WATCH: Salmonopoly [Marine Harvest & WWF]
http://www.wrongkindofgreen.org/2017/01/06/watch-salmonopoly-marine-harvest-wwf/
http://www.wrongkindofgreen.org/2017/01/06/watch-salmonopoly-marine-harvest-wwf/
I posted a link to the State of the Ocean 2015 back in November. Here is a link to that post.
SALISH SEA COHO SALMON DECLINES – IS THE PROBLEM IN THE OCEAN OR FRESH WATER?
There is a paper in this pdf that looks at this question on page 209. It looks at Black Creek where they count smolts and returning adults. The takeaway is to look for the ratio of smolt to adult and that will tell you what is happening. I volunteer on a river that is very close to Black Creek and I'm finding similar results. IMHO the problem is in the SOG or when they pass by the fish farms. The question is, are the fish farms 100% of the problem..... I don't think so as it appears to me that it's a case of death by 1000 cuts. There are some cuts that we can do something about and some that we cannot. The trick is to know what to do and where we can make an impact. That's one of the reasons I support getting the fish farms off the salmon migration routes as soon as possible.
http://waves-vagues.dfo-mpo.gc.ca/Library/365564.pdf
[QUOTE="Fishmyster, post:
So if you choose to believe that water chemistry, invertebrates populations and algae changes do not effect fish populations and it is all about fish farms it is your choice. I think you are being a little gullibly.
Your welcome for the link to the report. I think it's great that you are interested in trying to find answers. That's something many of us are trying to do. I just have to point out that you need to look at that graph again and this time think about the Smolt to adult survival ratio over time. This to me is the most important point of this summary of the original paper. Here is what I think is the point the authors are trying to make.Thanks guys or this report. Lots of interesting info!
Do you guys read that graph differently than me?
A little lesson for you when accepting conclusions from all these reports you keep posting. It is often the missing information that is most important.
I have no idea which rivers you are sampling but I hope that the increase in size is due to the increase in nutrients in those systems form returning pink and chum salmon.
The question I have for those rivers you speak of is if salmon farms are spreading disease how do spawning salmon return after going by salmon farms twice in their life and produce healthy offspring.
It is safe to mention that disease, bacteria and virus activity are quite different in fresh and salt water.
Again I don't know what rivers you work on so thats not much to work with.
why is it sea lice counts increase in the fall vs lower in the spring?
why are sea lice counts higher in inlets that have no farms vs lower in inlets where farms exist?
can you give us an example of where this best prawning takes place?some of the best prawning is below a fish farm where do you read they are disappearing?
how about the second question...paper for which question?
can you give us an example of where this best prawning takes place?
Your welcome for the link to the report. I think it's great that you are interested in trying to find answers. That's something many of us are trying to do. I just have to point out that you need to look at that graph again and this time think about the Smolt to adult survival ratio over time. This to me is the most important point of this summary of the original paper. Here is what I think is the point the authors are trying to make.
1980's for every 100 smolts that left the river 15 adults returned
1990's for every 100 smolts that left the river 6 adults returned
2000's for every 100 smolts that left the river 2 adults returned
It does not seem to me that we can point the finger at the freshware as being responsible for the decline when clearly the evidence is pointing to something in the saltwater environment.
Here is a link to the original paper that this data was taken from.
Abstract
Understanding the factors contributing to declining smolt-to-adult survival (hereafter “smolt survival”) of Coho Salmon Oncorhynchus kisutch originating in the Salish Sea of southwestern British Columbia and Washington State is a high priority for fish management agencies. Uncertainty regarding the relative importance of mortality operating at different spatial scales hinders the prioritization of science and management activities. We therefore examined spatial and temporal coherence in smolt survivals for Coho Salmon based on a decision tree framework organized by spatial hierarchy. Smolt survival patterns of populations that entered marine waters within the Salish Sea were analyzed and compared with Pacific coast reference populations at similar latitudes. In all areas, wild Coho Salmon had higher survival than hatchery Coho Salmon. Coherence in Coho Salmon smolt survival occurred at multiple spatial scales during ocean entry years 1977–2010. The primary pattern within the Salish Sea was a declining smolt survival trend over this period. In comparison, smolt survival of Pacific coast reference populations was low in the 1990s but subsequently increased. Within the Salish Sea, smolt survival in the Strait of Georgia declined faster than it did in Puget Sound. Spatial synchrony was stronger among neighboring Salish Sea populations and occurred at a broader spatial scale immediately following the 1989 ecosystem regime shift in the North Pacific Ocean than before or after. Smolt survival of Coho Salmon was synchronized at a more local scale than reported by other researchers for Chinook Salmon O. tshawytscha, Pink Salmon O. gorbuscha, Chum Salmon O. keta, and Sockeye Salmon O. nerka, suggesting that early marine conditions are especially important for Coho Salmon in the Salish Sea. Further exploration of ecosystem variables at multiple spatial scales is needed to effectively address linkages between the marine ecosystem and Coho Salmon smolt survival within the Salish Sea. Since the relative importance of particular variables may have changed during our period of record, researchers will need to carefully match spatial and temporal scales to their questions of interest.
http://www.bioone.org/doi/full/10.1080/19425120.2016.1161683
There is a study that confirms what you're saying ( I think) in that pdf link I posted. here is the link again.. check out page 167.
TELEMETRY-BASED ESTIMATES OF EARLY MARINE SURVIVAL AND RESIDENCE TIME OF JUVENILE STEELHEAD IN THE STRAIT OF GEORGIA AND QUEEN CHARLOTTE STRAIT, 2015
http://waves-vagues.dfo-mpo.gc.ca/Library/365564.pdf
I wonder what is going on with Burrard Inlet? From the pdf...
"Survival of smolts released into the ocean near West Vancouver had three times higher survival to the northern Strait of Georgia than smolts released in the lower Seymour River, indicating that Burrard Inlet is a mortality hotspot."
What about the green line on the graph? can you see it? The spawner- smolt ratio indicated a far greater variable from fresh water than marine! So rather than posting someone else's conclusion I would like you to explain in your own words how you figure 600 smolts per spawner down to ? has less effect than the marine survival.
I am also curios if you, AA, or FI think that chemistry or insects have any importance to fresh water smolt production??? If so to what % of influence would these factors have?