Daura, S.Z.

English

Aquatic Commons

ENVIRONMENTAL ISSUES ON NUISANCE WEEDS
Alh. SANI ZANGON DAURA, Dan Masanin Daura
('Honourable Minister of Environment,)
Federal Ministry of Environment
Abuja FCT Nigeria
INTRODUCTION:
Nigeria is under siege by green invaders
species alien to our aquatic ecosystems.
These. intruders reached the system
through• both intentional and un-
intentional human activities and are
spreading at alarming rates threatening the
Nigeria's biodiversity and natural habitat
within the inland and coastal waters. The
seriousness of the problem is widely
acknowledged. In July 2000, the House of
Representatives concerned about the
persistent problem of the invasive species
and the great loss to the national economy,
resolved that:
Control measures should commence
immediately to avoid the entire river
system being completely overtaken by
the weed
A multidisciplinary task force be set
up to tackle the menace;
The various attempts aimed at
addressing the problem be harmonized
under the supervision of the Ministry
of Environment with technical, finan-
cial, managerial inputs from Transport
and Water Resources Ministries and
their parastatals as well as relevant
governmental agencies and depart-
ments;
• The President be urged to release the
approved funds in the year 2000
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budget to National inland \Vaterways
Authority to enable it clear the
imported weed harvesters at the ports;
and
• A think4ank be set up under the
Ministry of Environment to formulate
a National Master Plan for the control
and find use for the plant.
Even before this resolution, upon
inception, the Ministry of Environment
had identified water hyacinth and other
invasive plants and indeed animals as a
major threat to the environment and
natural resources conservation in the
country. The Ministry evolved long term-
plans to address the menace. Among such
plans is the setting up of a National
Committee on Water Hyacinth and Other
Invasive Species, as a means of bringing
all institutions and individuals working on
water hyacinth control under an umbrella
to avoid duplication of efforts and to forge
a partnership for concerted action. Also
planned is the adoption of an integrated
approach that will employ multiple control
measures.
Furthermore because of the trans-
boundary nature of the invasive plants,
efforts at controlling them have been at
global, regional, sub-regional, and
national levels. For example, under the
United Nations Convention on Biological
Diversity, there is the Global Invasive
Species Progrnmme. Concerned about the
adverse impacts of the invasive aquatic
plants, ECOWAS in 1992 embarked on a
sib-regional programme to control inva-
sive floating plants covering Niger, Benin,
Chad, Cote d'Ivoire and Nigeria.
Water hyacinth has invaded many of the
nation's waterways disrupting irrigation,
navigation and the operations of
traditional fishermen. The weed chokes
irrigation canals, blocks fish breeding sites
and encourages mosquito breeding. In
1990, the World Bank estimated the
economic loss due to the water hyacinth
increase to be as high as N5 billion per
annum. This amount would be
significantly higher today because of the
much greater spread of the weed
particularly in the coastal areas.
A key to Nigeria's success in containing
these invaders, may well lie in the sharing
of what critical information exist on the
prevention and control of invasive weed
before an irreversible damage is done to
the sustained productivity of the well
being Of the Nigeria aquatic ecosystem. Iii
the past Government made tremendous
efforts to control water hyacinth and other
aquatic nuisance, through various
Mithstries and Agencies, with
disproportionate results, One of the factors
to which this performance could be
attributed is the absence of coordination.
The approach was fragmented and
sectoral ly based. Overlapping, sometimes-
conflicting responsibilities and duplicated
efforts tended to create problems of
accountability and encouraged wastage.
Considering the failure of past
uncoordinated control efforts, I wish to
commend the timeliness of this
conference. This is because the forum will
create the necessary atmosphere for cross
fertilization of ideas on the control and
utilization of the aquatic weeds that have
occupied the natural habitat of indigenous
species of flora and fauna..
THE NIGERIAN NUISANCE WJEDS
At the inaugural meeting of the National
Council on Environment in May 2000,
twelve States of the Federation submitted
memoranda on invasive weeds. These
States include Kwara, Akwa -Iborn, Kogi,
Ogun, Rivers, Kebbi, Cross River,
Bayelsa, Delta, Ondo, Benue and Lagos.
These States complained of massive
invasion by water hyacinth (Eichhornia
crassipes), water lettuce, (Pistia stra-
holes), Niger grass (Echinochloa stag-
niina) and Kachalla/Typha grass invasion.
The Council adopted the emerging memo-
randum, urging the Ministry of Environ-
ment amongst others to put in place a
coordinated strategy for control and utili-
zation of floating weeds. This reinforced
the need for the planned National Coinmi-
thee on Waler Hyacinth and Other Inva-
sive Species.
In line with International Resolutioti
reached at United Nations Conference on
Environment and Development (IJNCED)
in 1992, Nigeria elaborated a National
Agenda 21 to serve as an action plan
towards Sustainable Development in the
21st Century. The objectives of Nigeria's
Agenda 21 include the following:
i. integrate environment into develop-
ment planning at all Levels of govern-
ment and the pri'ate sector;
ii. commence a transition to sustainable
development;
iii. address sectoral priorities, plans,
policies and strategies fOr the major
sectors of the economy; and
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iv. simultaneously foster regional and
global partnership
The issue of water hyacinth received
special attention under the caption
"Control of Water Hyacinth And Other
Invasive Infestations ". The overall goal is
to control water hyacinth and other
invasive infestations in Nigeria's waters
by the year 2005. Strategies for
implementation proffered are as follows:
1. Inventorise the spread of the weed in
all river systems especially in the
coastal states;
2. Develop an infestation index map to
determine control options;
3. Adopt an appropriate control option to
ensure that the weed is no longer a
menace using integrated control
methods (that is mechanical, biolo-
gical and chemical) as would be
appropriate for various sites;
4. Identify alternative sustainable utiliza-
tion of water hyacinth and other
invasive species
The vastness of the Nigerian landmass put
at 923768 km2 provides a wide range of
suitable ecology for such invasion. In
other words a remarkable range of niches
exist within Nigerian borders for new
biological invader species from virtually
anywhere. Trade and advancement in
biotechnology have opened the new
biological connections with numerous
ecological regions of the world similar to
those obtainable in Nigeria. But these
plants particularly the water hyacinth is
native to Brazil in South America from
where it was introduced by man through
his activities to North and Central
America, the Cacibbean, and at a later
stage to Africa.
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However in its native range, in the
Neotropics, water hyacinth poses no
problems. In the natural habitat, natural
agents keep it under check but in alien
environment the plant grows fast,
displacing indigenous species from
existence in addition to reducing the
diversity and population of species that
sustain the livelihood of our people.
In the last 90 years the spread of water
hyacinth and the other invasive weeds, has
been spectacular and disastrous. It
colonizes still or slow moving waters,
developing extensive thick mat that
dramatically alter the ecology of invaded
aquatic eco-systeins.. The problems
created and the damages caused by water
hyacinth is greater than those created by
other floating aquatic weeds. It is widely
acclaimed to be the world's worst aquatic
weed, which form dense impenetrable
mats on water. The propensity to spread
fast within a short time and the attendant
socio-ecological problems constitute a
great challenge to the scientific world.
POTENTIAL USES OF THE WATER
HYACINTH AND OTHER INVASIVE
WEEDS
I have catalogued the woes attending the
invasion of water hyacinth. However, as
bad as these invasive weeds are, some of
them have potentials to• contribute to the
economic and social wellbeing of humans.
It is indeed speculated in some quarters
that some of these aquatic weeds could be
utilized for food and or ingredients for
animal feeds, raw material for paper
board, biogas production, waste water
treatment, water quality management and
fertilizer production.
Certainly, water hyacinth, Niger grass and
water lettuce can be used for a variety of
purposes, some of which have been
enumerated above. However, the only
problems that could emerge in this
direction include:.
• How to harvest the invasive weeds at
minimal cost.
• How to dry the weeds at minimal or
no cost and market the product.
+ Sustained availability of the weeds for
easy harvesting as raw materials for
some form of industry all year round.
• Composition of the available weeds,
which is over 95% water.
• Marketing of the end product would
require a good road from the mainly
inaccessible locations the weeds
abound the remote areas.
These are no doubt strong areas of
research investigations. In our quest to
devising means of control and utilization,
these areas cannot be overlooked. This is
particularly so because it has been widely
expressed that utilization of water
hyacinth for now may not be economical.
This because the present environmental
costs far outweigh the economic benefits,
when one considers the problems the
weeds create in inland waterways,
irrigation canals, fish catches, loss through
repairs and maintenance of boats,
enhancement of breeding places of disease
vectors and aquatic ecosystem degradation
and biodiversity loss.
The theme of this conference is on the
control and utilization of water hyacinth. 1
will therefore not attempt delving into
detailed methodology for control. This is
because I will not want to fumble on the
issue eminent scientists are itching to
download their research findings.
However, it will suffice to say that there
are three basic methods in the control of
invasive weeds viz:
• Physical Removal / or Mechanical
Drainage;
+ Use of Chemical Herbicide and Spray;
and
• Biological Control Methods.
Amongst the three options, the use of
chemical herbicides and sprays is environ-
mentally unfriendly. The environmental
costs result in pollution and reduced level
of oxygen in the water body. Gentlemen
and ladies, as I stated earlier, there are
other means of control. These, I believe
the gathering will adequately address.
CONCLUSIONS
Preventing and controlling biological
invasions successfully would depend on
understanding the different invading
species- Niger Grass, Water Lettuce,
Water Hyacinth, Kachalla Grass/Typha
Grass, Nypa Palm, etc. Understanding the
invader species pathways of introduction
and reproduction will enable development
of technologies to combat the menace.
This would best happen when information
is effectively shared
. between federal,
state, and local government, commercial
interest, NGOs, private sector and
decision iaakers. This joint action will
greatly enhance control measures geared
towards battering the tide in favour of the
nuisance biological species.
The type of information that need to be
shared for meaningful achievements
include: -
• Characterizing pattern of invasion in
space and time by species and
transport mechanism;
26
• Identifying ecological and economic doubt that the outcome of this conference
impacts; will ensure that Nigeria conquers, tame
and domesticates water hyacinth foi
+ Predicting invasive species pathways; human use.
+ Establishing best management prac- It is evident all that is required is
tices for prevention eradication and comprehensive information on the
control; d invasive species, for development of
• Assessing effectiveness by monitoring effective management plans that
how well invasion is being limited or minimizes the risk and adverse impacts of
curtailed. the alien species. This conference, it is
expected will play a very vital and pivotal
Through sharing such information with role in creating and assessing policy
states, local government agencies, NGOS, actions that are required in this battle to
academia, research institutes, other nations control the invader nuisance.
and concerned communities, the body of
luiowledge increases in addition encou I have no doubt that the organizers of this
rages and enhances extant management conference shall achieve their noble goals
activities, and together we shall rid Nigeria of
nuisance weeds and protect the Nigerian
The high points of the conference which environment in the 2l Century.
include documentation of available control
and utilization strategies, leave me with no



Environmental issues on nuisance weeds

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Environmental issues on nuisance weeds

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