Let's take a look at outmigration for spring/summer and some of the fall chinook in the Snake River Basin. If you wonder where I got the numbers, here is the report from NOAA last November. I'll also include it below.
NOAA estimated that we released 15,762,755 hatchery spring/summer chinook smolts into the Snake River Basin above Lower Granite Dam (the first of eight dams an outgoing smolt from Idaho waters would have to cross to get to the ocean). Of those releases, 14,616,514 came from hatcheries in Idaho and 1,146,241 came from hatcheries in Oregon. They then discussed the difficulties in estimating fall chinook due to the variations in when they might decide to leave. Nevertheless, they did post up some fall chinook numbers in that report. Essentially, they cut to the chase and said 429,240 fall chinook arrived at Lower Granite Dam, which is different than the total hatchery release numbers they gave for spring/chinook in that they only looked at those arriving at the dam. There's nothing untoward about that, I am simply pointing it out so that you follow.
NOAA also extrapolated the number of wild spring/summer chinook smolts and they came up with a different type of number than you see for those raw hatchery release numbers but the same kind of number they had for fall chinook we just discussed in the previous graph. They arrived at 1,367,581 wild smolts arriving at Lower Granite Dam, which is different than those released smolts numbers above the dam.
They then calculated the number of hatchery smolts that arrived at Lower Granite Dam, which was 10,171,808 spring/summer hatchery smolts plus the 429,240 fall chinook smolts for a total of 10,601,048. Those arriving hatchery fish plus the arriving wild smolts (1,367,581) are then added together to get to 11,968,629 smolts arriving at Lower Granite Dam. The percentage of wild fish at the dam was 11.43 percent of the total.
Now, we can make some pretty solid assumptions based on these numbers, at least the numbers for hatchery spring and summer chinook. We have a known number of release and a known number of arriving at dam. So, we had 15.76 million released and 10.17 million arriving at the dam. We lost a little more than a third (35.6%) of the hatchery smolts between their various release points in Idaho and eastern Oregon and Lower Granite Dam.
Remember this is 2014 and not the terrible water year that is this year 2015. We lost a third of the hatchery fish before they got to the dam, an interesting question I would like answered is how many of those die in the reservoir, versus how many die in the rivers above the dam? It's a good question. The answer of which should be pretty easily obtained with all the gadgets we stick in these fish for that very purpose. I am sure that answer is out there, I just haven't run across it in a manner that would be in context with these numbers. The takeaway here is that we lose a third of those hatchery spring and summer chinook smolts before they get to Lower Granite Dam. How much of that carnage is due to Lower Granite Reservoir, I do not know. How much of that loss is due to various risks within the rivers above the dam and reservoir, I do not know. We don't know how many wild smolts we lost in the rivers and reservoir, we only have the number of arriving wild smolts. We also don't know do to variations in when the fall chinook decide to leave how to figure out how many of those we lose between the rivers and reservoir above the dam.
The report has a lot more information in it than I am going to go into here, but I thought I would throw in some of the other numbers I noticed in the chinook portion of the report. The report also covers coho, sockeye and steelhead.
2.8 million Snake River ESU fish were transported by barge from Lower Granite to below Bonneville Dam, of those 807,720 were wild smolts. A total of 7,154,617 Snake River unlisted and listed fish counted at Bonneville Dam. It appears, using rough math, as though we lost about 4.8 million more Snake River smolts between Lower Granite and Bonneville dams. I am simply subtracting the total Snake River fish count at Bonneville from those arriving at Lower Granite Dam. I could have missed an important nuance in the numbers, so if I have and someone spots it, please let me know. Using that method, we lost 40 percent of the smolts in the hydropower corridor.
We can never come to an exact number due to not knowing the exact number of wild smolt production and also not knowing a solid, reliable release to outmigration number for hatchery fall chinook. So please recognize the 35.6 percent loss above the dam was a solid number from spring and summer hatchery releases to the number of spring and summer hatchery smolts arriving at the dam and this latter number is merely a percentage of the number of fish (wild and hatchery) lost between Lower Granite and Bonneville dams, which is why it is a higher percentage, but actually a smaller total number of fish lost. We do however, have a body count that make those Arnold and Sylvester movies seem tame. We've now lost at least 10.39 million fish and we are still 145 miles from the Pacific Ocean. A rough percentage of lost fish at this point would be roughly 66 percent, though if we knew the release numbers for outmigrating fall chinook and the actual smolt production number in the wild that percentage would likely be lowered somewhat.
Now I want to get away from this 2014 NOAA memo on outmigration and look at something completely different. Snake River Spring and Summer Chinook Salmon-The Choice for Recovery, go there and read it if you want that is why I placed a link to it. I'll share it below, too, in case that link dries up someday.
This second report notes that the runs were declining in the Snake River after the construction of Bonneville (1938), McNary (1953), The Dalles (1957) and Ice Harbor (1961) dams. We then added John Day (1968), Lower Monumental (1969), Little Goose (1970) and finally Lower Granite (1975) dams.
Here you will see that when there were three Columbia mainstem dams and only one lower Snake River dam (1962-1967) we had a smolt to adult return rate (SAR) of 4 percent. That SAR is smack dab in the middle of the recovery range of 2-6 percent. SARs decreased dramatically as each new dam came online, this report stated. The SAR dropped to 3.5 percent with the completion of Lower Monumental Dam in 1969. With the completion of Little Goose Dam in 1970 the SAR dropped to 3.2 percent. Then by 1972 the SAR dropped to 0.8 percent. This is before we added Lower Granite Dam.
Now, I want to point out yesterday's post, in 2014 we had a fairly decent SAR if you count the hatchery fish, but that number is marred first because you can't count all the hatchery fish and again we don't have solid number on wild smolt production to come up with a really good SAR for the actual endangered fish. But no matter how you slice it, the SAR was still short of recovery's lowest bar of 2 percent. If that was simply a SAR for wild fish, it would far below that lowest bar.
So we are not lacking in effort, when you consider all the smolts we produce at hatcheries, all the work we do to mark these fish and place electronics in them so they can be counted and identified at various spots along their journey. We don't lack in effort or in our zeal to kill virtually anything that might eat a salmon or steelhead, and we still come up short even when we add in the hatchery fish returns during what is considered a good year in these waning days of the Snake River Basin wild salmonids.
On the other front, the costs of keeping these dams now far outweigh any benefit derived from them and we have tripled the energy-producing capability of these four lower Snake River dams with wind energy in the Pacific Northwest. Barge traffic is shrinking at incredible rates, and all the other arguments for these dams are sideshows at best and hardly a reason to continue marching Snake River Basin salmonids to their extinction.
Fisheries biologists in the Pacific Northwest largely agree that removing the four lower Snake River dams is the one thing we can do to ensure wild salmonid recovery in the Snake River Basin. We just had 70,000 people sign a petition to have those deadbeat dams removed delivered to the president and on October 3 you can be a part of the Free the Snake Flotilla, go to that link and register and show up and show your support for wild salmonids of the Snake River Basin.