Summary Status of Lake Trout and Lake Whitefish Populations in The
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Technical Fisheries Committee Administrative Report 2006: Status of Lake Trout and Lake Whitefish Populations in the 1836 Treaty-Ceded Waters of Lakes Superior, Huron and Michigan in 2005, with recommended yield and effort levels for 2006 A Report Submitted by the Modeling Subcommittee to the Technical Fisheries Committee A.P. Woldt (United States Fish and Wildlife Service), S.P. Sitar (Michigan Department of Natural Resources), Editors Recommended Citation formats. Entire report: Modeling Subcommittee, Technical Fisheries Committee. 2007. Technical Fisheries Committee Administrative Report 2006: Status of Lake Trout and Lake Whitefish Populations in the 1836 Treaty-Ceded Waters of Lakes Superior, Huron and Michigan in 2005, with recommended yield and effort levels for 2006. http://www.michigan.gov/documents/dnr/2006-status-report_215230_7.pdf Section: Woldt, A.P., Bence, J.R., and Ebener, M.P. 2007. Executive Summary in Woldt, A.P., and Sitar, S.P. (eds.). Technical Fisheries Committee Administrative Report 2006: Status of Lake Trout and Lake Whitefish Populations in the 1836 Treaty-Ceded Waters of Lakes Superior, Huron and Michigan in 2005, with recommended yield and effort levels for 2006. http://www.michigan.gov/documents/dnr/2006-status-report_215230_7.pdf 2 Table of Contents Executive Summary............................................................................................................ 4 Stock Assessment Models................................................................................................... 8 Recommendations and Future Directions to Improve Assessments................................. 17 Status of Lake Trout Populations...................................................................................... 23 Lake Superior................................................................................................................ 23 MI-5 (Marquette - Big Bay)..................................................................................... 23 MI-6 (Au Train - Munising) .................................................................................... 27 MI-7 (Grand Marais)................................................................................................ 31 Lake Huron ................................................................................................................... 35 MH-1 (Northern Lake Huron) ................................................................................. 35 MH-2 (North-central Lake Huron) .......................................................................... 40 Lake Michigan .............................................................................................................. 45 MM-123 (Northern Lake Michigan)........................................................................ 45 MM-4 (Grand Traverse Bay)................................................................................... 50 MM-5 (Leelanau Peninsula to Arcadia) .................................................................. 55 MM-67 (Manistee - Ludington)............................................................................... 59 Status of Lake Whitefish Populations............................................................................... 63 Lake Superior................................................................................................................ 63 WFS-04 (Marquette - Big Bay) ............................................................................... 63 WFS-05 (Munising)................................................................................................. 66 WFS-06 (Grand Marais) .......................................................................................... 72 WFS-07 (Tahquamenon Bay).................................................................................. 70 WFS-08 (Brimley) ................................................................................................... 74 Lake Huron ................................................................................................................... 81 WFH-01 (St. Ignace)................................................................................................ 81 WFH-02 (Detour)..................................................................................................... 82 WFH-03 (Drummond Island) .................................................................................. 86 WFH-04 (Hammond Bay) ....................................................................................... 91 WFH-05 (Alpena) .................................................................................................... 94 Lake Michigan .............................................................................................................. 95 WFM-01 (Bays de Noc)........................................................................................... 96 WFM-02 (Manistique)........................................................................................... 101 WFM-03 (Naubinway)........................................................................................... 104 WFM-04 (Beaver Island)....................................................................................... 107 WFM-05 (Grand Traverse Bay)............................................................................. 112 WFM-06 (Leland - Frankfort) ............................................................................... 117 WFM-07 (Ludington) ............................................................................................ 121 WFM-08 (Muskegon) ............................................................................................ 125 Appendix 1. Lake whitefish management units............................................................. 128 Appendix 2. Lake trout management units.................................................................... 129 3 EXECUTIVE SUMMARY Prepared by Aaron P. Woldt, James R. Bence, and Mark P. Ebener In August 2000, the State of models resulted in estimates of Michigan’s Department of Natural abundance and mortality which were Resources (MDNR), five tribes of the combined with growth and maturity data Chippewa/Ottawa Resource Authority for whitefish and lake trout in each stock (CORA), and United States Department or management unit to project of Interior’s U.S. Fish and Wildlife recommended yield levels (upper Service negotiated an agreement bounds) for calendar year 2006. (Consent Decree) to resolve issues of Recommended yield limits were allocation, management, and regulation obtained by either limiting mortality to a of fishing in 1836 Treaty-ceded waters maximum rate, achieving a minimum of lakes Superior, Michigan, and Huron spawning potential reduction, or (U.S. v. Michigan 2000). The Consent projecting harvest for a specified level of Decree states that mortality of lake trout fishing effort. The maximum allowable shall be regulated with yield and effort mortality rate (A) on whitefish was 65%, limits in 1836 Treaty-ceded waters. In while the maximum mortality rate on management units where the state and lake trout was either 40 or 45%. In some tribes both have commercial whitefish areas the mortality rate was not fisheries, the mortality of whitefish shall considered for lake trout, and yields be regulated with yield limits. The were instead tied to levels of fishing Consent Decree provides specific effort as part of a process for "phasing guidelines on how these yield and effort in" total mortality rate targets as limits should be calculated. A Modeling specified in the Consent Decree. The Subcommittee (MSC) of the Technical target spawning potential reduction for Fisheries Committee (TFC) was whitefish ranged from 20 to 35%. established and charged with developing Harvest limits were allocated to State the yield and effort limits required in the and CORA fisheries for each stock Consent Decree. following the percentages specified in The MSC assessed population status the Consent Decree. and mortality rates of 18 different stocks The 2006 MSC recommended of lake whitefish and nine stocks of lake harvest and effort limits for whitefish trout that are within 1836 Treaty-ceded and lake trout are provided in the waters. Where feasible, we developed attached report. However, final 2006 and fit statistical catch at age (SCAA) harvest limits for all lake trout units have models using a nonlinear modeling and not yet been finalized by the parties. statistics program (AD Model Builder, This is the first time under the 2000 Otter Research Ltd.) to estimate age- and Consent Decree that final harvest limits year-specific population abundance and have not been produced prior to the end mortality rates. In three units the of a fishing season. As a result, only available data did not allow us to MSC recommended lake trout harvest develop reliable population estimates in limits are given in this report, except in this way, and instead we have used a units where harvest limits were finalized more descriptive approach. SCAA as part of a Court Order. The MSC will 4 issue an addendum to this report in the control, should allow spawning stocks to future to include all 2006 harvest limits continue to build in MH-1. A drastic once they are finalized by the parties. decline in sea lamprey-induced mortality In Lake Superior there are self- in MH-2 is the main reason total sustaining stocks of lean lake trout, and mortality remains below target in this the SCAA models and target mortality area. Continued