|
Showing 1 - 1 of
1 matches in All Departments
Destruction of habitat is the major cause for loss of
biodiversity including variation in life history and habitat
ecology. Each species and population adapts to its environment,
adaptations visible in morphology, ecology, behaviour, physiology
and genetics. Here, the authors present the population ecology of
Atlantic salmon and brown trout and how it is influenced by the
environment in terms of growth, migration, spawning and
recruitment. Salmonids appeared as freshwater fish some 50 million
years ago. Atlantic salmon and brown trout evolved in the Atlantic
basin, Atlantic salmon in North America and Europe, brown trout in
Europe, Northern Africa and Western Asia. The species live in small
streams as well as large rivers, lakes, estuaries, coastal seas and
oceans, with brown trout better adapted to small streams and less
well adapted to feeding in the ocean than Atlantic salmon. Smolt
and adult sizes and longevity are constrained by habitat conditions
of populations spawning in small streams. Feeding, wintering and
spawning opportunities influence migratory versus resident
lifestyles, while the growth rate influences egg size and number,
age at maturity, reproductive success and longevity. Further, early
experiences influence later performance. For instance, juvenile
behaviour influences adult homing, competition for spawning
habitat, partner finding and predator avoidance.
The abundance of wild Atlantic salmon populations has declined in
recent years; climate change and escaped farmed salmon are major
threats. The climate influences through changes in temperature and
flow, while escaped farmed salmon do so through ecological
competition, interbreeding and the spreading of contagious
diseases. The authors pinpoint essential problems and offer
suggestions as to how they can be reduced. In this context,
population enhancement, habitat restoration and management are also
discussed. The text closes with a presentation of what the authors
view as major scientific challenges in ecological research on these
species."
|
|
Email address subscribed successfully.
A activation email has been sent to you.
Please click the link in that email to activate your subscription.