If one could meander aimlessly on all available mats then there might be a number of points taken to make some sense.

But for now the mystery of the missing sediment still lies in the depths of the lake. And I shall still contemplate how to get this done on the next expedition!



3. Plant specimens. Collect inflorescence of totora, and polygonum. Rhizomes and plant matter of both. Also other plants growing on mat including moss, fungi, and small plants. Photograph, collect seed, and some plant matter. Conduct walking survey around crater to locate plants types, collect seed and photograph.

Most of this objective was completed. Samples were taken for totora at Rano Kao and Rano Raraku and sent on to Heather at the UC Davis who will be conducting DNA and nutrient identification on the seeds and stems of the totora. Since she collected totora at 45 sites between North and South America, we hope to be able to identify these current plants into some association with others locations, answer the question of introduced or native plant, and if there are different species of totora existing on the island. The seeds that I have identified and used in the radiocarbon dates vary and I will also use the collected modern seeds as a comparison to the changes in seed overtime to once again, identify change over time in the lake environment, species type and perhaps some link with human use of the plant.

A totora rhizome was collected and is now in portland in a pot hoping to live and be studied. Samples of plants that were living on the mat were collected and pressed into a specimen identification book for further identification as to the native plants on the lake. Photographs were also taken in order to preserve the living environment and understanding of the variances of this lake ecology.

A walking survey was not conducted as we ran out of time due to rain. Although species of plant were identified from afar: Sugarcane is a very bright green and with cameras we could see patches on the east and west slopes of the crater that are growing wild, although once cultivated on the slopes. There are also grape plants, with an unknown species yet to be determined growing on the north slope of the crater. Banana plants were also seen on the slopes again wild. Growing near to the hiking paths are avocado and Tuyaba or Guayaba.

• 
  Notes to Heather Carpenter:
  
  H,
  Here is the information on the samples I sent to you:
  
  Plant collection information for Rano Kao Expedition 2008 (RKE08):
  
  Te Pito O Te Henua is the ancient name for the little island otherwise known as Rapa Nui by the polynesians, And Easter Island by the Europeans. It was formed by 3 volcanoes in the Nazca Plate, one of which was the largest and most spectacular is the crater lake known as Rano Kao, but does not have a Maunga name for the volcano that existed before it as does Poike known as Maunga Puka Tikei, and Rano Aroi within Maunga Terevaka.
  
  Rano Kao is a crater lake formed 1million years ago that is approx. 1 km across on the lake surface now, and 1.5 km across rim to rim. Within this crater standing 110 meters above sea level is the lake, with a floating mat of totora and polygonum that was created sometime within the last 3000 years. Today the floating mat is approx 2-4 meters deep above 12 meters of water in the basin and covers approximately 90% of its surface.
  
  Rano Kao – collected by KJI, Wed 26 March 2008
  @ North side of lake edge near Acacia forest
  
  27.10.931 S latitude
  109.26.276 W longitude
  Water temperature 25C
  
  Notes:
  Muddy, boggy climate
  Dark water clear but brown/black
  Species of mosquitofish abundant, small up to 5cm long
  Totora seems to be thriving offset from the shore approx. 6m (20’)
  Totora width on the margins, lake edge 10m (30’)
  Aproximately 4 meters tall on the lake edge
  There are many fallen trees on the slope to the lake due to strong wind and erosion
  There are approx. 70 stems per square meter of Totora
  5-10% are dead
  Bottom mass is about 1m (1-3’) both above and below water surface
  Collected 15 stems and 5 influorescence
  Cut top 10cm off and put remaining 20cm in plastic bag
  C- split one bag with 8 and put in dry silica. The other 7 were wrapped in alum foil
  Water was collected @ site in a 50ml polycarbonate bottle
  
  
  Rano Raraku – collected by CLG, Wed 26 March 2008
  @ East side of lake edge
  
  Notes:
  Rano Raraku is a shallow water lake approx. 3 meters deep and home of the Moai quarry
  It is visited frequently and lately was used for totora collection for Tapati Feb 1-16 2008
  Therefor this lake was badly trodden and shows signs of extreme erosion within the crater
  The exterior is also eroded very quickly as now some Moai are under earth and not visible
  There were no coordinates taken at this lake sample collection
  The lake was mostly damaged around the perimeter of the lake by humans and horse both
  There were 0.5 meter depressions around perimeter from walking and trampling
  
  The totora in this lake grows about 10m (30’) from the water edge
  Polygonum is in this space in some places that weren’t disturbed growing at least 1m (3’) tall and 10m (30’) deep into the lake.
  There is a tier system of low plants between the ground soil and water edge, then the polygonum and then the totora.
  The totora has been broken, pushed over and mounded around most of the perimenter on the south and east the worst.
  I walked around trying to find less trampled and disturbed totora
  Specimens 1-2m (3-6’) tall
  10 stems were taken with 5 influorescences
  5 stems 20cm long were put into plastic bags with silica and 5 were wrapped in alum foil after 10cm were cut from the tops.
  A water sample was taken from undisturbed, or a least disturbed place on the south side.
  The water on the lake edge was muddy, white to clay like red, smells, and an irrigation pipe is present that leads out of the entry which looks like a desert from such high erosion.
  
  
  
  4. Photograph coring adventure, plant collection, survey, and all pertaining to research to compile a documentary both for dissertation and education.
  
  A video camera as well as digital camera were taken on this adventure. Although the important parts of coring were missed due to all hands being busy coring and none to film. I have 3 hours of video that include interviews in Rapa Nui and Spanish on the plants and information on Rano Kao from Alejandro and Selma Tuki. Am trying to locate a translator for help in this as my Spanish is good enough to ask the question, but deciphering things will take a lot better than my own.
  
  Photographs are posted on myspace page at www.myspace.com/gossen along with a video of the coring in 2005 both for the lake and the coral.
  
  I will be producing a video for my final dissertation which will give a broader depth of understanding as well as more entertainment, and educational value to the people of the island as well.
  5. Sample Palm Root cast. Take soil sample in root cast to identify pollen, and whatever else may be located within the casts.
  
  Two samples were taken from two locations at the road quarry on the way up to Rano Kao near the airport. This is the location that Chris Stevenson and I worked to identify the palm casts that were uncovered when a frontloader scraped dirt from the hill to manufacturer building materials. We did a survey and I went back to this spot to take a small soil sample in hopes to process it for pollen to see if there is in fact palm pollen that happened to be in the palm cast roots.
  
  6. Petroglyph photograph and identify known areas that have plant relation. (Conversation and advice from Georgia Lee)
  
  I have the sketch copy from Georgia, but the actual rock was not located to take an actual photograph.
  
  
  7. Mineral collection in crater to help identify minerals in lake sediment core.
  
      There was no time for a geologic survey which would have been conducted along with the walking survey of the lake.
  
  
  
  Remaining work and analysis once cores return to USA
  
  o Ship cores to LRC = $75? depends on weight
  o Archive and identify and scan the cores at LRC – Candace Labor and time while in Minn.
  o Sample and pick seeds for RC dating 4 locations = $2400 or use dating of existing dated mat?
  o Sample for isotope analysis (10 samples at 20cm intervals = $1200 or 20 samples at 10cm intervals = $2400)
  o Sample similar for pollen samples and process at UMN – Candace labor and time
  o Sample similar for raw sediment macrofossils at UMN – Candace labor and time
  
  
  The above estimated budget is as follows actually:
  
  Expedition Expenses:    travel, coring, gear rental, lodging, food, equip. etc. for March 17-29   
  Total costs    $8,046.42             
  less Aviva    4100    $3,946.42         
  less PSU grant    500    $3,446.42         
  less camera gift    300    $3,146.42      total candace spent
             
  
  
  Current Research:
  
  On April 22, Candace flew to Minneapolis for a 5 week research mission.
  For 4 days, Wed – Saturday April 23-26, I worked at the LRC on the new mat cores from the island.
  
  The cores were opened, identified and marked. The 25 – 50cm sections were then photo scanned
  and then placed on the Geotek XYZ multi-section automated split core logger, for high-resolution magnetic susceptibility, natural gamma radiation, and color spectrophotometry.
  
  ICD sheets were made with the photo scans and magnetic susceptibility overlay, and descriptions were logged for each section.
  
  Smear slides were made at locations of interest, as well as some collections of macrofossils were made.
  
  The cores have been wrapped and put into D-tubes until further funding has been located to continue work.
  
  Costs for this work are currently being logged, I need to find funds to pay for:
      40 sections of ABS tubing that Anders cut and sent to me for the cores
      D-tube, and materials used in lab to secure the cores
      Disk with ICD and scans
      Repository costs to archive the 2005 and 2008 cores
  
      Flight to Minneapolis     $390
      Rent for 5 weeks:     $282
      Food @ $20day    $750
      Incidentals        ?
     
  
  Expections of Research in the year 2008-2009.
  
  Radiocarbon date at least 4 samples, picking scirpus seeds to match good chronology in the lake sediment cores that used the same process of seeds for dating.
  4 samples @ $600 = $2400
  
  Time and labor to pull the samples and pick seeds currently are not accounted to be paid for.
  
  If core 1 is used for the research which is what I suggest since it is contiguous, good in structure and 4 meters in length, then more dating would be advised. Perhaps double the effort and make 8 dates = $4800
  
  Isotope sampling has money allocated for 20 samples at $120 cost at Brent Wolfe’s Isotope lab in Waterloo, Canada. $2400
  
  Rob Dunbar has offered isotope analysis, but the details are in the works, as well as radiocarbon dating both that could train Mike since he was there to help core the lake.
  Details undetermined.
  
  Samples for pollen and macrofossils are highly requested as to follow up with proper
  assessment of isotope analysis, which is what was done for the lake sediment cores.
  Pollen sample processing: $30 a sample x 20 to match isotope = $600
  
  Theoretical analysis of Magnetic Susceptibility scans, isotope analysis, pollen, macrofossils and core information are currently on hold pending finding funding to pay
  for time and expenses for sample processing.
  
  
  
  Operations of the LRC (National Lacustrine Core Repository)
  
  
  Core Storage_Refrigerated (4°C) space for 10,000 meters of core, approximately 2,200 meters of which is at the Core Laboratory, and the remainder at two separate locations. Most of this space is in the form of racking for standard 1.5m ODP D-tubes. A refrigerated shipping container is also available for field storage and core transport to Minneapolis.
  LRC Core Laboratory
  0. Large (~3,800 square-foot) laboratory with ample space for rapid, efficient core processing and dedicated stations for most procedures
  0. Dual medical cast saw core splitter
  0. Band saw for splitting indurated sediments
  0. Geotek standard multi-sensor core logger • delivered March 2004; whole- or split-core logging for gamma density, acoustic (p-wave) velocity, electrical resistivity, and magnetic susceptibility
  0. Geotek XYZ multi-section automated split core logger • delivered August 2004; split-core logging for high-resolution magnetic susceptibility, natural gamma radiation, and color spectrophotometry
  0. DMT CoreScan digital linescan camera • 100 or 200 pixels/cm, whole-core, glare-free images
  0. Geotek Geoscan-III digital linescan camera • 100, 200, or 400 pixels/cm, whole-core, glare-free images
  0. Core description tables and cradles
  0. Stations for: sampling, biogenic silica, diatom preparation, pollen prep, thin section prep, grain size prep, XRD prep, stable isotope prep, smear slide prep, pollen concentrate AMS-14C prep
  0. Liquid analysis spectrophotometer
  0. Binocular, petrographic, pollen, and diatom microscopes
  0. Centrifuges, drying ovens, fume hoods
  0. Freeze dryer
  0. Programmable muffle furnace
  UIC TIC & TC coulometer
  
     
  
  
  Final Photos:

Ki, me and Alejandro (a very wet day on the lake)

After the swim

From the Moai Quarry looking at Tongariki, me, Mike and Rosanne (ki behind the camera)

that’s all folks……..

Many thanks to all that helped along this way to get there, to be there and to come home!

Enrique Tuki and Ricardo Crisostomo CONAF; Eric Alarcon and Eugenio, SAG; Selma Tuki; Nico Haoa; Chris Stevenson and Aviva/Earthwatch;  Aquatic Research Instruments; Anders Noran and Amy Myrbo, LRC; Rob Dunbar and Mike Osborne; Rosanne Hawarden; Ki Istre; Alejandro Naoa; John Snodgrass; and my Aku watching over us at the island.

and a special thanks to John Flenley and David Feek, for being my mentors in teaching me how to core at Rano Kao a few years ago, who I will be forever grateful to.