Thank you for the invitation and the opportunity.
I'd like to begin with a brief introduction about what these steelhead are. I'm a biologist, and would be reporting to you in that capacity.
Interior Fraser steelhead is a group of steelhead populations that spawn and rear as juveniles in some of the inland portions of the Fraser River watershed in British Columbia, portions that begin immediately inland from the coastal mountain range.
Interior Fraser steelhead are valued, and were, until recently, used directly by first nations communities and sport anglers supporting culture as well as tourism and recreational economies. These values manifest themselves in the interior part of the province where the steelhead reside for quite a period of time in the latter stages of their upstream migration.
Interior Fraser steelhead are also a bycatch in some salmon fisheries that occur along the southern B.C. coast and along the Fraser River. While these steelhead are migrating from offshore habitats in the north Pacific toward their spawning and rearing areas, that migration spans a period approaching three months. In terms of biodiversity, interior Fraser steelhead are comprised of at least three discrete evolutionary significant units of biological diversity and are exceptional examples of the species they belong to, Oncorhynchus mykiss.
As for abundance trends and current status, interior Fraser steelhead populations, along with most of the steelhead populations along the B.C. coast and Puget Sound, as well as many salmon populations, have been declining in survival and abundance for at least three decades.
Thompson River and Chilcotin River steelhead, which comprise sizable components of the interior Fraser steelhead group are currently at about one-tenth of their former abundance in comparison to the abundance in the 1970s.
Thompson and Chilcotin steelhead, as you heard, are currently classified as endangered by COSEWIC, and a recommendation was made in February 2018 to place them in schedule 1 of the Species at Risk Act. Under the B.C. provincial classification system, they are classified as an extreme conservation concern.
With respect to factors causing decline, the evidence to date suggests that the most likely causes responsible for the decline and survival of abundance include an increase in predation in the inshore marine habitats; increased predation from marine mammals, particularly pinnipeds; an increase in competition in the offshore ocean habitat, from an increase in a natural and enhanced abundance of salmon in the north Pacific; and finally, fishing, predominantly in the form of bycatch and salmon fisheries.
All factors are partially or wholly human-induced effects. Fishing is obviously a wholly induced human effect. The increase in pinniped populations particularly is largely attributed to marine mammal protection in both Canada and the U.S. The increase in competition and offshore ocean habitat is largely the result of salmon production in the U.S., Japan and Russia. Canada is a relatively minor source of salmon entering the north Pacific.
Over the past 90 years for which we have abundance and biomass estimates for the north Pacific, salmon are more abundant now than ever. About 40% of the current biomass of salmon in the north Pacific originates from hatcheries, with the remainder originating from natural and enhanced production from sources not associated with hatcheries, for example, fishways and range expansion or spawning channels and enhancements of that type.
Decline in survival diminishes the amount of mortality that can be sustained by the steelhead through human activities, such as fishing. Currently any amount of mortality will inhibit or delay potential recovery. The potential for recovery to formerly observed abundances rests almost entirely with the recovery of survival between the smolt stage, when these fish migrate to sea as juveniles, to the stage of full maturity and spawning.
There is little potential to recover to formerly observed abundances by improving the survival during the freshwater stage of life, meaning the egg stage to the ocean-migrating smolt stage. However, maintaining and improving freshwater survival may help the populations persist and avoid extirpation from the freshwater habitat range that they occupy.