Patricia M. Dieter Charles P. Madenjian Benjamin S. Leonhardt Sofia A. Silvis 20250701 tabular digital data Reston, VA U.S. Geological Survey [(Author's Name)(Author's ORCID)(Author's Affiliation)]: [(Patricia M. Dieter)(0000-0003-1686-2679)(U.S. Geological Survey, Great Lakes Science Center)]; [(Charles P. Madenjian)(0000-0002-0326-164X)(U.S. Geological Survey, Great Lakes Science Center)]; [(Benjamin S. Leonhardt)(0000-0002-7140-4227)(U.S. Geological Survey, Great Lakes Science Center)]; [(Sofia A. Silvis)(0000-0003-0839-4983)(U.S. Geological Survey, Great Lakes Science Center)] https://doi.org/10.5066/P138MJQ9 Annual spring (May) and fall (late October through early November) gillnet assessment surveys were conducted by researchers at the USGS Great Lakes Science Center (GLSC) in northern Lake Michigan, including the Northern Refuge, between 1998-2024. Total length, weight, sex, maturity, and sea lamprey wounds were recorded for each lake trout and burbot caught in the gill nets. Lake trout were aged: (1) by decoding information on an extracted coded wire tag; (2) using fin clip information; or (3) enumerating annuli on a maxilla bone. Burbot were aged by enumerating annuli on an otolith. Catch of both lake trout and burbot have been recorded for each of the gill nets that have been set. Restoring a self-sustaining population of lake trout (Salvelinus namaycush) to Lake Michigan is a top priority for managers of the lake’s fisheries. This restoration effort has: (1) been ongoing for nearly six decades; (2) involved stocking millions of lake trout into the lake each year; (3) involved annual control of the Sea Lamprey (Petromyzon marinus) population; (4) required extensive coordination between state, federal, and tribal agencies; (5) involved regulations on lake trout harvest; and (6) required billions of dollars. The lake trout was the top native apex predator in Lake Michigan, and therefore it played a critical role in the structure, function, and stability of the lake’s ecosystem. Moreover, the lake trout population has historically supported valuable commercial and recreational fisheries. Thus, restoration of the lake trout population would accrue both ecological benefits to the lake’s ecosystem and economic benefits to human users of the lake’s resources. The Northern Refuge of Lake Michigan was established in 1985 under the auspices of the Great Lakes Fishery Commission (GLFC) to enhance the lake trout rehabilitation program. This refuge spans 2232 km2 of the northeastern section of the lake, and the refuge encompasses a portion of the Beaver Island archipelago. To facilitate the attainment of a sufficiently large spawning population of lake trout, the refuge is closed to all fishing for lake trout. The overall goal of the GLSC in the Lake Michigan lake trout restoration effort has been to better understand lake trout population dynamics in the Northern Refuge (and neighboring waters) so that fishery managers can make better informed decisions regarding the rehabilitation of the Northern Refuge lake trout population. The burbot (Lota lota) is also a top native predator in the Lake Michigan food web. Evidence has emerged that burbot represents a potential impediment to lake trout restoration in the Northern Refuge, because burbot have been shown to readily feed upon newly stocked lake trout. One goal of the GLSC is to better understand burbot population dynamics in northern Lake Michigan so that fishery managers can: (1) better understand the effects of invasive species on native fishes in northern Lake Michigan, and (2) better understand the potential role of burbot as an impediment to restoring lake trout to the Northern Refuge. 1998 2024 ground condition Complete None planned Northern Lake Michigan -87.4512 -84.6387 46.1000 44.9959 ISO 19115 Topic Category biota environment USGS Thesaurus population and community ecology aquatic ecosystems water temperature field sampling native species fish Integrated Taxonomic Information System (ITIS) lake trout Salvelinus namaycush burbot Lota lota USGS Metadata Identifier USGS:6818cdbad4be0208bc3dfeec Common geographic areas Lake Michigan Integrated Taxonomic Information System (ITIS) lake trout Longnose Sucker walleye round whitefish lake whitefish burbot Smallmouth Bass yellow perch cisco bloater rainbow smelt round goby White Sucker Channel Catfish Kingdom Animalia animals Subkingdom Bilateria triploblasts Infrakingdom Deuterostomia Phylum Chordata chordates Subphylum Vertebrata vertebrates Infraphylum Gnathostomata Superclass Actinopterygii ray-finned fishes spiny rayed fishes Class Teleostei Superorder Protacanthopterygii Order Salmoniformes salmons Family Salmonidae salmonids trouts and salmons salmons trouts Subfamily Salmoninae Genus Salvelinus chars Species Salvelinus namaycush lake trout TSN: 162002 Subfamily Coregoninae Genus Prosopium round whitefishes Species Prosopium cylindraceum round whitefish TSN: 162008 Genus Coregonus whitefishes Species Coregonus clupeaformis lake whitefish TSN: 161941 Species Coregonus artedi cisco lake herring TSN: 623384 Species Coregonus hoyi bloater TSN: 623394 Order Osmeriformes argentines smelts Suborder Osmeroidei Superfamily Osmeroidea Family Osmeridae smelts Genus Osmerus rainbow smelts Species Osmerus mordax rainbow smelt TSN: 162041 Superorder Ostariophysi Order Cypriniformes minnows suckers Superfamily Cobitoidea Family Catostomidae suckers Subfamily Catostominae Tribe Catostomini Genus Catostomus common suckers Species Catostomus catostomus Longnose Sucker TSN: 163894 Superorder Acanthopterygii Order Perciformes perch-like fishes Suborder Percoidei Family Percidae true perches perches Genus Sander pikeperches Species Sander vitreus walleye TSN: 650173 Genus Perca yellow perches Species Perca flavescens yellow perch TSN: 168469 Family Centrarchidae sunfishes Genus Micropterus black basses largemouth basses Species Micropterus dolomieu Smallmouth Bass TSN: 550562 Suborder Gobioidei gobies Family Gobiidae true gobies gobies Genus Neogobius round gobies Species Neogobius melanostomus round goby TSN: 172072 Superorder Paracanthopterygii Order Gadiformes grenadiers gadiforms cods hakes Family Gadidae codfishes true cods cods Subfamily Lotinae cuskfishes Genus Lota burbots eelpouts Species Lota lota burbot eelpout TSN: 164725 No access constraints. No use constraints. Charles P Madenjian U.S. Geological Survey, MIDCONTINENT REGION RESEARCH FISHERY BIOLOGIST mailing address

1451 Green Rd

Ann Arbor MI 48105 US 734-214-7259 734-994-8780 cmadenjian@usgs.gov Tim Desorcie, Steve Lengnick, Caleb Geister, Lynn Benes, Melissa Kostich, Steve Farha, Nikki Berry, Marty Simonson, Katie Anweiler, Joe Bergan, Lyle Grivicich, Erin Grivicich, Dylan Stewart, Kris Bunce, Shawn Parsons, Matt Dawson, Robert Stasney, Tyler Chapman, Travis Cronk, Jake Gapczynski, Mike McCann, Phil Pepper, Mark Brown, Tom Girard, Brad Briggs, Dave Paavola, Keith Peterson, Chuck Hatcher, Gary Eck, Jim Page, Jerry Ranville, Ted Eggebraaten, Dale Hanson, Ted Treska, John Netto, Jeff Holuszko, Dave Warner, Bo Bunnell, Greg Jacobs, Deirdre Jordan, Scott Koproski, Jim Harris, Nate Skop, Kris Snyder, Pat O'Neill, Eric Crissman, Chuck Bronte, and Dave Clapp made important contributions to data collection. In some years, U. S. Fish and Wildlife Service and Michigan Department of Natural Resources kindly provided their research vessels, vessel crew, and technical staff to carry out the data collection. Great Lakes Science Center U.S. Geological Survey 2022 dataset https://www.sciencebase.gov U.S. Geological Survey Project page for the full database where these data and others are collected. https://doi.org/10.5066/p9xvolr1 Charles P. Madenjian Benjamin S. Leonhardt Patricia M. Dieter Steven A. Farha 20250112 publication n/a Wiley https://doi.org/10.1111/fme.12787 Charles P. Madenjian Patricia M. Dieter Timothy J. Desorcie Stephen A. Lengnick Timothy P. O'Brien Lynn M. Benes Steven A. Farha Benjamin S. Leonhardt 20230817 publication n/a Wiley https://doi.org/10.1002/nafm.10915 Charles P Madenjian Patricia M Dieter Sofia A Dabrowski 20240114 dataset https://www.sciencebase.gov U.S. Geological Survey https://doi.org/10.5066/p13yof5y Data are recorded by experienced science staff. Unusual values were often realized during sample processing and checked right away to ensure accuracy. For each fish species, weight was plotted against total length to identify outliers and then make the appropriate corrections. For more recent years, data were checked with physical data sheets to ensure correct information was entered digitally. Data in all tables were checked to correct values that fell outside of a plausible range for each variable. We are unsure of the data checking steps for earlier years. Data are only from Northern Lake Michigan collected via gill nets. Some data are missing (e.g., coordinates in 1998) and that is further described in the Entity and Attribute section of this metadata record. The Target 7 Lake Trout Assessment Refuge surveys have been done each fall by the GLSC since 1991 except for 1994. A survey was not done that year because of the Lake Michigan Mass Balance project. Latitude and Longitude are mapped using ArcGIS to verify they are in the correct area of the lake and no points are on land. Depth data are checked against the ship logs. Charles P. Madenjian Timothy J. Desorcie 20110108 publication North American Journal of Fisheries Management vol. 30, issue 3 n/a Wiley ppg. 629-641 https://doi.org/10.1577/M09-108.1 Digital and/or Hardcopy 2011 publication date Madenjian and Desorcie, 2010 See Process Step - Target Descriptions target code 7 Schneeberger, P. Toneys, M. Elliott, R. Jonas, J. Clapp, D. Hess, R. Passino-Reader, D. 1998 publication Ann Arbor, MI Great Lake Fishery Commission http://www.glfc.org/pubs/lake_committees/michigan/lwasses01.pdf Digital and/or Hardcopy 1998 publication date Schneeberger et al., 1998 See Process Step - Target Descriptions for target 225 Charles P. Madenjian Timothy J. DeSorcie Ralph M. Stedman 199801 publication Journal of Great Lakes Research vol. 24, issue 2 n/a Elsevier BV ppg. 404-410 https://doi.org/10.1016/S0380-1330(98)70831-7 Digital and/or Hardcopy 1999 publication date Madenjian, Desorcie, and Stedman 1998 See Process Step - Target Descriptions target code 7 E.L. King T.A. Edsall 197912 publication Ann Arbor, MI Great Lakes Fishery Commission Special Publication 79-1, December 1979 http://www.glfc.org/pubs/SpecialPubs/SP79_1.pdf Digital and/or Hardcopy 1979 publication date King and Edsall, 1979 Sea Lamprey wound field guide associated with wounding data found in the Biodata csv. Stanford H. Smith Howard J. Buettner Ralph Hile 196109 publication Ann Arbor, MI Great lakes Fishery Commission Technical Report No. 2, September 1961 http://www.glfc.org/pubs/TechReports/Tr02.pdf Digital and/or Hardcopy 1961 publication date Smith, Buettner, Hile, 1961 For more information about management units, which are recorded in the Gear data table as MU. Charles P. Madenjian Timothy J. DeSorcie 199908 publication North American Journal of Fisheries Management vol. 19, issue 3 n/a Wiley ppg. 658-669 https://doi.org/10.1577/1548-8675(1999)019<0658:SOLTRI>2.0.CO;2 Digital and/or Hardcopy 1999 publication date Madenjian, Desorcie, 1999 See Process Step - Target Descriptions target code 7 Charles P. Madenjian Patricia M. Dieter Timothy J. Desorcie Stephen A. Lengnick Timothy P. O'Brien Lynn M. Benes Steven A. Farha Benjamin S. Leonhardt 20230817 publication North American Journal of Fisheries Management vol. 43, issue 4 n/a Wiley ppg. 1017-1034 https://doi.org/10.1002/nafm.10915 Digital and/or Hardcopy 2023 publication date Madenjian et al., 2023 See Process Step - Target Descriptions target code 7 William Wellenkamp Ji X. He Darren Vercnocke 20150402 publication North American Journal of Fisheries Management vol. 35, issue 2 n/a Wiley ppg. 296-301 https://doi.org/10.1080/02755947.2014.1001045 Digital and/or Hardcopy 2015 publication date Wellenkamp, He, Vercnocke, 2015 See Process Step - Laboratory Target Descriptions Upon data collection, each vessel "operation" (uniquely made up of a year, vessel, serial, and sample type) also gets assigned one or more "target codes." The purpose of target is to provide context in which the data were collected, and usually refers to the overall purpose of the survey. This data release is filtered by the "target codes" - 7, 225 - which are described below: Target 7 – Lake Trout Assessment – Refuge Author of process step: Charles Madenjian This code refers to the setting of gill nets in the fall (October - November) for spawning lake trout in the Northern Refuge of Lake Michigan. For more details on the sampling protocol, please refer to GLSC publications by Madenjian and DeSorcie (1999), Madenjian and Desorcie (2010), and Madenjian et al. (2023). 800 feet of net. 100-foot net panels repeated twice. 4 ½” – 6” in 1/2” increments. Target 225 – LWAP – Spring Gill Net Survey Author of process step: Charles Madenjian This survey involves setting gill nets in May each year for lake trout and burbot. The GLSC became involved with the spring Lakewide Assessment Plan (LWAP) survey in 2001. We use a protocol similar to the one described in Schneeberger et al., 1998. The GLSC has done the spring LWAP survey in northern Lake Michigan each year since starting in 2001. 1600 feet of net. 2 ½” – 6” in ½” increments. Repeated two times (replicate panels). Madenjian, Desorcie, 2010 Schneeberger, et al., 1998 Madenjian, Desorcie, and Stedman, 1998 Madenjian, Desorcie, 1999 Madenjian et al., 2023 1998 Laboratory Fish samples collected in the field are brought back to the GLSC lab. Lake Trout Coded Wire Tags (CWT) from stocked fish are extracted and read. The fish information such as year class is found from the Great Lakes Fishery Commission (GLFC) website (http://fsis.glfc.org/stocking/find_cwt_events/) and included in the GLSC database. We can tell the age of the fish from the CWT. In more recent years, we have been able to estimate the age of lake trout for non-CWT fish using the maxilla. See Wellenkamp, He, Vercnocke, 2015. In earlier years, the scale was used to estimate the age of lake trout. Burbot otoliths and yellow perch fin ray spines have been used to estimate ages of fishes. Wellenkamp, He, Vercnocke, 2015 2024 Data Data are collected on the boat and in the lab. These data are either directly input into a relational database or are transcribed from paper records into the relational database. Data are then queried from the database using SQL for further analysis. 2025 USGS_LM_1998-2024_gear_data.csv Comma Separated Value (CSV) file containing operation data relating to sampling with gillnets. Each row contains a unique sampling event (year-serial). LiftID can be used to connect with the Biodata csv. Producer Defined LiftID Unique identifier made up of "the data collecting agency," "the year of data collection," and "the serial assigned to that operation assigned by the captain in the pilot house log." In short, the code is made up of Agency + Year + Serial. Producer Defined Text. Alpha-numeric code. LAKE Lake name where data were collected. Producer Defined Michigan Lake Michigan Producer defined AGENCY Agency who collected these data. Producer Defined USGS U.S. Geological Survey, Great Lakes Science Center Producer defined LOCATION Port or general location where sampling was conducted. More specific location information can be found in the transect, latitude, and longitude columns. Producer Defined Text. TRANSECT Code that represents the first or second gillnet set deployed in the same location-depth category (i.e., net replicate). Transect is only entered for LWAP (target 225) surveys. Producer Defined << empty cell >> No Data. Data not relevant for Fall surveys (target 7). Producer defined 1 First net deployed at a given location-depth. Replicate 1. Producer defined 2 Second net deployed at a given location-depth. Replicate 2. Producer defined 3 Third net deployed at a given location-depth. Replicate 3. Producer defined 4 Fourth net deployed at a given location-depth. Replicate 4. Producer defined LATITUDE Latitude where data were collected in decimal degrees. WGS84 datum. Producer Defined << empty cell >> No Data. There are a set of data from 1998 where latitude and longitude were not recorded. For these one can look at Location, MU, and GRID to understand where the data were roughly collected. Producer defined 45.253717 45.930033 LONGITUDE Longitude where data were collected in decimal degrees. WGS84 datum. Producer Defined << empty cell >> No Data. There are a set of data from 1998 where latitude and longitude were not recorded. For these one can look at Location, MU, and GRID to understand where the data were collected. Producer defined -87.21685 -85.13675 MU Management Unit Code. Also known as the statistical district. Code specific to states. Historically connected to the statistical districts connected to the commercial fisheries catch. More details about each statistical district can be found here http://www.glfc.org/pubs/TechReports/Tr02.pdf. Producer Defined << empty cell >> Where No Data, M Unit was not defined. Producer defined Alphanumeric code. GRID Grids were designated for each of the Great Lakes as a way to know approximate locations of commercial fishing gear before development of modern navigation aids such as LORAN and GPS. Each lake is divided into 10 minute grids, each cell is given a numeric identification based on row and column. A specific GRID number could include multiple Management Units (i.e., statistical districts). Producer Defined 211 616 YEAR Year of the operation of data collection. Producer Defined 1998 2023 MONTH Month number of the operation of data collection. Producer Defined 5 11 DAY Day of the operation of data collection. Producer Defined 1 31 TARGET The Target Code is the means of providing context in which the data were collected, and usually refers to the overall purpose of the survey. For more information see the process steps. Producer Defined 7 Target 7 – Lake Trout Assessment – Refuge Producer defined 225 Target 225 – LWAP – Spring Gill Net Survey Producer defined SurveyType Defined survey to distinguish the two types of surveys completed. A way to easily distinguish the time of year (spring vs. fall), and sampling methodology between surveys. Producer Defined LWAP When the Target code is 225, the survey type is equal to "LWAP." LWAP stands for "Lake-wide Assessment Plan". For more information see the process steps. This survey occurs in the spring. Producer defined Spawner When the Target code is 7, the survey type is equal to "Spawner". For more information see the process steps. This survey occurs in the fall. Producer defined GEAR All data here were collected using the gear "gill net." See the process steps for more information. Producer Defined Text. NIGHTS How many nights the net was left out to fish. Producer Defined 1 3 nights NetLength(km) The length of net used. (Note in the original database, this is collected in feet. That value is multiplied by 0.0003048 to record in kilometers for this data release). Producer Defined 0.21336 0.51816 km DepthBin Code to represent a depth category. DepthBin is only entered for LWAP (target 225) surveys. The depth categories are according to the LWAP, see Schneeberger et al. 1998 for more details. Producer Defined << empty cell >> No Data Producer defined 1 shallow depth range, 15-30 meters Producer defined 2 mid depth range, 31-45 meters Producer defined 3 deep depth range, 46-60 meters Producer defined AvgDepth(m) The average bottom depth of the lake recorded from the ship's sounder calculated from the beginning depth and the end depth of the transect or operation. Producer Defined << empty cell >> No Data. Where null depth data were not collected. Producer defined 4.2 69.95 meters Depth1(m) Bottom depth of the lake recorded from the ship's sounder at the beginning of a transect or operation. The locations of the ship's sounder or correction for hull depth may affect this value. Producer Defined << empty cell >> No Data. Where null depth data were not collected. Producer defined 3.0 65.5 meters Depth2(m) Bottom depth of the lake recorded from the ship's sounder at the end of a transect or operation. The locations of the ship's sounder or correction for hull depth may affect this value. Producer Defined << empty cell >> No Data. Where null depth data were not collected. Producer defined 4.0 82.0 meters SurfaceTemp_C Surface temperature of water. Producer Defined << empty cell >> No Data. Where null temperature data were not collected. Producer defined 1.3 16.2 Celsius BottomTemp_C The water temperature where gillnet was fishing at time of set. Producer Defined << empty cell >> No Data. Where null temperature data were not collected. Producer defined 0.0 14.4 Celsius NetMaterial Net Material Name. Descriptive name indicating the material that made up the net. Producer Defined Text. MinMesh(mm) Minimum mesh size in millimeters. Size of mesh, stretched measure, used in nets - the size of mesh determines the size of fish caught. Producer Defined 64 114 mm MaxMesh(mm) Maximum mesh size in millimeters. Size of mesh, stretched measure, used in nets - the size of mesh determines the size of fish caught. Producer Defined 152 152 mm USGS_LM_1998-2024_bio_data.csv Comma Separated Value (CSV) file containing biological data of fish caught from gillnets. Each row represents an individual fish. LiftID can be used to connect the Gear csv to represent a unique sampling event. Producer Defined LiftID Unique identifier in the Gear table made up of "the data collecting agency," "the year of data collection," and "the serial assigned to that operation assigned by the captain in the pilot house log." In short, the code is made up of Agency + Year + Serial. This code can be used to connect the Biodata csv with the Gear csv. Producer Defined Text. Alpha-numeric code. LAKE Lake in which data were collected. Producer Defined Michigan Lake Michigan Producer defined AGENCY Agency who collected these data. Producer Defined USGS U.S. Geological Survey, Great Lakes Science Center Producer defined FishID Unique identifier for each fish in the spreadsheet. This code is made up of "the data collecting agency," "the year of data collection," "the serial assigned to that operation assigned by the captain in the pilot house log," and "the system assigned unique code recorded as each fish is added to the originating database." In short, the code is made up of Agency + Year + Serial +gn_fish_id Producer Defined Text. Alpha-numeric code. Meshsize(mm) Mesh Size in Millimeters. Measurement of mesh size of net, in millimeters (stretched measure). Producer Defined 64 152 mm SpeciesName Common name for the fish species caught. For full taxonomic information see the taxonomy section of this metadata record, which is generated using ITIS (Integrated Taxonomic Information System) codes. Producer Defined Text. SpeciesNumber Code associated with the fish species name. This code is retained in the originating database. Producer Defined Numeric code. Length(mm) Total length of fish measured to the nearest millimeter. Lake Trout with length of 0 has an unknown length and weight. Producer Defined 0 930 mm Weight(g) Weight (in grams) of an individual fish from the fish counted and measured. Producer Defined << empty cell >> No Data. Data not collected where null. Producer defined 4 9320 g R_D Round or Dressed weight of the fish. Producer Defined R Round weight. Total weight of fish with everything in tact. Producer defined CWTAgency Coded Wire Tag (CWT) ID number that is usually 6-digits long. The CWT is a stainless steel micro-tag implanted into the nose of the fish. The number on the CWT allows for identification of Year Class, Strain, Stocking Location, and other information pertaining to the stocked fish which can be found on the Great Lakes Fishery Commission website http://fsis.glfc.org/stocking/find_cwt_events/. Code 70000 represents a lost CWT, 80000 represents a CWT was not found in the sample, 90000 represents a damaged CWT. Producer Defined << empty cell >> No Data. Where null no CWT was collected. Producer defined Numeric code. AGE Age of fish in years. Producer Defined << empty cell >> No Data. Age not assessed or agreed upon where null. Producer defined 2 31 years AgeStructure This field indicates the structure(s) used to determine an age estimate for the specimen. Sometimes an age structure is listed without an AGE. This can signify that an age structure was kept but an age was not determined. Producer Defined << empty cell >> No Data Producer defined Scale Scale of the fish. Rings that are formed on the scale can be used to estimate the fish's age. This is for lake trout only in this dataset. Producer defined Otolith Otolith of the fish. After preparation of the structure, annuli were read to determine an age estimation. Producer defined CWT Coded Wire Tag. See CWTAgency for more details. This is for lake trout only in this dataset. Producer defined Fin Clip One or more fins of the fish were clipped to represent the year the fish was stocked. This method was used prior to CWTs. Fins were clipped on a known 6-year rotation. For example, Left-Pectoral Right Ventral fins were clipped in 2003 and 2009, so we know the year class of those fish if we collect the fish with those fins clipped. Producer defined Maxilla Maxilla of the fish. This is for lake trout only in this dataset. This structure was generally used if the fish had no fins clipped or a CWT was missing or lost. After preparation of the structure, annuli were read to determine an age estimation. Maxilla were utilized only in more recent years. Producer defined Spine Dorsal fin spines. Used for Yellow Perch only in this dataset. After preparation of the structure, annuli were read to determine an age estimation. Producer defined None Kept A structure to determine age was not saved. This code was not always available or used; in most of the years, the field was left null/blank instead. Producer defined SexAgency Sex of fish specimen. Producer Defined 0 Sex not determined - Either it was unknown or not recorded. Producer defined 1 Male Producer defined 2 Female Producer defined MaturityAgency Stage of maturity of specimen sampled. Producer Defined 0 Unknown Producer defined 1 Immature Producer defined 2 Mature Producer defined 3 Gravid Producer defined 4 Ripe Producer defined 5 Partly spent Producer defined 6 Spent Producer defined 7 Abnormal Producer defined 16 Resorbing. For females that did not release eggs but instead are resorbing them. Producer defined FinClipAgency Code that characterizes the specific fin(s) that were clipped on the fish. Producer Defined << empty cell >> No Data. Where null fin-clip data were not collected or assumed no fins were clipped for non-lake trout species. Producer defined AD Adipose Producer defined ADLV Adipose-left ventral Producer defined RV Right ventral Producer defined D Dorsal Producer defined ADLP Adipose-left pectoral Producer defined NC No clip. This is assumed to be a wild, naturally produced fish rather than stocked from a hatchery. However, there are some cases were no fin is clipped, but a CWT is present. This could be from missing the clip in the hatchery or a regrowth of the fin. Producer defined LV Left ventral Producer defined ADRV Adipose-right ventral Producer defined ADRP Adipose-right pectoral Producer defined RP Right pectoral Producer defined LP Left pectoral Producer defined LPRV Left pectoral-right ventral Producer defined RPLV Right pectoral-left ventral Producer defined LPLV Left pectoral-left ventral Producer defined RPRV Right pectoral-right ventral Producer defined LPRP Left pectoral-right pectoral Producer defined ADLPRV Adipose-left ventral-right ventral Producer defined A1-A3 Total wound count of sea lamprey wounds of the classification type A1-A3. Wounds are classified by the “Illustrated Field Guide for the Classification of Sea Lamprey Attack Marks on Great Lakes lake trout” by King and Edsall, 1979. GLFC Spec. Pub. 79-1. Producer Defined 0 3 count A1 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 2 count A2 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 2 count A3 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 3 count A4 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 3 count B1 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 2 count B2 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 2 count B3 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 2 count B4 Number of sea lamprey wounds of this classification type. See King and Edsall (1979). Producer Defined 0 3 count U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P138MJQ9 No fees. 20250701 Great Lakes Science Center mailing address

1451 Green Rd

Ann Arbor MI 48105 US 734-994-3331 GS_ASK_GLSC@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999