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Stocking - Helping or Hindering Fisheries Recovery ??
Can we believe those genetic constraints we're persistently warned about ? Or all those papers and reports ??
Tyne rod catches 2004 - 09 are consistently x5 those of the Towy, as are stocking levels..
The EA Press Release dated 12th March 2009, announcing a visit by Norwegian fishery managers to Kielder Hatchery stated,
“……The hatchery rears salmon from eggs in order to restock rivers such as the Tyne, Yorkshire Esk and Trent. It has been important in supporting the recovery of the River Tyne, the best salmon river in England and Wales……. Ecology Officer Niall Cook said “We aim to share our good practice in salmon management and monitoring with our guests, and explain how we have helped make the Tyne the best salmon river in England and Wales……..”
The Controversy about Salmon Hatcheries
The use of hatcheries has been a subject of lengthy debate in the management of salmon and trout resources in the Pacific Northwest. The problem has resulted in part from the wide distribution of hatchery fish in circumstances where natural populations were disadvantaged by management policy involving hatchery fish and the confusion of the effects of management with the effects of artificial propagation. Recently, the controversy has been epitomized by the recommendations to fisheries management agencies that excess hatchery fish should not be allowed to spawn in the wild, and hatchery fish should be excluded from salmon populations listed under the Endangered Species Act. The authors of the present article disagree with those recommendations and conclude that hatchery fish have an important role in recovery and supplementation of wild stocks. The present article is an attempt to help give balance to the discussion by providing a different perspective on hatchery fish and the literature pertaining to artificial propagation.
Norwegian Salmon Stocking.pdf
"The effects of stocking
Atlantic salmon, Salmo salar,
in a Norwegian regulated river"
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Restocking of salmonids—opportunities and limitations
M.W. Aprahamian et al
Abstract
Stocking can be a cost effective method of enhancing salmonid populations, in particular where the aim is to restore populations or mitigate against developments. There are risks associated with any intervention and it is suggested that all stockings undergo risk screening in order to identify the high risk areas. The main concern regarding stocking relates to the impact on the genetic fitness of the wild population, and proposals to minimise the impact while still maintaining a fishery are made. To ensure that the greatest benefit from a stocking programme is realised, stocking rates should be optimal for the type of habitat being stocked. How this can be determined is presented together with guidelines for stocking different types of habitat. Benefit, in terms of cost of adult return or per adult fish caught, enables comparisons to be made with other management options. Information on survival rates of wild and hatchery-reared fish, unit cost of production and the economic value of fish and fishing is summarised enabling simple estimates of cost: benefit to be determined.
© 2002 Elsevier Science B.V. All rights reserved.
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The role of stocking in recovery of the River Tyne salmon fisheries.
N.J. Milner1 et al
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Management of salmonid fisheries in the British Isles: towards a
practical approach based on population genetics
A.F. Youngson et al
Abstract
The evidence for structuring of Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) into distinct reproductive populations and for genetic differentiation and local adaptation is compelling. The effect of genetic variation among populations is demonstrably a factor determining the economic value of salmonid fisheries in the British Isles. Genetic considerations are, therefore, a matter of self-interest for fisheries managers and a shared interest with those advocating more general approaches to the conservation of diversity and variation. The local population is the basic unit of production and, therefore, the preferred unit of management. However, salmonid populations are numerous and many are small. These factors limit practical possibilities for management at the population level. We suggest that this difficulty can be addressed by combining populations in fisheries-biased management units that comprise interchangeable, nested groupings of populations that are both genetically and biologically meaningful. This population-based approach addresses the necessity of managing the fisheries in ways that are consistent with the conservation of adaptive potential in relation to the dynamic aspects of populations, their capacity to respond to changing environmental conditions, and the likelihood that salmonids will remain a worthwhile resource for the future.
Crown Copyright © 2002 Published by Elsevier Science B.V. All rights reserved.
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Resolution by the Parties to the Convention for the Conservation of Salmon in the North Atlantic Ocean
to Minimise Impacts from Aquaculture, Introductions and Transfers, and Transgenics on the Wild Salmon Stocks
The Williamsburg Resolution
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Potential Genetic Interaction Between Wild and Farm Salmon of the Same Species Petersen
Small escapements of farm fish into large healthy wild stocks are expected to have a
small negative effect on fitness, in the short-term. However, these intrusions will
likely have long-term benefits