Jakeller
Supporting Member
I'm currently taking a fish and wildlife conservation class at Santa Rosa Junior College, and today we went to the Warm Springs Dam steelhead hatchery and the coho recovery program’s facility. The steelhead program is specifically designed to replace the fish habitat and population that was lost once Sonoma Lake was built. (There is a genetically distinct population of rainbow trout in the lake now. Steelhead are just rainbow trout that have gone to the ocean and come back) During the spawning season (we are at the end of it now), the steelhead will naturally swim up and go through a weir, which traps them in a holding tank. Once there are enough fish, they will corral them with a fake wall that squeezes them into a box they can seal off and pump co2 into. The co2 makes the fish slightly unconscious so they can slide onto a sorting table and be organized by sex, as well as scanned for pit tags.
(sorting table. Fish come up the elevator on the right side. Each tube with a white bucket goes to different holding tanks)
Even though they are somewhat incapacitated, they wake up quick. One jumped out of the trough and got a excited a little early.
Once the eggs are fertilized they used to put them into hatching racks where water rains down on them and constantly supplies cold, oxygenated water. They used to use these for steelhead, but they switched to hatching jars. The Coho recovery program is a lot more picky about their eggs and still use hatching racks, although their new system is a lot nicer than the one in the picture. They are more picky about Coho because it is endangered both federally and statewide. In order to stop inbreeding, they analyze the genetics of every fish that they artificially spawn as well as check the motility of the males sperm to make sure they have the best success. The reason the Coho program still uses hatch trays is because each tray holds one female’s eggs and only her eggs. The tray is then broken down into 4 sections with each section fertilized by a different male. This means each brood has four distinct genetic sets, creating the greatest diversity.
These are the steelhead hatching jars. Each raceway is a single females set of eggs, but multiple males. Less organized because the goal is production versus the Coho which is for conservation purposes.
Extremely young alevin steelhead with the yolk sack still attached.
Cleaning out dead alevin steelhead.
Young coho in a raceway (4,000 per raceway)
Once the coho are a few inches they get moved to large round tanks that are deeper than they look because they are set into the ground. They really pump the flow in these tanks so that the coho can get stronger and get used to stronger ocean currents. Something I thought was interesting was that they have to flip the flow occasionally because the fish were getting swim bladder issues. They aren’t 100% sure why it was happening, but something about swimming in the same direction for months on end would mess with their development.
(Coho getting pit tags and weighed. There is a national database so they can see where fish were introduced if they are caught again)
Lastly, the only filters they had were large sand filters for their hatching racks. Every other system runs on water piped directly from Lake Sonoma. This allows them to get constant cold water and manage the temperature because there are pipes at different levels in the lake which they can pull different water temps from. It comes with some drawbacks though because the lake and creek has New Zealand mudsnails which limits the reintroduction of the coho that they spawn to areas that already have the mudsnails. The drought we had a few years ago also raised water temperatures to the limit and the program would have lost its whole stock if lake levels didn't rise like they did. The Coho Recovery Program is super cool and raise over 150,000 smolts a year to be introduced around Sonoma and Marin County.
(sorting table. Fish come up the elevator on the right side. Each tube with a white bucket goes to different holding tanks)
Even though they are somewhat incapacitated, they wake up quick. One jumped out of the trough and got a excited a little early.
Once the eggs are fertilized they used to put them into hatching racks where water rains down on them and constantly supplies cold, oxygenated water. They used to use these for steelhead, but they switched to hatching jars. The Coho recovery program is a lot more picky about their eggs and still use hatching racks, although their new system is a lot nicer than the one in the picture. They are more picky about Coho because it is endangered both federally and statewide. In order to stop inbreeding, they analyze the genetics of every fish that they artificially spawn as well as check the motility of the males sperm to make sure they have the best success. The reason the Coho program still uses hatch trays is because each tray holds one female’s eggs and only her eggs. The tray is then broken down into 4 sections with each section fertilized by a different male. This means each brood has four distinct genetic sets, creating the greatest diversity.
These are the steelhead hatching jars. Each raceway is a single females set of eggs, but multiple males. Less organized because the goal is production versus the Coho which is for conservation purposes.
Extremely young alevin steelhead with the yolk sack still attached.
Cleaning out dead alevin steelhead.
Young coho in a raceway (4,000 per raceway)
Once the coho are a few inches they get moved to large round tanks that are deeper than they look because they are set into the ground. They really pump the flow in these tanks so that the coho can get stronger and get used to stronger ocean currents. Something I thought was interesting was that they have to flip the flow occasionally because the fish were getting swim bladder issues. They aren’t 100% sure why it was happening, but something about swimming in the same direction for months on end would mess with their development.
(Coho getting pit tags and weighed. There is a national database so they can see where fish were introduced if they are caught again)
Lastly, the only filters they had were large sand filters for their hatching racks. Every other system runs on water piped directly from Lake Sonoma. This allows them to get constant cold water and manage the temperature because there are pipes at different levels in the lake which they can pull different water temps from. It comes with some drawbacks though because the lake and creek has New Zealand mudsnails which limits the reintroduction of the coho that they spawn to areas that already have the mudsnails. The drought we had a few years ago also raised water temperatures to the limit and the program would have lost its whole stock if lake levels didn't rise like they did. The Coho Recovery Program is super cool and raise over 150,000 smolts a year to be introduced around Sonoma and Marin County.
