2017 Chinook Abundance Index

[ericl]

http://www.adfg.alaska.gov/static/applications/dcfnewsrelease/773707350.pdf

The SEAK (SE Alaska) & NBC (Northern BC) commies will be intercepting almost 50% fewer Chinook than last year.

Last year the Abundance Index was 2.06

 

[Fisherman Rob]

For those of us sport fishing in area 19 to 22... Yay!.... I think?
Not sure what this is saying about expected returns, and how many of those migrate through those areas.

Perhaps that's what the abundance index measures, so 2.06 down to 1.27 is a 38% decline in abundance, so we have a net gain of 12% escaping Alaska?

 

[california]

For those of us sport fishing in area 19 to 22... Yay!.... I think?
Not sure what this is saying about expected returns, and how many of those migrate through those areas.

Perhaps that's what the abundance index measures, so 2.06 down to 1.27 is a 38% decline in abundance, so we have a net gain of 12% escaping Alaska?

I dont think a 38% reduction in abundance can ever be a good thing. According to the bulletin the harvest is down 108K vs last year to 154 K, which is about a 40% decline, the same as the decline in the abundance. If all of it is true there should be 40% less fish coming south vs last year. In any event your math of 12% more escaping is not accurate as the absolute reduction in abundance is a much larger number than the reduction in catch allowance , so overall escapement south will be much lower than last year.

 

[ericl]

If you look at this graph:

http://wildfishconservancy.org/imag...ome2011journalchart.jpg/image_view_fullscreen

about 50% of Chinook caught in SEAK are canadian with a large chunk being the WCVI endangered fish. Numbers (predictions) of WCVI fish are up for 2017. Predictions for the north/central BC coast are up a bit as well. The graph does not do a great job of illustrating the Northern BC troll fleet catch (Haida Gwaii) but their catch composition is probably similar to SEAK. The NBC troll fleet will have a reduced catch based on the same abundance index.

The abundance index is based on a very few sampling of all Salmon run's - Stamp/Robinson creek hatchery & Campbell river fish are part of the index. Columbia river is part of the index.
I think there are around 22 streams that are in the index. Generally streams where Chinook returns are easily measured are in the index; on the Columbia there are fish counters at all the dams. Gleaning this info is very time consuming as none of the government agencies involved in this fiasco are very forthcoming.

For your info, the SEAK, NBC, and WCVI fisheries are known as AABM fisheries (Aggregate Abundance Based Management), and the Abundance Index is established by the CTC (Chinook Technical Committee) under the PST (Pacific Salmon Treaty).

In answer to questions, Fraser river numbers except the Harrison fish are way down making area's 19-22 not good, and while total numbers are down, the WCVI fish are not getting hammered by the SEAK commies like they usually are.

NOTE: in the pie chart only 3% of the SEAK catch spawn in Alaska. Their native runs in SEAK are extinct. They only have their hatchery fish, which they mark by thermally treating a bone in their head. Many of these fish are bred to remain close to shore when maturing, giving them fish to catch commercially from Oct - May. This fishery closes down when 45,000 "treaty chinook" (any fish without the thermal marking) have been caught. These 45,000 fish are subtracted from their abundance index calculated catch for the Summer season.