Harvest Module – Final Draft13 September, 2005
2.0Harvest
2.1Narrative describing current harvest impacts on listed species
The following sections describe the harvest impacts resulting from current, historical, and expected future fisheries. Under current impacts (section 2.2) we describe the ESA related harvest impacts limits, and average rates of harvest mortality that have occurred in recent years under the current management regimes. Current harvest is generally reduced substantially from past years. The section on historical impacts (section 2.3) provides perspective about past harvest mortality for comparison. The final section (2.4) comments briefly on expectations for future fisheries.
Salmon fisheries north of the U.S./Canada border are management pursuant to the Pacific Salmon Treaty. Fisheries south of the border are subject to applicable provisions of the Treaty as well. The current Treaty annex that defines agreed fishing regimes extends through 2008 with the exception of those that apply to FraserRiver sockeye and pink salmon fisheries that extend through 2010. Pacific coast ocean fisheries south of the U.S./Canada border are managed subject to the provisions of the Magnuson-Stevens Conservation and Management Act through the Pacific Fishery Management Council. Fisheries in the mainstem Columbia River are managed by the state, tribal, and Federal parties to U.S. v Oregon under the continuing jurisdiction of the Federal district court. The parties to U.S. vOregon most recently entered into an Interim Management Agreement for 2005 – 2007 that was then adopted by the court in May 2005. Tributary fisheries are generally managed by the states and tribes, and are generally reviewed with respect to ESA related impacts through section 7, 10, or 4(d) processes.
Salmon and steelhead from the ColumbiaRiver Basin may be caught in ocean, mainstem Columbia River, or tributary fisheries depending on their timing and distribution relative to fishery openings. Some of the listed ESUs are affected substantially by ocean fisheries, while others are subject to little or no ocean fishing mortality. All of the ESUs are affected to some degree by fisheries in the mainstem Columbia River. Characterizing harvest mortality associated with tributary fisheries is more complicated. Ocean and mainstem fisheries are assumed to affect all populations in an ESU equally (or at least all populations with a given life history type e.g., tule and bright Chinook or A-run and B-run steelhead). Because of their location, tributary fisheries generally affect one or sometimes a few populations, but have no affect on the remainder of the ESU. A fishery in the South Fork Salmon River directed at hatchery fish returning to the McCall Hatchery, for example, will have some limited affect on natural-origin populations in the area, but not the rest of the ESU. As a result, estimates of mortality to populations in tributary fisheries cannot simply be added to estimates of mortality to the ESU in the mixed stock ocean and mainstem fisheries unless it is clear that the additional impacts are population specific. Harvest mortality estimates described below therefore most often refer to impacts in ocean and mainstem fisheries, but additional comments about tributary fisheries are provided where possible.
Estimates of harvest mortality reported below account, to the degree possible, for all sources of fishing related mortality. Fishing mortality is often categorized as either direct or incidental. Direct mortality includes fish that are caught and retained. Incidental mortality includes that which occurs as a result of catch-and-release and drop off. Catch-and-release mortality occurs to a proportion of the fish that are caught and released because they are below a size limit or where release of a group of fish is required by regulation. For example, in a fishery directed at coho, Chinook sometimes must be released. Mark selective fisheries are commonly used to target marked hatchery fish, but require the release on unmarked and presumably natural-origin fish. Mortality rates associated with catch-and-release are fishery and species specific. Some additional fish may contact the gear but “drop off” before they are landed. A proportion of those fish is presumed to die as well. Ocean fisheries generally account for all sources of mortality. Recreational fisheries and mark selective commercial fisheries in the mainstem Columbia River generally account for catch and catch-and-release mortality. For nonselective commercial fisheries in the mainstem there is no associated catch-and-release mortality for target species since all the catch is retained. Drop off mortality is accounted for in some, but not all, Columbia River fisheries. Drop off is most often assumed to be 5% of the landed catch.
2.2Current impacts on listed species
Snake River Spring/Summer Chinook and Upper Columbia River Spring Chinook
The ocean fishery mortality on upriver spring/summer Chinook is very low and, for practical purposes, assumed to be zero based on the rare occurrence of CWT recoveries in ocean fisheries. Fisheries in the mainstem Columbia River are subject to a harvest rate schedule ranging from 5.5%-17% described in the 2005-2007 Interim Management Agreement. The harvest rate varies depending on the total abundance of upriver spring Chinook including the summer component of the Snake River spring/summer Chinook ESU. The harvest rate also depends on the abundance of natural-origin Upper Columbia River spring Chinook and Snake River spring/summer Chinook. The harvest rate schedule was modified slightly prior to the 2005 season to accommodate the inclusion of the summer component of the Snake River spring/summer Chinook ESU, but is otherwise the same as that used in the 2001 Interim Agreement. (Recent PIT tag information indicates that timing of Snake River summer Chinook is more similar to upriver spring run fish than the Upper Columbia River summer Chinook that are not listed and part of the Upper Columbia River summer/fall-run ESU.) Under the terms of the 2005-2007 Agreement survival may range from83%-94.5%. The observed harvest rate on natural-origin upriver spring/summer Chinook from 2000-2004 averaged 10.7% - 89% survival (from spreadsheet Table A11 in wssbatables04.xls associated with TAC 2005).
The harvest rates described above do not account for tributary harvest impacts which will be tributary specific and limited since most tributary fisheries are mark selective and/or located in terminal areas where surplus hatchery fish can be targeted.
Snake River Fall Chinook
Snake River fall Chinook are caught in fisheries from Alaska to California and are subject to significant ocean fishing mortality. NOAA Fisheries Service’s consultation standards require a 30% reduction in harvest from the 1988-1993 base period for ocean fisheries and likewise, a 30% reduction in harvest from the 1988-1993 base beriod for inriver fisheries. By combining these standards, the approximate allowable total adult equivalent exploitation rate is 54% or 46% survival. Harvest mortality in ocean and inriver fisheries has been lower than the allowable limit in recent years. The total exploitation rate for 2000-2003 averaged 44% or 56% survival. [[For this section and next several need to reference Dell’s tables
Fall season fisheries in the Columbia River are managed subject to the terms of the 2005-2007 Interim Agreement that limits harvest in the mainstem fishery to the 30% base period reduction. The 30% base period reduction in harvest rate is equivalent to an allowable harvest rate of 31.3% or 69% survival. The actual harvest rate in mainstem fisheries averaged 25% from 2000-2003 or 75% survival.
Fisheries in the mainstem Columbia River include those below Lower Granite Dam. Snake River fall Chinook are mainstem spawners so are not distributed broadly through tributary areas. There is little if any fishing in the mainstem above Lower Granite Dam. As a result, there is little or no additional harvest beyond that described above.
Lower Columbia River Chinook
The Lower Columbia River Chinook ESU includes three distinct life history types with different distributions and timing. As a result, the life history types are subject to different rates of harvest. Some populations have spring run timing. The others have fall timing, but these include populations referred to as tules and others referred to as brights. All are caught in both ocean and inriver fisheries.
Lower Columbia River spring Chinook populations are caught in ocean fisheries, and, in freshwater, primarily in tributary fisheries. There are no ESA related harvest rate limits on the harvest of the spring populations since each is supported by hatchery production and the historical natural spawning areas are blocked off. Differences in harvest between the spring populations relate primarily to tributary harvest that is managed to meet hatchery escapement goals. In recent years the average total exploitation rates for the Cowlitz, Kalama, and Lewis River spring Chinook populations have ranged from 29%-40% or 60%-71% survival.
ESA related harvest limits for tule Chinook are defined by limits on the Coweeman population that is in the Cascade ecological zone. The total exploitation rate limit for all fisheries is 42% - 58% survival. Tule populations above Bonneville are subject to additional harvest in the Zone 6 fisheries. Total exploitation rates on tule populations in the Gorge ecological zone averaged 62% in recent years - 38% survival.
LewisRiver bright Chinook are used as an indicator for bright populations in the ESU. LewisRiver brights have exceeded their escapement goal by a wide margin for 20 years. Harvest is managed to meet the escapement goal for LewisRiver bright, but, given the circumstances, harvest is limited primarily by constraints from other stocks. The 2000-2004 average exploitation rate on LewisRiver brights is 44% - 56% survival.
UpperWillametteRiver Chinook
Upper Willamette Chinook are far north migrating and subject to some ocean harvest, particularly in southeast Alaska and northern Canadian fisheries. The total adult equivalent exploitation rate in ocean fisheries from 2000-2003 averaged 11%. There are no specific, ESA-related limits on Upper Willamette Chinook harvest in ocean fisheries. The total exploitation rate for ocean and inriver fisheries combined averaged 18% from 2000-2003 – 82% survival.
All freshwater fisheries are managed subject to the terms of a Fishery Management and Evaluation Plan submitted by the ODFW and approved by NOAA Fisheries under ESA section 4(d). The total allowable harvest rate in all freshwater fisheries is 15%. However, the goal has been to keep impacts to natural-origin fish to substantially less than 15%, a goal that has been achieved primarily through implementation of mass marking and mark selective fisheries. The harvest rate in freshwater fisheries in the lower Columbia and Willamette rivers from 2000-2003 averaged 8%.
Snake River Steelhead
Few steelhead are caught in ocean fisheries. Ocean fishing mortality on Snake River steelhead is assumed to be zero. Upriver summer steelhead are categorized as A-run or B-run based on run timing and size characteristics. Non-Indian fisheries are subject to a 2% harvest rate limit on A-run steelhead in winter, spring, and summer season fisheries, and a 2% harvest rate limit on A-run and B-run steelhead in fall season fisheries. Treaty Indian fisheries are subject to a 15% harvest rate limit on B-run in fall season fisheries.
Fisheries in the mainstem Columbia River are currently being managed subject to the terms of the US v Oregon Interim Management Agreement for 2005-2007. The expected harvest rates on A-run steelhead in non-Indian and treaty Indian fisheries are 1.0% - 1.8% and 3.5% - 8.2%, respectively. The combined harvest rate on A-run steelhead is therefore expected to range from 4.5% - 10% or 90% - 95% survival.
The 17% combined harvest rate limit for B-run steelhead in fall season fisheries is the primary management constraint – 83% survival. The actual harvest rates for 2000-2003 were 1.4% in non-Indian fishery and 11.0% in treaty Indian fishery for a combined harvest rate of 12.4% – 88% survival.
Upper Columbia River Steelhead
Ocean fishing mortality on Upper Columbia River steelhead is assumed to be zero. Upper Columbia River steelhead have an A-run type life history. Harvest management constraints and harvest rates for natural-origin fish in Columbia River mainstem fisheries are therefore similar to those described above for Snake River A-run steelhead.
The expected harvest rates on Upper Columbia River steelhead in non-Indian and treaty Indian fisheries are 1.0% - 1.8% and 3.5% - 8.2%, respectively. The combined harvest rate on Upper Columbia River steelhead is therefore expected to range from 4.5% - 10% or 90% - 95% survival.
Middle Columbia River Steelhead
Ocean fishing mortality on Middle Columbia River steelhead is assumed to be zero. The Middle Columbia River steelhead ESU is comprised primarily of summer run populations, although there are two or three with winter run timing. The summer run populations have A-run type life histories. Harvest management constraints and harvest rates for natural-origin fish are therefore similar to those described above for Snake River A-run steelhead.
The expected harvest rates on summer run steelhead from the Middle Columbia River ESU in non-Indian and treaty Indian fisheries are 1.0% - 1.8% and 3.5% - 8.2%, respectively. The combined harvest rate on Middle Columbia River steelhead is therefore expected to range from 4.5% - 10% or 90% - 95% survival.
UpperWillametteRiver Steelhead
Ocean fishing mortality on UpperWillametteRiver steelhead is assumed to be zero. The UpperWillametteRiver steelhead ESU includes only winter run populations. In recent years, non-Indian mainstem winter and spring season fisheries have been managed subject to a 2% harvest rate limit on winter steelhead. UpperWillametteRiver steelhead are not caught in non-Indian summer or fall season fisheries, or treaty Indian fisheries above Bonneville Dam. The harvest mortality rate expected under current conditions is 2% - 98% survival.
Some recreational fisheries are still allowed in the Willamette and North Santiam rivers. However, these fisheries target marked hatchery fish in areas where hatchery fish are available; all unmarked (wild) fish must be released. Some mortality occurs associated with catch-and-release. The associated mortality is population specific depending on where the fisheries occur, but is expected to be less than 1.2%.
Lower Columbia River Steelhead
Ocean fishing mortality on Lower Columbia River steelhead is assumed to be zero. The Lower Columbia River ESU includes both winter and summer run steelhead populations. Harvest rates on winter run steelhead in mainstem fisheries are the same as those discussed for Upper Willamette steelhead – subject to a 2% harvest rate limit. Non-Indian fisheries in the mainstem are also subject to a 2% harvest rate limit for summer run steelhead, although the expected harvest rate under current conditions is 1%. For simplicity we assume that the harvest mortality rate to the Lower Columbia River steelhead ESU in mainstem fisheries under current conditions is 2% - 98% survival.
Harvest rates on winter and summer steelhead in tributary fisheries will be population specific depending in particular on the location and intensity of hatchery directed fisheries. Tributary fishery impacts are expected to be 5% or less (NMFS 2003, see pg 15).
Columbia River Chum
Ocean fishing mortality on Columbia River chum salmon is assumed to be zero. Non-Indian fisheries in the lower Columbia River have been limited to a harvest rate of 5% in recent years. Actual harvest rates have been on the order of 2% per year or less or 98% survival. Columbia River chum are not caught in treaty Indian fisheries above Bonneville Dam.
Lower Columbia River Coho
Lower Columbia River coho were recently listed as threatened under the ESA (effective August 29, 2005). Although NOAA Fisheries conducted section 7 conferences under the ESA for ocean and inriver fisheries in 2005, it has not yet established any long-term consultation standards.
Lower Columbia River coho are caught in ocean fisheries and non-Indain fisheries in the mainstem Columbia River below Bonneville Dam. Ocean and inriver harvest fisheries are managed using a harvest rate schedule developed by the ODFW that varies depending on parental escapement and marine survival. The allowable harvest rates vary from 0 – 57% when marine survival is high and escapement is near optimal levels. However, for 2000 – 2003 total ocean and inriver exploitation rates have averaged 14% - 86% survival.
OregonCoast Coho
OregonCoast coho are caught primarily in ocean fisheries with some limited additional mortality in tributary fisheries. Ocean and inriver harvest fisheries are managed using an exploitation rate schedule that varies depending on parental escapement and marine survival. The exploitation rate schedule sets limits for the combined ocean and inriver fisheries. The schedule allows for exploitation rates that vary from 0 – 45% when marine survival is high and escapement is near optimal levels. However, for 2000 – 2003 total ocean and inriver exploitation rates have averaged 9% - 91% survival.
Snake River Sockeye
Ocean fishing mortality on Snake River sockeye is assumed to be zero. The harvest rate on Snake River sockeye is currently limited to a maximum of 9% - 91% survival. The actual harvest rate from 2000-2003 averaged 4.5% - 95% survival.