[Coral-List] Mystery Event - Lankayan Island, Sulu Sea, Sandakan
allison.billiam at gmail.com
Wed Aug 22 16:47:53 EDT 2007
Arthur, I am thinking along the same lines as you for a cause in
Maldives. Dark, foul-smelling water was reported along with fish
kills. Deeper water is reported anoxic. Other causes seem improbable.
Incidentally there was a mystery kill in the Caribbean a few years ago
- should be in coral-list archives - although volcanic gas was a
suspect there, I don't know if it was ever resolved.
On 8/22/07, Arthur Webb <arthur at sopac.org> wrote:
> It's interesting you mention an atoll event. I was in Kiribati in the
> Central Pacific during Christmas 2003 and at that time there were reports of
> mass mortality along the ocean side coasts of at least 2 atolls in the group
> (Abemama and I think Nonouti). These atolls are tectonically stable and are
> far from any active plate boundaries and are thousands of kilometers from
> any significant land mass with surface run off. Additionally, both of the
> islands mentioned above have small populations who live a traditional
> subsistence lifestyle (few vehicle's, no electricity or reticulated water,
> few imported products, no intensive agriculture, etc) in relatively pristine
> terrestrial and marine environments.
> Whilst I did not witness the event I did travel to Abemama about 2 months
> after and the same story was repeated time and again that there was so much
> dead marine life on the ocean side reefs (and not the lagoon side) that
> "windrows" of dead fish lined the shores (both pelagic and reef associated
> species were mentioned). The people here too indicated the intolerable
> smell and plague of flys which followed but this seemed very much associated
> with the decaying marine life not the time of the event.
> I must say this utterly stumped me! These atolls are ancient seamounts
> which rise steeply from 3.5 4.0 km depth and the outside living reefs where
> the dead fish were first witnessed are the very upper living rim of these
> oceanic slopes. They are high energy environments and the concept of water
> residence times barely even applies and as mentioned there is no tectonic or
> terrigenous influence to speak of. Last, people reported that some had
> taken and eaten fish which was sluggishly floating (near death I guess)
> immediately following the event with no ill effect and otherwise of those I
> spoke to there was no living memory or oral history of such an event having
> happen before.
> My only thought was that through some freak anomaly of deep currents a slug
> of very cold and or deoxygenated water moved up the slope persisted for long
> enough to cause damage then sank again ............. anyway since we're on
> similar subjects I'd be interested if there's any similar stories or ideas
> out there.
> Arthur Webb
> Coastal Processes Adviser
> SOPAC Pacific Islands Applied Geoscience Commission
> Postal Address: Private Mail Bag, GPO, Suva, Fiji Islands
> Street Address: 241 Mead Road, Nabua, Fiji Islands
> Tel: +679 338 1377 Fax: +679 337 0040
> Email: arthur at sopac.org
> Website: <<http://www.sopac.org>>
> William Allison wrote:
> Several months ago something very similar was described at a Maldivian
> atoll. I'll try to track down particulars.
> On 8/22/07, Don Baker <reefpeace at yahoo.com> wrote:
> Dear Coral-L:
> Several months back, an event happened at Lankayan Island, north of
> Sandakan, Sabah, Malaysia (Sulu Sea), that resulted in the death of corals,
> sea cucumbers, giant clams and other marine life - from shallow water to
> approximately 3 meters.
> During this event, the seawater smelled putrid and noxious, whereas, it was
> initially assumed to be from all the dead marine life. The water salinity
> was measured at or near 25ppt, and very unusually strong currents were
> present near the southern portion of the island's shallow reefs. Wave force
> was rough at about 1 to 1.5 meters. The weather was sunny without any
> rainfall either at the island region nor on the North Borneo 'mainland.'
> Please refer to this publication with regards to page 9 / Sandakan Sub Basin
> and Sulu Sea Basin.
> The nearby islands to closest to Lankayan Island are the Philippines Turtle
> Islands - with Buan Is. the closest and to the south west. Buan Is. is
> classified as a "mud origin' type island mass, whereas, decades ago there
> existed active mini mud volcanoes there.
> Observation by the local fishermen in the same Turtle Island region have
> seen many large, upwelling mud plumes flowing from the under the sea
> (perhaps pushed out by the natural gas pressure in the Sandakan Basin edges
> near North Borneo?).
> In short, this event seems to point more so to a natural cause rather than
> from runoff from the N Borneo coastal regions. The lowering of the seawater
> salinity was also significant as well as higher than normal water
> temperatures in the same area. Could this also be a combination of 'ancient
> freshwater' also extruding along with the mud and perhaps natural gas?
> Lastly, the seawater visibility (noted by the tour divers in their
> complaints) was very poor [< 3 meters at times]. The color was 'gray' the
> same as the mud on Buan.
> Can anyone recommend an institution to confirm the cause of this event? Has
> anyone observed or know of any similar events worldwide? What would be the
> best way to monitor and gather data if this event is natural and caused by
> the oil/gas/'old' water? Is this event also dangerous with regards the
> Lankayan Island's proximity to such a event?
> Any advice, assistance, comments are welcome.
> Don Baker
> Reef Guardian Co-Founder
> Sabah, North Borneo
> Alternate Email: donbjr95 at hotmail.com
> "Dedication and motivated direction in achieving specific goals related to
> the care and protection of living things is not necessarily a guaranteed
> formula for success. Success is, more often than not, a direct result of a
> person's passion in addition to the above formula." [Don Baker, Marine
> Conservationist/Activist, 1998]
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