RIVER SLANEY: Potential for Sea Trout Development

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RIVER SLANEY Potential for Sea Trout
Development?

• Slaney River Trust
• Association of Rivers Trusts
• Seminar Bunclody 19 20th February 2007

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Symposium Themes

• Genetics Life History
• Stocks Fisheries
• Ecology Population Dynamics
• Management Conservation

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• 1. Importance Value
• 2. Key Issues
• 3. Management Challenges
• 4. Potential in Slaney

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• Sea trout are potentially a very valuable sport
  fish species. They have, for too long, been
  considered a poor relative of the salmon. The
  management and development and promotion of these
  fisheries demands a fresh, dynamic approach from
  both the Fisheries Boards and the owners of these
  fisheries.
• Inland Fisheries Strategies for Management
  Development.
• Central Fisheries Board. December 1986

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SOCIO-ECONOMIC IMPORTANCE VALUE

• An Historical Perspective
• Pre-1970
• Post-1970
• Practical Advantages
• for fishermen
• for fishery managers

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The decline of the River Wye salmon catch
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Angling advantages of sea troutthey can be
caught in big rivers
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. and in small rivers
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..in lakes
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. in estuaries - by the rods
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and by the nets also.
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including our few remaining heritage
instruments such as the coracle nets on the
Tywi and Teifi
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. and in the sea
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.they can be caught in daylight - on fly
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on spinner
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and with worm
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. they can also be caught at night on the fly
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Night here means. not just at sunset
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nor even just at twilight
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but in pitch-black and total darkness also
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. angling success can be quantitative
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.or qualitative
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. or both
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. other benefits to the angler are.

• Presents the true angler with more challenges and
  opportunities
• Comes naturally packed in a range of more
  convenient sizes for the freezer!
• Tastes nicer than salmon or brown trout
• Provides an opportunity to meet a far better
  class of angler!

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Method of Rod-Capture
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Practical Advantages

• Sporting attractions
• Widespread distribution
• Catchment utilisation
• Coastal migrations
• Up-stream movements on low flows
• Regeneration from resident brown trout
• Robust life-history

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The importance of sea trout in smaller rivers
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Robust Life History

• 1- 4 year old smolt age groups
• 0 - 3 maiden sea-age groups
• multiple repeat spawning visits to freshwater for
  up to 12 consecutive years.
• c. 25 survival from kelts
• High potential maximum lifetime egg deposition by
  repeat spawners.
• Less vulnerable to cataclysmic events affecting
  any single year class or age group of fish in
  either river or sea
• Adult size-range (8 oz - 24 lb) allows fuller
  use of available nursery stream and spawning
  gravels.

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KEY ISSUES 1.

• What is a sea trout?
• In a nutshell..!

• ?

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.What is it that determines if a juvenile trout
parr is destined to become
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. a small resident brown trout
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.or undergo the smolt transformation that
pre-adapts it to life in the sea
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.to become a larger migratory sea trout?
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Is it

• Nature or nurture?
• Genetics or environment?
• Or is it
• A Bit of both?

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Key Issue 2 The Marine Phase

• What happens to sea trout when they go the sea?
• Migration distances?
• Over-lapping feeding ranges?
• Differences in behaviour of
• different life-stages?
• different river stocks?
• Survival return rates?
• Illegal and inadvertent capture?
• Exploitation rates?
• Coastal mixed stocks?

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Do we have any mixed-stock fisheries for sea
trout?
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Are there any mixed stocks in the Irish Sea?
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Key ISSUE 3 CONSERVATION

• Are our stocks healthy?
• Is current level of exploitation sustainable?
• What needs to be done to maintain the fishery
• . in quantitative terms?
• . In qualitative terms?
• Are existing stock conservation measures adequate
  and appropriate

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Conserving .0sw finnock. A worthy catch or
irresponsible fish-mongering?
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The benefits of finnock conservation are.
more bigger fish next year!
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Conservation of . MSW Sea Trout?
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CONSERVATION OF PREVIOUS SPAWNERS
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ISSUE 4 Global Warming Climate Change?
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changes in temperature rainfall patterns
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WHAT ARE THE CHALLENGES?

• Integrated management of the sea trout / brown
  trout complex as a single biological unit
• Recognise and safeguard the enormous biodiversity
  (including genetic diversity) present in Salmo
  trutta
• Identify true stock status and maintain
  exploitation at a sustainable level
• Define and determine robust Biological Reference
  Points
• Conserve qualitative stock components
• Climate Change (more brown trout and fewer sea
  trout?)
• Recognise Importance of long-term studies
• Fill the many tactical gaps in our knowledge
• Investigate the marine phase of sea trout life
  history.
• Think Sea Trout Do not take them for granted.

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SLANEYSEA TROUT POTENTIAL?

• Establishing the potential
• Realising the potential
• Maximising/optimising the potential
• Maintaining the potential

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A Sea Trout Strategy for the Slaney?

• Identify main spawning and nursery areas for sea
  trout (and brown trout).
• Look after small tributaries and sub-tributaries.
• Reduce unsustainable selective fishing pressure
  in tidal waters by net fishery
• Implement sea trout conservation strategy with
  properly joined-up Rules Regulations for the
  entire river
• Improve collection of catch-data from the rod and
  net fisheries to establish a baseline and
  monitor change.
• Undertake a structured scale reading
  investigation to establish structure and
  composition of stock/catch to establish a
  baseline and monitor change.
• Encourage anglers to fish for sea trout..
  properly!
• THINK. IRISH. SEA TROUT!