U.S. Fish & Wildlife Service - Alpena FWCO Station Report
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Summary of the 1996 Activities
Of the Interbasin Lake Sturgeon Work Group
In Waters of Lake Huron, St. Clair, and Erie
Jerry R. McClain
U.S. Fish and Wildlife Service
Alpena Fishery Resources Office
Federal Building Room 204
145 Water St.
Alpena, MI 49707
(989) 356-5102, (989) 356-4651 Fax
Provisional data, not to be cited without permission.
INTERBASIN LAKE HURON REPORTS
INTERBASIN ST. CLAIR LAKE/ RIVER REPORTS
INTERBASIN LAKE ERIE REPORTS
Interest in the status and trends of lake sturgeon (Acipenser fulvescens) in the Great Lakes basin has been increasing within all natural resource agencies involved in fisheries management in recent years. Federal, state and provincial agencies have initiated status surveys and are in various stages of development of recovery or management plans for waters under their jurisdiction. However, fiscal and personnel constraints have limited full-scale projects due to other resource priorities. Small scale efforts had been initiated in U.S. and Ontario waters of Lake Huron in 1995 to begin determining relative abundance, age structure, and seasonal movement patterns in selected regions of the lake. Tagging studies had been initiated in Saginaw Bay by the U.S. Fish and Wildlife Services (FWS) Alpena Fishery Resources Office, and the southern main basin and north channel by Ontario Ministry of Natural Resources (OMNR) Lake Huron Management Unit. In addition, the Ohio State University (OSU) Department of Molecular Genetics had initiated a genetic analysis of lake sturgeon samples from western Lake Erie, the Lake St. Clair system, and Lake Huron to begin examining the degree of mixing of stocks in the respective water bodies. In 1996 representatives from the FWS, OMNR, Michigan Department of Natural Resources (MDNR), Ohio Division of Wildlife (ODOW), and OSU met in Mt. Clemens, Michigan to develop a coordinated effort for enhanced understanding of the current status of lake sturgeon in the Lake Huron to Lake Erie region of the Great Lakes, with special emphasis on the St. Clair waterway and the degree to which that existing population is contributing to stocks in the other lakes.
One of several action items developed at that meeting was for the Alpena FRO to compile an annual summary report of agency activities to share with all participating offices. Following is a summary of 1996 agency activities and plans for 1997 to update all interested parties of ongoing lake sturgeon efforts in Lakes Huron, St. Clair, and Erie. The initiative that has been launched by the involved offices to coordinate efforts and share information should enable the interested resource agencies to collect much more information, in a timely manner, on the status of this historically important Great Lakes fish species.
INTERBASIN LAKE HURON REPORTS
OMNR (Lake Huron Management Unit)
Contact: Lloyd Mohr
Phone: (519) 371-5669; Fax: (519) 371-5844
Lake sturgeon sampling in 1996 was again conducted with the assistance of commercial fishers in Ontario waters of Lake Huron. In most cases, fish were sampled by the commercial fishers themselves, following protocol developed and supplied by the LHMU. On two occasions LHMU personnel were directly involved in on site sampling. Two general locations were sampled in 1996, the north channel and southern main basin.
Lake sturgeon were captured in large and small mesh gillnets in the north channel and in trapnets in southern Lake Huron. Fishers targeting lake sturgeon in the north channel generally use 11.4 - 14.0 cm whitefish gillnets, set extremely slack to capture large lake sturgeon. Occasional sets of 33 cm mesh gillnets are used, but these sets are rare. More and more lake sturgeon samples are coming from small mesh nets (8.26 cm) targeting yellow perch. This year, over 50% of the samples collected from the north channel were from this gear type.
In southern Lake Huron, the majority of the lake sturgeon sampled were from walleye trapnets, set within 15 km of the mouth of the St. Clair River. No targeting for lake sturgeon occurs in this region of the lake. Incidental lake sturgeon catches in 12.1 cm and 12.7 cm lake whitefish gillnets makes up less than 25% of the total harvest in this end of the lake. Only 5 fish were sampled from commercial gillnets in this region of the lake. A total of 183 lake sturgeon were sampled in 1996, 58 from southern Lake Huron and the remainder from the north channel. Almost all of the fish sampled in southern Lake Huron (53) were collected in mid-October. A small sample was collected in July. This is NOT indicative of temporal availability of the fish, but rather the cooperative nature of the fishers and time available to assist in this program. In the north channel, samples were collected from May to November, with the largest numbers collected in May (26), June (58), and October (22). This is more representative of actual catchability of lake sturgeon in this region of the lake, although sampling bias cannot be excluded.
The following summary of biotic parameters were collected from sturgeon sampled in 1996
Southern Main Basin
North Channel Mean Total Length (mm) 1047 777 Median Total Length (mm) 1043 725 Total Length Range (mm) 635-1850 225-1580 Mean Round Weight (kg) 7.66 1.79 Modal RWT (kg) 6.55 1.70 Weight Range (kg) 1.59-17.01 0.06-7.75 Mean Age 13.7 7.2 Median Age 13.0 6.0 Age Range 3-60 1-26
Total length vs Fork length y = 0.9282x - 20.252 r2 = 0.9862
Total length vs Girth y = 0.411x - 36.12 r2 = 0.8693
Log TLEN vs Log RWT y = 3.3269x - 14.269 r2 = 0.9183
Depth and substrate information was collected from a small group of 40 samples in the north channel only. Twenty-eight of the these fish were captured over sand substrate, 7 over mud substrate, and 5 over rock/bedrock substrate. All of the sturgeon caught over sand substrate were sampled in early June, whereas all of the sturgeon caught over mud or rock were sampled in September. This is unfortunately heavily biased due to the fishing activity at the time.
The average depth of capture in the north channel was 13.8 m. The deepest that a lake sturgeon was captured and sampled was at 27.4 m and the shallowest was 4.6 m. The depth of capture varied from month to month although no pattern is evident. The deepest fish were seen in May while the shallowest were in June and November.
A total of 122 lake sturgeon were tagged using cattle ear tags placed on the left operculum. Two different sizes were used, although only 6 of the smaller tags were used. Of the 122 tagged, 31 were in southern Lake Huron and 91 in the north channel. This brings the total number of lake sturgeon tagged in these areas in the last 2 years to 75 in southern Lake Huron and 176 in the north channel. Two recaptures of 1995 tagged fish were reported in 1996. One fish was recaptured in the north channel in July, approximately 1 year after first being captured and approximately in the same area, within a radius of 5 km or less. This fish was not re-aged in 1996. It had grown 40 mm since 1995 when it was classified as age 7. It was released back into the lake. Another fish was recaptured in southern Lake Huron in October, having been first captured in June of the previous year. This fish was also captured in approximately the same location as it had been originally tagged. Unfortunately, this fish was not re-measured or sampled. It was however, released back into the lake. Several fish were recaptured in the general area in which they were originally captured within the same year. Most of these recaptures occurred within one month and within 5 km of the original capture site. This was most evident in the north channel.
Commercial fishers involved in this lake sturgeon program were asked to submit a summary report detailing any anecdotal information they may have. Several questions were also posed to them including, "Have you observed any changes in lake sturgeon abundance in recent years?". An overwhelming response was that more and more fishers are seeing very young lake sturgeon like they have never seen before. Ironically, the increase in fish less than 500 mm appears to have first occurred in 1995, coinciding with the commencement of our lake sturgeon assessment program. In southern Georgian Bay, one fisher reported in excess of 195 small lake sturgeon released in 1996 as compared to less than 30 in 1995. These were all in the less than 500 mm category. Adult numbers do not appear to be changing. Fishers speculated that recent improvements to water quality, some local river improvement programs, and less contaminant loading may have improved spawning success and hence recruitment. All targeted habitat improvement as the best approach to increasing lake sturgeon numbers and they pointed to power dams, pulp and paper operations (including dams), and other industrial water users.
Overall, 1996 was another successful year. We had fewer than expected samples from the southern Lake Huron area and hope to rectify that in the future. Cooperation in the north channel continues to be great. We continue to suffer from sampling bias due to the nature of our sampling. It is difficult to interpret much of the data given that lake sturgeon are being caught incidentally while fishing for other species. Depth of set, substrate type, water temperature, date, all are driven by other species and not directly by lake sturgeon. This limits our interpretive capability.
The cooperative program will continue in 1997 with increased samples in all locations, as the potential last year of a three year initial program. A new fisher is being recruited in southern Georgian Bay to complete our sampling of the major lake sturgeon areas in Ontario waters of Lake Huron. Two projects tentatively planned include 1) an assessment of a sport fishery that takes place in the north channel for 2 weeks in early June, and added assessment/tracking of spawning fish in 2 rivers in the north channel. Most of the field activity is planned to take place in late May and early June. This is contingent on field personnel being available as well as the program being financed. At this point in time, no funds have been assigned this project. OMNR personnel would like to conduct some of their own sample collections in order to identify some of the biases the commercial samples are likely to include. A proper index program with known gear targeting lake sturgeon in specific areas and times of the year is being discussed.
USFWS (Alpena Fishery Resources Office)
Contact: Jerry McClain
Phone: (989) 356-5102; Fax: (989) 356-4651
In 1995, in cooperation with the Michigan Department of Natural Resources (MDNR) and commercial fishers in Saginaw Bay, the Alpena FRO initiated a tagging program to begin piecing together information on relative abundance, movement, and life history of Lake Huron lake sturgeon. Beginning in the spring of 1995 and continuing through the 1996 season, one Saginaw Bay commercial fisher agreed to collect biological data on lake sturgeon encountered as by-catch in their trap net fishery using protocol developed by the Alpena FRO. In addition, to ensure minimal stress to the fish, fishers agreed to apply tags to the fish immediately upon removal from the nets. In 1995 and through August 1996, Floy (Model FT4) Cinch-up tags were applied to all sturgeon encountered by the fishers. The tags were inserted through the musculature posterior to the dorsal fin. In 1996 (September), based on standardization efforts developed at a meeting of the Interagency Lake Sturgeon Work Group, a switch was made to Monel self-piercing animal ear tags that were attached to the left operculum. To assist in the collection of biotic data on Saginaw Bay lake sturgeon and to enhance the chances of tag recaptures, self-addressed data return cards were distributed to several state licensed commercial fishers in 1995 by MDNR personnel regulating the fishery. Fishers were asked to cooperate by filling out the data cards and forward them to the FWSs Alpena FRO. In 1996 the tagging operation was expanded to include additional fishers who expressed an interest in assisting in the project.
Biotic data collected by the fishers includes; total length (T.L.), fork length (F.L.), girth, and weight when possible. Abiotic data include; latitude/longitude, water depth, date, and gear and mesh size. In addition, the tag type, agency, and identification number of tags applied or observed are also recorded.
A total of 56 lake sturgeon have been sampled since the project was initiated. Of this total, only three of the sampled fish have come from outside Saginaw Bay. A total of 29 of the sturgeon have been tagged by participating fishers. In 1995, 6 Lake Huron fishers returned data cards for 22 lake sturgeon, 13 of which were tagged by participating fishers. In 1996, 6 fishers returned data cards for 34 lake sturgeon, with 16 fish tagged by commercial fishers. Data cards from nine different commercial fishers have been returned since 1995. Only a single recapture was reported in 1996 of a fish tagged in 1995.
A majority of the sturgeon are captured in small-mesh (4.8-7.6 cm) trapnets fished in the shallower regions of the inner Saginaw Bay. The average depth of the net sets where the sturgeon were recovered was 7.0 meters. Depths ranged from 2.1 meters to 31.4 meters (one fish caught in the DeTour area early in 1996 in a whitefish gillnet).
Data collected to date on the Saginaw Bay lake sturgeon are biased seasonally and temporally by the nature of the fishery, making analysis difficult. There are, however, temporal differences in habitat overlap between lake sturgeon and the commercially targeted species. The overlap is greatest in the spring and fall period, with May and October being the months when sturgeon are most frequently by-caught. This temporal information may prove useful is developing future sampling protocol for assessment activities targeting lake sturgeon.
Biotic data have been collected from 55 sturgeon with all fish being returned to the lake in good condition. A majority of the sturgeon sampled in Saginaw Bay to date have been fish larger than 70 cm (T.L). The mean total length for all sturgeon was 109 cm with sizes ranging from 55 - 173 cm.
Standardization of data parameters analyzed in this and the Ontario portion of the survey allow for exchange and application of the various morphological relationships with some degree of confidence. The following regressions were developed for these relationships:
Total Length vs Fork Length y = 1.0948x - 0.3448 r2 = 0.941
Total Length vs Girth y = 0.4873x - 9.8569 r2 = 0.8757
The tagging and data collection activities made possible by the cooperation of the Saginaw Bay commercial fishers will continue in 1997. With the addition of the new participating fishers in the tagging study it is hoped that considerably more sturgeon will be tagged and as this number increases, recapture information should begin to develop that may aid in defining seasonal movement patterns and relative abundance of sturgeon in the Saginaw Bay region of Lake Huron.
Alpena FRO will be adding a staff position in 1997 (3 year term appointment) whose primary responsibility will be to assume a lead role for all sturgeon related activities from this office. Addition of this position will provide for better communication and coordination with the commercial fishers involved in this project, both in Lake Huron and Erie. In addition, it will enhance the coordination role this station has assumed for the inter-agency, inter-basin efforts in the Huron to Erie Corridor. One of the initial responsibilities will be the consolidation of tagging data from all participating agencies into a common database.
The Alpena FRO will also be assisting on a lake sturgeon telemetry study in the St. Clair system with MDNR (Mt. Clemens Fisheries Research Station) and the University of Michigan. Ultra-sonic and radio tags were ordered with FWS funds in late 1996 and are scheduled for delivery in early 1997. A biological technician will be hired by Alpena FRO and stationed in the Mt. Clemens area to provide assistance for sturgeon tracking and personnel safety to a graduate student funded by MDNR.
INTERBASIN ST. CLAIR LAKE/ RIVER REPORTS
MDNR (Mt. Clemens Fisheries Research Station)
Contact: Mike Thomas and Bob Haas
Phone: (586) 465-4771; Fax: (586) 465-7504
E-mail: firstname.lastname@example.org & email@example.com
In 1996 effort was directed at targeting lake sturgeon in the St. Clair River and Lake St. Clair. Sampling techniques included set-lines and trawling, and tagging was initiated utilizing Monel cattle ear tags. Following is a brief summary of data collection for lake sturgeon in 1996:
Set lines were fished in the St. Clair River during late May and early July. The lines were 250 feet long with 25 baited hooks spaced 3 meters apart. Four lines were fished for 3 nights each in May for a total of 12 sets. Four lines were again fished for 2 nights in July for a total of 8 sets. In addition, 2 lines were fished for 3 nights in Lake St. Clair in early June for a total of 6 sets. From the 20 sets in the St. Clair River a total of 8 sturgeon were captured. One fish caught in July had been caught with a set-line and tagged in May. No sturgeon were captured from the 6 sets in Lake St. Clair. There was no by-catch during setlining, the only fish caught were sturgeon. Three of the sturgeon were caught on hooks baited with round gobies. One of 8 sturgeon caught on set-lines experienced moderate tissue damage from the hook.
Trawling was conducted in Lake St. Clair from June through October. A total of 74 sturgeon were captured in 108 trawl tows made with a 10 meter headrope bottom trawl. An additional 94 trawl tows were made with a 4.9 meter headrope bottom trawl in shallow nearshore areas but no sturgeon were captured. Trawl caught sturgeon seemed to experience little stress. A high density location was found in Lake St. Clair, 10 minute tows containing 4 or more sturgeon each were common.
Biotic parameters collected from all sampled sturgeon (set-lines and trawls) included: total length, girth, weight, lamprey scars, and barbel counts. No fin rays were taken for aging purposes, nor was it practical to attempt external sexing. Sturgeon collected ranged in length from 43 to 183 cm (TL) and ranged in weight from 0.45 to 42.7 kg. In addition, tissue samples were collected and provided to the genetics lab at the Ohio State University. Abiotic parameters collected included: location (lat/long), water temperature, secchi depth, and water depth for all sturgeon collected.
A total of 80 sturgeon were tagged with Monel cattle ear tags attached to the left operculum. There were some initial problems with gill damage and bleeding on the first couple of fish tagged, but after some practice the problem was eliminated.
one sturgeon caught by set-line in the St. Clair River in July had been captured by set-line and tagged in the same area in late May. The fish had shed the tag, but was easily identified by size and genetic tissue sample site (plug).
A new Federal Aid project proposal has been submitted to cover sturgeon sampling/tagging in the St. Clair River and Lake St. Clair. Collection efforts will be expanded during the spawning run in the St. Clair River (late May - early June) with set-lines and trap nets. All sturgeon will be tagged and biodata recorded as in 1996. Trawling will be conducted in Lake St. Clair from June through October, with tagging and biodata collection being implemented as in 1996.
A study proposal has been developed in cooperation with the University of Michigan and the FWS (Alpena FRO) to track adult and juvenile sturgeon in the St. Clair River and Lake St. Clair with telemetry.
INTERBASIN LAKE ERIE REPORTS
ODOW (Sandusky Fisheries Research Station)
Contact: Dave Davies
Phone: (419) 625-8062; Fax: (419) 625-6272
Personnel from the Sandusky Office of ODOW have compiled sturgeon sighting reports from all sources over the past few years. In general, there appears to be a definite trend of increasing encounters with lake sturgeon in Lake Erie. This is especially true in the western basin of the lake with increasing encounters of juvenile sturgeon. Only 7 sturgeon were reported in the 1989-1992 period, but reports have increased from 3 in 1993, 7 in 1994, 22 in 1995 and 35 reported in 1996. Biodata have been recorded for a portion of these fish and the total length information is included in the summary of Ontario waters of Lake Erie.
Following is a summary of the sources of sturgeon reports to the Sandusky Office since 1989 These 74 Sturgeon reports have come from 19 grids in the 1989-1996 period and are summarized as follows:
Number Ohio Commercial 43 Canadian Commercial 5 Pennsylvania Commercial 1 Ohio Sportfishing 9 Ohio seen alive 3 Ohio found dead 2 Michigan found dead 3 New York found dead 5 Canada found dead 1 ODOW index fishing 2 Total 74
Grid No. 326 1 521 1 704 1 706 2 717 4 905 2 806 1 903 1 904 1 905 14 906 6 908 1 910 1 1006 27 Total 63
Grid No. 127 1 327 3 425 2 702 3 802 1 905 1 Total 11
ODOW has purchased Monel cattle ear tags and hopes to begin tagging sturgeon in Ohio waters of Lake Erie as part of this inter-basin tagging study in 1997. In addition, 50,000 sturgeon sighting cards have been printed and distribution will begin in 1997. The card is previewed in Ohios 1997-98 fishing regulations and the preview is illustrated in Attachment 1. Distribution of this card throughout the Lake Erie basin should greatly enhance the number of sighting reports, provide increased biotic and abiotic information on sturgeon encountered, and increase public interest in the status and eventual recovery of this historically important species.
OMNR (Lake Erie Management Unit)
Contact: Don MacLennan
Phone: (519) 825-4684; Fax: (519) 825-3163
A collaborative effort was initiated in 1996 between OMNR, FWS, and an Ontario licensed commercial fisher from Kingsville in western Lake Erie. The fisher had reported significant numbers of juvenile size lake sturgeon being caught as by-catch in perch and walleye gillnets in western Ontario waters of the lake in 1995, and had stated an interest in assisting in the tagging study. Sturgeon are reported to be routinely encountered by the fisher in small mesh gillnets, both in bottom sets for yellow perch and in "canned" walleye nets.
The Lake Erie Management Unit (OMNR) issued a special permit to allow the fisher to participate in the study in 1996. Biotic and abiotic information was to be collected from all by-caught sturgeon, tags attached and the fish returned to the water. In addition to participation in the tagging study, pectoral fin tissue was collected from 25 of the fish and supplied to the Ohio State University for genetic analysis. Sampling protocol, tags, data sheets, and DNA sample equipment were provided by the FWS (Alpena FRO and Lower Great Lakes FRO).
Biotic and abiotic data were collected from 43 lake sturgeon encountered as by-catch between May and August 1996. Biotic data included total length, fork length, and girth. Abiotic data included date, location (lat/long), gear type, type of set (bottom/canned), water temperature, depth, tag ID number, and substrate type (if known). Total length ranged from 34.0 to 81.3 cm with a mean of 44.9 cm. Depths where sturgeon were captured ranged from 9.5 to 11.2 m with a mean depth of 10.4 m. Water temperature ranged from 8.3 C in May to 23.3 C in August with a mean temperature of 18.1 C.
A total of 22 sturgeon were tagged during the May - August period. Monel cattle ear tags were attached to the left operculum of each fish. Three recaptures of previously tagged fish were reported, and occurred in the same general location and within two days of being tagged. Two sizes of tags were available for this project, however, only the larger tags were available during the early season when a number of small fish were encountered. In those situations, due to incompatibility of fish and tag sizes, the fish were returned untagged to the water. After acquisition of the smaller tags the fishing activity was focused on walleye utilizing canned nets and fewer sturgeon were encountered.
There is considerable information indicating recent and ongoing recruitment of lake sturgeon in the western Lake Erie basin. Increasing frequency of sturgeon encounters by sport fishers in Ohio waters of Lake Erie, as well as more reports from commercial fishers in Ohio and Ontario waters, support this opinion. As illustrated by the length-frequency distribution (Figure 1), a large proportion of sturgeon reported from Lake Erie since 1989 are fish less than 70 cm.
Figure 1. Length-frequency distribution for lake sturgeon reported from all sources for Lake Erie, 1989-1996. (Information assembled by D. Davies, ODOW).
The tagging portion of the project will be continued in 1997, again through a cooperative effort of the FWS and OMNR. No DNA samples will be required in 1997. Because of the abundance of very small juvenile sturgeon this fisher encounters, an even smaller tag will be purchased prior to the fishing season. With a full range of tag sizes any sturgeon encountered as by-catch should receive a tag. Biodata was not collected on all fish encountered in 1996, due in part to a belief on the part of the fisher that only fish for which DNA samples were collected were to be measured. Clarification and better communication between the FWS and the fisher in 1997 should result in significantly more information on this population of lake sturgeon.
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