In recent years our local waters of
Tampa Bay and the Gulf have been invaded by a silent enemy, a deadly killer with
the unusual name of "RED TIDE"
or "RED DEATH" as
called by the locals. This Red Tide is one of natures weapons against marine
life and in particular some species of fish, particularly bottom feeders.
Red Tide invaded our waters
at the beginning of June 2005 and is working it's way up the coast from down in the south,
where it seemed to start. Thankfully by November 2005 it had at last gone. This
year of 2006 has only seen a few weeks of trouble to the north of our location
with a minimal fish kill.
Karenia Brevis is the scientific
name of Red Tide and is a tiny celled algae that becomes toxic as a result of a
massive multiplication of these cells or algae bloom. The reason for the name
is that when this algae bloom occurs, the sea turns red in places with the
amount of bloom that is produced. It also produces a choking smell that get's
you right in the throat and can be particularly dangerous to asthmatics or any
other persons who suffer from respiratory problems.
- Very Low (1-5,000 cells/liter) = Little or no
- Low (5,000-100,000 cells/liter) = Shellfish
- Moderate (100,000-1 million cells/liter) = Some
respiratory irritation and possible isolated fish kills
- High (1 million + cells/liter) = Respiratory
irritation, fish kills and water discoloration
RED TIDE begins life miles offshore on the Florida
Gulf Coast and is carried onshore by prevailing winds and ocean currents. It
strikes unannounced and as the blooms progress, the density of these red
organisms increases to several million cells per litre of water and the affected
area increases to many square miles. The result, unfortunately is devastating
fish kills with the contamination of shellfish beds and the production of
During 2005 we saw large fish
kills particularly in the intra coastal waterway spreading outwards to about 8
miles offshore. Very few species seem immune and we have seen Jewfish to 200lbs
plus floating on the surface. Our picture above show the fish we found just off
From the species that we have seen floating on
the surface it is the bottom feeding species such as Mullet, Grouper and Red
seem to be killed in numbers.
Scientists are unsure what causes
precipitates the algae to bloom. However they theorize that it is probably
caused by a combinations of things such as tide, air pressure, sunlight, high
water temperature, high air temperature and a further combination of nutrients.
Our only protection against this
phenomenon is large amounts of rain and strong offshore winds to break up the
algae. Unfortunately both have been non existent. RED TIDE.
What a tragedy, as these fish move out into the shallower waters of the Gulf to
On the 3rd Dec 2001 whilst out
fishing we counted some 23 Red Drum weighing about 20 to 25lbs each floating on
the surface, killed by
Scientists tell me that in 1986 the
lasted for 16
In 2005 the
was in evidence for 3 months. Even Hurricane "DENNIS" did not break it up as was thought.
Eventually it disappeared some 3 months later. As I said early 2006 has been
unusually clear of the infection.
The phenomenon also occurs in other
waters of the world and I have seen it once in 26 years of fishing in the waters
of the English Channel when the sea almost looked like blood. In fact the
was so thick with
algae, that our echo sounders could not penetrate the growth to see the seabed
below. This lasted for nearly a month and the fishing was non existent.
For more information on Red Tide