Decision-making for fishing often relies on stock assessments that
estimate population size – but these estimates can be unreliable. Traditional
assessments often use time-series data that can determine a stock's underlying
production, reference points, and biomass. Assessments can be prone to error
when, for example, there are changes in the stock distribution relative to the
sampling frame of the abundance indices or a lack of observations of the stock
declining and rebuilding. Some commercial fish populations are also not covered
by current monitoring programmes. In addition, servicing monitoring data needs
can be very expensive, and ecosystem-scale assessment methods will further
increase costs for monitoring and measurement by agencies. Given these
potential errors and costs, looking at alternatives to traditional assessment
methods and monitoring are highly relevant for management.
While population genetics tools have long been available for stock
assessment and management, genetic/genomic methods have the potential to offer
alternatives to traditional assessments and monitoring. For example, new
studies have used advanced genetic tools to estimate exploitation rates and absolute
stock biomass, as well as population and individual fish identification and
stock structure. These include genetic mark-recapture for real-time harvest
rate monitoring, absolute abundance of adult population size, mortality and
age-specific relative reproductive output estimated by close-kin
mark-recapture, and parental-based tagging. Environmental DNA (eDNA) techniques
promise new methods for monitoring communities and ecosystems. While there is
much potential for genetic/genomic methods to improve stock assessment and
monitoring, a number of questions need to be addressed in order to realize this
potential.
The major objective of this session is to address some of these
questions, specifically:
- What genetic and associated statistical tools are available for resource monitoring and assessment?
- How can genetic methods for stock assessment and monitoring be applied to fisheries management in practice in order to provide more reliable tools to support integrated fisheries management advice? Are genetic methods suitable for assessing small/local populations, which may not be quantitatively assessed by traditional methods? What is the potential for eDNA to complement/replace current monitoring?
- Relative to existing techniques, under what circumstances do the genetic methods for stock assessment and monitoring offer more cost effective monitoring and stock assessment?
- What practical and technological obstacles need to be overcome in order to apply genetic methods for stock assessment and monitoring?