You might be wondering what on
earth a lake ball is? The species itself is called Moss Balls of Lake Myvatn
and Lake Akan is a species of filamentous green algae named Aegagropila linnaei
that grow into large green balls with a velvety appearance. Moss Balls is also
called marimo (In Japanese for "ball seaweed"), also known by several
names such as Cladophora ball and Lake ball. These beautiful Moss balls grow in
sizes of 12 to 30 cm across, subject on where you find them. However, “Marimos”
are rare and is known to occur only in Iceland, Scotland and Japan, primarily
Lake Akan in Japan and Lake Mývatn in Iceland. Recently, moss balls appeared in
a large numbers on Dee Why Beach, in Sydney, the first such spotting of this
alga in the southern hemisphere. It is currently believed to be one of only two
locations where it exists in the world. Around two years ago that the marimo
had decreased to such an extent that there are hardly any left, the remaining
balls are scattered over a rather small area and their condition is not good.
“They look rather limp, not firm and beautiful as they should be and hollow
inside.
Marimo doesn’t grow around a
core, such as a pebble. In its place, the algal filaments grow in all
directions from the centre of the ball, continuously branching and thereby
laying the foundation for the spherical form. Surprisingly, the ball is green
all through, although light only reaches very short distance into the ball. The
chlorophyll inside the ball remains dormant in the dark, but becomes active
when uncovered to light if the ball breaks apart. Moreover, moss balls are
found submerged in the lake’s bed where the mild wave action often turns them over
maintaining its spherical shape, at the same time ensuring that they can
photosynthesize no matter which side is turned upwards. In Japan the Marimo is
well protected and revered, and officially a natural treasure since 1920.
Hence, at Lake Akan a boundless effort is spent on the conservation of the lake
balls that includes an annual 3 day Marimo festival. Where small hand rolled
balls of free-floating filaments is sold in shops as souvenirs. Moreover,
Marimo is also a staple in many Japanese aquariums.
Meanwhile in Lake Myvatn, lake
balls are gradually vanishing. Around ten years ago, the lake balls in Lake
Mývatn were two to three layers thick on the lake bottom. Nowadays, they’re
mostly gone, and their disappearance is attributed to pollution caused by
mining operation in the area that commenced in the 1960s. Therefore, the big
amount of phosphorous and nitrogen dumped into the lake has radically increased
the lake’s bacteria that feed on those nutrients, swarming so compactly that
they blocked the sunlight that reached down to the lake’s bottom. Thus, in the
less sunlight, the algae start to die off, revealing more of the lake bottom’s
loose sediment. Furthermore, the wind and the waves that once rolled the balls
into their shape stirred the loose sediment covering the left behind algae,
further depriving them of sunlight. The Marimo was given a status of protected
species in Iceland in 2006, but it was already too late. In Japan the marimo is
a natural treasure while in Iceland they are a protected species.
Source: Charismatic Planet