Conservation of Atlantic salmon - gene banking: principles and considerations

Considerations in the utilisation of gene banking

Gene banking (whether live banking or cryobanking) is not a simple, or cheap, process and, as such, should not be initiated without a thorough evaluation of the approach, which looks at not only the risks and opportunities of the banking option/s but also puts these in the wider picture of the alternative conservation strategies that might be employed. The aims of any gene banking undertaking are the preservation of genetic material as part of a process of preventing of extirpation of a population, or group of populations of salmon. As such, there are two broad management situations where such approaches might be considered and initiated:

1. In extremis, where a population/s has declined by a significant extent and/or is threatened with extinction.

2. As a coordinated strategy to obtain and preserve a representative genetic coverage of populations before they reach a seriously impacted state and so hedge against future negative impacts.

In order to both reduce/eliminate negative impacts of a gene banking intervention, and maximise the ability to meet conservation objectives, it is vital that a thorough plan is developed in support of each gene banking proposal. This formal plan should cover the rationale, objectives, operation, monitoring and cost/risk/benefit of the proposal, be reviewed by experts in the field and the programme should undergo periodic review while underway. There are considerable risks associated with such interventions that must be addressed. In some situations, gene banking may be the best and, perhaps, only tool to prevent the loss of genetic diversity of a stock and/or its total extinction. Even so, it may not be the best way to re-establish a population, depending on the nature of change that caused population decline and whether the original genetic constitution is fit for future conditions. Therefore, a clear conservation strategy must be carefully thought through at the outset of any gene banking intervention.