Atlantic salmon has been extirpated from many rivers. It seems reintroduction projects progress relatively slowly in Rivers Elbe and Rhine, and a long-running reintroduction program was recently abandoned in Connecticut River. I’m looking for rivers where Atlantic salmon has been successfully reintroduced.
Atlantic Salmon in New Zealand (more extreme than reintroduction): https://www.niwa.co.nz/freshwater-and-estuaries/nzffd/NIWA-fish-atlas/fish-species/atlantic_salmon
Atlantic Salmon reintroduction is a complex issue involving riverine, coastal, and Marine systems. As you mention, success is wide in range. I consider the projects as ongoing struggle and often with mixed results. Success is not easily quantifiable as it might take many years of restoring the biophysical system as well as population dynamics of all stages of the population. Connecticut river had poor success in reintroduction because of a focus on releases and not looking at the whole biophysical system of coastal ocean, watersheds, and land use beyond just release of fry or parr stages to streams. Recently wild Salmon returned to Farmington (tributary of Connecticut River) which is exciting to a abandoned project (http://america.aljazeera.com/articles/2016/2/23/presumed-dead-wild-atlantic-salmon-return-to-connecticut-river.html). Some other projects that continue their efforts with continued efforts:
Maine: http://atlanticsalmonrestoration.org/
Great Lakes: https://www.glsc.usgs.gov/06-06-2017/1579675415
Lake Ontario: http://www.bringbackthesalmon.ca/
Quebec: http://www.parcparcours.com/jacques-cartier/fiches/saumon_en.html
Don't know if they were ever completely eradicated from the rivers, but I think some Danish river re-introductions might have been success stories based on stocking and stream restoration (maybe Gudenåen?). If you check with the Danish salmonid researchers they probably have more information...
There are landlocked populations in Chile I think. Otherwise streams in New England.
Years ago I worked on a re-introduction project in Lake Ontario streams (Canadian side). There were rumors at the time that there was evidence of natural spawning (around 2000). I haven't paid attention in a long time so I cannot tell you if 'success' continued, but, you could contact Chris Wilson at Trent University). He has been involved in the project more recently and may be able to tell you if the re-introduction has been successful. Presently, in Newfoundland there is a population of spawning Atlantic salmon in Corner Brook Stream. That population was reported extirpated in the 1980's. The person to contact about that system is Don Ivany with the Atlantic Salmon Federation (Newfoundland office).
Not native there though.
Lake Sebago in Maine had a successful reintroduction in the 1800s in think....then extirpated a second time.
There was a programme to restore Atlantic salmon to the River Thames, S.E. England - and indeed there is now a wild salmon population established there, but it seems that this came about through natural recolonisation rather that the success of the introduced fish (see https://www.sciencedirect.com/science/article/pii/S0006320711002801). Similarly there is now a thriving salmon population in the River Clyde, W. Scotland, many years after it became extinct due to pollution - but again this is due to natural recolonisation (following extensive efforts to improve water quality and remove obstacles to migration) rather than due to any reintroduction of fish (see here for an early assessment: http://www.gov.scot/Uploads/Documents/Decline%20poster.pdf; the population has continued to expand since this survey).
Hi Neil,
How are you? It's been a long time since we talked. I am very interested in your question and in fact I would also like to know if there are data on rivers in which there are historical data on the presence of Atlantic salmon before its extinction, and in which reintroduction projects have worked without the natural recolonization from other nearby rivers.
This seems to be a potentially relevant paper:
Article Recovery and re-establishment of Atlantic salmon, Salmo sala...
Hi David,
have you flicked through the Crisp's book?
Crisp 2000 TRout and Salmon: Ecology, conservation and Rehabilitation.
I don't know but he could mention some experiences.
Best regards
Jorge
Hi Daniel
Atlantic salmon has been successfully reintroduced in rivers in southernmost Norway, where populations were lost during the last century because of water acidification. These rivers were continuously treated with crushed calcium carbonate (lime) from the 1980s onwards, and the water quality was improved and the rivers were stocked with salmon. But with the return of Atlantic salmon, the abundance of anadromous brown trout, which survived the long period of acidification, decreased (Hesthagen et al. 2017). As lime has a positive effect on trout abundance in the control rivers (with no salmon), the reduced trout density probably results from interspecific competition with salmon.
Reference
Hesthagen, T., Larsen, B.M., Bolstad, G.H., Fiske. P. & Jonsson, B. (2017) Mitigation of acidified salmon rivers: Effects of liming on young brown trout. - Journal of Fish Biology 91: 1350-1364. doi:10.1111/jfb.13454.
Daniel
We are currently working on a reintroduction of anadromous salmon to Rattling Brook in Newfoundland. We have a long history of introducing salmon in areas where they never where in Newfoundand mostly above natural barriers but Rattling is a bit unique as it was cut off from the sea in 1958 by a hydroelectric project. A few years ago a local group convinced the hydro company and government to provide passage and they started a reintroduction via adult transfers, it is early days yet but they have seen both smolt leaving the system and adults returning (albeit in modest numbers).
- Badges
- Science method
- Similar topics
- Mathematics
- Statistics
- Statistical Techniques
- Meta-Analysis