Ontario Ministry of Natural Resources
Upper Great Lakes Management Unit - Lake Superior
Lake Sturgeon Assessments
2001-2002 Update

 

Contents        Black Sturgeon River    Kaministiquia River    Goulais River    Pic River

 

Black Sturgeon River: Lake Sturgeon Assessments

The Black Sturgeon River is one of Lake Superior’s largest north shore tributaries.  The majority of the river alternates between slow moving water with deep channels of silt and sand and riffle-pool areas containing large amounts of cobble and gravel.  The Camp 43 dam, also known as the Twin Rapids dam, is located approximately 16.3 km above the river mouth. The dam has fragmented this population into an isolated land locked stock and Lake Superior stock.  Access to spawning, nursery and foraging habitat in the upper Black Sturgeon River is therefore, no longer available.

In August 2001, biological information was collected from lake sturgeon that were congregating in the shallow water below the Camp 43 dam.  Seven sub-adult lake sturgeon (695-912mm fork length) were dip netted and sampled.

 

Lake sturgeon caught below the Camp 43 Dam
Lake sturgeon caught below the Camp 43 Dam

 

A comprehensive study to collect baseline information on the Black Sturgeon River  population was carried out from May 27 to June 14, 2002.  Lake sturgeon were captured using 45.72m 254mm (10”) and 305mm (12”) stretched mesh, multifilament gill nets.  All sturgeon were sampled for fork length, total length and were tagged with a five digit, white floy tag applied along the left-hand side of the dorsal fin.  A small section of the distal portion of the left pectoral fin was removed for genetic analysis. Water temperatures ranged from 11.5 to 16.3 0C during the sampling period. Nine sturgeon were captured from twenty-four lifts. The following table summarizes the fish attribute information.

 

Date

Tag Number

Fork length (mm)

Total Length (mm)

Legal Length (mm)

Weight (g)

Sex

28-May-02

09008

935

990

577

7250

M

28-May-02

09011

1240

1306

750

18144

M

30-May-02

09013

990

1069

605

9000

M

30-May-02

09014

1250

1292

798

16783

M

31-May-02

09015

1140

1219

762

14061

M

31-May-02

09016

940

1020

585

17100

M

07-Jun-02

09017

1075

1162

685

9400

?

07-Jun-02

09018

1162

1232

744

13608

M

14-Jun-02

09019

1020

1085

662

10400

?

 

Kaministiquia River: Lake Sturgeon Radio Telemetry Updates

In June of 2001, six additional juvenile sturgeon ranging in weight from 1.25 kg (2.7 lbs) to 2.75 kg (6 lbs) were radio tagged.  Tracking commenced soon after the radio tags were implanted and will continue for the duration of the tag life.

What have we learned since September of 2000?

The adults tagged seem to be river residents as none have been located in Lake Superior.

Evidence that the juveniles do leave the river came to light with the capture of one fish in a commercial net, approximately 100 km away near Hovland, Minnesota.  Another juvenile that couldn’t be located in the river returned 22 months later.

Warm weather and high water levels characterized the spring of 2001.  Six of the radio tagged adults began to migrate upstream from the lower river on May 4, 2001 at 8 0C and arrived at Kakabeka Falls from May 10 to May 22nd.  These fish spent two to four weeks in the spawning area and had returned to the lower river by June 12, 2001.  One adult stayed at the Falls until August13th.  The adults were most often located just downstream of the Falls and above the Ontario Power Generation hydro plant (850m downstream).

Cold weather and low water levels characterized the spring of 2002.  Two radio tagged adults left the lower river and moved upstream on May 13, 2002 at 8.9 0C.  These fish were unable to access the portion of the river previously utilized in the spring of 2001.  Low water levels and minimal flows over Kakabeka Falls forced the fish to congregate below the hydro plant.  The control dams and intake are located upstream of the Falls and are used to draw water for hydropower interests.  During years of low springtime flows the present hydro operating policy may negatively affect lake sturgeon spawning success by preventing access to traditional spawning areas. The radio tagged sturgeon returned to the lower river by June 25th.

 

Kakabeka Falls in May 2002
Kakabeka Falls in May 2002

 

 

Goulais River: Lake Sturgeon Assessments

The Goulais River is one of the largest tributaries of eastern Lake Superior.  Historically, First Nations people, commercial fishermen and local residents have fished its waters for spawning lake sturgeon and other game species. The Goulais River Watershed covers an extensive area and the river and its feeder streams were important to lumber companies to drive logs to local sawmills until the early 1900s. Presumably, deforestation and log sluicing in the Goulais River Watershed had detrimental effects on the river and indirectly the lake sturgeon. There was increased sedimentation, and bark and logs covered feeding and spawning areas on the river bottom.

As settlement increased in the Goulais River valley exploitation of spawning game species, notably walleye and lake sturgeon, developed as a traditional activity for local residents in Searchmont. The preferred spawning sites for lake sturgeon are adjacent to this settled area.

An electric lamprey barrier was located on the river from 1956-1960. The barrier was not only selective for lamprey, but also numerous game species, including sturgeon, were killed. The barrier inhibited the upstream passage of lake sturgeon, thus preventing access to spawning locations.

The purpose of this study was to gather information on the population and physical characteristics (size and age at maturity) of Lake Superior lake sturgeon when they are present in the Goulais River. This information will provide managers and biologists baseline data to identify opportunities to enhance and rehabilitate lake sturgeon stocks.  Consistent with the Fish Community Objectives for Lake Superior, the Working Group of the Lake Superior Binational Program has suggested that population levels of lake sturgeon may be useful as a potential indicator of ecosystem health (Ecosystem Principles and Objectives for Lake Superior, Discussion Paper, 1994).

The netting exercises on the upper Goulais River from Searchmont to Whitman Dam Falls in May 2000 produced only one productive site, at the pool at the base of the falls.  Additional sites were sought out this year on the lower Goulais River from the boat launch on Grant Side Road to the mouth.  No new sites were discovered as water depths were inadequate for netting and watercraft safety.  All netting exercises were performed in the large pool at the base of the Whitman Dam falls from May 08 to May 29, 2001. The lake sturgeon (n=9) ranged in size from 4.9 kg (11 lbs.) to 22.9 kg. (50.5 lbs.). All the sturgeon except one were identified as ripe males by externally examining the fish for their reproductive condition. Fish attributes were recorded and a pectoral fin ray was removed for aging. This information will provide managers and biologists with baseline data on the population status of this spawning stock.

Seasonable temperatures and low precipitation characterized the weather during the netting exercise. Water levels decreased significantly during the project, which may have deterred further migration of the lake sturgeon up the Goulais River. Surface water temperatures ranged from 10 to 15.5 º C.

 

Summary of 2002 Pic River Lake Sturgeon Assessment
Prepared by Henry Quinlan

Introduction

Eight agencies cooperated to sample lake sturgeon and collect tissue samples for genetic analysis in Lake Superior in 2002.  Participating agencies included Ontario Ministry of Natural Resources, Department of Fisheries and Oceans, Pic River National Park, Pic River First Nation, Bad River Band, Great Lakes Indian Fish and Wildlife Commission and the U.S. Fish and Wildlife Service.  The 2002 work schedule developed by the cooperating agencies proposed that lake sturgeon be sampled in the Pic, Michipicoten, and Kaministiquia rivers, Ontario and the Bad and White rivers, Wisconsin.

All rivers were sampled with the exception of the Michipicoten River.  Release of large volumes of water by Great Lakes Hydro during the scheduled period of sampling resulted in our inability to safely work on the river and no attempt was made to capture lake sturgeon in 2002.

 

Dan Couchie (Pukaskwa National Park) releases lake sturgeon
Dan Couchie (Pukaskwa National Park) releases lake sturgeon
after data collection.

 

Results

This is a large river with low to medium gradient that empties into northeast Lake Superior at Pukaskwa National Park near the community of Marathon.  Population characteristics and abundance of lake sturgeon in the Pic River system is currently unknown.

Three tributaries to the Pic River system were sampled in the survey effort.  They were the Black, Little Black, and Kagiano rivers.  The Little Black River is a tributary to the Black River, which joins the Pic River about 2 miles from the mouth at Lake Superior.  The Kagiano River confluence is about 8 miles downstream from Manitou Falls, located about 60 river miles upstream from Lake Superior.  Manitou Falls is the downstream most barrier to fish passage on the Pic River.

We conducted 64 separate sampling efforts on the river over a period of 14 days.  Gear used was primarily large mesh gillnets (8” and 10”) as well as some set lining.  Gill net effort totaled 47 net nights.  Net length ranged from 50-200’.  Set line effort totaled 17 night sets.  Length of set line ranged from 25-100 feet.  Nets and set lines were checked daily.  Bait used for set lines was lake herring.  We sampled 2 large areas, one covering 10 miles upstream from the Lake Superior and a second at impassible barriers on the Pic and Kagiano rivers, approximately 60 miles upstream from the lake.

A total of 17 fish were caught.  One fish was captured twice.  Sixteen lake sturgeons were sampled, tagged and released.  In the Pic River 13 lake sturgeons were captured including the recaptured fish.  Three lake sturgeons were captured in the Kagiano River, and one in the Black River.  Three fish were ripe males in spawning condition and the sex of the remaining fish was undetermined.  We suspect that several were mature but unripe fish and that the smaller fish were non-spawning or immature individuals.  The lake sturgeon captured in the Black River is not included in the chart below.  Total length of that fish was 96.5 cm.

 

Bill Gardner (DFO) releases sturgeon after workup
Bill Gardner (DFO) releases sturgeon after workup
at the mouth of the Kagiano River.

 

Summary

This was the first year a fish survey (other than sea lamprey) was conducted in the Pic River, Ontario.  As a result a lot of crew effort was spent learning where and how to sample this river system.  Information and assistance provided by local individuals from  OMNR, Pukaskwa National Park and Pic River First Nation proved invaluable to field crews and enabled us to accomplish more than we could have without their help.

The majority (14 of 16 individual fish) of sturgeon were captured in the Pic River near the confluence of the Pic and Kagiano rivers.  This area also received greater sample effort, which may in part account for the greater catch.

Suitable spawning habitat appears to be present at Lower Falls on the Kagiano River, at Manitou Falls on the Pic River, and below the hydro power station on the Black River.  Of these sites, the Kagiano River appears to have more area with suitable substrate and flow conditions.  Local anglers indicated that sturgeon were present at Lower Falls of the Kagiano River  moreso than at Manitou Falls on the Pic River.  The Nama River, a tributary to the Pic River, may also support spawning lake sturgeon.  Logistics of sampling the Nama River are more difficult due to lack of access, but this tributary should be considered in future surveys.

The cooperating Lake Superior agencies intend to continue sample collection in the Pic River and other selected Lake Superior rivers in 2003 to acquire the requisite number of tissue samples (30) for the study design.

 

Pic River

 

For questions please contact Mike Friday


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