Red tide .. The
environmental and wastefully phenomenon
In many cases the prosperity of type or
more of phytoplankton at the same time accompanied with or by varying colors in
the sea water like olive green, yellow, brown, the red building brick color, or
even the color of blood, from here came what is known as metaphorically
phenomenon of "red tides" that does not mean more than the phenomenon
of the flourishing of phytoplankton, accompanied contamination can be
distinguished visually This phenomenon is also a double-edged weapon for humans
and life in the seas. Among about 5000 phytoplankton type, which could be
identified in the bodies of water in the world, there are about 300 species
have been able to make this phenomenon, of which 40 species have a capacity to
produce toxic substances under certain environmental or special physiological conditions
of the specie . These toxic substances may kill the human when he is dealing
with fish or other marine organisms carrying these poisons. The red tide is not
new to mankind it is known to human beings for more than 1000 year and the
first case registered historically return to poisoning of human after
addressing Oyesters, fish contaminated by poisons produced by minutes algae
during the red tide in 1793 when
"Captain George Vounkoufar" with the crew reached Columbia, in an
area now known as the "Gulf of poison" and injured crew poisoning,
and some died. Vounkoufar and his crew known lately that members of Indian
tribes inhabiting the region prohibit members, but denied the shellfish during
the period which shows a shimmer of the sea water during the night when
swimming or move vessels and this is known symptoms of cytometry phenomenon
that accompany some periods of red tide. This phenomenon also known by British
fishermen on the British coast since the late 1800s.
The red tide passes through four stages to become a reality can be
distinguished visually:
1-The
up phase : the stage necessarily requires the presence of a sufficient number
of active cells effective in the same zone with certain specifications. As well
as environmental conditions suitable for reproduction. These cells may be reached
or transferred to the prosperity area or may arise out of the boom area itself.
Marine currents and the wind played an important role in the transition of
cells from one area to another while the Sacs buried inside surface of the
seabed main factor for the emergence of red tide in the transition from mere
Sacs prosperous cells.
2-
Growth stage : it is the stage where the algae grows and its speed vary
depending on the kind of divisive causes of the phenomenon and is usually
confined these velocities ranged from less than a cell and even two cells per
day. This has jump quickly to reach times in the few periods followed by the
water changing color becomes visible to the naked eye. The continuation of this
phase subject to the continuity of appropriate conditions for growth,
particularly with respect to light and temperature and nutrients this period does
not exceed a few days and may not exceed the daylight hours.
3-
Consistency phase : this stage mean that the water changing color visible to
the naked eye. There is a red tidecontinue weeks may extend to one month or
more, while its presence might not continue in limited hours because of several
factors. The more the trainer Red tide depending on the type causing it
whenever increased seriousness of the situation and this is the stage that
often accompanies the death of fish and other marine organisms to many factors,
we will have later, but they include mainly the extreme variation in dissolved
oxygen in the water between periods of night and the day, and continued thermal
and saline slope of the water column, the apparent difference in the
temperature and salinity of surface water (more temperature and less salinity)
and the water player over bottom,play an effective role in the continuity of
this stage. Vertical migration of certain types of phytoplankton play an
important phase in the continuity of red tide phenomenon.
4-
Collapse stage : In this stage ,the color of the water return to its natural situation
, prosperity decline and expiration of it ,showing that the natural, chemical
and biological conditions in the surrounding environment had suffered from a
sharp and markedly change and may be broken thermal or saline slope resulted
whichever process of up-welling and this may be for unfair grazing of the algae
by zooplankton is biologically valid reason for the decline of red tide and expiration
of the phenomenon.
How human being helped in the spread of
red tide?
Although the red tide phenomenon depends
on the presence and continuity of factors involved in the manufacture of human
but that there were other factors has nothing to do with it. It was noted that
the emergence of the red tide revolved with periods of heavy rains, especially
at forests and planted heights and water are rainfall in the sea and endured
from organic materials is the abundant food for algae. However, the role of human
being had clearly limited to the following :
1-Direct
exchange on watercourses flowing in rivers and seas : such residues althuogh
was treated in part to get rid of the plankton, it is considered one of the
most important sources of nutrients for algae, research has proven the
importance of ammonia in the sewage that is the best elements of the different
sources of nitrogen, which algae absorbed directly, and the use of detergents
in populated areas and the adjacent coast including dentists high proportion of
phosphate has helped to the presence of the phenomenon and prosperity.
2-Industrial wastes : it was noted at
the beginning of the 1960s, since nearly fifty years that some ports that are
beside a wooden vessels industries experiencing heavy presence of red tide due
to certain types of phytoplankton called golden algae (Diatoms), which entailed
the attention of researchers in the impact of the remnants of this industry on
the phenomenon, and there is a similar monitor on remnants of the paper
industry, chemicals, even heavy industries.
3-Exchange of agricultural land remnants
: human adopted to face the growing of his numbers strongly on the development
of productive arable land which necessitated the use of various types of
chemical fertilizer containing mainly nitrogen and phosphate is moving with the
exchange of irrigation water directly or indirectly into the sea, has been
observed that there are periods of the presence of red tide followed the
irrigation in certain seasons, that the change in the ratio of nitrogen to
phosphate is an important factor in selecting the type or types of micro -
algae grow in enormous density.
4-Establish of fish farms : studies have
shown that the production of fish farms around the world can during 10-20 next
year to fill the apparent shortage expected in natural fisheries but such that
fish farms despite the importance of it is a viable and fertile environment for
breeding of phytoplankton and devise new types of red tide.
5-Establishing of tourist resorts : that
the establishment of such investment projects necessarily require appropriate
conditions to enjoy swimming and the diving in the calm waters, which means the
establishment of breakwaters and limited industrial lakes. Despite the
simplicity of thinking, it clearly has helped the spread of red tide in finding
suitable environmental conditions for its presence.
Damage of red tide :
Public Health : The dangers caused by
red tide on the health of citizens, which was a focus of attention in the
developed world on several elements, including the following :
1. Contaminated drinking water in many
lakes, especially some species of poisonous blue algae, which may cause
regional conflicts about water sources in the near future.
2. The shellfish and crustaceans that
have the ability not only to absorb poisons imposed by some micro - algae, but
it goes beyond retention and collected even after cooking turmoil. There are
about 2000 cases of poisoning recorded annually in the world, 15% had died.
About 100 grams of flesh of mollusks infected may be enough sometimes to death
of a person depending on the type of phytoplankton ,detachment of poisons, and the
kind of toxins and its concentration .
3. Secretions for certain types of red
tide caused burns to the skin and the sensitivity of the chest of tourists.
4. Presence of red tide hampered diving
destinations that require water net because of the absence of vision, as well
as some marine sports. So the damage to marine tourism, generally has its
reflections in national income.
5.Fish death : that the mass death of
fish present in seawater and farms during some periods of red tide is a serious
threat to the national security of some countries that rely on fish as their
main source of food, and on the existing industries of it. The estimated losses
caused by one poison type of phytoplankton more than 250 million dollars in Japan
There are other losses could be felt at
the longer term, including the following :
1. The nocuous effect on fish eggs and larvae
which may affect fisheries for a long time.
2. Loss fisheries of bottom fish which characterize by a high economic value and
for long periods.
3. The threat of industries based on
production of crustaceans and mollusks, which is estimated in billions of
dollars.
Remedial steps :
1.
Controlling the amount of out-going water and treat it and try to re-use in
irrigation of some crops.
2. The minimum use of fertilizers.
3. Work on the application of the laws
governing the establishment of tourist resorts along the beach and the
subsequent creation of barriers to the waves.
4. The need to sign international
agreements between the States bordering on the same coast to coordinate among
themselves, especially with regard to sewage treatment.
5. An accurate calculations regarding
the required reduction in the quantities of salt food and the exchange of
information so as not to affect the fish resource .
6. Ongoing education through various
media for all citizens and fishermen.
7. Ongoing training for workers in fish
farms and the use of modern tools for nutrition.
8. A follow-up programs in short periods
of time.
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