Lake information report

Name: FLORENCE

Nearest Town: CAMBRIDGE Primary County: Isanti Survey Date: 06/17/1991 Inventory Number: 30-0035-00

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Public Access Information

Lake Characteristics

Fish Sampled for the 1991 Survey Year

Length of Selected Species Sampled for All Gear for the 1991 Survey Year

Fish Stocking Activity

Fish Stocked by Species for the Last Ten Years

Fish Consumption Guidelines

No fish consumption guidelines are available for this lake. For more information, see the "Fish Consumption Advice" pages at the Minnesota Department of Health.

Status of the Fishery (as of 06/17/1991)

AS NOTED EARLIER IN THE SURVEY, FLORENCE LAKE EXPERIENCE PARTIAL WINTER KILLS FROM TIME TO TIME. FOLLOWING SUCH EVENTS, THE FISH POPULATIONS HAVE RESPONDED SPORADICALLY. WHEN COMPARING FISH POPULATIONS TO PREVIOUS SURVEY CATCHES, TI SHOULD BE TAKEN INTO CONSIDERATION THE RESPONSE OF FISH POPULATIONS TO THE LOW WINTER DISSOLVED OXYGEN LEVELS IN THE LAKE. THE DIFFICULTY IN ALL OF THIS IS THAT FISH MIGRATION (UPSTREAM AND DOWNSTREAM) PLAYS AN IMPORTANT ROLE TO THE FISH POPULATION IN FLORENCE LAKE. THE LAST LAKE SURVEY ON FLORENCE LAKE HAPPENED TO FALL ON THE SAME YEAR A PARTIAL WINTERKILL OCCURRED (1986). SINCE 1986, WINTER DISSOLVED OXYGEN RECORDS HAVE NOT INDICATED SERIOUS WINTERKILL PROBLEMS, EVEN DURING THE LATE 1980'S DROUGHT PERIOD WHEN THE LAKE LEVEL WAS VERY LOW. IN JUNE, 1991, POPULATION ASSESSMENT WAS CONDUCTED ON FLORENCE LAKE. TO DETERMINE THE STATUS OF THE FISH POPULATIONS, THREE GILLNETS AND FOUR TRAPNETS WERE SET AND THREE SHORELINE STATIONS WERE SEINED. BASED ON THE RESULTS OF THESE EFFORTS THE STATUS OF THE FISH POPULATIONS COMPARED TO LAKES OF THE SAME LAKE CLASSIFICATION STATEWIDE ARE DESCRIBED. THE NOP NET CATCH (8.33/ SET) WAS SLIGHTLY ABOVE THE PREVIOUS SURVEY CATCH (7.67/SET). THIS WAS HIGHER THAN THE STATEWIDE MEDIAN CATCH (6.58/SET) AND FALLS WITHIN THE FIRST AND THIRD QUARTILES, 2.92/SET AND 13.25/SET, RESPECTIVELY. THE NOP CAPTURED RANGED FROM 14.0 TO 35.9 INCHES WITH A MEDIAN LENGTH GROUP OF 19.0- 19.9 INCHES. THE MEAN WEIGHT WAS 2.05 POUNDS WHICH IS SLIGHTLY BELOW THE STATEWIDE MEDIAN WEIGHT FOR NOP OF THIS LAKE TYPE (2.20 POUNDS). AGE ANALYSIS DETERMINED THAT CAPTURED FISH WERE FROM ONE TO SEVEN YEARS OLD. AVERAGE BACK- CALCULATED LENGTHS FOR EACH AGE CLASS WERE TYPICAL OF NORMAL GROWTH RATES THROUGHOUT THE STATE. SEINE HAULS CAPTURED 3 YOUNG-OF-YEAR NOP. THE WAE NET CATCH (1.00/SET) WAS THE HIGHEST CATCH EVER RECORDED DATING BACK TO THE INITIAL SURVEY IN 1955. UNTIL 1991, ONLY ONE WAE WAS CAPTURED BY GILLNETTING (1982) FROM ALL OF THE SURVEYS. THIS 1991 CATCH WAS BELOW THE FIRST QUARTILE (1.25/ SET). THE THREE FISH CAPTURED RANGED FROM 18.0 TO 21.9 INCHES. THE MEAN WEIGHT WAS 3.33 POUNDS WHICH IS HIGHER THAN THE STATEWIDE MEDIAN WEIGHT FOR WAES OF THIS LAKE TYPE (2.17 POUNDS). AGE ANALYSIS DETERMINED THE FISH TO BE THREE AND FIVE YEARS OLD. AVERAGE BACK-CALCULATED LENGTHS FOR EACH AGE CLASS SHOWED GROWTH RATES FASTER THAN NORMAL GROWTH RATES THROUGHOUT THE STATE. AS MENTIONED EARLIER, THEIR PRESENCE IS MOST LIKELY DUE TO MIGRATION.

For more information on this lake, contact: Area Fisheries Supervisor PO Box 398 306 Power Ave N Hinckley, MN 55037 Phone: (320) 384-7721 Internet: Hinckley Fisheries E-Mail: Hinckley.Fisheries@state.mn.us	Lake maps can be obtained from: Minnesota Bookstore 660 Olive Street St. Paul, MN 55155 (651) 297-3000 or (800) 657-3757 To order, use D0100 for the map-id.
For general DNR Information, contact: DNR Information Center 500 Lafayette Road St. Paul, MN 55155-4040 TDD: (651) 296-6157 or (888) MINNDNR Internet: www.dnr.state.mn.us E-Mail: info.dnr@state.mn.us	Turn in Poachers (TIP):     Toll-free: (800) 652-9093