Nigeria, the country of many rivers is also rich in lakes, and wetlands, sustainable and wise use of these inland aquatic ecosystem and water resources has become a matter of widespread and intense concern. Unhealthy freshwater ecosystems and seriously diminishing and unequal availability of quality freshwater call for high quality limnological research and expertise to underpin the enhancement of sustainable fisheries and aquaculture development.In every regard of national health, agriculture and economics, the continued over exploitation and misuse of finite freshwater resources is directly causal to the progressively deteriorating fish production and general standard of living.The integration of basic understanding of inland ecosystems with applied problems and their solutions should be of fundamental concern to all stakeholders in our freshwater resource. This is a basic element in creating an attractive and security ensured economic for investment in fisheries development, including aquaculture. This is the focus of this pape

Adegun, B.

Ajayi, O.T.

Azionu, B.C.

Okongwu, I.O.

Ovie, S.I.

Aquatic Commons

SALVAGING THE FRESHWATER ECOSYSTEMS IN NIGERIA: GREAT THREAT TO
SUSTAINABLE FISHERIES AND AQUACULTURE DEVELOPMENT.
By
B.C. Azionu, S.1. Ovie, 1.0. Okongwu, B.Adigun and O. Ajayi.
National Institute for Freshwater Fisheries Research, (NIFFR)
P.M.B. 6006, New Bussa, Niger State, Nigeria.
ABSTRACT
Nigeria. the country of many rivers, is also rich in lakes, reservoirs and wetlands. Sustainable
and wise use of these inland .aquatic ecosystem and water resources has become a matter of
widespread and intense eoncem. Unhealthy freshwater ecosystems and seriously dirninish:ng
and unequal availability of quality freshwater call for high quality limnological research and
expertise to underpin the enhancement of sustainable fisheries and aquaculture development.
In every regard of national health, agriculture and economics, the contincred over exploitation and
177iSLISe of finite freshwater resources is directly causal to the progressively deteriorating fish
production and general standard of living. The integration of basic understanding of inland
ecosystems with applied problems and their solutions should be of fundamental concern to all
stakeholders in our freshwater resource. This is e basic element in creating an attractive and
security ensured economic environment for investment in fisheries deve/opment, including
aquaculture. This is the focus of this paper.
INTRODUCTION
Nigeria, the country of many rivers, is also rich in lakes, reservoirs and wetlands.
Sustainable fisheries 'production and development depends largely upon good aquatic
.environment. It is generally accepted that the future well-being of a developing country such as
Nigeria, will depend upon a much wiser balance between exploitation and conservation of natural
resources in order to achieve sustainable systems that would avoid environmental degradation.
The quality of the aquatic medium determines success to a very large extent in fisheries and
aquaculture. Paulin (1989) noted that "the aquatic medium is in direct and immediate contact
with the metabolic processes of fish". Relevant soil structure and composition and natural
environmental factors (e.g. pH, dissolved oxygen concentration, temperature, salinity) all
influence the quality of the medium, which is turn determines the health of the fish and their
performance.
For quite sometime. Nigerian freshwater ecosystems are being damaged at accelerating
rates by toxic contamination from industrial and urban pollution, infectious diseases, dam
construction, irrigation, factory farming, forest and wetland destruction. Consequently, there has
been a steady increase in the quality and diversity of discharges that reach our freshwater
environment. VVithout question, the lack of available quality freshwater has emerged as the
greatest threat to sustainable fisheries and aquaculture.
Freshwater must be a national commons. Most human beings in developing countries
like Nigeria. view Freshwater as a universal heritage pf society. Our common societal heritage of
freshwater demands ecological maturation in the use of these finite resources.
In every regard to national health, agliculture and economics, the continued over
exploitation and misuse of finite freshwater resources is directly causal to the progressively
deteriorating fish production and general standard of living We must recognise that fisheries and
aquaculture development depends on maintaining satisfactory water quality. The integration of
193
basic understanding of the freshwater systems with applied problems and their solutions should
be of concern to all stakeholders in our freshwater resources.
The paper highlights the importance of freshwater in Nigeria for fisheries including
aquaculture and examines the various sources of degradation their impacts and possible control
measures. Finally, the paper underscores the role of limnologists and relevant
institution/organisations in protecting the freshwater environment from degradation. Decisions
are needed now, than before to secure our freshwater resources to sustain this generation and
coming generation of Nigerians.
VIPORTANCE OF FRESHIACTERS AND THEIR FISHERIES
FTeshwater of Nigeria
Nigeria has abundant freshwater resources with a total cover of about 15 hectares (Ita,
1093). These vast freshwater ecosystems are distributed all over the country (though unevenly)
i'rorn the costal region to the arid zone of the Lake Chad Basin. Freshwater resources constitute
an important part of Nigeria natural resources especially as water source of hydroelectric power
generation, irrigation, transportation, domestic and industrial water supplies and fisheries. In
Nigeria, a large proportion of both urban and rural populations lives beside the lakes, rivers,
reservoirs, swamps, floodplains, lagoons, wetlands and estuaries, all of which are important
ecosystems for fisheries and aquaculture.
iltrDdaind Fisheries
The inland fisheries sub-sector is private sector driven and operates mainly in the remote
rural areas, costal and inland fishing areas of Nigeria. It contributes about 86% of the domestic
fish production (F.D.F..2003). It is a source of employment, income and nutrition for millions of
,rural dwellers that depend on fish for livelihood. It is estimated that not less than 3.0 million
Nigerians are engaged in Artisanal fish production. Indirect employment is offered to people who
engage in the production of fishing inputs such as canoes/boats, nets, hooks etc. The sub-sector
also offers employment to blacksmiths, outboard engine mechanics' and spare-parts dealers,
fishing boat builders etc.
Aquaculture
F.D.F. (2003) noted that the national annual aquaculture production is estimated at
25,000 metric tonnes about 6% of domestic fish production. However, the annual potential for
aquaculture production is estimated at about 2.5 million metric tonnes. Thus, aquaculture can
contribute.significantly to domestic fish production and when combined with improved freshwater
fisheries management, has the potential to eliminate fish importation which was put at a cost of
US $241,066,537 or N27,963,718,292 (at $ - N116) in the year 2000, and even earn foreign
exchange (F.D.F, 2003).
The appraisal serves to. bring to the fore the magnitude and importance o four freshwater
fisheries resources which are already at risk form pollution and other environmental perturbations,
if control measures are not promptly taken.
AJOR TREATS TO NIGERIA FRESHWATER ECOSYSTEMS
Water Pollution: Impact on fish and Fisheries.
Water pollution in Nigeria occurs in both rural and urban areas. In the rural areas
freshwater systems such as rivers, streams and lakes are usually polluted by inorganic
substances used in agricultural activities usually pollute streams and lakes. Such substances
include fertilizers pesticides and herbicides. These substances applied on farmlands are
sometimes washed down by rain into stagnant ponds and pools of water on the plain and also
into storage reservoirs. Excessive load of fertilizers (nutrients) in the water, generate, excessive
growth of phytoplankton, which in turn can lead to high biological oxygen demand, thus resulting
194
in aquatic pollution as a result of drastic oxygen depletion of the water, causing much stress to
the great majority of fish species, which gradually die off.
Ita (1993) reported that fertilizers and effluents from the industrial city of Kano pollute
Jakara reservoir in Kano State. High levels of toxic heavy metals have been detected in the
reservoir. (Butt, 1985; Adeniji and Mbagwu, 1990). These authors also detected high levels of
copper, chromium, zinc, iron in and manganese in fish from the reservoir. Warwade Reservoir,
also in Kano, was equally found to be polluted.
Some pesticides used in Nigeria, are known to cause serious environmental problems.
Contamination of water by pesticides directly or indirectly can cause fish kills, reduced fish
productivity and lethal concentrations of undesirable chemicals in edible fish tissue, which can be
harmful to humans eating these fish.
Many factories in Nigeria are located on riverbanks and use the rivers as open sewers for
their effluent, Improper disposal of untreated industrial wastes has resulted in -coloured, murky,
odorous and unwholesome freshwaters, fish kills and a loss of water quality. The major
industries responsible for water pollution in Nigeria include petroleum, mining (for gold, tin and
coal), wood and pulp, pharmaceuticals, textiles, plastics, iron and steel, brewing, distillery
fermentation, paint, beverages and food. Petroleum industry presents the greatest threat to tvater
quality. From time to time, accidental oil spillages oCCur which endanger freshwater fisheries
among other resources Anko et. al. (2001) reported on the increased pollution levels of the
coastal areas of Cross-River State by petroleum product spillage,. He noted that the increased
pollution in the Cross-River State is a problem of fishery industry. Lagos lagoon was once very
productive but now unsuitable for fishing as a result of urban pollution.
Recent VVorld Bank report notes that the problem associated with tack of quality
freshwaters in Nigeria threatens to place the healthy of about 40 million people at risk. The study
suggests that it would cost in excess of US $9 million a year to correct, such problems it
freshwater contamination goes on unchecked.
Other eources of threat
Nigerian freshwaters and also being damaged by infectious diseases, dam construction.
irrigation. factory farming forest and wetland destruction. The construction of dams for water
resources development, for instance, hydroelectric generatiqn result to damage to fisheries owing
to changes in ecosystem characteristics. West (1989) noted that the Kainji Dam construction led
to an overall reduction through loss of highly productive fisheries in the flood plains downstrearn
as a result of flood regulation. Raji (1992) reports that one of the threats to Lake Chad fisheries is
the damming of the inflow rivers both within and outside Nigeria. The construction of dams in
Nigeria mainly on the Hadejia-Jamara rivers and the tributaries has reduced the discharge into
the lake, thus limiting the extent and duration of the lakes flOodplains. Such floodplain areas are
essential to many fish species as spawning, nursery and feeding grounds. He further noted that
both channelization (for irrigation) and water abstraction (for irrigation, livestock and .domestic
use) an major activities in the Chad basin area and are likely to be some of the contributing
factors to the increasingly dwindling fisheries.
Dadtly (1989) reported huae fisheries potentials of Nigerian wetland systems among
other resources. They are known also to help maintain water quality, promote rapid growth of
plants. absorb toxic metals and chemicals and clean up polluted waters. The author further
stressed that inspite of the huge potential of these freshwater systems, wood fuel gathering,
industrial developments, overgrazing, extensiv.e irrigation projects, urbanization and hydroelectric
dams among-others, are rapidly degrading these ecologically and environmentally important
systems. The various impacts of upstream impoundments on downstream wetlands primary
resources particularly on Niger River have been dOcumented. (Chude, 1979; lta and Mohammed
1979).
195
CURRENT EFFORTS TO PROTECT NIGERIAN FRESHWATER
National Policy on Environment.
The Federal Government of Nigeria by decree 58 of December, 1988 established The
Federal Environmental Protection Agency (F.E.P A., F.G N. 1988a) The FEPA had the statutory
responsibility for overall protection of the environment. The National Policy on environment
articulated by FEPA was launched on 27th November 1989 (FEPA, 1989) The goal of the Policy
was to achieve sustainable development in Nigeria and in particular to:-
Secure for all Nigerians a quality environment adequate for their health and we.11-being
Conserve and use environment and natural resources for the benefit of present and
future generations.
Restore, maintain and enhance ecosystems and ecological processes essential for the
functioning of the biosphere and for the preservation of biological diversity and to adopt
the principle of optimum sustainable yield in the use of natural resources and
ecosystems.
Raise public awareness and promote understanding and to encourage individual and
community participation in environment efforts
Cooperate in good faith with other countries, international organisations and agencies to
achieve optimal use of Tran boundary natural resources and effective prevention or
abatement of transboundary environmental pollution.
Policy consolidation was pursued through the introduction of guidelines and standard for
environmental pollution abatement strategy.
However, environmental protection measures are only meaningful if the environment to
be protecte,d is adequately understood. Neither over-protection nor under-protection is desirable.
ideally standards should be set based on scientifically generated environmental baseline data
Such data are scarce in Nigeria in the present circumstances
Strategies Under the National Policy on Environment for Water resources Management.
Management approach is based on an integrated holistic and systematic view of
environmental issues. The programme activities of the policy arms to e.stablish and strengthen
legal, institutional, regulatory, research, monitoring, evaluation, public information and other
relevant mechanisms for assuring the attainment of the specific goals and targets of the policy
They will also encourage environmental assessment of proposed activities. which may affect the
environment, or the use of natural resources prior to commencement.
As part of the strategies for the implementation of the National policy on environment
the water sector, a comprehensive national water resources master plan has been drawn up with
the support from the Government of Japan, through the Japan International Cooperation Agency
(JICA). For the first time, a decree on water resources protection and management has been
promulgated. (FGN, 1993), with the purpose of:-
, Promoting the optimum planning. development and use of the Nigeria's water resources.
Ensuring the co-ordination of such activities as are likely to influence the quality, quantity,
distribution; use and management of water.
Ensuring the application of appropriate standards and techniques for the investigation,
use, control, protection, management and administration of water resources
Facilitating technical assistance and rehabilitation for water supplies
ROLE OF NIGERIAN LIIVINOLOGISTS
It has earlier been stated that environmental protection measures can only be
meaningful, if the environment to be protected is adequately understood. OL1F common societal
neritage of freshwaters demands ecological maturation. lt is essential that the leaders of
Limnology the practitioners of freshwater resources assume leadership roles in demanding
196
national and international condemnation of malicious and wasteful use of freshwaters The
condemnation demands not simply criticisms but leadership in offering solutions for ecological
maturity in 'wisely using our public trust, the water, as a common property for all. To understand
the environmental and ecological complexities of our freshwaters, limnologists must work as a
team with other scientists relevant to freshwater environment to be able to safe guard the huge
potentials of the vast freshwater resources now under severe threat.
CONCLUSION AND RECOMMENDATIONS
Freshwater is a common trust of humanity. Nigeria is richly endowed with this very
important natural resource with huge potentials for thriving fisheries and aquaculture. Since
sustainable fisheries production and aquacultural development depends largely upon good
aquatic environment, we must understand the complexities of the biological metabolism that
influence quality and long-term sustainability of freshwater resources. We must understand the
management necessary to maintain acceptable level of water quality. It is also important to
understand that the cost of water use must reflect true environmental values. It is only then that
we can advance to the ecological maturity essential for sustainability and ,development of our
freshwater fisheries and aquaculture.
The limnological community of Nigeria must move united, assertively and with dispatch if
they are to remain professionally active and relevant.
REFERENCES
Adeniii, H.A. and I.G. Mbagwu, (1990). Study of physico-chemical characteristiCs of some
heavy metals in Jankara Reservoir, Kano State, NIFFR Annual Report, p. 136-140.
Anko: E.O. and A.A. Eyo (2001). Fisheries Development in Nigeria with Special refe.rence to
Cross River State. In. Proceeding of the 17m Annual conference of Fisheries Society of
Nigeria (FISON).
Butt. I.A. (1985). Report on the Industrial Pollution of Jakara Dam, Mihistry of Health, Kano
State: Nigeria.
Chude. L.A. (1979). Impacts of Kainji Dam and the proposed Jebba -Dam on the fish and
Fisheries of Lake Ndakolowu and Middle Niger. A seminar Paper delivered at KLRI, 14p.
Daddy, F. (1989). A proposal for Wetland research Strategies in Nigeria. In. proceeding of the
National Conference on Two Decades of Research on Lake Kainji; Eds. J.S.O. Ayeni and
A_A Olatunde, P. 529-537.
F.D.F. (2003). Presentation on the Fisheries Sub-sector at the Presidential Forum. 73p.
FEPA (1989). Our National Environmental Goals. Special Publication No.3. Federal
Environmental Protection Agency, Lagos.
FGN (1988a). Federal Environmental Protection Agency Decrees No. 58. Federal Governrrient
of Nigeria, Government press. Lagos.
FGN (1993). Water Resources Decree No. 101 of August 1993. Federal Government of Nigeria.
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197


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