19/07/2005 - The Environment
Agency is asking people not to be alarmed
if they see large slicks of ‘sewage’ in coastal
waters and estuaries around Cornwall. The
slicks are more than likely to be seasonal
algal blooms.
The yellow-brown coloured slicks are the most
common type of marine algae, Phaeocystis,
which is also known local as May Bloom.
Despite its name this species of algae usually
starts to form later in the summer, around
June or July. There have been recent blooms
on the Camel Estuary. The appearance of the
algae is normally caused by rainfall washing
nutrients from fields into inshore waters
followed by warm sunny weather. This combination
provides ideal conditions for the algae to
bloom.
Phaeocystis forms unsightly creamy brown
foam in the water which turns darker brown
and lumpy as it decays. This looks very similar
to raw sewage. As the algae breaks down it
smells strongly of rotten eggs or vegetables,
causing further confusion.
However, despite its alarming smell and appearance,
the algae is not toxic.
"Every year we get reports of sewage
slicks on inshore coastal waters and of course
we treat each one seriously and carry out
tests. But almost always, despite its unpleasant
appearance, the ‘sewage’ turns out to be a
marine algae," said Claudine Fontier
for the Environment Agency.
"There are some species of algae that
can pose a health risk to marine life as well
as humans. These are less common and in some
cases cause discolouration of the water known
as Red Tides.
"If you see one of these less common
blooms or have concerns that what you see
is not algae please contact the Environment
Agency’s free 24 hour hotline 0800 80 70 60."
Leaflets showing how to identify different
types of marine algae are available from the
Environment Agency on 01208 265049.
