KOROR STATE GOVERNMENT MARINE TOUR GUIDE ... - C3

exchange is limited by the tunnels. This, combined with the relatively deep nature of the
lake prevents refreshing surface waters from ever reaching its depths. Now, the only
organisms that inhabit the waters below approximately 45 feet (15m) are bacteria that
can live without oxygen and both produce and are able to tolerate high concentrations of
hydrogen sulfide.
Why is hydrogen sulfide poisonous to humans?
Hydrogen sulfide is poisonous to humans because it prevents the delivery of oxygen to
our tissues, which, ultimately, can kill us. Like oxygen, hydrogen sulfide is a gas that is
soluble in water. Unlike oxygen, however, hydrogen sulfide can enter our bloodstream
directly across our skin. Once in the blood, hydrogen sulfide binds to our hemoglobin
(the molecule that binds oxygen and delivers it to tissues throughout our body), which
prevents oxygen from doing the same and leads to death by oxygen deprivation
(asphyxiation).
Where can I find more information or references on marine lakes?
The Coral Reef Research Foundation website is a good source of information about
marine lakes and includes a list of publications.
www.CoralReefResearchFoundation.org.
GOOD PRACTICES: HOW CAN WE ENSURE THE LONG-TERM EXISTENCE OF THE JELLYFISH AND
THEIR HOME WHILE ENSURING A PLEASURABLE EXPERIENCE FOR ALL VISITORS?
1. ALWAYS REMIND YOUR GUESTS NOT TO TAKE ANYTHING BUT CLEAN SNORKEL GEAR INTO
THE LAKE AND DO NOT TAKE ANYTHING FROM THE LAKE INTO THE OCEAN. This includes
things that appear dead, like seashells or rocks, which can be home to unnoticed, but
potentially invasive, organisms.
The unintentional introduction of non-native species is probably the biggest threat to the
long-term survival of the jellyfish population and, more generally, the ecological health of
the lake.
Because Jellyfish Lake is isolated from the surrounding ocean (there is no direct
exchange of water), any living organism found in Palau’s waters outside of the lake is
considered non-native to the lake (even if native to Palau more generally). This includes
organisms from other lakes. Thus, all organisms potentially pose a risk to the lake
should they be introduced.
The reverse is also true; lake organisms are non-native to Palau’s ocean environment.
Please do not move anything from the lake to the ocean, or vice versa. Help preserve
the separation of Jellyfish Lake and Palau’s ocean flora and fauna that originated 10,000
to 12,000 years ago!
Unfortunately, the threat of an exotic species introduction to the lake has already been
realized. A non-native sea anemone, tentatively identified as a species of Aiptasia, was
introduced to the lake sometime in 2003. Since its discovery in late 2003, the sea
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