Biophysical Survey of the Enchanted River: A Scientific Report

Foreword by Ms. Ethel Wagas:

This article is an output from FCD’s project entitled “Rapid Resource Assessment of Four Philippine Underwater Cave Systems”, funded by The Deutsche Gesellschaft für Internationale Zusammenarbeit GmbH (GIZ) under the PAME Project, in partnership with the Department of Biology of the University of San Carlos and the local government unit of Hinatuan, Surigao del Sur.

This was the very first scientific investigation on the flora, fauna and water properties of the Hinatuan Enchanted River Underwater System. The exploration was made possible through the collaboration divers, field scientists and representatives from the local government – with the aim of better understanding the ecosystem of both the underwater cave system and its connecting river. This is also the first scientific article produced by the Filipino Cave Divers published in Annals of Tropical Ecology.

Ethel Wagas

Ethel Wagas

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Exploration of Katipunan Spring in Siargao

Thinkpad in the jungle

Thinkpad in the jungle

Background

At the onset of summer 2013, website designer and videographer JM Libarnes, accompanied by Siargao’s tourism officer Donna Tiu, visited a little known spring in Siargao. Libarnes published a video of the spring on YouTube , and from then on, curious visitors started to make a detour on their way to Siargao and take a glimpse of this new attraction.

The spring is located 500 meters southwest of Barangay Katipunan, Pilar municipality, on the island of Siargao, Surigao del Norte, Philippines (9°49’41.99″N, 126° 5’24.15″E). It feeds a small river that meanders for 4.5 kilometers along embankments of Nipa and mangrove trees, finally flushing out to sea at the eastern part of Siargao Island. The barangay (population 600+), is accessible through the Corazon junction in the middle of the Dapa-General Luna road. The junction is 8 kilometers from Dapa, and only 7 kilometers from General Luna.

Map

The Katipunan junction Map

The Katipunan junction

The Katipunan junction

The way to Katipunan

The way to Katipunan

Exploration

Soon after seeing the YouTube video, cave diver and FCD member Jake Miranda (Punta Bilar Dive Center-Surigao City) contacted local authorities of his intention to visit the spring in the hope of finding and exploring the underground source of the spring. Miranda had earlier sought the assistance of Dir. Mundita Lim of DENR-PAWB to send representatives from the DENR-PAWB Caraga to assess the area. After the DENR assessment, permission was finally granted by no less than the governor of the province, Gov. Sol Matugas, who had earlier visited the site and gave specific instructions that no “dives” should be done in the area.

Katipunan basketball court

Katipunan basketball court

Katipunan River

Katipunan River

Boarding the small boat

Boarding the small boat

Local guides

Local guides

On the morning of June 6, 2013, Miranda, with the support of Barangay Chairperson Flora Forcadilla, and aided by local volunteers, made shallow dives in the area. The team explored two small dry caves as well. After an exhaustive search, no “accessible” underwater entrance leading to an underground cave was found.

Dry cave being explored

Dry cave being explored

Inside the headspring

Inside the headspring

Locals listening to how caves are formed.

Locals listening to how caves are formed.

The katipuneros

The katipuneros

According to sources in the internet: “The soil type in Siargao Island is 80% Bolinao clay, 10% Bolinao clay steep phase, and 5% Jamoyaon clay loam.” In the Katipunan area, underneath this loamy soil, is more of the limestone substrate acting as the underground canal for rainwater. The rolling topography of the island, low altitude of the ridges southwest of the spring, and the presence of other “springs” nearby, may account for the weaker flow of water in the Katipunan spring. It is but one of the many outlets of water in the area. The longest river in Pilar municipality is actually the one that sources from Barangay Maasin-this river has a total distance of 8.5 kilometers. Such river systems have tourism potential as a river cruise attraction.

Still one cannot discount the possibility of finding a large dry or wet cave system in the area.

Developing the Spring into a Tourism Attraction

There are two springs in the river. The first spring one sees as you head upriver has a muddy bottom profile, thus swimmers have to contend with water turning murky at the slight disturbance. The furthermost spring, the “headspring,” this one with rocky limestone bottom, is the one that can be turned into a “natural” swimming pool.

Deep spring but murky when disturbed

Deep spring but murky when disturbed

Shallow spring can be made deeper.

Shallow spring can be made deeper.

Guide shows stones that should be removed.

Guide shows stones that should be removed.

This spring, which flows from the side of a rocky outcrop, had an observed average water flow of 30 liters per second. Because of the shallow “catchment” pool, the water quickly cascades to the river. During low tide, when the river drains all its water to the sea, the pool is only knee deep at its deepest. The water during low tide is fresh and clear.

During high tide, when sea water flows into the river, the pool fills up and water level rises by at least 4 feet, making the pool deep enough for swimming. During high tide, the water in the pool turns salty but remains clear.

The local barangay can turn this main spring into two pools-one shallow pool for children, and a deeper pool for adults. But they must first remove the stones left by crab fishermen who put them there.

Recommendation

A tourism master plan must be designed and implemented by the barangay council with inputs from the local tourism office. The steps can be:

1. First, an initial meeting for the creation master plan involving the council and the tourism office must take place. The components of the master plan will be the objective, work design, tourism fees, economic activity, marketing and sustainability.

a. Objective-To bring in local and foreign tourists to the spring pool.
b. Work Design-To effectively and efficiently use available manpower, funding and other resources to meet the objective.
c. Tourism Fees-To design affordable tourism fees to attract tourists to the area.
d. Economic Activity-To collect fees, encourage economic enterprise such as food catering, river cruise, boat ferrying and tourist guiding.
e. Marketing-To place directional and informative signs from Dapa and General Luna leading to Barangay Katipunan.
f. Sustainability-To train the local populace in embracing and protecting this natural resource.

2. Second, a work schedule should be finalized to remove the stones, erect cottages, build or redesign boat ferries, and place road signs leading to the area.

3. There are also food products that can be marketed by Barangay Katipunan. Locals can sell and cook on site the popular dried flying fish called “Bang-si” and mud crabs which are aplenty in the area.

Breakfast of dried fish and crabs

Breakfast of dried fish and crabs

Breakfast is ready

Breakfast is ready

Cheap Bang-si

Cheap Bang-si

(end of report)

Copy furnished to:
1. DENR-PAWZCMS, DENR XIII Caraga
2. Office of the PAMB-SILAS
3. Hon. Sol F. Matugas Governor, Surigao del Norte (care of Donna Tiu, Tourism Office of Siargao)
4. Hon. Lucio Gonzales, Pilar Municipality, Surigao del Norte
5. Hon. Flora Forcadilla, Barangay Chairperson, Barangay Katipunan, Pilar Municipality
6. FCD/file

PAWOD – A TREASURE TROVE FOR SCIENTISTS

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At the Photo Documentation Project on May 31, 2013 we (FCD divers Bernil and Doc Amores) managed to collect specimens for our resident scientists.

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Prehistoric remnants of coral colonies, likely millions of years old, are preserved by the Pawod environment. 1. A pair of specimens embedded in the walls of the northwest quadrant of Doc’s Chamber. 2. Close-up showing the intricate details of the coral polyp cavity.

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1. A unique formation of scorched small bits of branching coral randomly embedded in soft limestone. 2. Close-up of a branch showing the well preserved cavity of the once (millions of years ago) living coral polyp. 3 and 4. A collection of bits of coral skeleton of the branching variety.

Q & A

  1. How old are these specimens?
  2. What geologic events and forces brought about the possible widespread scorching?
  3. If these coral skeletons are indeed scorched, what intense flash burn occurred? Super volcano (nearest one is in Carmen, Cebu)? Meteor/asteroid?
  4. If these are scorched, then the specimen were surface located..and eons older than Pawod cave.

Pawod cave is a mute witness to all these events. It has kept and preserved all these evidences over eons. Whilst we do not have any answers yet to the above questions, one thing is for sure

PAWOD NEEDS TO BE PROTECTED AND PRESERVED..NOW!

 

 

 

 

 

 

PAWOD COMPREHENSIVE PHOTO DOCUMENTATION PROJECT: PHASE I – NORTHWEST QUADRANT OF DOC’S CHAMBER

northwestquadrant

The staged comprehensive documentation project of Pawod Underwater Cave System (PUWCS) is underway. Phase I was done on May 31, 2013. Cave divers: FCD’s Bernil and Doc Amores. Photographer: Doc Amores. Photography was done using Nikon DSLR in housing, Tokina 10-17mm fisheye lens, Nikonos SB 105 strobe. Phase I covers the northwest quadrant of Doc’s Chamber. Phase II will be the northeast quadrant of Doc’s Chamber, Phase III the south half; and Phase IV, the Bernillian Tunnel and The Well.

Natural Features

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1. As is typical of dissolution caves, boulders are strewn all over the floor of Doc’s Chamber. These boulders represent the sturdy rock formations that withstood the dissolving effect of the carbonic acid that sipped into the aquifer over thousands or even million of years
2. Silt. Owing to the low position of Pawod as compared to the rest of the area, dust and other debris are drained to the cave during heavy downpours. The existing silt represents the accumulation over eons.
3. Entrance to Bernillian Tunnel. The tunnel is the only feature that branches out of Doc’s Chamber. It is approximately 152 meters long.
4. The northwest quadrant is characteristically lined by dark materials. It could be tannic in nature, but on further glance, it appears scorched.

HUMAN ACTIVITIES IMPACT

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1. The guideline. This is the most essential tool in cave diving. Figure shows arrows that point to the cave exit. Loss of line following is one of the most serious mishaps in cave diving. Futile disorientation situations can result in out-of-air supply situation. The arrows are typically marked with the installer’s initials or identification and the approximate distance to the cave mouth.
2. Concrete blocks. Unscrupulous divers installed many of these concrete blocks without permission. The process of installing them probably contributed to significant erosion changes where fresh limestone dislodgement of various sizes are noted on the floor. At the very least, the presence of the blocks has destroyed the natural ambience of the cave.
3. Divers. The linings of Pawod are very porous limestone that easily get dislodged even with minor forces. Divers should be properly credentialed and briefed prior to entry into PUWCS.
4. Garbage. Figure shows garbage as far as 5 meters inside the cave. The Pawod pool is strewn with garbage of all imaginable kinds and origins. The area needs serious clean-up.

THE PAWOD UNDERWATER CAVE SYSTEM

INTRODUCTION

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360-degree view of the cave-in rim rendered flat. The water hole is on the right side.

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The cave-in area highlighted.

The Pawod Underwater Cave System (PUWCS) is one of Lapu-Lapu City’s most precious natural resources. It is a dissolution cave formed over thousands, maybe millions of years. It is located in Barangay [bar-ang-gai] Agus [Ah-gus] along Mactan Island’s circumferential highway. “Agus” is the local term for spring. The barangay is named after the springs gushing fresh water into Agus cove, approximately 185 meters from Pawod. Because of reversal of flow between PUWCS and the cove, the springs disappeared about 40 to 50 years ago. The reversal happened due to overextraction of Mactan’s water table in order to meet the water needs of Mactan Island’s population which has ballooned ten times over the years.

SURFACE TOPOGRAPHY

To this date, one can still see the prehistoric cracks resulting from the cave-in revealing the PUWCS.The area is circular in shape and measures approximately 33 meters across. The main pool is a small part of the cave-in’s north edge. This is the water hole known to most kids growing up in the area..including the author. On the other side is Pawod Gamay [Gah-mai], local phrase meaning “Small Pawod”.

DISCOVERY OF THE PAWOD UNDERWATER CAVE SYSTEM – THE AUTHOR’S FIRST-PERSON ACCOUNT

When I came home to Mactan Island in 2000, I was the only cave diver in the Visayas-Mindanao area. Cave diving was unheard of then. Having been certified in the extensive cave systems of north central Florida (USA) which have the same geological make-up  of limestone as Mactan. I suspected that there could be similar cave systems in Mactan. Exploration of potential sites started in 2002. Pawod was the third spring explored. On the very first try the 1 X 3 meter opening was discovered when my light beam running along the shallow wall suddenly disappeared . Entry into the main chamber was awe inspiring, realizing that this was the first time light has shone into the expansive walls after thousands, maybe millions of years. The other features were discovered after subsequent explorations. Of necessity, these were solo dives as there was no other cave diver around then.

THE FEATURES OF PUWCS AFTER FULL EXPLORATION

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*Doc’s Chamber is approximately 15X20 meters, maximum depth is 11 meters. At very low tide, a small air space maybe noted at the dome.
*The Well is the farthest dead end where fresh water gushes out at the maximum depth of 21 meters. It is 152 meters from Doc’s Chamber.
*Paul’s Peril is a vertical restriction. Back-mounted gear is a tight squeeze.
*Bernillian Tunnel is the lone branch of the underwater cave. It ends blindly at The Well.

PAWOD – ITS PLACE IN THE GROWING CAVE DIVING CULTURE IN THE PHILIPPINES

It is estimated that 1% of scuba divers would want to become cave divers. Here in the Asia-Oceana area, there are approximately one million scuba divers. That figures to 10,000 cave diver wannabes. Before the discovery of Pawod, the only sure place to go and have a good cave certification course is in Florida (USA). For one coming from the Philippines and other parts of Asia-Oceana, this will entail enormous expenses. For air fare, certification course fee, equipment and air fills and lodging, a 10-day course in Florida will cost approximately US$6,500, compared to if you have the course done in Pawod here in Mactan Island which amounts to approximately US$2750. One can see the benefit in savings alone..not to mention the exotic ambience of Mactan Island where there is pleasure to be had day and night. In Branston, Florida there is nothing but forest and backward native Floridians.

After my discovery, I happened to meet Paul of Mandarin Divers of Hong Kong who was on his way to become a cave instructor. I introduced Pawod to Paul without any preconceived ideas to see if the features are enough to make it a cave certification site. Indeed, they are! Since then a handful have been certified at Pawod, including our very own filipinocavediver Bernil, the front end of a line of 10,000 cave divers.

Article by:

Dr. Alfonso Y.  Amores

Dr. Alfonso Y. Amores

Hinatuan Enchanted River Expedition 2013

Hinatuan Enchanted River Expedition 2013

By Jake Miranda, TDI

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Dive Team

1. Jake Miranda, TDI Full Cave Diver #495188

2. Ivar Almhjell, TDI Full Cave Diver #488306

3. Michael Allen, PADI Divemaster

4. Johm Rey Pingkian, SDI Divemaster

The Cave

Hinatuan Enchanted River begins as an underwater spring that spouts freshwater from a deep source in the ground. The source of the water may be from aquifers surrounding the area that collect the water from heavy rainfall common in Hinatuan . The exiting water makes it all the way to sea snaking along its own river bed. The river is in the municipality of Hinatuan, in the province of Surigao del Sur.

It is a five hour drive from Surigao City or a three hour drive from Butuan City. With better roads this year, it is now just a four hour drive from Davao City. It is already a tourist destination and has ample facilities like shaded cottages, restrooms and food stalls.

It is managed by its own tourism staff. As it is with water springs, there is an underwater cave in its depths.

Through past explorations of Mantaga Adventure Divers led by Dr. “Doc” Amores and Bernil Gastardo, they were able to find the cave entrance and initially map the cave area to a max depth of 87 meters. The most notable find was a good sized-chamber at a depth of 50 meters. Diving deeper than 50 meters into a further passage is the realm of trimix gases.

enchanted diagram

Diving at Enchanted River
For any kind of diving activity in the area, one needs prior consent and expressed permission from the municipal government through Ferdinand Barrios. Mario Tecson of the tourism staff will inspect your dive licenses and let you sign a waiver.

They are quite efficient to the point that they will reserve the nearest cottage for your dive group. For cave diving, the process is quite thorough but painless. You will also have to get in touch with cave pioneers Dr. Alfonso Amores or Bernil Gastardo for coordination of dive objectives.

For this expedition our objective was to check the entrance which was inaccessible in 2011.

Dive#1

After an easy setup at the cottage we all headed to the nearest ramp. I was Diver#1 and Ivar was Diver#2. Michael and JR were our standby rescue divers outside of the cave entrance. Dive#1 was made at high, slack tide. This was done to ensure easy access into the cave such that the flowing water from the spring would be slowed down by the rising seawater entering the mouth of the river. At least that makes sense in theory and proven so in past dives in the area.

Diving to the bottom of the pool, you will see a large log that marks the split into a right and left lane to get to Doc’s Door and the entry point to Mayor’s Chamber. The right lane, called Bernil’s Crawl is a crawling descent to Doc’s Door. The left lane, called Patrice’s Way is an easier access, because it hugs a cavity on the left wall lessening the current flow.

We tried entering through Bernil’s Crawl but there was substantial sediment deposit in the fissure, making the current flow faster than we can manage. We ended up switching to Patrice’s Way to get to Doc’s door. After hurdling some meters at Doc’s Door we were finally in Mayor’s Chamber. It took us 11 minutes from dive entry to reach Mayor’s Chamber.

This chamber was previously measured by Doc’s team to be 37 meters long and 31 meters wide with a max height of 8 meters. This time more sedimentation on the bed made the bottom closer to the ceiling. There were several fish swimming with us inside the chamber. We also found two lines laid during Doc Amores’ second expedition. The lines and the steel bar anchors were almost buried by the deposited sand. We then explored the chamber up to Kelvin’s Knee Cap which was at 52M depth, made our turnaround at 20 minutes and exited again through Doc’s Door and Patrice’s Way.

We surfaced after a total dive time of 57 minutes. Dive Summary of Dive#1: Entry 11:12H, maximum depth at 51.4M, on 21%O2 and 50%O2 at 17M and 100%O2 at 4M. Exit 12:09H, 57 minutes.

Dive#2

This time Ivar was Diver#1 and I was Diver#2. We made the dive on the descending low tide. We knew from previous expeditions that the current flow of the freshwater would be stronger with the absence of an opposing force-the flooding seawater.

True enough the current was stronger. Even Patrice’s Way proved hard to enter. We were exerting too much effort and breathing more air than usual just to try to push into the cave. Ivar called off the dive right before Doc’s Door. We made a difficult exit as both of us were trapped on several wedged rocks. We did not have time to recover our reels.

It was a humble retreat back to the main entrance. Dive Summary of Dive#2: Entry 14:44H, maximum depth of 39.0M on 21%O2 and 50%O2 at 17M and 100%O2 at 4M, Exit 15:18H, 34 minutes.

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Discussion
There is an observed erosion of the surrounding limestone walls both at topside and underwater, possibly caused by swimmers in the pool, and tourism development in the area. The porous and softened limestone easily breaks off and then descends to the bottom. Most of this eroded rock gets deposited at the cave entrance.

While Patrice’s way is still wide enough for divers to enter the cave, the pile-up of sediment in Bernil’s Crawl will eventually divert the water flow into Patrice’s way, thus making it harder to overcome the outgoing flow. Further erosion could amplify the current through the restrictions. We suspect that depending on the month of the year, one or both entrances could be partially blocked. The sedimentation is an issue for cave divers. While constant water movement and immersion will dissolve it through time, it will make the cave harder to access for cave divers.

The entrance particularly the limestone sand and pebble bottom will always change depending on how the water flow will shape it. Thus the door to this nature’s wonder is ever changing.

Acknowledgement

1. Hinatuan Enchanted River Underwater Cave Expedition 1 (Feb. 19-20 2010)

Team members Gastardo, Guillermo and Amores

Report written by: Dr. Alfonso Y. Amores

2. Hinatuan Enchanted River Underwater Cave Expedition 2 (July 2-8, 2010)

Team members Neilsen, Amores, Duncan, Ramos, Livingston, Laborda, Mak

Report written by: Dr. Alfonso Y. Amores

3. Hinatuan Enchanted River Underwater Cave Expedition 3 (June 11-14, 2011)

Team members Amores, Holder, Gastardo

Report written by: Dr. Alfonso Y. Amores

Thank you to Ferdinand Barrios, the tourism, planning, development officer of Hinatuan Municipality, and Mario Tecson, tourism operation assistant of Hinatuan Enchanted River Management, and to the discoverers of the cave, Mantaga Adventure Divers, led by Dr. Alfonso “Doc” Amores – NACD (USA) # 3042 and Bernil Gastardo – IANTD Cave Diver #95508, for their data from past three expeditions and their advice for our trip.

Written by:

Jake Miranda

Jake Miranda

 

 

 

Siargao’s Blue Cathedral

blue cathedral

Being unfamiliar with scuba diving does not really prevent you from admiring all that Caraga has to offer under the water if one looks at all its endless coastlines, countless islands, islets and shoals.

Surfing in Siargao became such a phenomenon that there is one more product that perhaps we did not seriously take a look at because we were all focused on what was on the surface-surfing and island-hopping.

In Siargao, there is the majestic wonder called the Blue Cathedral, an underwater rock formation with a vertical hole. Blue Cathedral’s top is a 20-meter diameter hole at a depth of 20 meters. Then as you descend into it there’s a sliding slope that leads to its two caverns-the North and East caverns.

On the north cavern you will see a jagged rock that has split off from the top ceiling (Sword of Gabriel), going into this hole will lead you to 10 meter high and 30-meter long cavern (at average depth of 30 meters) that will spill you North into the Pacific waters. On the east cavern is the other cavern Devil’s Pipeline (15 meter high and 40 meter long tunnel), shaped more like a Cloud 9 pipeline than a cavern. You need a good light here to appreciate the tunnel’s grand design. At the end of Devil’s Pipeline is the Arm of God (30 meter long rock perched on three columns that reach out East to the Pacific), as there are spaces between the columns you will tend to see blue-lit water out of those spaces. We call these spaces the Eyes of God.

The size of a large church, it does look like a cathedral because of sun rays entering the hole and the three entrances (top hole, north and east caverns) welcoming schools of pelagic fish like jacks, tuna and barracuda and sometimes sharks from the Pacific Ocean. One diver jokingly said that this indeed feels like a church because when you see it, all you can say is “Oh My God!”

What a wonderful new gift the Lord Almighty has given to Siargao.

Out of Blue Cathedral is the lip of the Siargao shelf meeting the blue Pacific waters. The terminal depth of 50 meters goes on for several kilometres, and on any given day you can see the bottom. Diving here is not for the faint-hearted. It is also not predictable like any house reef dive. Like Cloud 9, the Blue Cathedral faces the Pacific Ocean. Like a surfer waiting for swells, a diver must carefully plan for a break in the current to come in the hole.

This ‘holy’ dive site just sits in front of the Cloud 9 pavilion where from your boat you will still get a ‘heavenly’ glimpse of the surfers riding the waves.

Indeed you are in surfing and diving heaven.

Article by:

Jake Miranda

Jake Miranda