The 2023 spawning season at the hatchery is now officially over.
Approx 30 fish, returnees to the hatchery, and 20 fish from our Land based broodstock were processed to produce a little over 100,000 fertilized eggs. These are now all under incubation. Egg picking (removal of dead eggs) will commence in the next week. Strict protocols have been observed and each batch of eggs have been recorded in terms of their breeding group. This ensures that the only fish used as future broodstock are derived from wild stock. This year we were happy to help the Otago Harbour hatchery get back on its feet by supplying them with approx 50,000 eggs and milt. This transfer was organized by the respective Fish and Game organizations. All adult fish that were not required have been returned to McKinnons Creek. We are still holding 37,000 rising one year old fish that will soon be fin clipped and released back into the River. All in all it has been a very satisfying year and a massive thanks must go out to all those who have helped in any shape or form. From our growing number of volunteers to those who generously donate and also our many supporters. The environment around the hatchery is now looking better than ever with the thousands of native plants that have been planted, and the willows and scrub removed. We have had visits from ECan, DOC, local Iwi, and various other groups who have all been impressed with the hatchery and the environmental improvement. Click on photos to enlarge. We were very sad to loose one of our stalwarts from our team late last month. Tim Wakefield was a volunteer in our group whose contribution to the hatchery will be sorely missed. RIP Tim.
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The annual breeding program is with us once again. This is a very busy time at the hatchery because it entails stripping eggs from ripe female fish, fertilizing the eggs with milt from selected males, and incubating them in specially designed incubation towers. The whole process is labour intensive and has to be done in a professional manner if good results are to be achieved. Dryness of all receptacles is essential and hygiene is a must. There are strict protocols to be observed and the make up and history of each batch of eggs is recorded. So far this year we have processed 20 fish and have nearly 45,000 eggs under incubation. Our goal this year is the same as last year, 100,000 eggs. While we could do more, this is about the limit our team of volunteers can manage. The hatchery relies solely on donations and grants for its funding and recently put out a call for donations from supporters to help fund a shortfall in our fish food supplies. Our request was well received and we thank all those who contributed. Feeding fish is not a cheap exercise at at around $3500.00 USD per metric ton, it is our most expensive factor of the whole operation. Thank you one and all again.
Recently we had a film crew at the hatchery, making a documentary about the Rangitata river and the communities around it. The hatchery features in the film and should be on TV in the near future. We have had 2 fin clipping days so far this year and have clipped around 53,000 out of our estimated 90,000 rising 1 year old fish. Both days have attracted nearly 40 helpers and despite some inclement weather on the first day, all went well. The fish were released into ponds where they could move into McKinnons at their will. They hung around for a while but had mostly all moved out within a week. Fin clipping of juvenile fish is a recognized way of identifying hatchery reared fish.
Well quite a bit actually!.
Firstly the trap went in January and a steady stream of adult salmon trickled in to be sorted and transferred to the adult pens closer to the hatchery. To date 180 salmon have passed through the trap, some kept for the breeding program and others let through to McKinnon's Creek to do their thing naturally. We have been lucky that a good sized stream from the main river (Rangitata), joined up with the hatchery stream, making it very easy for fish to get into McKinnon's creek, hence the excellent returns this year. The work on clearing broom, gorse and scrub and replanting with native species is progressing well. Offending willows have been removed and more spawning areas have been opened up in the stream. There is no let up for the happy campers who run the hatchery after the winter chills with a sustained period of growth for the new fish approaching.
The rising 3 year olds (brood stock for 2023) are growing well and should be of a good size when it comes around to spawning time in April/May next year. The fish kept back for the following year have been thinned out with a number released back into McKinnons creek. This year group are also growing well. It is a challenge keeping back a few brood stock as a back up for returning fish due lack of space to keep them. We manage however but could certainly do with another tank. Some of the fry that started in the shed, have been transferred to the south raceway outside and the remainder spread around the inside tanks. Soon all of last years fry (around 90,000) will be in the outside raceway. This make their management much easier as the grow to release weight. New fish food has recently been purchased for our growing fish and this has put a sizeable dent in our finances. We have been very lucky in the past with donations from other hatcheries and this has helped. The following note has been compiled by Alan Brooks who is working closely, along with Paul Hodson, with RDR Management to confirm that the return stream from the fish screen, is fit for purpose and will return small migrating fish safely back to the river.
Fish Screen RDR. You will be aware that the Project has been switched over with the Fish screens and bypass operational. We were invited to a workshop in 6/2022 by RDR in which this was the first time that we received plans for the actual bypass. We had a critical look at all sections and made our views known to them. There are a number of concerns that we have expressed.
***************************************** And now for the Great News - Salmon Legacy for Future Generation Please refer to the attached table which I believe establishes a Conservative Estimate of Smolt to Sea in Year 2022. I believe this the best news we have heard for years and will start our Legacy that we have cried out for and all but given up on. Mark these dates down on your Diary and tell all you fellow anglers to get ready. Year 2022, this year 1.5million smolt will get to sea from the Rangitata. Fishing season Year2022/23 we should see and increase year1 precocious Males Fishing season Year2023/24 an increase in 2 years old fish Fishing season Year2024/25 we are could get up to 10,000 but le us assume 4,000+ or more Adult returns Logically the majority will return to the Rangitata, but it will also support the Opihi and Orari Rivers. So, mark those dates and watch this space. See table below for our calculations. Rangitata River Projected River Hatch and Smolt to Sea, Year 2022 Alan Brooks Dated 8/21/2022 Totals [1] Adult Salmon to Headwaters CSIFG 1800 [2] Females Run Mix 60% 1080 [3] Egg count Conservative 3000 per Female 3240000 [4] Headwaters Hatch 50% 1620000 [5] Estimated loss to sea 10% 1458000 ****RDR now clear*** [6] Say 1.5Million ************************************** Rangitata Prior 3 Years [1] Adult Maximum 500 [2] Females Run Mix 60% 300 [3] Egg count Conservative 3000 per Female 900000 [4] Headwaters Hatch 50% 450000 [5] RDR Losses 50% min 225000 [5] Estimated loss to sea 10% 202500 [6] Say 203000 ************************************** Summary to Sea Year 2022 1500000 Prior 3 year average 203000 Increase 7.389162562 Times Work continues at the hatchery with things progressing well out there. McKinnons creek has had a good flow and the Rangitata river is not far from its confluence with the hatchery stream. All good indications for good access to and from the hatchery for (Scientific name) Oncorhynchus tshawytscha.
The fry, at present in the hatchery shed and starting to put on weight with an average weight of around 1.2gms. A big thank you to all those who have helped out including the weekend teams over the winter. A quick summary of statistics is as follows; Adult Salmon returns to McKinnons Creek 2022 inc other data. Males. Non fin clipped. 6. Males. Fin clipped. 6. Females Non fin clipped. 7. Females. Fin clipped 18 Approx 10 small Jack fish returned to creek. Egg stripping started 3/5/22. Completed 17/5/22. 43 female fish were processed, being almost a 50/50 ratio of returnees to the hatchery and 3yr old land based broodstock to produce approx. 120,000 eggs. 120 x 3yr old land based broodstock fish, not used were returned to McKinnons creek. This was 20 males and approx. 100 females. 1yr old fish released 2022. 4000 to McKinnons creek 13/7/22 400 kept back for brood stock 13/7/22 1000 to RDR for testing/release. As at 6th September we are holding approx. 95,000 fry average weight 1 gram. 5000m of these are from non clipped females crossed with non clipped males (P1). These are kept separate. The remainder are a mix of P2, P3, P4, P5. A number of fish have been observed spawning in McKinnons creek and a number of Reeds have been spotted. All hatched salmon fry have now been removed from the incubators and put in stainless steel tanks inside the hatching shed and in the outside SS tank (No 4). Our best guess count is 95,000 young fish. All have had their 1st feed and are getting used to swimming freely in their environment.
All the remaining 1 year old fish have been released except a small number for possible future broodstock. Recently there has been two occasions when water from the flooded creek has gone through the shed despite our sandbagging efforts. No damage done but its becoming a bit of a pain every time we get heavy rain. |
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