Dragon`s Eye

Dragon’s Eye
a lake in Rogoznica
Rogoznica Primary School
School year 2012/2013
Introduction
Coming to Rogoznica from the North and the South side, there are two
signs on which it says “Dragon’s Eye” (“Zmajevo Oko”). If you follow the signs,
you will soon be in the town of Rogoznica where you will see more information
about the location of “Dragon’s Eye”.
It really pays to follow the signs because they take you to a small path
leading to a spectacular lake, which has become the object of research for many
Croatian and world scientists.
Some general information
The Lake is situated on the peninsula Gradina, on the narrow slip
of land that separates the bays of Soline (Miline) and Koprišće. The lake is
surrounded by vertical rocks from 4 to 24 metres in height. The surface of the
lake is 10,000m2, and the biggest depth measured is 15 metres.
The first ever known research of the lake was done by professor Buljan
in 1956. He claims that the lake was created by a cave whose roof caved in,
which resulted in a hole. After the Ice Age, about 10 thousand years ago, when
the sea level rose by about 100 metres, that hole filled up with sea water which
found its way through underground canals and cracks.
Buljan established that the lake water has poisonous gases – sulphuric
hydrogen - which was the first such finding on the East coast of the Adriatic
Sea. He also discovered that the water is divided into layers, and that there is no
oxygen at the depth of more than 9 metres.
Every few years the water layers mix and the water becomes white.
Sometimes the layer of water without oxygen spreads all over the lake and all
organisms in it die, and after that, a few years are needed for life in the lake to
renew. The people of Rogoznica call this phenomenon “the boiling of the lake”
or “the lake going wild.”
On the west side of the lake there are four little underwater caves. At
the entrance they are three to four metres high and they get smaller towards the
end. The longest cave is 8 metres long. There exists no tunnel to which the lake
is connected with the sea, as it was once thought; there are ten places through
which sea water enters the lake.
The saltiness of the lake is high, and the temperature of water layers
varies, so that the bottom layer can be 5 degrees warmer than the top one. On
the surface, the lake water is green and blue, and then it becomes yellow, and on
the border where there is no oxygen the water is red. From there to the bottom
it is gray and dark brown, so that nothing can be seen.
The lake has many different inhabitants and some species become much
bigger in the lake than in the surrounding sea. Oysters and mussels in the lake
grow quite big, even much bigger than the Adriatic average.
Many years ago the inhabitants of Rogoznica used to throw live fish in
the lake, which they would catch in the surrounding sea, and leave it in the lake
to grow for a year and then catch it again. The fish was enormous after its stay
in the lake!
The phenomenon of “water mixing”
The last case of water mixing in the so-called “water column” or “water
pillar” in the lake happened in 1997 when at the end of September the water
became milky green, and all organisms that could swim rose to the surface. Two
days later they all died. Chemical analyses showed that the whole water column
was without oxygen and on the surface there was sulphur. Even today scientists
do not agree about the cause because there were no measurements taken before
or immediately after the event. Since that time some species that used to live in
the lake have not appeared again.
For years scientists had been trying hard to protect the “Dragon’s Eye”
as a special ecological value. They finally succeeded in 2010 when “Dragon’s
Eye” was included in the national ecological network so that today it is a part of
protected natural heritage and is under state control.
Eyewitness reports
From 1942
In Rogoznica there is a lady who is 84 years old now and as a thirteen
year old girl she witnessed the phenomenon of mixing water. She and her
friends were minding sheep in the fields not far from the lake, when suddenly
around 2 o’clock in the afternoon, a loud, terrifying noise was heard. It was like
thunder coming from the inside of the lake and the lake water level rose and the
water spilled into the sea. The fish were thrown out and the surface was so thick
that nothing could sink. After that the water suddenly withdrew. Nobody alive
then could remember that the water in the lake had risen so much and spilled
into the sea.
From 1997
Lots of people remember what happened in 1997. A middle-aged man
says that one day there was a terrible smell in the whole of Rogoznica. It was
impossible to breathe. People went to the lake and were surprised when they
saw a white lake, no blue or green patches on the surface, just a creamy, white
cover. There were thousands of dead fish, crabs, shrimps and other organisms
floating on the surface. People knew that the lake “had boiled.”
Legends
Since “Dragon’s Eye” is very unusual and has occasional drastic and
very dramatic changes, all kinds of stories have developed among the people of
Rogoznica and they are still told today.
The most famous legend says that two brothers owned the land on
which the lake is now located. The soil was very fertile so the crop was always
rich, and the brothers always split it fairly. However one of the brothers became
blind and at the time of the following crop he warned his brother, “If you trick
me, the ground will open and our fields will sink into water, and from the water
a dragon will jump out and it will swallow you.” The brother did not split the
crop fairly, a big hole opened in the ground, it filled with water, and from the
water rose a dragon, swallowed the cheating brother and returned back to the
depths of the lake, where it still lives. Occasionally it moves and then the water
rises in the lake, and if it accidently poisons the animals in the lake with its
breath, then the smell is felt outside the lake.
Drawing on cover of school magazine “Dragon’s Eye” from 1995.
Science-Fiction fans have their own legend which says that on the
bottom of the lake there is a space ship which occasionally tries to establish a
connection with other space ships and when it tries to move, the lake has weird
changes.
There is a legend that mentions heroes from Ancient Greece. According
to the legend, on the peninsula of Heraclea, today known as Rogoznica, lived
a dragon Murin, who protected the inhabitants from enemies. As a sign of
appreciation, the inhabitants gave him the most beautiful girl every year. Not a
single girl survived in the presence of such a horrible monster. One day a man
called Aristoles came to Heraclea. He was a great-grandson of Jason who was
one of the Argonauts and he fell in love with the girl that had to be handed over
to the dragon the next day. Aristoles could not allow that so he challenged the
dragon to a duel. They fought all day and in the end, thanks to the spear which
was made by Hefest himself, Aristoles found a way to the dragon’s heart. The
dying dragon was furious because the gods betrayed him and he dug out his
own eyes. He threw one eye as far as he could and it fell where the Adriatic Sea
is now the deepest, and for the other one he didn’t have enough strength to
throw it somewhere. The eye slipped out of his claw and fell on a rock. At that
very moment it melted the rock, made a big hole which was filled by the sea
giving us the lake called “Dragon’s Eye.”
Conclusion
“Dragon’s Eye” is certainly one of the most important natural
phenomena in this part of Dalmatia. It has not become a tourist attraction as yet,
but it is very popular with the local population, especially the children because
they love swimming in it. Before the sea is warm enough for swimming, the
lake is much warmer so the swimming season starts very early for children in
Rogoznica and lasts much longer than anywhere else on the Adriatic Coast.
This booklet is the result of a research project on which a group
of eighth graders from Rogoznica Primary School worked during
the school-year 2012/2013.
The source of the text is a collection of work on the Primošten-Rogoznica area
called “Povid”, published by Matica Hrvatska, 1997.
The selection of texts and their translation was done by:
Duje Cvitić
Marko Galić
Marija Kovačić
Kristina Lovrić
Project coordinator: Maja Janković - English teacher