July 27, 2018
Which Came First, The Fish Or The Egg? Understanding Where Your Blackwater River Rainbow Trout Came From
You’ve caught a fish at a locally stocked lake in B.C. – but where did the Society get the eggs that produced the fish? Each spring and fall, Society hatchery staff head afield to collect the “ingredients” for a productive fishery. In many cases, this work is done at an egg-collection station at a lake. Fish culturists live-trap trout, char, and kokanee (the sockeye salmon’s freshwater counterpart) that are ready to spawn. One-by-one, they harvest their gametes: eggs and milt (sperm), to spawn the next generation of fish. Some of our egg-collection sites include Dragon, Premier, Pennask, and Beaver lakes – collectively referred to as “broodstock lakes.” In this blog series, we will explore where we get our eggs by looking back in time at the origin of the fish at the end of your line.
So, you’ve caught a Blackwater rainbow trout – where did that fish come from?
It was stocked into the lake in which you caught it when it was a fry or yearling. Before that, your fish was once a fertilized egg that grew into a fry, and thrived in one of our five trout hatcheries (Vancouver Island, Fraser Valley, Summerland, Clearwater, or Kootenay).
Where did this fish's parents live?
Historically, the original fish for this strain came from the Blackwater River, located in the Ilgachuz Range northwest of Quesnel in central British Columbia. Your Blackwater trout's mom, and maybe dad too, were stocked into Dragon or Premier lake as yearlings. Once the mom reached reproductive maturity, a Society fish culturist caught her, and harvested her eggs at either of the lakes’ egg-collection stations.
The dad of this fish may have also come from either of these lakes, before being captured by a Society fish culturist. He may also have been part of a captive population at one of the previously mentioned hatcheries.
To ensure the gentlest handling during fertilization, we like to transport gametes to the hatchery whenever possible. Sometimes, however, the parents are transported to the hatchery and spawned on-site.
What happens next?
Back at the hatchery, the dad’s milt was mixed with the mom’s eggs to fertilize the eggs. After this process, the fertilized eggs were moved to the incubation room. The incubated eggs would all hatch and grow up into fry at the hatchery. Blackwater fry just like these are stocked into lakes across the province. After a year of growth in the lake, they will develop into catchable-sized trout, and could end up on your hook.
What lakes are stocked with Blackwater trout?
Every year, our hatcheries raise and release over six million trout, char and kokanee – from juvenile fry to catchable-sized fish. To see where we stock the Blackwater strain of rainbow trout, use the Detailed Stocking Report tool, and filter by Blackwater R under Stock Strain. If you notice Dragon under Stock Strain, these are rainbow trout whose parents are from Dragon Lake’s naturally spawning population. The origin of the naturally spawning Dragon population includes both the Blackwater strain and other previously stocked rainbow trout. To make it easier for hatchery staff to distinguish between the two strains, all Blackwater-strain fish released into Dragon Lake are fin-clipped prior to release.
Author: Freshwater Fisheries Society of BC Staff
Photo Credit: "Eyed Eggs", Eiko Jones; "Blackwater rainbow trout", Morgan Martin; Freshwater Fisheries Society of BC Staff
