The Issue
Coastal ecosystems, such as estuaries, marshes,
shallow bays and wetlands, mangroves, coral reefs
and sea-grass beds, play a major role in the life
cycle of many marine organisms, including
economically important fish species, by providing
breeding, nursery and feeding grounds. About 95% of
world marine production originates from coastal
ecosystems. Marine fisheries are threatened by the
accelerated degradation of ecosystems, land
reclamation, drainage, coastal construction, sewage
and wastewater discharge, and many other competing
uses.
Reported freshwater fish yields account for
approximately 6 percent of the total global fish
production of about 120 million tonnes but many
policy makers seem to be unaware of its importance
for food supplies and income generation.
Environmental degradation and increasing land and
water scarcity in most regions of the world are
threatening inland fish production.
Industrialization, urbanization, deforestation,
mining and agricultural land and water use often
cause degradation of aquatic environments, which is
the greatest threat to inland fish production.
A number of lakes in Asia are being reduced in
size due to abstraction of water for agriculture
and other uses. Other lakes undergo eutrophication,
increased sedimentation and intensified aquatic
plant growth, as well as encroachment of
agriculture into their margins, with consequent
changes in their ecosystem. While much attention
has been devoted to the problems faced in tropical
and subtropical water bodies, concerns have been
raised for more attention to be paid to the
preservation of cold water habitats in developing
countries.
Impacts of the external environmental on
aquaculture may be positive or negative. Nutrient
enrichment of water bodies may provide nutrients
beneficial to aquaculture production in some
extensive culture systems (e.g. seaweeds,
molluscs). However, excessive loadings with urban
and industrial wastes can have severe consequences
for aquaculture operations, particularly shellfish
culture, when exposed to contamination with toxic
pollutants, pathogens and phycotoxins. With
increasing aquatic pollution and physical
degradation of aquatic habitats by other
developments, aquaculturists can face risks of mass
mortalities of farmed stock, disease outbreaks,
product contamination and reduced availability of
wild seed or broodstock.
Solutions
Coastal zones can best be protected under
integrated coastal area management schemes
which aim at optimizing the sustainable utilization
of that highly productive environment. Fisheries
and aquaculture, although often considered
secondary in economic value compared to other
stakeholders, need to receive proper attention. At
regional and sub-regional level, river basin
management schemes are needed, giving proper
attention to all stakeholders, including fisheries,
in the allocation of water resources and ensuring
adequate water quality for the different legitimate
uses of the systems. It is vital that governments
empower fisheries and aquaculture authorities to
promote actively the interests of fisheries and
aquaculture as well as adequately participate in
resource management decision-making.
Actions taken
The concept of Integrated Coastal Area
Management has been largely adopted (included in
UNCED Agenda 21) and aims at increasing the
compatibility and overall sustainability of
competing resources use in coastal areas. FAO has
elaborated a set of guidelines for the management
of agriculture, forestry and fisheries within
coastal area management and also developed specific
guidelines for Integrated Coastal Fisheries
Management (ICFM) to assist the fishery sector in
dealing with this growing concern. Overall,
however, the key corrective actions are needed from
the coastal and inland industries that are
responsible for the coastal pollution and
degradation. In that respect, UNEP is currently
implementing a Global Plan of Action for the
Protection of the Marine Environment from
Land-based Activities. In EU member countries the
establishment of river basin management plans has
recently become obligatory.
Outlook
The Joint Group of Experts on the Scientific
Aspects of Marine Environmental Protection
(GESAMP) recently concluded that, at global
level, the most serious sources of environmental
problems associated with land-based activities are
sewage, physical alteration and destruction of
habitat, nutrients, and sediment mobilisation.
Litter, heavy metals, hydrocarbons and
radionuclides, although often meriting a high
priority at local levels, are not considered as
priorities at the global level. Persistent
organic pollutants (POPs) such as pesticides,
although currently receiving high attention at
international level, may well divert attention from
the before mentioned anthropogenic causes of more
serious and widespread damage to the marine
environment.
Demand by, and competition among various sectors
for water &endash; in terms of quantity and quality
&endash; will increase significantly in the future.
Degradation of aquatic habitat in many areas is on
increase, resulting from expansion of industries,
mining, agriculture, and from deforestation. Ever
increasing pollution in many regions represents
major threat to inland aquatic ecosystems and
habitats. Further disturbances result from
impoundment and channelling of water bodies,
excessive abstraction or diversion of water, soil
erosion and manipulation of hydrological
characteristics of rivers, lakes and floodplains.
While the water quality in many European river
systems is steadily improving, environmental
degradation affecting freshwater areas is
increasing in Africa, Asia-Pacific, Latin America
and the Caribbean. Recent global assessments of
freshwater resource availability confirmed that
some regions are or will be facing serious water
shortages. Environmental stresses are particularly
severe in those watersheds that are already
substantially modified or degraded. As a result,
most inland fish producers there will suffer from
the lack or inadequacy of rights and institutional
support and from the non-integration of inland
fisheries management with water and land
management.
Unlike capture fisheries, aquaculture at least
offers opportunities to adapt farming systems and
management practices to optimize aquatic food
production under sometimes sub-optimal
environmental conditions.
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reference sources
Barg, U., Dunn, I.G., Petr, T. &
Welcomme, R.L. 1997. Inland fisheries. In:
A.K. Biswas (ed.): Water Resources.
Environmental Planning, Management, and
Development: pp. 439-476. McGraw-Hill, New
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Barg, U. & Phillips, M.J. 1997.
Environment and Sustainability, p. 55-66.
In: Review of the State of World
Aquaculture. FAO Fisheries Circular No.
886 (Revision 1). Rome, FAO, 163 pp.
Petr, T. 1997. The future of fisheries
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Petr, T. (ed.). 1999. Fish and
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Petr, T. & Morris, M. (eds). 1995.
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October 1994, and Country reports
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Working Party of Experts on Inland
Fisheries, Bangkok, Thailand, 17-21
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