The Value of Diversity in Our Fish Populations
Just as financial investors diversify their portfolio of assets to minimize loss, fisheries managers may diversify their portfolio of conservation strategies to minimize species and life history loss. This is often called the "portfolio effect" when it comes to fisheries management - it reduces risk of loss by displaying a diverse array of life histories, or pathways from hatch to spawn for any given species. This can also be expressed as the timing of upstream migration, timing of spawning , and the age of maturation.
Rainbow Trout (Steelhead) are a common and popular species within the Ganaraska Region watershed, are capable of maturing across a wide breadth of ages, and are able to survive spawning multiple times within a season and across seasons. Steelhead are can mature at the age of 1, or as old as 5 or 6. Within one spawning population/year, the spawning population may consist of a wide breadth of ages and life history pathways. Highlighted below are four mature spawning male Rainbow Trout, that have taken different pathways to maturity that were captured by GRCA staff. The value of this diversity is risk is spread out, ensuring that all eggs will become fertilized, and the genetic diversity within the population is maximized.