Week of May 19 & 26, 2003
Highlights of the Great Lakes Fishery Commission's Lake Committee Meetings
Following are highlights of the Annual Lake Committee meetings for Lakes Erie, Michigan and Ontario. The reports for Lakes Superior and Huron will be summarized on the next posting.
The upper lake committee meetings — for Lakes Michigan, Huron and Superior— were held in Milwaukee, WI, March 17-20. The lake committee meeting for Lake Erie was held in Port Huron, MI, March 24-25, and the Lake Ontario committee meeting was held in Niagara Falls, ON, March 27-28. The Lake St. Clair session meeting was also
held in Port Huron March 25 after the Lake Erie Committee meeting. Ed.
Product Review - Mr. Twister by Mepps
Lake Erie Fisheries Review for 2002
Lake Michigan Fisheries Review
The 2002 total estimated lakewide harvest of walleye was approximately 2.4 million fish, a 17% decline from 2.9 million in 2001, and was the lowest harvest since 1978. The total harvest represented about 71% of the total allowable catch (TAC) of 3.4 million walleye and included walleye caught incidentally in commercial fisheries for other species. The sport harvest of 1 million fish was the lowest sport harvest since 1976 and represented a decline of 31% from 2001. Commercial harvest of walleye declined 5%, to 1.4 million fish in 2002, and was a continuation of a significant drop since 1998. The commercial harvest was the lowest since 1983 and only 65% of the 1975-2002 mean.
Total sport effort continued the declining trend seen since 1988 dropping 18% to 3.4 million angler hours, the lowest since 1978. Sport effort declined across all Mgmt Units with only the Michigan fishery showing an increase in 2002. Total commercial gill net effort decreased 35% to 13,515 kilometers of net with decreases in all Mgmt Units.
Sport catch-per-unit effort (CUE) showed a slight decrease in the west and east ends of the lake, but a slight increase in the central basin (Mgmt Units 2 and 3). The average sport catch rate of 0.30 fish per angler hour was 30% below the 1975-2002 mean. Commercial CUE increased substantially to 104 walleye/kilometer of net in 2002, the second consecutive year of increasing catch rates for the commercial gear, after a trend of declining Cues since the mid 1980s. The increase in 2002 represents a 96% increase over the year 2000 catch rate of 53.2 walleye/kilometer commercial CUE increases have been most pronounced in the west and west-central basins.
Age 3 walleye, the '99 year class, comprised the majority of harvests in both the sport (54%) and commercial (68%) fisheries followed by age 4, the '98 year-class, which contributed only 13% and 9%, respectively. These two year-classes comprised 73% of the harvest in Unit 1 and 74% in Unit 2, but only 43% and 30% of the harvest in Units 3 and 4, respectively.
The Lake Erie Committee (LEC) developed a Coordinated Percid Management Strategy (CPMS) to protect and rebuild the walleye and yellow perch stocks in Lake Erie. A number of indicators were reviewed which demonstrated large changes had occurred in the 1990s:
• reduced and more variable fishing success (sport and
• declining abundance
• fewer older fish
• increased reliance on juvenile fish in the harvest
• reduced survival
• geographic distribution declining in east and central
basins to a stronghold in the west
• declining growth rates
The Committee noted that walleye harvest may not have been the sole cause of the problem. Changes in walleye habitat, Lake Erie’s food web, nutrient loading, and exotic species introductions may have altered conditions that promoted exceptional recruitment historically. Excessive harvest, however, might restrict or prevent walleye recovery.
To halt these trends and promote recovery of walleye, the LEC agreed that development of a conservative total allowable catch for 2001 to 2003 would best achieve the CPMS objectives.
The reproductive success of walleye in Lake Erie has shown considerable variability from year to year. Accurate prediction of recruitment success has challenged fisheries scientists worldwide for over 100 years. In any given year, numerous random factors such as winter and spring weather conditions (temperatures, warming rates, storms, runoff, etc.) can directly affect egg survival and hatching success. Fry survival is affected by types and densities of zooplankton available, as well as by fry predator abundance. In recent times, invasions by zebra mussels and round gobies have further impacted walleye recruitment by altering spawning habitat, increasing predation on eggs and fry, and indirectly by creating shifts in the zooplankton community. The only tool available to managers is maximizing the number of spawning fish by implementing restrictive harvest strategies. More spawners produce more eggs and therefore increase the likelihood of a large hatch.
A major objective of the CPMS is to reverse declines and rebuild stocks of Lake Erie walleye. A ceiling of 3.4 million walleye, based on average recruitment in 2003 and reduced fishing mortality, was recommended. Unfortunately, age-2 recruitment for 2003 is now forecasted to be substantially below average (approx. 11.4 million fish) and for 2004 will be as weak or weaker than the record low recruitment of the '95 year class.
The walleye population in western Lake Erie is still in a precarious state. Since 1990, above average recruitment has occurred only three times in 15 years. The extremely poor recruitment of the '02 year class will further reduce the number of age 2+ walleye in 2004. Without above average reproductive success in 2003, stakeholders should expect an even lower RAH in 2005. If the recruitment patterns that have prevailed during the 1990s continue through the next 10 years, RAH levels could fall below 2 million fish annually.
If the fishery expanded and harvested the maxi-mum RAH of 3.4 million fish in 2003 (a 48% in-crease in fishing mortality), the mean expected catch (or RAH) in 2004 would decline to 2.9 million fish and the abundance age 2+ walleye would decline 35% to 16.8 million fish, painting a bleak picture for the future.
If fishing mortality is held unchanged from 2002, the mean RAH would be 2.4 million fish in 2003 and 1.7 million fish in 2004, with an age 2+ walleye population of 17.7 million at the start of fishing in 2004, again suggesting reduced potential for recovery.
A drastic 67% reduction (815,000) in fishing mortality from 2002 would result in RAH of 0.8 million fish in 2003 and 2004, with an age 2+ population of 19 million walleye in 2004, the minimum level required to prevent further declines in the walleye stock. The Walleye Task Group recommends a TAC for 2003 below the 3.4 million ceiling agreed upon by the LEC as part of the CPMS.
Recommended Allowable Harvests (RAHs in millions of fish) for Lake Erie walleye using fishery and survey data through 2002, and recruitment projections for 2003 and 2004 from recruitment regression. The RAH 2003 values presented are the CPMS ceiling value, an RAH representing fishing mortality rate (F) equal to that in 2002, and an RAH level consistent with maintaining a minimum population size of 19 million walleye in 2004.
2003 RAH F(% of 2002)
N2004 N2005* N2005**
16.8 15.3 26.3
17.7 16.5 27.5
19.0 18.6 29.6
*Projected 2005 parameters if 2005 recruitment is 50% of average recruitment since 1990 (5.5 million age 2 walleye).
**Projected 2005 parameters if 2005 recruitment is 150% of average recruitment since 1990 (16.5 million age 2 walleye).
The lake-wide total allowable catch (TAC) in 2002 was 9.333 million lbs. This allocation represented a 31.5% increase from a TAC of 7.1 million lbs in 2001.
The reported '02 harvest of yellow perch totaled 9.228 million lbs., which was a 33% increase over '01. Harvest from Mgmt Units 1 to 4 was 2.9, 4.2, 2.0 and 0.159 million lbs. respectively. Although the '02 harvest was within the lake-wide total allowable catch, TACs were exceeded by 2% in Unit 2 (Ontario), 13% in Unit 3 (Ohio) and 20% in Unit 4 (Pennsylvania and Ontario).
The distribution of harvest among jurisdictions in 2002 remained similar to 2001. Yield increased in 2002 for all jurisdictions: Ohio (26%), and Ontario (35%), and considerably for Michigan (107%), Pennsylvania (875%) and New York (63%). Ontario’s harvest increased in 2002 in MU 1 (79%), MU 2 (22%), MU 3 (19%) and MU 4 (144%).
Ontario’s reported yellow perch harvest is represented exclusively by the commercial gill net fishery. The sport harvest of yellow perch in Ontario waters is not routinely assessed.
Age and Growth
The yellow perch harvest in 2002 consisted mostly of the '98 (age 4) and '99 (age 3) year classes, with other age groups including the '96 year class contributing. Recruitment of age 2 yellow perch to the fishery was low, due in part to low selectivity but also to year class strength that was characterized as weak based on survey data. The '98 cohort was exceptionally abundant in the MU 4 harvest (64%), underscoring the differences in stock dynamics between Mgmt Units.
2003 Population Size Projection
Stock size estimates for 2003 remained high relative to the time series, and increased from 2002 in all management units. This is due to favorable recruitment of two-year-old fish from the 2001 year class, though estimated abundance of older yellow perch in 2003 is lower than 2002 in all units. Overall, yellow perch abundance increased by 8%, 23%, 41% and 19% in management units 1 to 4 respectively.
See chart below
Yield (Millions of Pounds)
RAH (Recommended Allowable Harvest)
Min. Mean Max.
Unit 1 1.609 2.443 3.278
Unit 2 2.849 3.970 5.092
Unit 3 1.853 2.735 3.616
Unit 4 special strategy: Y/R not applied
Total 6.311 9.148 11.986
The RAH for 2003 was set at 9.9 million lbs., up about 570,000 pounds over 2002. Excellent yellow perch fishing potential exists this year.
Adult abundance continues below the annual average for the 1990s. The 2002 Ohio sport harvest of just over 702,000 walleye was lower than expected, due to lower than long-term average angler effort throughout Ohio waters and poor spring weather. Only the western basin anglers had lower catch rates than the previous year. The good 2001 year class will enter the fishery this year, offering hope for improved harvest and catch rates; however, the very poor 2002 year class will not help in the future rehabilitation efforts. The daily bag limit for walleye remains at four during March and April and six for May through the following February.
Yellow perch fisheries improved again in 2002 relative to previous low years of the 1990s, owing to successful re-production in four of the last six years and reduced fishing mortality. The strong 1996 and 1998 year classes and the moderate 1999 year class were responsible for this continued increase. With poor reproduction in 2000 and good reproduction in 2001, the numbers of adult fish will be about the same in 2003 compared to a year ago. Ohio’s sport and commercial fishermen met their allotted quotas in 2002. The 30-fish daily bag limit for anglers and individual trap net quotas are still in effect for 2003.
Smallmouth bass populations, and associated sport fisheries, appear to have declined slightly after the increase observed in the late 1990s throughout Lake Erie. Fishing effort for smallmouth bass decreased in Ohio waters to the lowest seen since 1996. Catch rates declined slightly for the second consecutive year. A 5-fish daily bag limit and a 14-inch minimum length limit were implemented in 2000.
Sport fisheries for white bass have improved compared to
lows seen in the mid 1990s. Seasonal effort and catch was affected by poor weather. The successful 1996 hatch and moderate hatches in 1998 and 1999 have contributed to the sport and commercial fisheries. The very good 2001 hatch will continue this moderating trend.
Steelhead angling has improved dramatically in the open
1999 have contributed to the sport and commercial fisheries. The very good 2001 hatch will continue this moderating trend.
lake during the summer, as more anglers target
steelhead while trolling. Lake catches, at 41,347, were the highest recorded and exceptional catch rates for those seeking steelhead were observed. Tributary and lake fisheries will remain very good with continued stocking of yearling Little Manistee River (Michigan) strain steelhead.
The 2002 total sport harvest, for the private and charter boat fisheries, was 7.6 million fish and 4.7 million pounds. Yellow perch (87%) and walleye (9%) represented the majority of the total harvest in numbers. Total angler effort (4.6 million angler hours) for the two fisheries decreased 11% from 2001. The private boat fishery accounted for 92% of the harvest and 89% of the angler effort. The primary target species were yellow perch (47%) and walleye (41%) for the private boat fishery, and walleye (78%) for the charter boat fishery. A total of 861 charter guides were licensed in Ohio for 2002. This was a 2% drop from 2001 and well below the ten-year mean of 998.
The private boat harvest of 0.51 million fish was a 43% decrease from last year’s harvest of 0.90 million fish. Walleye harvest was the lowest recorded since the first year of the survey in 1975. Targeted walleye effort of 1.7 million angler hours was 33% lower than in 2001 and the third lowest since 1975.
The 2002 charter boat fishery harvest of 190,000 fish was a 26% decrease from 2001. The harvest rate of 0.47 fish per angler hour was lower than last year (0.63) and lower than the ten-year mean of 0.56.
Private boat anglers harvested 6.3 million yellow perch and expended 1.9 million targeted angler hours during 2002. Harvest and targeted effort were the highest since the mid 1980s. Harvest rates remained unchanged at 3.2 fish per angler hour from 2001.
The charter boat harvest and target angler hours increased 6% and 27%, respectively, from 2001. Harvest was the highest since 1989 and target effort since 1991. Harvest rates decreased 21% from 4.83 fish per angler hour in 2001 to 3.81 fish per angler hour in 2002. Percent of limit trips by charter anglers remained high at 42%.
The 1999 year class comprised 42% of the sport yellow perch harvest followed by the 1998 (38%) and 1996 (9%).
The private boat effort of 311,553 angler hours was a 25% decrease from 2001. The harvest of 34,458 was a 26% decrease and the lowest since 1992. As in previous years, the release rate was considerably higher than the targeted harvest rate.
The Charter boat fishery showed the opposite trend with harvest (49%), targeted effort (38%) and targeted harvest rate (41%) all increasing compared to 2001. The 1996 and 1998 year classes combined constituted 43% of the smallmouth bass harvest in Ohio’s waters. Fish of age-6 and older comprised 58% of the harvest.
The small boat harvest (-50%) and the targeted effort (-70%) both decreased compared to 2001. As in past years, very few angler trips were targeted for this species; therefore the majority of the white bass were harvested as incidental catch from anglers targeting other species. The majority of the harvest was from the '99 year class (52%) followed by the '01 year class (24%).
The 2002 estimated sport harvest of 46,623 white perch was over a 200% increase compared to 2001. Angler hours targeting white perch totaled 1,638 in 2002 compared to 0 from 2001. The 1999 (42%) and 1998 (40%) year classes comprised the majority of the harvest.
The combined private and charter boat harvest of 41,357 for 2002 was a 41% increase compared to 2001, and the highest since the stocking program began. Steelhead trout are harvested primarily from the central basin, with 46% of the catch from District 2 and 52% from District 3. Combined (private and charter) targeted angler hours decreased 35% from 2001. The harvest rate for both the private and charter boat anglers targeting steelhead trout was 0.22 fish per angler hour.
On both the Maumee and Sandusky Rivers, walleye harvest increased slightly compared to 2001. An estimated 32,889 walleye were harvested from the Maumee River, and 4,620 walleye from the Sandusky River.
The 2002 commercial harvest from Ohio waters of Lake Erie totaled 4.02 million lbs, up 16% from 2001. Trap nets accounted for 58% of the harvest and total dockside value was estimated at $2.5 million. Total seine effort has fallen steadily since 1998 and was the lowest on record in 2002.
The total allocation to the trap net fishery in 2002 was 1,438,074 lbs. With quotas filled, total harvest ranked highest since 1990.
White bass landings totaled 161,664 lbs in 2002, down from 226,664 lbs landed in 2001. The 1999 year class comprised 73% of harvest.
White perch landings totaled 269,512 lbs, up from 155,555 lbs in 2001. The 1999 and 1998 cohorts led six year classes represented in the harvest.
Whitefish landings fell to 6,539 lbs, lowest since 1993. The 1996 and 1995 cohorts led eleven year classes in the harvest of whitefish.
A total of 2.1 million lbs of "other species" were landed, accounting for 53% of the total commercial harvest from Ohio waters of Lake Erie. Carp led all other species.
The DOW stocked 411,601 age-1 steelhead trout into selected Lake Erie tributaries in 2002. The DOW initiated annual stocking into the Vermilion River in 2002. The Vermilion River received 66,199 yearling Little Manistee River strain steelhead from the Castalia State Fish Hatchery. Other annual stockings were completed in the Rocky (90,110), Chagrin (90,156), and Grand (90,131) rivers, and Conneaut Creek (75,005). An additional 75,000 were in Conneaut Creek by the PA Fish and Boat Commission.
Stocking numbers for Ohio steelhead for 2003, will be Vermilion River, 55,000; Rocky, Chagrin, and Grand rivers, 90,000 each; and Conneaut Creek, 75,000. The DOW continues to implement improvements to the Castalia State Fish Hatchery to meet annual target program demands for 400,000 year-ling steelhead trout averaging 6-9". ²
• Lake Erie has 842 (317 United states, 525 Canada) tributaries
• 21 (10 US, 11 Canada) tributaries have historical records of production of sea lamprey larvae.
• 8 (5 US, 3 Canada) tributaries have been treated with lampricide at least once during 1993-2002.
• Of these, 4 (2 United States, 2 Canada) tributaries are treated on a regular 3-5 year cycle.
• Treatment was successfully completed on 1 U.S. stream, Crooked Creek.
• Mortality of non-target organisms was insignificant.
Tributaries trapped included the Big Cr., Youngs Cr., Cattaraugus Cr. (Spooner Cr.)and Grand R.
The Tributaries with Barriers (all in Ontario) include: Little Otter Cr., Clear Cr., Big Cr., Venison Cr. (Big Cr.) Forestville Cr., Normandale Cr. and Youngs Cr. ²
An outbreak of Type-E Botulism again occurred in New York waters of Lake Erie from July through December. Fish species affected included freshwater drum, smallmouth bass, rock bass and other benthic species, including mud-puppies. Gulls, loons, mergansers and, most particularly, long-tailed ducks were the most significantly affected birds. As in past years, stomach contents of affected fish and birds often contained round goby, quagga mussels, and mudpuppies, indicating a likelihood that these species were a source of the botulisum toxin.
Warmwater Fisheries Management
Assessment trawling in 2002 found high abundance levels for YOY smelt, alewife, trout-perch, emerald shiners, round goby and yellow perch. Most notable indicators were the highest levels observed yet for yearling-and-older yellow perch and a continuation of the alternate year high abundances seen in rainbow smelt.
Assessment found abundance of the 2001 year class of walleye to be higher than average, while growth rates of younger walleye continue to be very fast. Smallmouth bass catches remained near the highest levels observed for this 22-year time series, with the age-2 and age-3 cohorts being dominant. Bass growth rates are near an all-time high. Yellow perch catches remained high, with most fish being from the '96 and '98 age classes.
Coldwater Fisheries Management
Total gill net effort collected 205 adult lake trout, representing 15 year classes in 2002, compared to 249 in 2001. The 2002 catch was dominated by ages 2, 3 and 4, while ages 5 through 10 were in low abundance. Growth rates remain excellent for all ages.
Sea lamprey wounding rates on adult lake trout declined significantly in 2002 to 3.3 wounds per 100 fish.
A total of 449,500 salmonines were stocked in New York waters of Lake Erie in 2002. In addition, 283,500 lake trout sac fry were stocked on Brocton Shoal. Yearling brown trout were stocked for the first time in many years, replacing yearling domestic rainbows.
Angler diary cooperators had another excellent year in 2001, especially for tributary anglers. Catch rates for open lake anglers averaged 3.3 hours per fish, while tributary catch rates averaged 1.6 hours per fish.
Wild, young steelhead sampling concentrated on sampling a number of small Lake Erie tributaries. A total of 10 streams were sampled in fall 2002, with Reiters Creek, Beaver Creek (2nd Gulf), and Connoisarauley Creek showing the most potential for natural production.
Forage Fish Assessment
Forage fish assessment found relatively low numbers of yearling smelt in 2002, continuing the alternate year cycle seen in smelt abundance over the past several years. In addition, round gobies continue to make up a significant component of nearshore prey fish, however, their numbers declined in 2002 for the first time since their discovery in eastern Lake Erie. Alewife were found in their highest numbers during the 11-year period of this survey.
Sport Fishery Assessment
Open lake sport fishery effort in 2002 was estimated at 341,860 angler-hours, which was the lowest estimate seen during the 15-year time series of the creel survey.
Estimated harvest of walleye was 18,378, compared to 14,669 in 2001. Smallmouth bass harvest was 11,552, which was the second lowest seen in the 15-year time series. Walleye and bass catch rates, 0.12 and 0.71 fish per hour, respectively, rank '02 fishing quality about average for these species. Yellow perch harvest of 45,863 fish was the highest seen since 1989. The overall catch rate for yellow perch was 1.28 fish per hour.
Commercial Fishery Assessment
Marketable harvest by just one commercial fisherman totaled 1950 lbs of yellow perch, 864 lbs of burbot, 668 lbs of rock bass, and 176 lbs of suckers in 2002.
The total biomass of fish harvested during 2002 is estimated at 18.7 million lbs. The peak harvest for the survey period (1985 to present) was 56.6 million lbs during 1985. Harvest averaged 41.0 million lbs from 1985 through 1992, and 21.0 million lbs from 1993 to the present, with a general downward trend. The 2001 and 2002 harvest estimates show a slight increase, primarily driven by salmonid sport harvest increases. The bulk of the reduction in harvest during the early 1990s is due to closure of the commercial alewife fishery and a reduction in chinook harvest.
Benthivore harvest is dominated by lake whitefish with the commercial fishery being the primary source. Total benthivore harvest of 3.9 million lbs during 2002 was the lowest for the 17-year period. 2002 is the first year the harvest estimate was below the target range of 4 to 6 million lbs.
The salmonine harvest of 12 million lbs during 2002 continued an increasing trend since hitting a low of 6.1 million lbs during 1992. This is the second consecutive year that harvest has reached the 10 million lb level. Salmonine forage appears to be plentiful. Chinook harvest during 2002 reached 7.4 million lbs, the highest level since 1987. Anglers enjoyed their most productive chinook fishery since the collapse in 1988. Recent cutbacks in stocking levels may have contributed to this success. Coho salmon levels were estimated at 1.8 million lbs and have increased in recent years.
Steelhead trout have decreased since record levels in 1998 (1.2 million lbs) however, they have remained stable, on average, at 1.1 million lbs since 1992. Most states have reported lower than normal harvest in rivers and streams, possibly a result of low water levels.
Lake trout harvest was the lowest during the 17-year period, at just under 1 million lbs. Only 8% of the salmonid harvest was made up of lake trout, possibly due in part to an increased availability of the other salmonid species.
The brown trout fishery has remained near average with 400,000 lbs harvested and continues to provide a supplementary nearshore fishery for many agencies.
More on Yellow Perch
Sport harvest of yellow perch has remained constant the past four years at a level of nearly 400,000 lbs since the low of 200,000 lbs in 1998. Yellow perch populations declined precipitously since the mid-1990s, due to minimal recruitment after 1988. Illinois and Wisconsin have closed seasons on sport harvest for yellow perch, while Illinois, Indiana and Wisconsin have reduced their bag limits in recent years. The 1998 year class is the predominant year class harvested in the yellow perch sport fishery on a lakewide basis.
Walleye were below the target of 200,000 to 400,000 lbs for the 17-year period, except for 1994 through 1996. This level has edged up slightly as a result of harvest in northern Lake Michigan and commercial harvest by the tribal units as part of the 2000 Consent Decree and is approaching the minimum target of 200,000 lbs.
Commercial harvest has shown a decreasing trend over the 17-year period, and lake whitefish provided the bulk of the fishery in recent years. Lake whitefish harvest in 2002 dropped to a record low of 3.8 million lbs. This is a decrease over the 2001 harvest level of 4.7 million lbs. The primary commercial harvest of yellow perch occurs in the Green Bay area of Wisconsin. During 2002, only 18,200 lbs were harvested in Wisconsin waters of Lake Michigan, Green Bay perch stocks had remained relatively strong while populations in the remainder of the Lake crashed. However, the Green Bay perch stocks are now following a pattern similar to Lake Michigan as harvest of yellow perch in Wisconsin waters of Green Bay declined for the second year in a row.
Alewife was the dominant prey fish in Lake Michigan in 2002, with an estimated lake-wide biomass of 60.526 kilotonnes (kt). Lake-wide biomasses of deepwater sculpin, bloater, slimy sculpin, and rainbow smelt were estimated at 37.183 kt, 28.252 kt, 1.875 kt, and 1.019 kt.
While bloater biomass continued its decline in 2002, alewife biomass has trended neither upward nor downward between the early '80s and 2002. The decline in bloater biomass began in 1990 and can be chiefly attributed to consistently poor recruitment from 1992 through 2002. Rainbow smelt biomass declined during '92-'97, and has remained low since 1997. Deepwater sculpin biomass has shown neither an increasing nor decreasing trend from 1990 to 2002. Although slimy sculpin abundance exhibited an overall increase between 1990 and 2000, slimy sculpin abundance was substantially lower during 2001-2002 than in 2000.
Since its establishment in the 1950s and subsequent dominance, the alewife has become a key member of the fish community. The alewife has remained the most important constituent of salmonine diet in Lake Michigan for the last 35 years and has been the focus of fisheries management issues in Lake Michigan. A commercial alewife harvest was established in Wisconsin waters of Lake Michigan in the 1960s. In 1986, a quota was implemented and the estimated alewife harvest declined from about 7,600 metric tons in 1985 to an estimated average annual incidental harvest of only 12 metric tons after 1990. There is presently no commercial fishery for alewives in Lake Michigan.
Relative abundance of adult alewives in Lake Michigan was higher in 2002 than in any other year during 1974-2002, as relative abundance was recorded at 443 fish per tow in 2002. However, most of the adult alewives caught in 2002 were relatively small. Even so, relative abundance of adult alewives, on a weight basis, did nearly double between 2001 and 2002, with abundance increasing from 6.3 to 11.5 kg per tow.
Catch of age-0 alewives decreased from 195 fish per tow in 2001 to 39 fish per tow in 2002. During the 1990-2002 time period, highest age-0 abundances of alewives occurred during 1990, 1998, and 2002.
The 1998 year-class appeared to be an especially strong one, as this year-class dominated the catch of adult alewives during 2002. Furthermore, the 1998 year-class dominated the catch of age-1 and older alewives during 1999-2001 as well.
Condition of Lake Michigan alewives decreased about 15% between the 1984-1995 and 1996-2001 time periods. Weight of a 175-mm alewife decreased from 44.7 g during 1984-1995 to 38.5 g during 1996-2001. This drop in condition may be related to the decline in Diporeia abundance during the 1990s.
Adult bloaters have decreased in abundance to only 66 fish per tow, a continuation of a trend of decreasing abundance in this species during the 1990s. The 2002 catch rate represents the lowest value since 1980. The decline in adult bloater abundance during the 1990s was expected because bloater recruitment was poor during 1992-2002. Age-0 bloater abundance has ranged from 0.1 to 3.4 fish per tow during 1992-2002, with a catch of only 0.1 fish per tow in 2002.
Adult rainbow smelt abundance decreased from 24 fish per tow in 2001 to 19 fish per tow in 2002, declined substantially from 1992 to 1997, and has remained low since 1997. Causes for the decline remain unclear. Interpretation of the long-term time series by fisheries biologists for adult rainbow smelt abundance remains difficult.
Catches of deepwater sculpins in Lake Michigan decreased to 199 fish per tow in 2002, compared with 266 fish per tow in 2001. From a standpoint of number of fish per tow, deepwater sculpin abundance has increased somewhat during 1990-2002. From a standpoint of kg of fish per tow, deepwater sculpin abundance has just increased slightly or leveled off between 1990 and 2002. Leveling off of deepwater sculpin abundance during the 1990s coincided with a leveling off of burbot abundance.
Catches of slimy sculpins in Lake Michigan increased from 34 fish per tow in 2001 to 43 fish per tow in 2002. Overall, slimy sculpin abundance showed an increasing trend during the 1990s. This increase in abundance may have actually begun in 1986, when an emphasis was first placed on stocking lake trout on offshore reefs rather than stocking lake trout in areas closer to shore in Lake Michigan.
Diporeia has dominated the diet of slimy sculpins in Lake Michigan since the 1970s. Slimy sculpins inhabit shallower waters than deepwater sculpins, and therefore slimy sculpins may be more susceptible to the decline in Diporeia abundance, which has been most drastic in the nearshore waters of the lake, compared with deepwater sculpins.
It was estimated a total lake-wide biomass of prey fish available to the bottom trawl in 2002 of 128.855 kilotonnes. Alewives, constituted 47%, deepwater sculpins - 29%, and bloaters - 22% of the total biomass.
Total prey fish biomass in Lake Michigan has shown a declining trend during 1989-2002, and this decline is mainly attributable to the tremendous decrease in bloater biomass. The current bloater biomass is at about 8% of the peak value in 1989. Total prey fish biomass did increase slightly between 2000 and 2002, due to an increase in alewife biomass. Apparently, the 1998 alewife year-class was an exceptionally large one. Nonetheless, alewife biomass declined during the 1970s, but fluctuated with no consistent trend during 1982-2002. Rainbow smelt biomass declined between 1992 and 1997, and has remained low from 1997 to 2002. Deepwater sculpin biomass has fluctuated without trend during 1990-2002. ²
Michigan DNR officials are reminding anglers that their participation is needed again this year in lakes Huron and Michigan with an ongoing trout and salmon study. DNR fisheries workers annually distribute nearly one million chinook salmon in the Great Lakes. These fish are marked with a coded-wire tag and clipped adipose fin. The tags are implanted into the snout of the fish and are not visible to the angler.
Trout or salmon with only an adipose fin missing may contain such a tag. Anglers who catch these fish are asked to record the following information: angler's name and address, species of fish, length, weight and sex of the fish, along with the date of capture and capture location.
Anglers are asked to freeze only the head and take it with the requested information to the nearest MDNR Fisheries Division office or participating drop-site location. A list of drop-sites and the tag recovery form are available on the MDNR website, www.michigan.gov/dnr .
"This research is a vital part of our effort to maintain healthy, plentiful populations of trout and salmon for Great Lakes anglers to enjoy," said DNR Fish Chief Kelley Smith. "This information has been used in selecting stocking locations and evaluating the performance of different strains of trout and salmon. Providing this in-formation will help determine the course of Michigan's fishing future."
Participating anglers will receive a letter describing the stocking history of the fish they caught and possibly a reward lure. Between 5,000 and 7,000 salmon and trout with CWTs are processed annually. Rainbow trout, lake trout, and chinook salmon accounted for the majority of fish collected for CWT processing in 2002.
For more info, contact the MDNR Charlevoix Fisheries Research Station at 231-547-2914.
Open-water fishing effort was 2,945,848 hours during 2002, 8% above the five-year average of 2,717,456. The shore and pier fisheries had a strong increase for the second consecutive year after a long-term downward trend in effort. The moored-boat fishery also showed increased angler effort over 2000 and 2001, but was still 14% below the five-year average. The ramp fishery increased 12%, while charter and stream effort were about average.
Wisconsin anglers had an excellent salmonid fishery during 2002. Trout and salmon harvest was 401,207, 31% above the five-year average. Coho and chinook salmon harvest showed the largest increases. Coho harvest was 31% above the 5-year mean, and the chinook harvest was 83% above the 5-year mean, and the highest recorded since 1987.
The estimated open-water harvest of yellow perch was 242,309 fish, a decrease from the last few years. In recent years, the yellow perch harvest has been supported almost entirely by the 1998 year class. As the aging 1998s decline in abundance, yellow perch harvest will likely continue to decline in the near future. Walleye harvest was estimated at 16,039, while smallmouth bass and northern pike harvests were 18,561 and 1,868, respectively.
See chart below
The Wisconsin DNR operates three salmonid egg collection stations on Lake Michigan tributaries. The Strawberry Creek Weir (SCW) is the primary facility for chinook salmon. Buzz Besadny Anadromous Fisheries Facility (BAFF) is a primary egg collection station for three strains of steelhead and brown trout, and serves as a backup for chinook salmon egg collection. The Root River Steelhead facility is a primary egg collection station for the three strains of steelhead, and serves as a backup for coho and chinook salmon egg collection.
In 2002 the projected salmonid egg quotas were: 3.8 million chinook salmon eggs, 2.0 million coho salmon eggs, 1.5 million steelhead eggs, and 0.8 million seeforellen brown trout eggs. The entire chinook salmon egg quota was collected at SCW in 2002.
The coho salmon return to BAFF in the fall of 2001 was 175, an all time low and is well below the eleven year average of 2,033. Approximately 0.1 million coho salmon eggs were collected.
The steelhead return to BAFF in 2002 was 379, with the majority returning in the spring as Chambers Creek and Ganaraska strains. This was the second lowest spring steelhead return and the lowest fall return since BAFF was established for steelhead egg collection. During the previous ten years an average of 1,935 steelhead have been processed each year at BAFF.
A record number of 10,439 chinook salmon were captured and examined at the RRSF in the fall of 2002. The majority of the chinook (10,011 or 96 percent) were passed upstream.
A total of 2,548 coho salmon were also examined at the RRSF in the fall of 2002. The majority of coho salmon (2,076 or 81%) were passed upstream, and 192 coho were transferred to a WDNR hatchery for holding until the fish ripened and gametes could be collected. Approximately, 0.85 million coho eggs were collected.
Steelhead return to RRSF in 2002 was 1,604. Most of these steelhead (1,303 or 81%) returned in the spring and were likely either Chambers Creek or Ganaraska strain. The steelhead returning in fall (301 or 19%) were primarily Skamania strain. Approximately 1.4 million steelhead eggs were collected at RRSF in spring 2002 and at this time the egg take from fall steelhead has not been completed.
The total reported chub harvest from commercial gill nets was 1,334,302 lbs for 2002, an increase of 24% from 2001. Commercial smelt trawlers harvested an additional 147,465 lbs incidental to the targeted smelt harvest.
The reported commercial harvest of lake whitefish duringquota year 2001-02 dropped to 1,469,626 lbs with 3.4% of the total harvest from
pound nets, 70.6% in trap nets, and 26.0% in gill nets. The total annual quota of whitefish for Wisconsin commercial fisherman has been increased four times since it was first established at 1.15 million lbs in quota year 1989-90 and is currently at 2.47 million lbs.
In 1991 rainbow smelt rules were established and the harvest quota set at 2.358 million lbs, of which no more than 830,000 lbs could be caught in Green Bay. During 1999, a new quota was established that reduced total harvest to 1,000,000 lbs, of which no more than 351,993 lbs could be harvested from Green Bay.
Commercial smelt trawlers reported catching 294,541 lbs of rainbow smelt during 2002. This reported catch was 19.8% higher than the reported 2001 harvest of 246,170 lbs. Despite the increased catch in 2002, the 2002 rainbow smelt harvest was only 54% of the average catch of the previous five years (1997-2001).
Commercial trawlers on Green Bay reported a rainbow smelt catch of 291 lbs.
The adult spawning population of walleye in the Fox River for the spring of "02 (age 3 and older; and greater than 370 mm) was estimated at 8,058 and is the lowest in sixteen years. Harvest in 2001 was less than 3% of the estimated 16,000 adult walleye in the spring of 2001. Harvest alone could not account for a 50% decline the spawning population the following year, 2002. A poor 1999 year class may also be contributing to the low abundance. It was estimated only 127 three year old male walleye were recruited to the spawning population in survey year 2002.
The walleye catch for Wisconsin waters of Green Bay was estimated at 43,000 walleye during the open water season in year 2002 down from 55,700 caught in 2001, a 23% reduction. This marks the second consecutive year showing a catch reduction.
Yellow perch abundance in Green Bay increased steadily through the 1980s and has declined since then. The population growth was fueled by the production of strong year classes in '82, '85, '86, '88, and '91. Since 1991 there has been only one moderately strong year class that appeared in 1998. The estimated total biomass of yearling and older yellow perch rose from under 1,000,000 lbs in 1980 to over 10 million lbs in 1988, and in the year 2000 of less than 500,000 lbs.
The decline in the population during the 1990s can be attributed to poor recruitment of young-of-the-year fish, as assessed in the late summer of each year. Following over a decade of good production of young fish, we have seen only one reasonably strong year class (1998) since 1991. The hopeful 1998 year class was abundant as 1 year olds in our trawl survey in 1999 and has been seen as the strongest year class through 2002. During 2001 and 2002 the majority of both the commercial and sport harvest has been comprised of the 1998 year class, 88% and 81% respectively.
Stringent harvest regulations are still in place in order to protect remaining adult yellow perch population in Wisconsin waters as well as lake-wide. Although the '98 year-class raised some hopes of rebounding, the recruitment of yellow perch following 1998 has been extremely minimal.
In S.E. Wisconsin, beach seining indicates another year of poor reproductive success, yet an improvement of 2001. Poor reproduction since 1998 is showing up as extremely weak year-classes.
Nearshore fishing opportunities for Lake Michigan trout and salmon have declined since the late 1980s due to changes in species or strains stocked, reduction in the Lake Michigan forage base or perhaps from clearer water nearshore making trout and salmon more difficult to catch. With reduced yellow perch abundance and salmon and trout moving farther offshore, anglers have requested the Wisconsin DNR to evaluate the stocking of rainbow trout to increase nearshore fishing opportunities. After receiving input on the project, Arlee strain rainbow trout were selected for the experiments study.
Kenosha, Milwaukee, Algoma, Sheboygan,, Manitowoc, and Sister Bay each received 12,000 Arlee in early 2001. In 2001 anglers harvested 1,324 Arlee. In ‘02, they harvested 1,605 Arlee. Creek-survey data is encouraging and indicates Arlee rainbows may be benefiting near-shore anglers. The experimental stocking of Arlee rainbow trout will continue to 2004. ²
MILWAUKEE – Results from a year’s worth of assessment activities on southern Lake Michigan show yellow perch continuing to struggle.
"The Perch drop is linked to food supply decline" said Scientist John Janssen. "Hypothesis points to zebra mussel as likely culprit. Zebra mussels are thought to be the reason for a crash in the population of a tiny crustacean that lives in the soft sediments that prevail on the lake bottom on the Michigan side. They are the top food of yellow perch once the perch reach 2" in length. "Yellow perch thought to be suffering from poor reproduction may actually be producing normal numbers of offspring."
Underwater surveys conducted in June 2002 indicated that yellow perch are laying eggs in good numbers – at least compared to recent years. But surveys turned up low numbers of perch hatched from those eggs, continuing a 14-year-trend of paltry year-classes interrupted by "fair" year classes in 1995 and 1998.
"We actually saw a fairly big increase in the number of egg masses we saw compared to some of the earlier egg deposition surveys, and those eggs probably hatched as they always have," says Brad Eggold, WI DNR southern Lake Michigan fisheries supervisor. "But that time between hatching and coming back to nearshore water and surviving that first winter – that seems to be doing them in. That’s the black hole."
Assessment results, Eggold and other fisheries biologists say, support continuing DNR’s ban on commercial fishing for yellow perch and a restrictive bag limit of five fish per day for sport anglers. More importantly, those results support a theory and subsequent research to help explain that "black hole" in the yellow perch life cycle.
Janssen believes wind and water currents may be blowing newly hatched yellow perch across southern Lake Michigan to where they may have a limited food supply. So, Janssen and DNR crews in mid-summer 2002 towed a large, fine mesh net behind boats to track the fates of newly hatched yellow perch. About 10 days after hatching, the young perch had drifted and were most abundant about 10 miles offshore. A few days later, the young fish were found in good numbers as far as 25 miles offshore.
"We found that 10 -12 days after hatching in Wisconsin, we were getting good numbers of fish a third of the way to Michigan," Janssen says. The young fish find themselves far from home in an environment that may have little food, perhaps as a result of growing populations of the exotic zebra mussel.
On the east side of Lake Michigan, which tends to have a soft bottom, zebra mussels eat phytoplankton, Janssen says. Phytoplankton that settle to the bottom, particularly diatoms, are the primary food of the burrowing amphipod, the main organisms young perch feed on where there are soft bottoms. Zebra mussels also may filter the water, increasing the clarity so other fish may more easily see and prey upon the young perch.
"If you get fish blown to what is a food desert, you’ve got a problem," Janssen says. "Those fish have another problem in how do they find their way back home. It could be a substantial number of them don’t." Typically, after yellow perch in Lake Michigan hatch they swim up to the surface and get caught in the currents. "After 40 or 50 days, if they’re lucky, they manage to come ashore in Wisconsin where there is rocky habitat," Janssen says. If the fish are unlucky, they get blown to the Michigan shore, where there may be a growing lack of food, presumably because of the zebra mussels.
Whatever the factors leading to the demise of young perch, the population assessments DNR and other cooperating agencies and universities did in 2002 seemed to point to the same trends visible since the mid-1990s. Young yellow perch aren’t surviving to enter the fishery; the 1998 year-class, which is mainly contributing to sport fishing opportunities, is declining fast.
Specifically, in 2002:
• DNR crews using SCUBA gear to survey spawning sites in early June found the highest number of egg masses – 573 egg masses or 11.53 per 1,000 square meters – since such sampling began in 1997. That total compares to a low of nine egg masses in 1997, and the second highest total of 223 in 2001, and likely reflects the 1998 year-class in its peak sexual maturity in 2002.
• Crews in June captured a total of 1,812 yellow perch during the spawning season, including 167 females and 1,645 males in two lifts. The number of fish and of female fish caught was down from 2001. Of the 167 females, the majority of them had spawned already, 34% were not yet ready to spawn, and 11% were ripe but hadn’t spawned.
• In 2002, DNR fisheries staff collected spines from 402 perch caught by anglers to determine the fishes' age. Of that total, 94% were from the 1998 year-class.
• Crews in August and September conducted young-of-the-year (YOY) sampling and found 1.3 yellow perch per 100 ft. of seine haul, up slightly from the last two or three years, but considerably lower than in the 1980s. For the first time this year, DNR crews also used very small mesh gill nets to do additional sampling, building an index to assess the numbers of YOY yellow perch.
•DNR winter assessments in December 2002 and February 2003 using gill nets with different size meshes hauled in only 81 fish, in some part a reflection of windy conditions in December, January and February that limited the amount of time the boat spent on the water. Again, the 1998 year-class showed up very well, with 88 percent of the fish from that year class. There were few numbers of young perch.
• Analysis of creel surveys showed that the Lake Michigan perch harvest of 97, 747 declined from 2001’s sport harvest of 133,660, but was still the second-highest since the five-fish bag limit was implemented in 1996. It was driven by Milwaukee County, which supplied two-thirds of the Lake Michigan total, and reflected the 1998 year-class.
• In order to provide additional protection to the 1998 year-class, especially mature females, the closed season was changed from all of June to May 1 to June 15, effective 2002.
"What these assessments show is that the yellow perch population is still struggling," Eggold says. "The harvest and creation of future year classes has been dependent on this '98 year class and they’re going to be age five this year. They’re still capable of spawning quite effectively.
The 2002 assessment results show perch have decreased 90% since the mid-1980s. Eggold says continuing the ban on commercial fishing and the low sport bag limit should provide the protection the fishery needs to recover, and he remains optimistic that the yellow perch population will bounce back.
"Historically, they have rebounded from very low numbers in the past," he says. "But it’s going to take a set of environmental factors to come together to produce good year classes."
• Lake Michigan has 511 tributaries.
• 121 tributaries have historical records of sea lamprey larvae.
• 63 tributaries have been treated at least once during 1993-2002.
• Of these, 32 tributaries are treated on a regular 3-5 year cycle.
• Treatments were completed successfully in all 15 scheduled tributaries.
• Bayluscide was applied during treatment of four Lake Michigan tributaries to reduce the use of TFM.
• The Days River was treated for the fifth consecutive year to prevent recruitment of larval sea lampreys into offshore areas in Lake Michigan.
• 33,349 lampreys were trapped at 17 sites in 15 tributaries during 2002.
• Estimated population of spawning lampreys was 94,037.
The 2003-2004 Guide to Wisconsin Fishing Regulations is now available. Contact the Bureau of Fisheries Management and Habitat Protection at (608) 267-7498 for more details.
These new rule changes took effect April 1, 2003, unless noted:
Trout Regulations Simplification
The entire trout regulation category system was simplified, with the changes effective March 1, 2003. Category 1 waters, those that had no minimum length limit and a 10 fish daily bag limit, were eliminated, and the number of waters listed in categories 2, 3, and 4 were reduced. This change resulted in 546 fewer waters needing to be listed in the trout regulations. The different types of special regulations, category 5, were reduced from 12 to 8, affecting 50 waters. An additional 55 waters now have special regulations. To check on specific changes, please see the Wisconsin Trout Fishing Regulations and Guide, 2003-2004.
Great Lakes Cisco and whitefish
The daily bag limit for cisco, lake herring, whitefish, and their hybrids has been changed to 10 fish in total on all Great Lakes waters.
Muskellunge in Green Bay and Lake Michigan
The minimum length limit for muskie has been increased to 50" on Green Bay, Lake Michigan and Lake Michigan tributaries in the northern muskellunge zone (north of Waldo Boulevard in the City of Manitowoc).
Yellow perch in Lake Michigan
The closed season for yellow perch has been changed to May 1-June 15 on Lake Michigan and tributaries.
Salmon in Lake Superior
The 15" minimum length limit for salmon on Lake Superior has been eliminated.
Brook trout in Lake Superior
The minimum length limit for brook trout on Lake Superior has been increased to 20" and the daily bag limit has been reduced to 1.
Unattended fishing lines
During the open-water portion of the fishing season, anglers will be required to remain within 100 yards of all their lines at all times.
The deadline for registering a sturgeon speared from Lake Winnebago system waters has been permanently changed to 1:30 p.m. on the day speared and the closed hours for sturgeon spearing have been changed to 12:30 p.m. to 6:30 a.m. the following day. This rule went into effect as an emergency rule for the 2002 spearing season.
Size and/or bag limits that differ from the statewide rules have been established on the following waters:
Bayfield County – A catch and release only season has been established for brook trout on Whittlesey Creek, the Bark River, and their tributaries.
Green Lake County –The gamefish season on Big Green Lake has been changed to the statewide open season and is now open from the first Saturday in May until March 1.
Kenosha County – The minimum length limit for bass has been increased to 18", the daily bag limit for bass reduced to one in total, and the daily bag limit for panfish has been reduced to 10 in total on Vern Wolf Lake.
Langlade County – The minimum length limit for bass on Greater Bass Lake has been increased to 18" and the daily bag limit reduced to one in total.
Oneida County – The minimum length limit for muskellunge on Clear Lake has been increased to 50".
Sawyer County – The minimum length limit for muskellunge on Moose Lake has been increased to 40". The minimum length limit for muskellunge on the Chippewa Flowage has been increased to 45". The daily bag limit for panfish on Sissabagama Lake has been reduced to 10 in total. A 14-18" protected slot limit with only one fish longer than 18" allowed has been established for walleye on Winter Lake and the Brunet River upstream from Winter Lake to the Lake Loretta dam. The minimum length limit for walleye on Black Dan, Clear, and Island lakes has been increased to 28" and the daily bag limit reduced to one.
Vilas County – The minimum length limit for walleye on Escanaba Lake has been increased to 28" and the bag limit reduced to one effective May 3, 2003.
Walworth County – A 14-18" protected slot limit with only one fish longer than 18" allowed has been established with a daily bag limit of three in total for bass on Lulu Lake.
Waukesha County – A 14-18" protected slot limit with only one fish longer than 18" allowed has been established with a daily bag limit of three in total for bass on Eagle Spring Lake.
Fisheries Review for 2002
In recent years, the Lake Ontario ecosystem has undergone dramatic changes resulting primarily from the introduction of exotic zebra and quagga mussels. In addition, improvements in wastewater treatment have reduced excessive nutrient concentrations to historic, more natural levels, thereby lowering the productive capacity of the Lake Ontario ecosystem. Surveys conducted by the U.S. Geological Survey in 2002 documented further deterioration of the abundance and distribution of the deepwater amphipod, Diporeia. This phenomenon is thought to be directly linked to the continued expansion of the range of quagga mussels into deeper waters, as is the recent concern regarding potential shifts in the abundance and distribution of the shrimp, Mysis.
The exotic round goby was first documented in the New York waters of Lake Ontario in 2001, and numerous, confirmed reports received in 2002 documented the presence of this species from the Lower Niagara River in the west to the Thousand Islands region of the St. Lawrence River in the east. The first gobies documented in a U.S. fisheries assessment program were collected by the U.S. Geological Survey Research at 55 m depth off Olcott. Also, round gobies were documented for the first time in the diets of cormorants from Pigeon and Snake Islands in 2002.
Also in 2002, a relatively small number of dead fish and birds found along the Lake Ontario shoreline tested positive for type-E botulism. While type-E botulism has caused large-scale fish and bird mortalities in Lake Erie since 1999, Lake Ontario has not yet experienced mortalities of this scale.
The effects of these changes on the fish community have not been manifested completely nor are they fully understood.
The exotic zooplankton Cercopagis pengoi was first observed in Lake Ontario in June 1998 in the Chaumont Bay area. In 2002, C. pengoi biomass peaked in late July, and was lowest in embayment habitats, and was highest in offshore habitats. Surveys suggest that a lake-wide decline in small zooplankton species/life stages occurs in Lake Ontario coincident with peak densities of C. pengoi.
Prey Fish Assessments
· Adult (age-2 and older) alewife abundance in 2002 bottom trawl surveys declined relative to levels observed in 2000 and 2001. The weight of a 165 mm alewife, as an index of adult alewife condition, was the second lowest on record. Catches of age-1 alewife in 2002 suggest that the 2001 year class will increase adult abundance in 2003 above the near record-low levels observed in 2002.
· Numbers and biomass of age-1 and older rainbow smelt in 2002 were similar to 2001, and just above the record-low levels observed in 2000.
· Slimy sculpin abundance at depths increased for the third consecutive year, however, abundance remains well below the peak observed in 1991.
· Lake-wide hydroacoustic estimates of yearling and older alewife in 1997-2002 varied between 0.4 and 1.0 billion fish. Following reduced abundance in '97 and '98, abundance increased in 1999 and 2000 due to the exceptionally strong '98 year class. Abundance in 2001 declined due to reduced presence of the '98 year class. Abundance did not decline further in 2002, presumably due to recruitment of the 2001 year class.
· Fish stocking included 1.63 million chinook salmon, 646,000 rainbow trout, 500,000 lake trout, 518,000 brown trout, and 92,000 Atlantic salmon.
· 340,000 lake trout and 167,000 brown trout were stocked offshore by military landing craft in a continuing effort to reduce predation on newly stocked fish by cormorants and predatory fish.
· Preliminary results evaluating the relative performance of shore-stocked vs. barge-stocked brown trout suggest that shore-stocked brown trout outperformed barge-stocked fish in both open lake and tributary fisheries.
· Mean weight of age-1 chinook salmon returning to the Salmon River hatchery in 2002 was the third heaviest observed since the survey begun in 1986. In contrast, mean weights of age-2 and age-3 chinook of 2002 were among the lowest observed.
· Evaluations of the performance of steelhead pen-reared at Oswego Harbor are very favorable. To date, 73 coded wire-tagged steelhead have been collected from the Oswego River, Salmon River, and the open-lake fishery. Sixty-one of the 73 returns were pen-reared fish.
Lake Trout Restoration
In 2002, a total of 8 naturally produced lake trout (72 to 391 mm total length) were caught with bottom trawls. Survival of naturally produced lake trout to the fingerling stage in summer and fall occurred each year during 1993-2002. Further, survival to older ages has also been apparent. The distribution of catches of wild fish suggests that lake trout are reproducing throughout New York waters.
Lake trout harvest reached its lowest level in 2002 with an estimated 7,319 lake trout creeled, and increased to 9,866 fish in 2001. Lake trout harvest in 2002 increased to 15,718 fish, likely due to relatively poor summer fishing success for other species. In 2002, trophy lake trout harvest represented 26% of harvested fish.
Preliminary results suggest that offshore stocking substantially enhances catches of stocked, age-1 lake trout in bottom trawl surveys.
10,350 fingerling walleye were stocked into the Lower Niagara River. Smallmouth bass abundance increased slightly from the record low, 2001 level. Three year moving average catches for smallmouth bass, walleye, and rock bass are declining, whereas three year moving average catches for yellow perch and pumpkinseed are increasing.
Following three consecutive years of decline, yellow perch abundance in Lake St. Lawrence index gill netting increased in 2002. Smallmouth bass abundance remains above the long-term average. Walleye abundance increased 66% from 2001, and is now above the long-term average.
Sport Fishery Assessment
Fishing effort on the open waters of Lake Ontario declined to a record low level in 2002 (86,401 boat trips, 2.67 anglers/boat, 5.02 hours/boat trip). The total trout and salmon catch rate for charter boats decreased slightly from 2001 to 5.33 fish per boat trip, while that for non-charter boats increased slightly. Trout and salmon fishing declined to 1.13 fish per boat trip. This represents the lowest harvest rate observed in the 18-year history of the census.
Fishing effort targeting smallmouth bass has increased significantly over the 18-year history of the census, and was estimated at 27,920 boat trips in 2002.
Data on smallmouth bass fishing in Lake Ontario were analyzed in more detail as part of the evaluation of the impacts of cormorant predation. From 1985-90, harvest rates at Henderson Harbor were nearly equal to or greater than the lake-wide average harvest rates and averaged 1.16 smallmouth bass harvested/angler hour. From 1991-2002, smallmouth bass harvest rates at Henderson Harbor, adjacent to the Little Gallo Island cormorant colony, were all below the lake-wide average. The Henderson Harbor site continues to be the only localized bass fishery that has experienced a decline in harvest rate.
· For the fourth consecutive year, cormorant population control was continued through oiling of eggs with food grade vegetable oil at the Little Galloo Island colony.
· For the first time, exotic round gobies were documented in the diets of cormorants from Snake and Pigeon Islands.
· Estimated consumption of smallmouth bass by cormorant colony in 2002 was as follows: Little Galloo island – 470,000, Pigeon Island – 10,000, and Snake Island – 90,000.
· Estimated consumption of yellow perch by colony in 2002 was as follows: Little Galloo Island – 3.29 million, Pigeon Island – 270,000, and Snake Island – 1.73 million.
· Egg oiling on Little Galloo Island reduced cormorant chick production by approximately 93%, reducing the number of cormorant feeding days by 740,000. The resulting reduction in fish consumption was estimated at 270,000 smallmouth bass and 712,000 yellow perch.
· After increasing for three consecutive years, estimated fish consumption from three Canadian cormorant colonies in the upper St. Lawrence River declined slightly in 2002 to 5.786 million fish. Total, combined consumption in 2002 included 2.75 million yellow perch, 880,000 rock bass, 920,000 cyprinids, 640,000 pumpkinseeds, and 40,000 smallmouth bass.
· Smallmouth bass abundance in the Eastern Basin remains near record low levels. In addition, harvest rates of smallmouth bass in the Eastern Basin remain below the lake-wide average.
· VHF radio telemetry tracking of double-crested cormorants from Little Galloo Island suggest from preliminary results that approximately 40% of birds that abandoned treated nests may have relocated to another nesting site in time to successfully produce young.
Commercial fishing activity in the New York waters of Lake Ontario is limited to the embayments and nearshore open waters of the eastern end of the lake. Commercial fishing gear includes gill nets, trap nets, and fyke nets. Commercial harvest is generally targeted at the following species (in decreasing order of abundance): yellow perch, brown bullhead, sunfish, white perch, rock bass, and black crappie. In 2002, six active commercials reported 41,548 lbs of fish caught, dominated by yellow perch (37,113 lbs, $43.807).
Fishing effort within the area censused April-September 2002 was estimated at 86,401 boat trips. This was a record low effort estimate among the 18 years censused, a 13.6% decrease compared to 2001, and an 11.2% decrease compared to the '97-'01 average. Compared to the peak observed in 1990, effort in 2002 was down 131,422 fishing boat trips or 60.3%. Boat angler trips in 2002 were estimated at 230,865.
Comparisons of fishing boat trips with the previous 17 years (1985-2002) show a pattern of decline in all six months and all four geographic areas.
Fishing effort targeted at trout and salmon was estimated at 52,674 boat trips, a 17.3% decrease compared to 2001, an 18.5% decrease compared to the 1997-2001 average, and the lowest trout and salmon effort estimate among the years censused. Trout and salmon anglers still accounted for 61.0% of fishing boat trips in 2002, while chinook salmon remained dominant among trout and salmon anglers.
Among anglers not seeking trout or salmon, smallmouth bass was the dominant species sought. Effort targeted at smallmouth bass was estimated at 27,920 fishing boat trips, a 10.0% decline compared to 2001, but a 1.9% increase compared to the 1997-2001 average bass fishing effort estimate.
Charter boats remained constant at about 20,000 trips per year from '89 through '91, and then declined gradually with a record low in 2002. Among boats targeting salmon and trout (S/T), the average charter harvested 3.796 salmonines per boat trip versus 0.559 for noncharters. It was estimated that charter boats fishing for S/T accounted for 58.9% of all the salmonines harvested within the census area in 2002.
Coho salmon maintained its traditional position as the fifth most commonly harvested salmonine species in 2002, although harvest and catch both declined dramatically. Harvest was estimated at 1,870 coho, just 3.1% of the total 2002 salmon harvest. This was the lowest coho salmon harvest among the 18 years surveyed.
Chinook salmon was the most commonly harvested salmonine species in 2002, comprising 30.7% of the total S/T harvest. An estimated 18,307 fish were harvested within the area censused in 2002, the lowest chinook salmon harvest among the 18 years surveyed, a 27.1%decrease compared to 2001 (the previous record low). At present, there is no obvious explanation for the large relative reduction in chinook salmon harvest rate in
the east/central area.
Chinook salmon populations in Lake Ontario are heavily dependent on annual stocking programs, and chinook salmon stocking targets were substantially reduced in '93 and again in '94. This resulted in great deal of concern among fishermen and fishing related business owners, and many people have concluded that lower harvest rates observed in 1995 and 1996 were directly attributable to stocking cuts. Due to public concerns, the DEC chinook salmon stocking target was increased in '97 to an intermediate level of 1.67 million fingerlings.
Rainbow trout harvest de-creased to 6,866 fish, a record low harvest among the 18 years censused, a 57.1% decrease compared to the 2001 harvest. Rainbow trout dropped one position to the fourth most commonly harvested species of S/T in 2002, contributing just 11.5% of the total salmonine harvest.
Brown trout harvest decreased to 16,811 fish, a record low among the years censused, a 34.0% decrease compared to 2001. Brown trout were the second most commonly harvested S/T species in 2002 within the area censused, accounting for 28.2% of the total salmonine harvest.
Lake trout harvest increased with an estimate of 15,718 fish, a 59.3% increase compared to 2001, and a 49.8% increase compared to the 1997-2001 average harvest. Lake trout rose one position to the third most commonly harvested S/T species in the 2002 census, contributing 26.3% of the total salmonine harvest.
Total Salmonids: Total harvest of all species of trout and salmon in the 2002 fishing boat census was estimated at 59,719 fish, a 28.3% decrease compared to 2001, a 34.9% decrease compared to the 1997-2001 average harvest, and a record low among the 18 years censused. Numbers harvested for coho salmon, chinook salmon, rainbow trout, and brown trout, were all record lows among the years censused. Part of this decline can be attributed to the decline in fishing effort and a decline in trout and salmon fishing quality.
Smallmouth bass has been the most commonly harvested fish species in the fishing boat census since 1995, due in part to decreases in numbers of trout and salmon harvested, and due in part to increases in fishing effort targeted at bass. Total harvest was estimated at 43,161, a 31.2% decrease compared to 2001, and a similar 31.3% decrease compared to the 1997-2001 average number harvested.
Yellow Perch: Yellow perch harvest and catch within the area censused was estimated at 4,595 fish, a 35.4% decrease compared to 2001, and a 46.2% decrease compared to the 1997-2001 average harvest.
Lampreys Observed: Lampreys observed attached to fish caught decreased substantially with an estimate of 1,295, a 46.7% decrease compared to 2001, and a 32.0% decrease compared to the 1997-2001 average. Lamprey sightings in 2002 were estimated at 11.46 per 1,000 trout or salmon caught, a 34.9% decrease compared to 2001, and an 11.8% decrease compared to the 1997-2001 average.
Salmon River Creel Survey
Anglers caught an estimated 2,743 steelhead. Shore access anglers fishing the conventional regulations portion of the river caught 2,146 steelhead, which was 79% of the catch. Driftboat anglers caught 437 fish for 16% of the catch. Special regulations area fly-fishermen caught 144 steelhead or 5% of the total estimated catch.
Trout and Salmon Pen-Rearing Projects
Except for the one steelhead setback, the fourth year of pen rearing was considered very successful due to relatively low fish mortality and the goodwill generated through partnership in the pen projects. Evaluations of chinook salmon pen rearing will continue by creel surveys for several more years. ²
See TABLE 1: Fish Stocking in Lake Huron 2002
Adult alewives (age-2 and older) were less abundant in U.S. water of Lake Ontario in 2002 than in 2000-2001. Age-1 alewives were abundant, however, indicating that adult numbers should increase in 2003. Numbers and biomass of age-1 and older rainbow smelt in '02 were similar to '01 and just above the record low of 2000. Although abundance of slimy sculpins increased for the third consecutive year in 2002, it remained well below the 1991 peak. No deepwater sculpins were collected in 2002.
Alewife – The numbers and biomass of adult alewives (age-2 and older) in April-May 2002 were sharply lower than estimates for 2001 and were similar to numbers and biomass in 1996-1997. Adult alewives increased for two consecutive years in 2000 and 2001 due to a surge of recruits from '98 and '99. The 1998 year class, when first measured at age 1, was the largest year class of the 25-year period of record and the '99 year class was the seventh largest.
When '98 year class fish recruited to the adult portion of the population at age 2 in 2000, they lifted adult abundance above record lows, and it appears that when the '99 year class fish recruited at age 2 in 2001, they returned adult abundance to a level not seen since the early 1990s.
However, the 2000 year class was the second weakest on record, providing few age-2 recruits to the adult portion of the population, and this was one reason adult abundance declined in 2002. Another reason for the steep decline was that the low-phosphorus, dreissenid-rich lake is unable to support the number of adult alewives that were present in 2001 for multi-year periods.
The abundance of age-1 alewives in U.S. waters in spring 2002 was 27-fold greater than in the previous year, but only 13% above the long-term mean. Although only a moderately strong cohort, the 2001 year class should provide sufficient age-2 recruits in 2003 to lift adult abundance above the near record low recorded in 2002. In 2002, the adult portion of the alewife population was heavily dominated by three-year-old and four-year-old fish ('98 and '99 year classes). Age-4 fish comprised 47% of the catch and age-3 fish comprised 27% of the catch. The third most numerous age group was 7 (9%, 1995 year class), followed by 6 (8%), 5 (5%), and 2 (3%).
In fall 2002, alewife condition was the second lowest on record. The lowest fall condition index was in 1992, when the Lake Ontario ecosystem was just beginning to feel the effects of dreissenid colonization. Condition of alewives typically increases from spring to fall, but in 2002, condition declined over summer. Population expansion and continued erosion of lower food web support for alewives were likely reasons for the low and declining condition of alewives in 2002.
Prognosis for the Lake Ontario alewife population is mixed. Although the population was at a low level in spring 2002, indications are that it expanded in summer and may well expand again in 2003 due to favorable conditions for reproduction in spring 2002. However, the poor condition of alewives in a population at a historically low level of abundance suggests that the carrying capacity of Lake Ontario is still declining perhaps reflecting the dreissenid-linked collapse of Diporeia and the putative decline in Mysis.
Rainbow Smelt – Numbers and biomass of age-1 and older rainbow smelt in 2002 were similar to 2001 and were the record lows noted in 2000. Abundance of rainbow smelt has been at or near 25-year lows for three consecutive years with biomass averaging only 20% of that in the 1980s. Chronically high smelt mortality rates coincide with increased water clarity and the shift of rainbow smelt to deeper water that began in the early 1990s.
Slimy sculpin – Along the south shore of Lake Ontario, from Olcott to Oswego, slimy sculpin numbers increased from 964 per tow in 2001 to 1338 per tow in 2002. In fact, catches at a few depths exceeded 4,000 fish, the largest catches of slimy sculpins since 1991.
Deepwater sculpin – Management did not capture any deepwater sculpin in 2002 during the long-term assessment trawling and they did not conduct additional trawling to attempt to capture deepwater sculpin. During 1998-2000, they caught five deepwater sculpin at depths of 110-150m, two while conducting long-term assessment trawling, and three in a short-term assessment trawling that targeted deepwater prey fishes in mid lake, along the international boundary. Prior to 1998, the last documented record of a deepwater sculpin being captured in U.S. water of Lake Ontario was over 50 years ago. ²
OMNR fisheries biologist John M. Casselman, Glenora Fisheries Station, reports global warming will substantially increase year-class strength of warmwater species, such as smallmouth bass, an additional increase of 1°C increases abundance by 2.5x; 2°C by 6.0x, and 3°C by 14.7x. Year-class strength of northern pike, a coolwater species, an increase of 1°C decreases year-class strength by 2.4x and 2°C by 17.9x. A similar relation exists between May temperatures and recruitment of alewife, an important coolwater forage species.
For coldwater species such as lake trout, an increase in fall temperatures at spawning time has a major negative effect on year-class strength; an increase of 1°C decrease survival at hatch of 1.5x, 2°C by 2.4x, and 3°C by 20.1x. Global warming will significantly affect year-class strength and fish-community structure and dynamics in the Great Lakes Basin, substantially decreasing recruitment of coldwater and coolwater species and increasing relative recruitment of warmwater species. ²
The fish community objective for sea lampreys was met during 2002 with 1 mark per 100 lake trout. Wounding rates in Lake Ontario have been remarkably stable during 1985-2002, raging from 1-3 marks per 100 fish.
• Lake Ontario has 659 (254 US, 405 Canada) tributaries.
• 59 (29 US, 30 Canada) tributaries have historical records of production of sea lamprey larvae.
• 43 (22 US, 21 Canada) tributaries have been treated with lampricide at least once during 1993-2002.
• Of these, 29 (15 US, 14 Canada) tributaries are treated on a regular 3-5 year cycle.
• During 2002 treatments were successfully completed in 15 tributaries (8 U.S., 7 Canada).
• Wesleyville Cr., a small tributary located at the eastern end of Lake Ontario, was treated for the first time.
• Mortality of nontarget organisms was insignificant in the majority of tributaries treated. However, juvenile chinook salmon (less than 500), and common white suckers (less than 100) were killed in the middle of the treatment area of the Credit River when pH levels unexpectedly decreased to lower than expected levels.
Rivers treated included:
South Sandy Cr.
Port Britain Cr.
77 spawning-phase male sea lampreys were transported to the sterilization facility from trapping operations on the Humber River and Duffins Creek. The estimated population of spawning-phase sea lampreys for 2002 was 38,377.
Lake Erie yellow perch harvest in pounds 1990-2002.
Ontario* __ Ohio Michigan _Pennsylvania New York Total Catch
Year Catch % Catch % Catch % Catch % Catch %
1990 7,064,820 73 2,110,185 22 231,525 2 185,220 2 37,485 <1 9,629,235
1991 4,193,910 69 1,618,470 27 94,815 2 152,145 3 24,255 <1 6,083,595
1992 4,515,840 78 1,091,475 19 66,150 1 77,175 1 19,845 <1 5,770,485
1993 3,752,910 73 1,217,160 24 123,480 2 24,255 <1 13,230 <1 5,131,035
1994 2,443,140 55 1,838,970 42 66,150 1 55,125 1 11,025 <1 4,414,410
1995 2,096,955 54 1,673,595 43 77,175 2 30,870 1 6,615 <1 3,885,210
1996 2,537,953 53 2,135,836 44 134,810 3 11,246 <1 4,472 <1 4,824,317
1997 3,783,548 60 2,370,571 38 111,819 2 26,409 <1 2,387 <1 6,294,734
1998 3,828,351 65 1,871,779 32 132,051 2 29,065 <1 3,175 <1 5,864,421
1999 3,346,474 59 2,235,306 39 101,549 2 11,141 <1 3,234 <1 5,697,704
2000 3,271,780 54 2,651,134 44 67,010 1 43,563 1 2,458 <1 6,035,945
2001 3,642,684 52 3,127,521 45 70,910 1 99,548 1 15,319 <1 6,955,982
2002 4,924,958 53 3,943,387 43 147,065 2 187,724 2 24,952 <1 9,228,086
Species 1986 1988 1990 1992 1994 1996 1998 2000 2002
Brook Trout 4,587 5,148 5,927 4,431 7,481 419 159 199 144
Brown Trout 68,806 59,397 45,092 51,554 52,397 38,093 27,371 41,111 35,220
Rainbow Trout 26,483 60,860 51,711 79,525 114,776 77,099 110,888 72,278 74,031
Chinook 356,900 176,294 111,345 103,564 99,755 183,254 136,653 136,986 275,454
Coho Salmon 127,919 136,695 64,083 70,876 110,001 104,715 59,203 88,203 102,313
Lake Trout 96,858 89,227 75,177 52,853 53,989 36,849 82,247 31,360 39,865
TOTAL 681,553 527,621 353,335 362,803 438,399 440,429 416,521 370,137 527,027
TABLE 1: Fish Stocking in Lake Huron 2002 - NUMBER OF PREDATORS STOCKED INTO THE LAKE HURON BASIN
Chinook Coho Brown Rainbow Lake Atlantic Brook
Year Salmon Salmon Trout Trout Trout Walleye Salmon Trout Splake Total
2000 62,541,678 2,309,039 89,610,558 20,742,684 39,670,312 36,311,163 510,215 626,211 519,583 178,582-685
2001 3,667,071 0 389,069 670,728 3,570,696 1,068,395 35,909 0 30,820 9,432,688
2001 3,210,453 0 477,371 441,751 3,382,436 1,224,502 29,313 0 32,200 8,798,026
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