ON GRAYS HARBOR CHINOOK OVERHARVEST

ON GRAYS HARBOR CHINOOK OVERHARVEST

I thought this might help those ( & myself ) who wondered what exactly the NOAA over fished designation means for Grays Harbor. I dug this up in a Public Document Request so from a agency staffer is the thought on what it meant legally. A bit of technical reading but these are the best I can do at the moment. 

What this means is the NOAA and the Council (PFMC) (They) have determined that overfishing is occurring but the stocks are not in an overfished status at this time. They determined that a stock is currently being overfished using Maximum Fishery Mortality Threshold (MFMT). For Grays Harbor fall Chinook, the MFMT is 63%. That is, if overall fishing mortality (all fisheries) exceeds 63% the stock is considered to be experiencing overfishing, see EXCEL file. It is not concerned "Overfished", which is Maximum Stock Size Threshold (MSST). MSST is currently defined as half Stock maximum sustainable yield (Smsy), or 13,326 x 0.5 = 6,663.

Below is what actions are taken is a stock is determined to be experiencing overfishing, this is from the Amendment 16 of the PFMC's Fisheries Management Plan:

2.2.13.1 Overfishing
The STT will report postseason exploitation rates in the annual SAFE document, and when overfishing occurs, the Council shall:
1. notify the NMFS NWR administrator of the STT’s findings; 2. direct the STT to assess the mortality rates in fisheries impacting the stock of concern and report their findings; 3. immediately take action to ensure Council area fisheries are not contributing to overfishing, and; 4. notify pertinent management agencies of the stock’s status and the contribution of various fisheries to the total exploitation rate.

 

This is a little more in-depth.

Grays Harbor Fall Chinook:

Grays Harbor fall Chinook spawner escapement goal was reevaluated and changed in 2014.  The new natural spawning escapement goal is 13,500 naturally spawning Chinook for Grays Harbor with 9,880 for Chehalis River and 3,620 for Humptulips River.

The Grays Harbor fall Chinook spawner escapement goal was 14,600, 12,364 Chehalis River and 2,236 Humptulips River.  This goal was adopted in 1979 and was based on available spawning habitat and a spawning density of 36 fish per mile.  A level of 24 fish per mile was used for the mainstem Chehalis River and all tributaries upstream of Cedar Creek, reflecting lower productive potential.  This goal is defined as a natural spawning escapement goal.

The Chinook Technical Committee (CTC) is to review the biological basis for Chinook salmon management objectives under the Pacific Salmon Treaty (PSC, 2009), Chapter 3, Section 2. (b) (iv), The CTC shall “…evaluate and review existing escapement objectives that fishery management agencies have set for Chinook stocks subject to this Chapter for consistency with MSY or other agreed biologically-based escapement goals and, where needed, recommend goals for naturally spawning Chinook stocks that are consistent with the intent of this Chapter…”.  The abundance-based management regime for Chinook salmon established by the 2008 Pacific Salmon Commission (PSC) is intended to sustain production at levels associated with maximum sustained yield (MSY, measured in terms of adult equivalents) over the long term.  Therefore, the escapement goal for Grays Harbor fall Chinook was reevaluated based on spawner recruitment analysis.

The reevaluation of the Grays Harbor fall Chinook spawner escapement goal occurred in 2014.  Three spawner-recruit functions were considered (Shepherd, Beverton-Holt, Ricker), and the Ricker model was identified as being the most appropriate form for both the Chehalis and Humptulips datasets.  Brood years 1986 to 2005 were used in the analyses.  In all analyses, parent generation escapement (i.e., spawners) includes both natural- and hatchery-origin fish spawning naturally.  Spawner recruitment, biological based natural spawning escapement goals were developed for Chehalis and Humptulips rivers.  Based on the Ricker analysis model, a Chehalis River fall Chinook natural spawning escapement goal of 9,880 was proposed and 3,620 for the Humptulips River.  A harbor-wide natural spawning escapement goal of 13,500 was proposed.

On March 18, 2015 posted in the Federal Register Vol. 80, No. 52, NMFS proposes updates to management reference point values for Grays Harbor fall Chinook as recommended By the Pacific Fishery Management Council (Council) for use in developing annual management measures beginning in 2015.  These management reference point values are conservation objectives to provide necessary guidance for fisheries management within the guidance of the Magnuson-Stevens Fishery Conservation and Management Act.  There are four management reference points established in Federal Register V. 80:

  1. 13,326 natural area spawners for Grays Harbor (9,753 Chehalis, 3,573 Humptulips) goals.

  2. Smsy 13,326 natural area spawners.

  3. Maximum Fishery Mortality Threshold (MFMT, generally equal to FMSY), total exploitation rate of 63%.  Management all fishery exploitation to 63% or less.

  4. Minimum Stock Size Threshold (MSST, Smsy * 0.5), 6,663 natural area spawners (13,326 * 0.5 = 6,663.  If natural area spawners drop below 6,663, stock considered “over fished”.

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