2017 Nof Salmon Forecasts

Discussion in 'Saltwater' started by Smalma, Jan 7, 2017.

Tags:
  1. Jim Wallace

    Jim Wallace Smells like low tide.

    Joined:
    Jan 23, 2004
    Messages:
    6,554
    Likes Received:
    1,297
    Location:
    Cranberry Country...a glorified coastal swamp!
    In my experience, La Nina and/or neutral ocean conditions, with prevailing northerly or northwesterly winds helping to maintain the coastal up-welling of cold, nutrient-rich water, supplies the food chain from the bottom up. Hopefully, we'll have plenty of herring and other bait fish in the coastal waters this year.
     
    Matthäus likes this.
  2. Smalma

    Smalma Active Member

    Joined:
    Dec 12, 2004
    Messages:
    3,926
    Likes Received:
    2,809
    Location:
    Marysville, Washington
    DimeBrite

    Thanks for posting those links; am familiar with them as I came across them in my research last year

    A word of caution using the smolt numbers and expected ocean conditions to forecast this years returns is exactly the path that the co-managers when down last year and we know how that worked out. I believe it when a wry based on the expected ocean conditions. At this time last year the ocean conditions were still about the same as they were the year before and the forecasts reflected that condtion. Thankfully it appears that the ocean conditions began turning around about the time the NOF discussions were on going resulting in much more favorable conditions for the rest of the spring and summer and appears to continue into 2017. The end result is it appears that the actually returns may have been 4 or 5 times what would have been expected based on the forecasts. I am expecting the actual smolt to adult survival on a basin like the Snohomish will ultimately end up around 5%. To put that number in some context take a look at appendix C of the 2012 coho modeling paper for the South Fork Skykomish.

    The relevant wild smolt numbers for this year's forecast are from the 2016 outmigration which will produce the bulk of the adult coho returning this year. Have not heard an "official" smolt count as of yet. Will try to track down those numbers in the next couple weeks. That said figure 3 of the 2012 report helps to provide some insight into what the wild coho smolts may look like. As we all know 2015 was an extreme drought year for the region; the 1987 year in figure 3 had a similar drought (though some claim that 2015 was worst). From figure 3 it looks like we can expect that the freshwater survival of the coho in the rivers in 2015 are likely to be approximately 1/2 of "normal". Of the top of my head normal wild coho smolts numbers for the Skagit system is in the 1.0 to 1.1 million and the Snohomish around 1.6 million.

    The "unofficial" word on this years wild smolt numbers I have heard is that they were about 1/2 of normal or about what would be predicted from figure 3. That matches what I saw last fall and this winter on the Skagit sea-run cutthroat and bull trout. The numbers of first time returning fish (that were smolts in 2016 just like the coho) were down substantially from "normal"; 1/2 or less for the cutthroat and even lower for the bull trout.

    The good news on the smolt front is that the numbers of hatchery smolts were "normal".

    The other piece of information needed for a forecast is an assessment of the expected marine survivals to apply to the smolt numbers. Will it be similar to what was seen or if better how much better. As we saw in 2016 the timing of any ocean survival changes can be critical in accuracy of any forecast. Interested in what you think what that ocean survival may be like.

    Curt
     
    Bagman likes this.