Home » Education » Stewardship » Hatchery 101

Hatchery course from the Gold River Streamkeepers Society

 Hatchery 101
What it takes to start and run a hatchery.  A course given by the Puntledge River Hatchery personel. To download just click on the menu tab and click download or share.

puntledge river hatchery 101 course

Ponding

When and How?
ATU's (Accumulated Thermal Unit's) Best guideline for determining eyed eggs, alevin hatch to fry development Temperatures directly influence development. Warmer water speeds up development Colder slows down development.

1. -ATU's are (daily mean average temperature) * (number of days incubating). For example: If Chinook eggs were fertilized and placed in an incubator and the mean temp. was 10.0C. over a period of 30 days, you would have an ATU of 300. (avg. 10.OC * 30 days = 300 ATU's)
2. -Water Temperatures can be manipulated to accelerate or decelerate groups for early or late ponding.
3. -Well water usually warmer in winter and cooler in summer, i.e.: Rosewall Hatchery
4. -Surface water influenced by ambient outdoor temperatures.
5. -Finding the mean daily temperature and using this for ATU's recording.
6. -This may help you find the best time to take your daily temperature. If you can take temperatures every Vz hr. for a 24 hr. period and average them for a mean daily average. Then find the best time of day for taking temperatures that match the mean average. This may change during seasons but will be close enough for your needs. (If you are utilizing well water, the temperature will not typically fluctuate during the day but will weekly and monthly)
7. -As you fluctuate from 10C - no longer a true ATU. e.g. 17C will not add up to a true ATU reading, and similarly 2C will not either.

Development Stages in ATU’s ( Puntledge Hatchery Guideline only!!!)

Species  Eyed  Plant  Hatch  Buttoned 
Ponding
Release 
 Pink  230 440  463-592  1100-1400  1335 
 Chinook  268    495-562  960-990  1565-2100
 Coho  252    446-530  761  4491-5088
 Chum  236  440  500  812  1289
Steelhead  203    366-380 550-682  3597-4405 
Cutts  150-200    300 500-600   
           

 

 

 

 

 

 

 

 

Emergence Conditions and Fry Quality
When alevin development nears the "buttoned up" stage and it is close to the time of emergence, the conditions in the Incubator can affect the timing and survival of the emerging fry. When conditions are not optimum, alevins will try to leave the incubator before they are ready to exist as free—swimming fry. This is a sign of bad conditions in the incubator and remedial action may be necessary.

Conditions which result in early emergence

1) Low oxygen
2) High temperature/ low temperature
3) Disease — high fungus infection
4) High mortality — ammonia build-up from decaying alevins
5) Low flows
6) High silt build-up or silty water
7) Density- more room needed as they develop

The result of fry emerging early is that they are entering the stream environment early. The emergence from the streambed in nature is timed to coincide with spring zooplankton blooms in the ocean for ocean migrating fry, in lakes for sockeye, and it coincides with good food availability in streams for stream utilizing species such as Coho and Chinook. Releasing fry early results in them entering an environment that is not suitable for their survival. They don't grow well, and if they don't find food early in their life, they do not learn to eat and will soon die. Predation is also a major problem for early emerging fry because the food sources are limited and they are more susceptible to being eaten. Fry size at emergence is important because problems can be created later on during the rearing or the natural period of growth of fry.

Problems that can result from small, poor quality fry 

1) Small mouthparts mean small food necessary — small food clogs gills;
2) Slower growth — have to feed them longer;
3) Longer holding means they are more susceptible to disease;
4) Smaller size means they are more easily eaten by a larger number of predators;
5) Size range — causes problems in rearing;
6) Pinheading — they don't grow.

Size range
When fry are small and reluctant to eat food presented in commercial form, some end up growing big and some very small. If size range gets big enough, the big ones eat the little ones. Sampling the population to get a good average size is more work because the small ones are easier to catch. Food sizes must be mixed. Feed rates may not be accurate. On the whole, a large range in sizes of fish causes many problems and should be avoided. One way to avoid it is to release the first emerging and the late emerging, and only keep the large number that emerge at the peak of emergence.

Pinheads

When fry are just emerging from the gravel, they must learn to eat. They usually learn by having a lot of small particles of food available and by seeing other fish eating. When fry are very small and are poor quality, they are reluctant to eat small food. Eventually they lose their ability to learn how to eat. If fry do not eat or they eat infrequently, they gradually use up their body tissues and end up with a large head compared to their body. These are generally called "pinheads", although the original name referred to fish without proper mouthparts, which gradually wasted away. All of these problems can be avoided if optimum conditions are maintained and proper emergence timing is followed by frequent feedings of small sized food *Pinheads might also be caused by late ponding of fry.

Checking fry for Buttoned up bellies 

ATU's should be monitored and when approaching ponding stage (buttoned-up) a check should be carried out.
1. Check random heath tray by inspecting 25-100 fry in a 250-500ml beaker with 5cm water. Slit on belly buttoned up, still has up to 15% yolk sack left. Do not rush or pond too early
2. If unsure fill a 5-10 gallon pail % full w/ water and add 50-100 fry. Let them sit for 2-7 min. and see if 75-100% swim to surface. If they sit on the bottom put em back for a day or 2.
3. Remember that if you mix female eggs in incubators you will have large and small egg sizes. This relates to development. Large eggs longer duration small eggs shorter.
4. Grading females or eggs by size will give you a more uniform ponding and rearing fry size.
5. Try ponding in shallow tanks to allow swim up bladder to adjust. If you are using circulars or cap troughs you might try draining Vi of tank and add newly ponded fry. This will allow for swim up bladder to adjust and keep them from getting sucked on to screens while tank is filling.
6. Be gentle with newly ponded fish they are being subjected to stress and do not need more.
7. Let them adjust (hands off) for a day before feeding commences. And little amounts of feed several times a day.
8. If using a transport tank, make sure adequate oxygen levels and don't over saturate.
9. If ponding a large group into a raceway or large container. Be sure they are ready by putting a few thousand fry in and see what happens in 5-10 minutes.
10. Remember not to feed the bottom of tanks, as it will only create more work for you and more stress on fish by adding sediment to wastes. This equates to more screen cleaning and vacuuming.
11. At Puntledge we sometimes wrap a rubber strap (cut strips off tire tube) around each heath tray and place up to 10 trays in a tank with wheels. This keeps them in water from heath stack to ponding container.
12. We also installed a heath tray cassette system for a truck transport tank that will accommodate 20 trays per trip.
13. Ponding table was designed for transferring fish from heath trays into raceways.
14. A Bucket funnel is also a method for ponding a few trays.

puntledge river hatchery 101

puntledge river hatchery 101

PRIMARY FISH CULTURE PARAMETERS GENERAL

The primary water quality parameters are important to the successful operation of most hatcheries. With the exceptions of temperature and total gas pressure, the values of these parameters are adversely affected by the fish culture processes themselves. Table 1 lists these parameters and indicates how their values are changed by fish culture processes.

Previous | Stewardship | Next