State of World Fisheries and Aquaculture 2004 - Library

World review of fisheries and aquaculture
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Coastal development (including urban and industrial expansion and aquaculture)
and industrial activities in the hinterland also pose many threats to the health of
marine ecosystems when they pollute and degrade critical coastal habitats. These
land-based and coastal alterations adversely affect the livelihoods of coastal fishing
communities and industries, for example through a reduction of the sustainable yield
of fish stocks; modification of the resource species composition, health and diversity;
an increase in ecosystem instability and variability and a reduction of seafood quality
and safety. Periodic climatic phenomena such as El Niño can have a drastic impact on
fish populations and lead to the collapse of fisheries (e.g. the Peruvian anchoveta
in the Southeast Pacific in the early 1970s). Over the longer term, many fish stocks
follow decadal fluctuations that seem to respond to natural climatic cycles. The effect
of climate on fisheries is exacerbated in a situation of overfishing, when both fish
stocks and fishing industries become more vulnerable to the natural dynamics of the
environment. The assessment of these and other ecosystem–fisheries interactions is
still in its infancy and much more needs to be known about their effects on fishery
resources, fishing communities and industries, their causes and trends, and how to deal
with and adapt to them. The state of fishery resources and their ecosystems, however,
allows little room for delay in the implementation of measures that should have been
taken in the last three decades. Therefore the precautionary approach to fisheries,
recommended by UNCED, the United Nations Fish Stocks Agreement 13 and the FAO
Code of Conduct for Responsible Fisheries 14 needs to be implemented in practice.
Inland fisheries
Unlike the major marine fish stocks, inland fish stocks are less well defined and occur
over much smaller geographical areas, such as individual lakes, rice fields or rivers, or
over vast areas such as transboundary watersheds that are often situated in areas that
are difficult to access. These factors make it costly to monitor the exploitation and
status of fish stocks and, in fact, very few countries can afford to do so. As a result, the
majority of countries report only a small fraction of their catch of inland fisheries by
species, further compounding the problem of accurate assessment. Thus FAO is not in a
position to make global statements on the status of these resources.
It was reported in The State of World Fisheries and Aquaculture 2000 that
inland fishery resources are undervalued and under threat from habitat alteration,
degradation and unsustainable fishing activities. This trend unfortunately appears
to be continuing. LARS 2, a recent symposium on managing the fisheries of large
rivers, 15 noted that the availability of global information on river fisheries is poor, that
over 50 percent of inland fish species occur in rivers and that rivers contain a higher
proportion of organisms classed as endangered or threatened than do most other
ecosystems. Many river basins, especially in developing countries, support intensive
fisheries and in many cases catches have increased, although changes in their species
composition have occurred as catches of large and late-maturing species have declined.
River fisheries continue to provide substantial catches in developing countries, even
in the face of intensive exploitation. However, in the Mekong River, for the first time,
there is evidence that stocks are being overfished. 16 Numerous lake fisheries are also
13
The Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea of 10
December 1982 relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks was
adopted and opened for signature in 1995. For further information, see http://www.un.org/Depts/los/convention_agreements/
convention_overview_fish_stocks.htm; accessed September 2004.
14
Adopted by the 28th Session of the FAO Conference in October 1995. For further information, see http://www.fao.org/DOCREP/
005/v9878e/v9878e00.htm; accessed September 2004.
15
Second International Symposium on the Management of Large Rivers for Fisheries: Sustaining Livelihoods and Biodiversity for
the New Millennium, Phnom Penh, Cambodia, 11–14 February 2003. For further information, see http://www.lars2.org; accessed
September 2004.
16
C. Barlow, Fisheries Unit, Mekong River Commission, personal communication, April 2004.