This is what our side of the Lake is doing to keep "their" program alive. Yes, I agree that millions has been spent and obviously more is going to be due to politics. I'm more concerned that Steelhead are being shunted out for the Atlantics. To me they are very similar fish, the main difference is the steelhead have been here now over 150 years and are a natural fish. The Atlantics not since the 1800's. Given the number they've stocked I've only caught about 5 in the Lake over the past 20 years.
I apologize it took a while to put this together, we're in the midst of field season and this weather has thrown us a few complications. I'm borrowing a lot of what follows from a FAQ we're putting together with MNRF as they've also had questions come in over the last year about the Ganaraska River stocking and we've decided to collect them in one place. I've matched up your questions with what is in the FAQ and added a bit more content where you were a bit more specific. I re-arranged your questions a bit so we could start with the goals, and some questions were grouped where I had an answer that could address both.
Q - What are the goals for the stocking of Atlantic Salmon in the Ganaraska River?
The Ganaraska River strategy fits into the overall goal of the Lake Ontario Atlantic Salmon Restoration Program in the binational Fish Community Objectives for the lake: Restore naturally-produced populations of Atlantic Salmon to levels supporting sustainable recreational fisheries in the lake and selected tributaries and also provide recreational fisheries, where appropriate, through stocking.
To help achieve this goal we are going to try and develop a catch and release Atlantic Salmon fishery in the Ganaraska River. The Ganaraska River watershed provides good habitat, an excellent fish-way for both public viewing and fish assessment and the river is of sufficient size to support a recreational tributary fishery.
The stocking strategy for the Ganaraska River is based on the success observed in the Salmon River in NYS and comments received from the public during a consultation for the province's stocking plan for the Ontario waters of Lake Ontario. We are focused on stocking 50-70 thousand large yearling Atlantic Salmon up high in the watershed to encourage imprinting. The priority strain is Sebago Lake however we will include other strains. All the fish stocked in the Ganaraska River will be adipose fin clipped for future identification by anglers or with photos (we can also identify them with their genetics).
Q - How long will they spend in the river until the move out into Lake Ontario?
We have observed stocked yearlings leaving (smolting out) of the river within a week of stocking. Based on assessment in the Credit River, most of the stocked yearlings are at a size that encourages smolting that year. Some smaller stocked fish may remain in the river longer. We conducted some assessment in the fall of 2016 and observed a few Atlantics were still in the river. Based on smolt catches from the Credit River (we've had a smolt trap in the river for about five years, through 2016), yearlings that do not out-migrate the year they are stocked (year 1) but instead smolt out the following year (year 2) make up less than 1% of the catch at the smolt trap. Of the 50,000 yearlings stocked – fewer than 1,000 (conservatively) may remain in the river for an additional year.
Q - How will the newly born steelhead compete for food if not preyed upon by the Atlantic Salmon smolts once they emerge?
Q - Has the science been done to understand the inter-relationships between the various salmonids during early stages of life and the potential impacts for the Ganaraska River?
The Atlantic Salmon stocked into the Ganaraska River are stocked as yearlings and prior to the spring Rainbow Trout spawning run. As mentioned above these stocked fish have been observed out-migrating both over the Corbett Dam and through the Ganaraska fishway via the new video fish counter as quickly as five days post-stocking. Out-migration soon after yearling stocking has also been documented on the Credit River. Given the brief stream residency time post-stocking, the stocked Atlantic Salmon should not have a noticeable impact on Rainbow Trout fry.
Outside of that specific interaction, It is hard to predict the impact of Atlantic Salmon on Rainbow Trout. As you noted in your e-mail, the Ganaraska River wild migratory fish community is currently comprised of multiple salmon and trout species, and these are able to coexist within the Ganaraska River, appear healthy and are able to produce strong spawning runs each year. It is expected that Atlantic Salmon will also find their place in the fish community. There are a multitude of factors that contribute to the success or failure of a species in the natural environment, specifically, environmental variables, such as water temperature and discharge and flow (e.g., 2016 was a drought year). As another example, although we did not see significant mortalities and sick Rainbow Trout in our rivers, Rainbow Trout were also affected by a thiamine deficiency in the fall of 2014 (at least) that was observed in NY rivers with their fall run fish. It may have affected the Ontario fish but was not observed because they weren't in the rivers at the time the problem peaked, but would have affected subsequent spring runs.
Recent research has shown juvenile Atlantic Salmon do not impact survival and fitness-related traits of juvenile Brown Trout, Rainbow Trout, Chinook Salmon and Coho Salmon in laboratory studies. Atlantic Salmon tend to be less aggressive than Brown Trout and Rainbow Trout, but just as aggressive as Chinook Salmon and Coho Salmon; species are unlikely to be negatively impacted by competition with other species of lower or similar competitive ability. Diet studies of both juvenile Atlantic Salmon and Rainbow Trout have been conducted in several New York streams. Research found that there is dietary overlap, however, juvenile steelhead subtly alter their feeding behavior (selecting more terrestrial insects) in the presence of Atlantic Salmon. This behavioral adaptation may reduce competitive interactions between these species. One of the reasons for our extensive habitat work on the restoration rivers is that research in the 1990s found that with sufficient quality habitat, both Atlantic Salmon and Rainbow Trout could thrive, so the more habitat we can restore, the better for both species individually and in terms of competition; the benefits will also extend to other species where they overlap.
With regard to some of the other species, research has also shown juvenile Atlantic Salmon do tend to select, and are adapted for, different habitats than Pacific salmon and Brown Trout. The former selecting higher gradient habitats with stronger stream velocities, whereas the latter prefers slower deeper habitats (pools and runs) as juveniles.
Q - Will the river have enough food for all the competing trout and salmon?
Q - How much can one river sustain?
Stocking yearling Atlantic Salmon into the Ganaraska River could increase juvenile density but the impact depends on how long the stocked fish remain in the river and how many wild fish are also present. It is difficult to predict the year to year fish densities a river can support as it depends on the availability of resources (e.g. food and habitat) and the availability of these resources is in part, dependent on broader environmental conditions (i.e., water temperatures, water levels, water flow, invertebrate hatch timings, etc). If the maximum juvenile density that the river can support is exceeded, it is likely that stocked Atlantic Salmon would not do as well as Rainbow Trout (and Brown Trout). The naturalized Rainbow Trout population should have the competitive advantage over the stocked Atlantic Salmon. Given Rainbow Trout can outcompete Atlantic Salmon when resources are limited, and knowing the stocked Atlantic Salmon leave the river system shortly after the stocking event, Rainbow Trout natural production still should not be limited if the maximum juvenile densities are reached/exceeded; i.e. they would hold the upper hand in such situations.
Q - Will this lead to the eventual extinction of the Ganaraska Steelhead run due to the introduction of another 'invasive' species - the Atlantic Salmon?
Q - The steelhead of the Ganaraska are a 'naturalized' species; is there an attempt to establish a naturally reproducing strain of Atlantic Salmon in the Ganaraska River at the expense of the reproducing steelhead?
Elimination Rainbow Trout from the Ganaraska or other rivers is definitely not a policy position at the binational level or within MNRF (or one that would be supported by OFAH). Atlantic Salmon and Rainbow Trout seem to be figuring it out on the Salmon River using a very similar approach to stocking.
The Binational Fish Community Objectives are here: http://www.glfc.org/lakecom/loc/LO-FCO-2013-Final.pdf
Ontario's Lake Ontario stocking plan is here: http://apps.mnr.gov.on.ca/public/files/er/stocking-strategy-for-the-ontario-waters-of-lake-ontario.pdf
Broader provincial direction is in the Provincial Fish Strategy: http://apps.mnr.gov.on.ca/public/files/er/ontarios-provincial-fish-strategy.pdf
But just so you know, definitions like "native" are almost always viewed at the species level - going down further than that nothing extirpated - including wild turkeys, elk, peregrine falcons etc. - could be restored. And "invasive" also has its own definition used by the invasive species folks and new provincial legistation.
Q - Realistically, since they run in the summer and spawn in the fall what likelihood do anglers really have in angling for them? With the problems on the Ganaraska River in the recent falls during salmon runs, due to some 'morons' and the over-zealous reaction by Municipalities to simply take away opportunity to fish for returning salmonids, how could the Atlantic Salmon should they return to the Ganaraska be considered for angling?
We will need to wait and see how this fishery develops. With the new video fish counter on the Ganaraska River (and hopefully the Credit in the near future) we should see the fish returning and anglers will know there are fish in the river. Fishing for summer run migratory salmonids will be a unique opportunity and a new challenge for anglers. There are concerns over summer angling mortality, but we will have a better sense of the issue of that once the fishery is established and then we can work with anglers to reduce the risk.
I'm not sure if you're familiar with the new fish counter that has been installed on the Ganaraska River - it uses infrared technology to count fish and take a silhouette of them, and then a video camera (which switches to IR in low light) which takes a film clip to help confirm species if the silhouette can't (Chinook for instance are pretty identifiable just from their silhouette). The unit also takes stream temperature, flow, and gets a length estimate for every fish. The data will eventually be public and in real-time; or at least near-real-time, things like species ID will have to wait for an evaluation by a human. The counter will help improve management and understanding for all species on the river, but primarily the migratory ones. The unit was bought with MNRF capital funding made available because it was being used for Atlantic Salmon assessment, and the ongoing operation of it is being covered for the same reason. The unit was tested last fall and this spring, it was imported from Iceland and there was a learning curve to it and we needed to fit it into the existing infrastructure at the dam. It's only the second such unit in Canada, and the first in the Great Lakes (I think all the US ones are in California). I expect the counter will be "live" next fall.
I've attached an example video clip and silhouette from the counter (different fish).
Sorry for the long e-mail, please let me know if you have any follow-up questions or comments.
Yours in Conservation,
Chris Robinson, M.Sc.
OFAH Atlantic Salmon Restoration Program Coordinator
Ontario Federation of Anglers and Hunters
4601 Guthrie Drive, PO Box 2800
Peterborough ON, K9J 8L5
Phone: (705) 748-6324 Ext. 237
E-mail: [email protected]
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