GREAT LAKES NATIVE FISH RESTORATION
LAKE STURGEON
Lake sturgeon image

1998 SUMMARY REPORT of
NIAGARA RIVER and OSWEGATCHIE RIVER RESEARCH PROJECTS


U.S. Fish and Wildlife Service
Lower Great Lakes Fishery Resource Office

405 North French Road, Suite 120A
Amherst, NY 14228

Lake Sturgeon Program Coordinator: Christopher Lowie
Lake Sturgeon Biological Technicians: Thomas Hughes and Scott Schlueter

Image of a juvenile lake sturgeonImage of a really large adult lake sturgeon

March 1999
Administrative Report 99-01


Table of Contents

BACKGROUND

NIAGARA RIVER

OSWEGATCHIE RIVER

SUMMARY

 


BACKGROUND

The lake sturgeon, Acipenser fulvescens, is the only sturgeon endemic to the lower Great Lakes and is the largest of all fish species in the basin. Lake sturgeon mature at 15-20 years of age, spawn only periodically, and may survive to 100-150 years. Early commercial fishermen (pre-1850) perceived lake sturgeon as a nuisance fish because of fishing gear destruction. Later recognized for its commercial value, a targeted fishery for lake sturgeon intensified. The lake sturgeon fishery finally collapsed due to environmental changes and the lake sturgeon’s slow growth, late maturity, and infrequent spawning. From 1900 to the 1970s, little was known about the lake sturgeon population, except for its continued decline. Environmental factors affecting the decline include damming of tributaries preventing access to historical spawning grounds, destruction of spawning areas via siltation from deforestation, agriculture, and dredging, and pollution from nutrient and contaminant loads. Only a remnant population remains today, causing the lake sturgeon to be listed as threatened by New York State and the American Fisheries Society and as endangered by Pennsylvania and Ohio. Lake sturgeon are not protected in Canadian waters of Lake Erie and Lake Ontario.

The role of the Fish and Wildlife Service in restoring native Great Lakes fish stocks as part of ecosystem rehabilitation has become more clearly defined over the past five years, and continues to expand. The major causes of the demise of native fish are being addressed through various regulatory and management initiatives, with active cooperation of many agencies. This has set the stage for major progress in the restoration and rehabilitation of native fish species. With success stories of lake whitefish, lake trout, and burbot in all the Great Lakes, the opportunities for lake sturgeon rehabilitation has never been greater.

Interest in the restoration of lake sturgeon by Great Lakes scientists has increased greatly. The fish provides an unequaled symbol of ecosystem health and biodiversity. Restoration of this fish and its habitat is in keeping with the Service's "Fisheries’ Vision for the Future" and the "Fisheries Action Plan" which focus on interjurisdictional, native and depleted species and related ecosystem impairments. This stewardship project focuses on ecosystem and resource management and conservation through habitat protection and restoration.

The "Framework for the Management and Conservation of Paddlefish and Sturgeon Species in the United States" reaffirms the Service's commitment to restoring these particular species. Throughout this document, the Service is referenced as a partner and a national leader in the ecosystem management and conservation of sturgeon species. Problems identified in the Framework Plan are being addressed in this Stewardship Project.

In addition, the activities presented in this report support several recommendations stated in the "Great Lakes Fishery Resources Restoration Study" (1995) and the Service’s "Great Lakes Ecosystem Resource Goals and Objectives". This project also assists the New York State Department of Environmental Conservation in their protection and restoration efforts outlined in "A Recovery Plan for Lake Sturgeon in New York".

The Lower Great Lakes Fishery Resource Office’s (LGLFRO) Lake Sturgeon Program has matured, in a strategic fashion, from five components. These components include: (1) coordination of interjurisdictional activities; (2) evaluation of population characteristics and discreteness of remnant stocks; (3) assessment of habitat and rehabilitation requirements; (4) hatchery support technologies and brood stock maintenance; and, (5) public education. All components have continuous assessment procedures to enhance the effectiveness of associated strategies.

Purpose
The purpose of this document is to provide more detailed scientific information regarding the Lower Great Lakes Fishery Resources Office’s lake sturgeon research efforts implemented under the 1997 Stewardship Funds. This document should be added as a supplement to the 1998 Progress Report (Lowie et al. 1998). The Niagara River and Oswegatchie River research projects, initiated in 1998, are described below.

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NIAGARA RIVER

Lake sturgeon sampling in 1998 focussed primarily on the upper Niagara River (above Niagara Falls), and experimentally in the lower river (Figure 1). The objectives of the study were to: (1) determine the distribution, movements, and habitat utilization of adult and juvenile lake sturgeon, (2) determine the age and growth of adult and juvenile lake sturgeon, and (3) determine the genetic discreteness of Niagara River lake sturgeon.

The field season started 29 June, 1998 with six setlines deployed weekly in the east and west branches of the upper Niagara River (Figure 1). Setlines were configured according to protocols established by Michigan DNR; consisting of 300 foot mother lines (3/8" nylon) with 25 dropper lines (snews) attached at 10 foot intervals. Each snew consisted of 18" length of #36 tarred nylon twine, a net snap with swivel, and 1 Kirby sea hook size 4 (10/0) or one circle hook size 10/0 or 12/0. Setlines were baited primarily with round gobies; with native chubs, earthworms, and crayfish used periodically. Setlines were typically set at a 45-50 degree angle from the shoreline due to poor boat maneuverability in the river flows. Lines were fished for approximately 24 hours.

Fifty-three setlines were fished for a total of 89 individual setline nights. No lake sturgeon were collected via this method; however, one channel catfish (62.5 cm) was captured. Many factors likely contributed to the lack of success. Most importantly, large amounts of drifting algae and macrophytes were believed to be "clogging" the lines and bait, resulting in inefficient sampling. Also, the "needle-in-a-haystack" concept is likely applicable due to the inability to sample a large area with low numbers of lake sturgeon present. Aside from inefficient sampling, another problem associated with setlining included, drifting macrophytes on the surface caused floats to submerge, creating unmarked sampling gear. The enormous weight of the vegetation coupled with the fast current made pulling the lines a minimum 2-3 person task, which required an entire day to clean the lines as we pulled them in. This problem was likely associated with July sampling, when algae and macrophytes were abundant.


Figure 1.  The Niagara River.

Figure 1.  The Niagara River.

 

During August 1998, diver capture methods were implemented (experimentally) in the lower Niagara River. Chronologically, on 24 July our diver sighted numerous lake sturgeon while night diving in Peggy’s Eddy, a slack water area on the U.S. side of the lower river just downstream of Joseph Davis State Park (Figure 1). On 31 July and 1 August, we attempted to capture lake sturgeon via underwater snagging and netting. On 31 July, according to the divers "lake sturgeon were everywhere"; however, none were collected via snagging. A few lake sturgeon were hooked; however, they were too strong to remain hooked long enough for the boat crew to fish them. On 1 August, the divers netted two lake sturgeon underwater in Peggy’s Eddy using a standard salmon landing net (Table 1). On 14 August, the divers captured two more lake sturgeon in Peggy’s Eddy using the nets (Table 1).

Setlining began in the lower river on 27 July, followed by gillnetting on 4 August, after the initial diver success. Setlines were configured as stated above. Experimental gillnets, ranging in size from 2.5 to 10 inch stretch mesh, were set in Peggy’s Eddy, perpendicular and parallel to the shoreline. Six setline nights caught zero lake sturgeon, with similar problems occurring as described above. Thirteen gillnet nights caught three juvenile lake sturgeon (Table 1).

 

Table 1. Specifics of lake sturgeon collected in the lower Niagara River, 1998.

Date

Method

Total Length (mm)

Age

Depth of Capture (m)

Sonic Tag Number

1 August

Diver

337

1

13.7-15.2

 

1 August

Diver

705

3

13.7-15.2

266

11 August

Gillnet

854

5

10.0

347

14 August

Diver

966

6

9.1

338

14 August

Diver

847

5

7.6-9.1

356

25 August

Gillnet

866

5

8.7

248

27 August

Gillnet

725

4

9.3

239

 

Most lake sturgeon were captured in about 9.1 meters (30 feet) of water, with the exception of two diver caught fish in 15.2 m (50 feet) (Table 1). Biological measurements were collected from all fish, including tissue for genetics analysis. The six larger fish were marked with a tag for individual identification and received an ultrasonic tag for tracking purposes (Table 1; Figure 2).

Biologist conducting radio telemetry for lake sturgeonTracking started on a daily basis immediately after release, then twice per week, followed by twice per month. The last date of tracking was 11 December 1998. In addition to individual day tracking events, 24 hour tracking was performed on 31 August, 2 September, and 3 September to determine differences between day and night movements. Fish 266 remained in Peggy’s Eddy for 47 days, then moved downstream 5 kilometers (km) near the mouth of the river (Figure 3). Fish 347 entered Lake Ontario the day after it was released in Peggy’s Eddy, 5.5 km from the capture site. This fish continued to move slowly offshore in the lake (Figure 3). Fish 338 moved 6 km upstream the day after release. This fish continued to move upstream, then back down to the Stella Niagara area, followed 25 days after release by a large-scale movement to Lake Ontario (13 km) in one week (Figure 3). This occurred simultaneously when fish 266 moved to the mouth of the river. To date, an analysis of environmental conditions, which may have provoked these fish to dramatically move downstream, has not been completed. Fish 356 remained in Peggy’s Eddy for 88 days then moved upstream,6-8 km, to the Lewiston area (Figure 3). Two lake sturgeon, 239 and 248, have remained in Peggy’s Eddy during all tracking events (Figure 3 inset). We believe these fish are still alive and moving within a small range. In 1999, sampling will verify if these are live fish or lost tags circulating in the eddy currents.

Sampling and tracking the six sub-adult lake sturgeon has provided preliminary information regarding macro-habitat utilization. For example, all lake sturgeon were collected in a back-eddy environment. While remaining in the river, the lake sturgeon occupied nearshore, slower currents (eddys), with the exception of one point when fish 356 was found near Lewiston, NY in the center of the river where water velocity is higher (Figure 3). Also, as stated above, two fish have entered the lake environment. Depth measurements have been fairly consistent among all lake sturgeon locations, averaging 10.4 m (34 feet). Individual fish did not make large scale movements between day and night hours. However, their activity seemed to increase during night hours as shown by several small-scale movements within their locale.

Figure 2. Fishery Biologist Lowie and Biological Technician Hughes hold two juvenile lake sturgeon from the lower Niagara River. Notice the sonic tag applied to the dorsal scutes (white) and yellow disc tag applied to the dorsal fin area.

Figure 2. Fishery Biologist Lowie and Biological Technician Hughes hold two juvenile lake sturgeon from the lower Niagara River. Notice the sonic tag applied to the dorsal scutes (white) and yellow disc tag applied to the dorsal fin area.

Public Participation
Anecdotal information of lake sturgeon has been reported by recreationalists and commercial fishermen since 1994. This initiative has been implemented in all lower Great Lakes waters and continues to be a substantial contribution to population assessment in the Great Lakes. We summarized data from all sightings in the upper Niagara River from 1994-97, which included 40 reports of 117 fish (Figure 4).

Sightings from 1994-97 indicate successful natural reproduction and year class structure within the population as suggested by annual juvenile sightings, <24 inches. Also, the west river (mostly Canadian waters) has significantly (p = 0.00001) larger lake sturgeon (avg. 54 inches) reported than the east river (U.S. waters; avg. 21 inches) (Figure 5). This suggests possible habitat differences between the west and east rivers; however, data provided by participants indicate little difference. Average depth of sightings in the west and east rivers were 19 feet and 21 feet, respectively (p > 0.05) and substrate descriptions were similar. Many sightings were reported in June and July, likely biased by increased diving activity. The Frenchman’s Creek area received weekly dive trips throughout the diving seasons; however, a larger number of lake sturgeon were sighted during August (Figure 5), suggesting a high use area during this time.

Public education was significantly increased in 1998. First, an appreciation dinner was held at the LGLFRO for divers participating in the sighting program. As suggested at the dinner, a poster of the upper Niagara River was developed with current sightings (similar to Figure 4) and lake sturgeon educational items. The poster was placed in nine dive shops in Canada and the U.S. to increase awareness and sighting reports. A web page, entitled ‘Niagara River Lake Sturgeon 


Figure 3.  Locations of sonic tagged lake sturgeon.

Figure 3.  Locations of sonic tagged lake sturgeon.

 

Figure 4.  Niagara River lake sturgeon sightings 1994-1997 and 1998.

Figure 4.  Niagara River lake sturgeon sightings 1994-1997 and 1998.

 

Figure 5.  1994-1997 upper Niagara River lake sturgeon sightings identified by length and month of sighting.

Figure 5.  1994-1997 upper Niagara River lake sturgeon sightings identified by length and month of sighting.

 

Sturgeon Watch card Project’ was developed and placed on the Niagara Divers’ Association web site (www.vaxxine.com/nda). Lake Sturgeon Sighting Alert cards, developed by Ohio Division of Wildlife, were distributed to approximately 200 marinas, bait shops, and boat launches. Also, an ‘Alert’ notice was placed in the NYSDEC 1998-99 Fishing Regulations Guide to increase angler awareness and reports. As a result of the increased effort, 86 lake sturgeon reports with 120 sightings, were filed by our office in 1998 (Figure 3). Previously, the most reports ever submitted in one year to the LGLFRO was 12.

In 1998, 81 sightings from 59 reports (69%) were from the upper Niagara River. Compared to reports from 1994-1997, the 1998 upper river sightings showed increased diversity in the lengths of lake sturgeon in both the east and west rivers (Figure 6). Most sightings were reported in June and July, again likely due to increased diving activity. A significant finding from 1998 sightings was an abundance of YOY lake sturgeon at the northern tip of Grand Island, in the east river (Figure 6). Sixteen of twenty-four (66%) were sighted on 15 August. The lengths of most sightings were between 3 and 8 inches. This location is called the Grasse Island area due to a large island of emergent vegetation. The water currents appear to be reduced in this area. Divers reported substrates primarily of sand and gravel with some reporting cobble. Total depths averaged 15.5 feet, with a range of 12 to 18 feet. Vegetative abundance was reported sparse to moderate. The LGLFRO set gillnets and trawled in the area in mid-October; however only one mudpuppy was caught in the trawl.

Also, during the appreciation dinner divers suggested to conduct what was named a "mass dive." On 13 June, 1998, eight boats and a total of 26 divers from both Canada and the U.S. conducted the "mass dive" to better identify lake sturgeon distribution and abundance in the upper Niagara River (Figure 7). Two dives, spread across the width of the West Niagara River (Canadian side), covered approximately 6 km of river. Two juvenile lake sturgeon (approx. 12" and 24") were sighted by divers. These sightings were important because, prior to the "mass dive," only one juvenile had been reported (from 1994-1997) in the West River. Juveniles in the West River could be an indicator of successful reproduction occurring within this river branch.

The "mass dive" provided an excellent educational opportunity for the diving community to interact with LGLFRO biologists and learn more about the lake sturgeon. It also allowed LGLFRO biologists to further explore the potential for diver sightings to be used as a method of lake sturgeon population assessment.


Figure 6.  1998 upper Niagara River lake sturgeon sightings, identified by length and month of sighting.

Figure 6.  1998 upper Niagara River lake sturgeon sightings, identified by length and month of sighting.

 

Figure 7. Group picture of "mass dive" participants.

Figure 7. Group picture of "mass dive" participants.

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OSWEGATCHIE RIVER JUVENILE ASSESSMENT

The Oswegatchie River lake sturgeon project is in cooperation with the New York State Department of Environmental Conservation (NYSDEC) and the State University of New York - College of Environmental Science and Forestry. To determine the success of the restoration effort several objectives were set forth. These included determining the distribution, movement, and habitat utilization of stocked juvenile lake sturgeon in the Oswegatchie River, tributary to the St. Lawrence River at Ogdensburg, NY.

Juvenile lake sturgeon being floy taggedThe sampling to determine downstream distribution of stocked lake sturgeon was finished with a total of 88 river kilometers covered. Gillnetting was conducted on 48 nights consisting of 244 individual gillnet sets. This yielded 362 lake sturgeon comprised of 4 year classes. A total of 145 lake sturgeon were captured from the 1997 stocking year class, 175 lake sturgeon from the 1996 stocking year class, 39 from the 1995 stocking year class, and 1 lake sturgeon from the 1994 stocking year class. In addition, one native lake sturgeon was captured from the 1986 year class. The mean total length and weight for age class 1, 2, and 3 are 271.5mm and 78.7g (N=145), 456.5mm and 386.7g (N=159), and 560.9mm and 679.6g (N=28), respectively.

Diet analysis was conducted on 141 juvenile lake sturgeon captured in the Oswegatchie River. Of the 141 lake sturgeon stomachs pumped, 75 contained at least one prey item. In total 1,464 prey items were consumed by the 75 juvenile lake sturgeon. Major food items in the diet of lake sturgeon were Dipterans (Chironomidae), Ephemeropterans, and Trichopterans with a percent composition of 37.3%, 29.1%, and 13.1%, respectively. The next abundant food item was ostracods (4.3%) and Bivalvia (2.9%). Benthic samples were also collected to determine prey availability and to characterize habitat. At this time the samples are not yet processed.

Figure 8. Lake sturgeon age-class distribution in the Oswegatchie River, NY.

Figure 8. Lake sturgeon age-class distribution in the Oswegatchie River, NY.

 

After three consecutive years of stocking, the lake sturgeon showed an interesting distribution pattern. From the mouth at the St. Lawrence River upstream to Natural Dam, 88 river kilometers were sampled. The 1997 stocking year class was distributed in roughly the upper 40 kilometers of river (rkm 88 - 43), with the exception of two 1997 sturgeon occurring in the remaining 40 kilometers of river downstream (Figure 8). The 1996 stocking year class distribution overlaps the 1997 year class and continues downstream to the mouth of the river (rkm 88 - 0) (Figure 8). The 1995 stocking year class was distributed in the lower reaches of the river from river kilometer 18 to the mouth (rkm 18 - 0) (Figure 8).

Radio telemetry was used to describe movements and habitat utilization of stocked juvenile sturgeon. A total of 20 juvenile sturgeon were radio tagged and tracked biweekly. The radio tagged fish were composed of 10 newly released hatchery lake sturgeon and 10 naturalized lake sturgeon. The newly released sturgeon were obtained from the NYSDEC Warmwater Hatchery in Constantia, NY and the naturalized sturgeon were obtained through gillnetting in the Oswegatchie River. Habitat analysis will be conducted for high use areas of both the newly released sturgeon and the naturalized sturgeon.

Movements of radio tagged juvenile lake sturgeon were monitored and show an interesting pattern. The radio tagged lake sturgeon were released in pairs for comparison purposes, one naturalized fish and one newly released hatchery fish. The newly released hatchery lake sturgeon were held in a holding pen in the river until naturalized sturgeon could be obtained. At that point a pair would be released at the capture site of the naturalized sturgeon and movements monitored. The general pattern displayed by ten naturalized sturgeon is localized movements (approx. 200 - 300 m) with some exceptions. The ten newly released hatchery lake sturgeon show a general pattern of downstream movement, in some cases in excess of 70 kilometers. All ten newly released hatchery lake sturgeon moved downstream an average distance of 32 kilometers. Lake sturgeon that were radio tagged in 1998 will continue to be monitored in the 1999 field season.

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Summary of Preliminary Results and 1999 Activities

The information collected from all activities suggests lake sturgeon numbers are increasing, but still impaired with relation to historical abundance. Increased effort to educate the public has been extremely beneficial. Recent sightings in the Niagara River indicate age-class structure within the current population. For example, 36 lake sturgeon have been reported between 0 and 24 inches, 15 between 25 and 48 inches, 13 from 49 to 72 inches, and 1 greater than 72 inches. Although, setlines did not prevail as an effective method to capture adults in 1998, diver capture has proven to be effective with smaller lake sturgeon. In addition, areas have been identified where effective gillnetting and other methods can be implemented. The collection of tissue samples for genetics analysis is ongoing and our partners are in the process of identifying the DNA microsatellite loci for population identification. The LGLFRO will host a Great Lakes Lake Sturgeon Genetics Workshop in late-summer 1999.

A comprehensive study of the lake sturgeon population in the lower Niagara River will be the primary objective for 1999. Gillnetting, SCUBA diver capture methods, and baited setlines will be the primary methods used to capture adult and juvenile lake sturgeon. Lake sturgeon movements and habitat use will be examined in the Niagara River in order to identify and assess the current condition of adult spawning habitats, feeding habitats, and juvenile nursery areas. Ultrasonic telemetry of adult and juvenile fish will provide the necessary information to identify lake sturgeon "high use" areas in the river and to collect biotic and abiotic data within the lake sturgeon’s preferred habitats. Fish sampling in the upper Niagara River in 1999 will be more experimental in nature. Similar methods as those used on the lower river will be implemented on a limited basis, with a greater emphasis on locating concentrations of fish rather than capturing individuals.

With the Lake Sturgeon Sighting Program now in its sixth year, we will expand it even further. Updated posters, sturgeon alert cards and additional sighting forms will be distributed in several dive shops, marinas, and bait shops in both the U.S. and Canada. The posting of the ‘alert’ notice in the NYSDEC 1998-99 Fishing Regulations Guide is suspected to gather considerable attention and result in a large number of sighting reports. In addition, we will likely perform two "mass dives" in the upper Niagara River during June and September, 1999.

The Oswegatchie River restoration project, which encompasses evaluating the success of NYSDEC’s hatchery product and stocking strategies, has had tremendous success in 1998. The distribution, survival, and movements of the juvenile lake sturgeon will be completely analyzed during 1999.

Lastly, biologists from USGS Tunison-Cortland, Region 8 NYSDEC, and our office will be conducting lake sturgeon habitat assessments in the Genesee River, a tributary to Lake Ontario at Rochester. In brief, habitat and fish sampling will be conducted to evaluate the Lake Sturgeon Habitat Suitability Index Model, prepared by Ontario Hydro. Sampling will be conducted during the suspected spawning period and periodically throughout the summer months. If lake sturgeon are collected, radio transmitters will be applied for movement and habitat utilization information.


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