Inland waters and their species experience myriad direct
and indirect stresses in addition to overfishing, including altered
flows and habitat fragmentation due to dams and other
infrastructure, pollution, habitat degradation, nonnative
species introductions, and detrimental interactions with
hatchery-reared fish (Allan and Flecker 1993). Although the importance of other anthropogenic stressors in relation to fishing
may appear greater for inland waters than for the seas, the
contributions of pollution, species introductions, and other
human impacts in the collapse of coastal ecosystems should
not be underestimated (Boesch et al. 2001). As Jackson and
colleagues (2001) document in the context of marine fisheries,
overfishing commonly was the first disturbance in the historical
progression, followed by other factors including pollution
and eutrophication, mechanical habitat destruction,
introduced species, and climate change. Fish stocks are unable
to recover from historical overfishing because of a host
of current pressures, and in their altered state may be more
vulnerable to disturbances, including species invasions and
outbreaks of disease. A recent assessment of inland fisheries
(FAO 1999) concluded that most inland capture fisheries
that rely on natural stock reproduction were overfished or being
fished at their biological limit, and that the principal factors
threatening inland capture fisheries were habitat loss
and environmental degradation. Overfishing, then, may not
always be the sole or even the primary threat, but in conjunction
with other stresses it can be a serious one.
Inland waters and their species experience myriad directand indirect stresses in addition to overfishing, including alteredflows and habitat fragmentation due to dams and otherinfrastructure, pollution, habitat degradation, nonnativespecies introductions, and detrimental interactions withhatchery-reared fish (Allan and Flecker 1993). Although the importance of other anthropogenic stressors in relation to fishingmay appear greater for inland waters than for the seas, thecontributions of pollution, species introductions, and otherhuman impacts in the collapse of coastal ecosystems shouldnot be underestimated (Boesch et al. 2001). As Jackson andcolleagues (2001) document in the context of marine fisheries,overfishing commonly was the first disturbance in the historicalprogression, followed by other factors including pollutionand eutrophication, mechanical habitat destruction,introduced species, and climate change. Fish stocks are unableto recover from historical overfishing because of a hostof current pressures, and in their altered state may be morevulnerable to disturbances, including species invasions andoutbreaks of disease. A recent assessment of inland fisheries(FAO 1999) concluded that most inland capture fisheriesthat rely on natural stock reproduction were overfished or beingfished at their biological limit, and that the principal factorsthreatening inland capture fisheries were habitat lossand environmental degradation. Overfishing, then, may notalways be the sole or even the primary threat, but in conjunctionwith other stresses it can be a serious one.
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