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Lake Winnipeg Zebra Mussel Treatment and Control Project
Frequently Asked Questions & Answers
Since Zebra Mussels were found in Lake Winnipeg in the Fall of 2013, the Department of
Conservation has explored a number of options to address the issue, culminating in the
Treatment and Control Project in 4 harbours. This document contains answers to frequently
asked questions, including common questions posed by Manitobans in the community
meetings held this Spring. Should you have further questions or comments please reach us at
the AIS contact line or e-mail noted at
http://www.gov.mb.ca/conservation/waterstewardship/stopais/
For more information, please contact…..
General and Media Inquiries:
Project Coordinator Spokesperson – Rob Nedotiafko 204-792-2926 (cell)
Specific Harbour Authority / Marina Inquiries
Gimli Harbour Authority – Gord Gowie 204-642-2374
Winnipeg Beach Harbour Authority – Ed Isfeld 204-389-2649
Winnipeg Beach Boundary Creek Marina – Dean Thorkelsson 204-642-8116
Arnes Harbour Authority – Chris Dhalman 204-642-3050
Arnes / Silver Harbour Marina – Geoffrey Penner 204-642-7245
Balsam Bay Harbour Authority – William Thomas 204-754-2503
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Table of Contents 1) What was found and where in Lake Winnipeg? ............................................................................... 1
2) What are the actual numbers of zebra mussel found per harbour? ................................................ 1
3) What are the steps that we have taken so far? ................................................................................ 2
4) Who is on the Science Advisory Committee and was its recommendation unanimous? ................ 3
5) What other experts would support this approach?.......................................................................... 3
6) What are the key impacts of further invasion and timing of the same? .......................................... 4
7) How many fishers fish out of each impacted harbour (estimated)? ................................................ 4
8) How many fishers fish out of all other harbours in total? ................................................................ 4
9) Who have you consulted with by location? ...................................................................................... 4
10) What legal authority do we have to restrict access to the harbours? .............................................. 5
11) How many tonnes of potash will be likely applied? ......................................................................... 5
12) What other treatment options were looked at? .............................................................................. 6
13) Why were other treatment options ruled out? ................................................................................ 6
14) Has the Department checked again this Spring to see if mussels survived the winter; or, were
they deep enough to survive? .......................................................................................................... 6
15) If they exist outside the harbour, will the harbour closures be cancelled? ...................................... 6
16) Can any boats go over the barrier on a limited basis?...................................................................... 7
17) Could the application of anti-fouling paint on the commercial fishing skiffs reduce the risk of
spread if access is provided from the harbours. ............................................................................... 7
18) What alternate access will be provided to the fishers? .................................................................... 7
19) What is the estimated date of the harbour disruption(s)? ............................................................... 8
20) Can sand or anything else be placed on top of the ice, or the ice be broken up, at the Gimli and
Balsam Bay harbours to facilitate melting the ice quicker so the treatment can possibly be done
prior to the start of the commercial fishing season? ........................................................................ 9
21) What is the plan for the two harbours where stream flows enter? ................................................. 9
22) What is the reasoning behind when the barriers need to be in place? ............................................ 9
23) Is the permeability of the wharfs and break water walls not a concern? ........................................ 9
24) Can the treatment be delayed until either after the spring commercial fishing season finishes in
July or later in the fall? ...................................................................................................................... 9
25) Zebra Mussels have been known to be in the harbour for at least three years. ............................ 10
26) Is nitrogen in whatever will be applied? ......................................................................................... 10
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27) Will adding potash to the harbours contribute to an increase in algal growth and increased
eutrophication? ............................................................................................................................... 10
28) What is the encroaching threat from other jurisdictions? ............................................................. 10
29) What prevention efforts have been taken by Manitoba? .............................................................. 11
30) A very brief description of the potash potential and the chances of success as well as its
uniqueness and cost. ...................................................................................................................... 12
31) Have all approvals been provided? ................................................................................................. 12
32) Has there been any consideration given to safety and how the Canadian Coast Guard and Search
and Rescue auxiliary that operate out of Gimli will operate during the harbour closure? ............ 12
33) What about the safety of boaters who are out and unaware that the harbours are closed? ....... 12
34) The number of marinas. .................................................................................................................. 13
35) The plan to minimize impacts on marina owners. .......................................................................... 13
36) What has the extent of discussion been with Lake Wpg Research Consortium? ........................... 13
37) Will the treatment have any effect on either the boat finish, softer metals on the boats and /or
anodes? ........................................................................................................................................... 13
38) How will you know when the treatment is 100% effective? .......................................................... 14
39) What is Manitoba Hydro doing to prepare for potential effects of Zebra Mussels?...................... 15
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Lake Winnipeg Zebra Mussel Treatment and Control Project
Q & A Reference Book
1) What was found and where in Lake Winnipeg?
After checking the following areas:
accessible hard structure and dry docked boats from Gull Harbour on the west side of
Lake Winnipeg to Seymourville on the east side as well as veliger sampling at locations
along the west side.
In-depth assessment of Gimli, Winnipeg Beach and Balsam Bay Harbours (divers
checking substrate at depth), veliger sampling
navigational buoys removed from the Red River, Lake Winnipeg and Nelson River as well
as swimming and navigational buoys removed from Whiteshell Provincial Park locations.
Jenpeg GS station and results from annual zebra mussel monitoring at Generating
Stations along the Winnipeg River and the Selkirk GS.
Hard infrastructure on the Red River, from and including St. Andrews Lock and Dam
through Selkirk to Breezy Point, as well as veliger sampling at these locations
Monthly veliger sampling in the Red River at Emerson
Analysis of 64 water samples taken from the summer and fall Namao cruise
An underwater camera to check the stern of the Namao.
Divers checking under the ice at Gimli Harbour and at depth at Winnipeg Beach Harbour.
Zebra mussels were found or reported at:
Silver Harbour Marine Resort/Arnes Harbour – sailboat
Gimli Harbour – adults and veligers: underside of docks, dry docked vessels, bottom of
Namao
Willow Point – small man made harbour: underside of docks
Boundary Creek/Winnipeg Beach Harbour – underside of docks; watercraft; on a pier
below the depth of ice formation.
Whytewold Beach area – bottom step of swimming pier
Balsam Bay Harbour – underside of docks; commercial fishing boat
Recieved a report and verified the samples as zebra mussels – found dead on a piece of
PVC stuck amongst shoreline debris in Traverse Bay – 2011.
2) What are the actual numbers of zebra mussel found per harbour?
Adult zebra mussels:
Gimli Harbour - 150
Boundary Creek/Winnipeg Beach - 190
Balsam Harbour - 83
Whytewold swimming pier – 2 piers – 1/pier
2
Silver Harbour/Arnes – 12 (taken off sailboat)
Private dock on Willow Island Rd. – 2
Veligers (larval stage):
Gimli Harbour - 2
3) What are the steps that we have taken so far?
Initiated a standard rapid response protocol which has included to date, the following phases:
Confirmation - confirm the mussel was a zebra mussel
Demarkation – determine the distribution and magnitude of the zebra mussel, convene a
Science Advisory committee to review preliminary data and communicate with stakeholders
(Fall 2013 media release, interviews, articles, presentations)
Zebra mussel were found at four harbours – Silver/Arnes; Gimli; Boundary Creek/Winnipeg
Beach, Balsam Bay and a man made harbour as well as reported and confirmed from two
swimming piers removed from Whytewold and a PVC pipe with zebra mussels (appeared dead)
removed from shoreline debris along Traverse Bay (2011)
Data collected to date suggest a very early level of infestation.
Containment – evaluate the need for containment: shortly after the confirmation of zebra
mussels, the Department deployed the decontamination units and staff to key areas. While
there was a lot of fishing activity in the Red River and a tournament occurring at Traverse Bay,
many boats were already removed and being stored for the winter.
An enhanced containment plan including greater education and advertising and additional
decontamination unit staffing has begun. Additional resources will be considered as well.
Risk Assessment – the Science Advisory Committee reviewed the data collected and control
options available. After identifying the risks and benefits associated with various controls,
including no control, the SAC strongly recommended the Province eradicate the harbours with
liquid potash. The potassium in the potash is lethal to zebra mussels not to finfish at the
concentration required and is not considered a human health concern.
Federal and provincial regulatory bodies have reviewed requirements and indicated no
concerns: DFO approval to close Small Craft Harbours, DFO SARA permit, Transport Canada
Navigation Waters Act, provincial pest permit and live fish handling permit.
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Monitoring – a key to evaluating the long term success of the eradication effort as well as
determining whether there is an established zebra mussel population in the lake. Discussions
are ongoing with the SAC in terms of what is required for the upcoming open water season.
Communication to date has provided an update on findings and concerns associated with zebra
mussels and options the Province is considering.
Summary of Presentations to Stakeholders:
Lake Winnipeg Fisheries Co-Management Board (Nov & April)
CANMAN Fisheries Advisory Committee
Lake Winnipeg Research Consortium
Lake Winnipeg Environment Canada MOU Committee Meeting
Freshwater Harbour Authority Council (Feb & April)
Mid Canada Marine Boat Show
Manitoba Lodges and Outfitters
Manitoba Wildlife Federation
South Basin Reeves and Mayors
Walleye Angler Association of MB
Lake Friendly Alliance
Articles have been placed in The Mid Canada Boat Show guide; Lake Winnipeg Foundation
Newsletter; The Whiteshell Echo; The Grindstone Gazette; The Cottager Magazine (May)
4) Who is on the Science Advisory Committee and was its recommendation unanimous?
Recommendation was unanimous
Membership on the committee is:
Dr. Gerry Mackie (Prof Emeritus – U Guelph) – Zebra Mussel expert
Renata Claudi - MSc. – Zebra Mussel expert
Dr. Scott Higgins (DFO IISD) – Zebra Mussel expert
Justin Shead MSc. – MCWS – AIS expert and Water Science specialist
Dr. Jeff Long – MCWS
Dr .Patricia Ramlal - DFO
Dr Todd Morris – freshwater mussel expert
5) What other experts would support this approach?
Most likely AIS colleagues nationally and internationally as well as those with the authority to
manage invasive species in other jurisdictions.
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6) What are the key impacts of further invasion and timing of the same?
In areas where zebra mussels have established the following have been observed: Increase in water clarity Increase in aquatic vegetation Increase in toxic algal blooms Shift in food web Decrease in native mussel populations Lake Whitefish populations declined (average 20% decline in all great Lakes and up to 70-80% in Lake Ontario) Walleye in eastern Lake Ontario have declined. Reduced recreational potential Reduced value in lakeshore properties; increased cost to tax payers Clogged water intakes Severity and range of impacts can vary from waterbody to waterbody. In the Great Lakes it took approximately 5 years to become fully infested, the impacts peaking just after the five years and levelling off – to date none of the impacts have been reversible. Economic cost of zebra mussel to Ontario has been estimated at between $70-90 M/year.
7) How many fishers fish out of each impacted harbour (estimated)?
Arnes (Silver) – 8 Gimli Harbour – 64 Balsam Bay – 10 Winnipeg Beach (Boundary Creek) – 39 TOTAL: Approximately 120 to 140
8) How many fishers fish out of all other harbours in total?
649
9) Who have you consulted with by location?
In addition to relevant CWS provincial (head office and regional – including Compliance) and federal staff (SCH, DFO Science) Arnes (Silver Harbour): Silver harbour Resort Marina Owner and clients Yacht Club leader RM Mayor/CAO Town Administrative people Harbour authority
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Commercial fishers Local game and fish group Gimli: Mayor and CAO Gimli/Winnipeg Beach Commercial fishers Yacht club Harbour Authority Lake Winnipeg Research Consortium Canadian coast Guard and Coast Guard Auxiliary Search and Rescue Local Game and Fish Winnipeg Beach: Mayor and CAO Commercial fishers Boundary Creek Marina Owner Harbour authority Local game and fish Balsam Bay Mayor and CAO Commercial Fishers Harbour Authority Winnipeg: Lake Friendly Alliance
10) What legal authority do we have to restrict access to the harbours?
This is federal Small Craft Harbours authority
11) How many tonnes of potash will be likely applied?
It is estimated that a total of 404 metric tonnes of 20% KCl (liquid potash)will be required to
treat the ~356,000 to 427,000 M3 water contained in Gimli, Balsam, Arnes and Winnipeg Beach.
The estimated breakdown of potash per harbour is as follows:
Gimli - 181 tonnes
Balsam - 12 tonnes
Arnes - 115 tonnes
Winnipeg Beach - 92 tonnes
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12) What other treatment options were looked at?
Physical treatments: hand picking, re-suspending sediments, de-watering the harbours
Biological treatment: Zequanox
Chemical treatments: reduce pH, copper sulphate and chlorine
Non Chemical: electric current
13) Why were other treatment options ruled out?
They were ruled out for a number of reasons including for each option one or more of the
following:
Uncertain effectiveness
Would kill everything that was in the area being treated with long term environmental effects
Human health risks
Logistically impractical
Not approved for use in open water situations
14) Has the Department checked again this Spring to see if mussels survived the winter;
or, were they deep enough to survive?
Regional staff used an underwater camera to check the bottom of the stern of the MV Namao
and found zebra mussels attached in a six foot area. This provides evidence that if zebra mussel
found substrate below ice formation and scouring they can survive.
At the recommendation of the Local Implementation Committee (fishers, harbour authorities
and government) divers were hired to look for zebra mussels inside the harbour and at sites
outside of the harbours. On Thursday May 8th divers dove in Gimli harbour (inner breakwater
wall in front of the Namao , the underside of the Namao as well as the entrance of the
breakwater wall). Zebra mussels (3) were found on bottom of the Namao. Divers also dove at
Winnipeg Beach harbour and of the areas checked one zebra mussel was found on a pier. Diving
at sites outside of the harbours was postponed due to difficulty in identifying suitable locations
and for safey reasons.
15) If they exist outside the harbour, will the harbour closures be cancelled?
They could exist elsewhere, however the initial examination of the lake, while shortened by the onset of winter, involved checking other parts of the lake. A precautionary principle is being applied based on what is known and recommended by the Science Advisory Committee. It is known that the harbour areas are prime habitat for the mussels because they contain hard surfaces.
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Treating the mussels in the harbour also removes one of the main vectors to transport mussels from harbour to harbour -- the boats that moor there. This treatment represents one shot at removing them from the harbours and potentially eliminating them. Divers and cameras will be checking outside of the harbour, if conditions are safe.
16) Can any boats go over the barrier on a limited basis?
After discussions with the Local Implementation Committee (fishers, harbour authorities and
government), the containment barrier was re-designed so commercial and subsistence fishers
will be able to access the lake should the treatment overlap with the start of the commercial
fishing season. To offset potential dilution/loss of potash monitoring the potash concentration
will occur more frequently and potash will be added as required to maintain the target
concentration. Standard Operating Protocols will be developed with respect to addressing the
potential to move microscopic egg and veliger states outside of the harbour.
17) Could the application of anti-fouling paint on the commercial fishing skiffs reduce the
risk of spread if access is provided from the harbours.
Anti-fouling paint certainly works in prohibiting zebra mussel from attaching. It would not
address the potential for veligers to be drawn into the boat motor intake or carried in water
collected in the boat or on equipment. Nor would it address the risk of veligers passing over top
of the containment barrier.
Making the use of anti-fouling paint mandatory is probably premature because if the boats are
dry-docked for the winter the mussels will die anyway. If the lake ends up being severely
infested then it is likely wise for individuals to apply anti-fouling paint to reduce the negative
impact that mussels have on fuel consumption. It is likely best to wait and see what happens in
the first 2 or three years after this treatment. If zebra mussels increase in numbers by orders of
magnitude (e.g. 10x to 100x to 1000x) in first few years then anti-fouling paint or some control
option for industries/utilities would be recommended on a cost-benefit basis.
Non-ablative paints (do not leach the toxin) are preferred because they do not release toxic
compounds into the water. Hulls are not the only place that mussels attach; they also attach on
anchors, chains, anchor vaults, motors, etc., that are often ignored in control options. If the
coating contains metals, its toxicity may be affected by water hardness.
18) What alternate access will be provided to the fishers?
The revised plan is to provide “gated” barriers at Winnipeg Beach, Gimli and Arnes Harbours so there is no longer any need to provide alternative access sites for those fishers.
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Commercial fishers from Balsam Bay Harbour have offered to access the the lake from Victoria Beach Harbour.
Domestic fishers can also access the lake at the three “gated” harbours or if from Balsam Bay then the Victoria Beach Harbour as well as public launch facilities.
Recreational fishers can access the lake from harbours not being treated or other access sites around the south basin.
Those recreational boaters who have paid to moor at the “treated” harbours can moor their vessels but are encouraged not to leave for the duration of the treatment.
19) What is the estimated date of the harbour disruption(s)?
It is difficult to provide estimated dates as it depends on when the ice comes off the harbours
and in the case of Winnipeg Beach and Silver Harbour when the creek flow slows downs. Once
the barriers are in place the duration of the treatment may be up to four weeks.
The duration of the treatment depends on water temperature. The colder the water the slower
zebra mussels breathe and the longer it takes for them to take in the potash. At warmer
temperatures it takes less time. For example at 10 degrees C it can take 7-10 days for them to
die while at 15 degrees C it takes under 5 days.
While the zebra mussels will be taking the potash in at a slow rate as soon as it is put into the
water, once the water temperatures reach 10 degrees C it is estimated to take 7-10 days to kill
them all. The May 15, 2014 news release estimated the following chronology.
Boundary Creek Marina / Winnipeg Beach Harbour:
installation of the gated silt curtain: May 21 to 22
charging of harbour waters with liquid potash: May 23 to 25
estimated treatment completion date: June 3
Silver Harbour Marine Resort/Arnes Harbour:
installation of the gated silt curtain: May 23 to 24
charging of harbour waters with liquid potash: May 26 to 28
estimated treatment completion date: June 6
Gimli Harbour:
installation of the gated silt curtain: May 25 to 27
charging of harbour waters with liquid potash: May 29 to June 1
estimated treatment completion date: June 10
Balsam Bay Harbour:
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installation of the gated silt curtain: May 28 to 29
charging of harbour waters with liquid potash: June 2 to 3
estimated treatment completion date: June 12.
Please check our website at www.manitoba.ca/StopAIS to get the most up to date treatment
schedule dates.
20) Can sand or anything else be placed on top of the ice, or the ice be broken up, at the
Gimli and Balsam Bay harbours to facilitate melting the ice quicker so the treatment
can possibly be done prior to the start of the commercial fishing season?
Based on the current schedule, the ice will be off the harbours before the treatment starts.
21) What is the plan for the two harbours where stream flows enter?
For these two harbours (Silver/Arnes and Winnipeg Beach) the plan was to monitor the spring
stream runoff and as soon as it has slowed place the barriers at the entrance of each harbour.
There was also discussion on the feasibility of blocking the streams at their entrance into these
harbours to pump and pipe excess water around to Lake Winnipeg. The final decision was to use
“gated” barriers at these sites so in the event of a precipitation event the gate could be lowered
to discharge excess water.
22) What is the reasoning behind when the barriers need to be in place?
At 10 degrees C zebra mussels can start reproducing. A single female may produce up to 1
million eggs in a single spawning event. The eggs and larval stage are free floating and
microscopic so they are easily dispersed through current and by human activity. Therefore,
Spring treatment was strongly recommended by the Science Advisory Committee
23) Is the permeability of the wharfs and break water walls not a concern?
The permeability of the harbour wall is not expected to be a significant problem: diffusion of
potash through minor gaps and cracks is expected to be slow and will also result in killing any
mussels that may be lodged in these same openings. The consultant will monitor potash
concentrations within the harbour to ensure that sufficient potash is present to kill zebra
mussels.
24) Can the treatment be delayed until either after the spring commercial fishing season
finishes in July or later in the fall?
With the invasion of any invasive species there is only a small window to address the issue
before they become established. Because of the high productivity of zebra mussel delaying the
treatment provides a number of weeks or months for them to reproduce and move elsewhere
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either by current or by humans. This could facilitate a quicker spread and establishment in other
areas of the lake and potentially to other lakes within Manitoba.
25) Zebra Mussels have been known to be in the harbour for at least three years.
This is the first known occurrence of zebra mussels in Lake Winnipeg. Zebra mussel larvae were
found in the Red River near Wahpeton, North Dakota in 2010. These are believed to have drifted
into the United States portion of the Red River from upstream headwater sources. To date no
adult zebra mussels have been found in the US portion of the Red River.
Manitoba has been monitoring annually for drifting zebra mussel larvae at Emerson and
checking the navigation buoys removed each fall for the last decade. No zebra mussels, larval or
adult, have ever been found in the Manitoba portion of the Red River.
When the mussel brought into the Department in October was confirmed as a zebra mussel
staff at both the St. Andrew Lock and Dam and the Selkirk Generating Station were asked to
check these structures and no zebra mussel were found. Areas of shoreline and docking
infrastructure were also checked.
26) Is nitrogen in whatever will be applied?
There is no nitrogen in the potash that will be applied to the harbours. Nor does the potash contain phosphorous (P). The potash is made up of 98% potassium chloride (KCl).
27) Will adding potash to the harbours contribute to an increase in algal growth and
increased eutrophication?
Phosphorous is the limiting factor in plant growth and adding potassium will not contribute
significantly to eutrophication. Freshwater plants require up to 19 nutrients (chemical elements)
to grow and survive. These nutrients are available in different amounts and chemical forms in
freshwater ecosystems.
Plant growth can only be limited by any one of these elements at a given time.
The relationship between the availability of any nutrient and the need for that same nutrient is highly imbalanced. So, the demand for nutrients can be shown against its supply. With potassium it does not matter how much is added because plants have a low demand for it compared to other limiting nutrients and low demand yields no significant growth.
28) What is the encroaching threat from other jurisdictions?
Since first found in the Great Lakes zebra in the mid 1980’s zebra mussel have spread
throughout much of the United States mainly on tailored watercraft. As of April 29, 2013 there
were 107 Minnesota waters infested with zebra mussels.
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29) What prevention efforts have been taken by Manitoba?
Manitoba’s aquatic invasive species program is one of the strongest in the country. The province has done extensive work to educate the public about zebra mussels and what can be done to keep them out of the province’s waterways. The province has monitored the Red River and other bodies of water for the presence of veligers for many years. In addition, a boat inspection program has been in place for the last decade to examine boats for zebra mussels at border crossings. As well, the province has representatives that sit on the board of the Invasive Species Council of Manitoba. This non-profit organization provides centralized and coordinated province-wide leadership to the prevention, early detection, management and potential eradication of invasive species in Manitoba. Representatives also sit on the National and International committees established to provide a collaborative approach to addressing the threat of invasive species.
In the spring of 2012, the province introduced two new high-heat, high-pressure mobile self contained decontamination units to remove invasive aquatic species from boats entering Manitoba at border crossings, fishing tournaments and high-traffic boat launches around the province, a first-in-Canada technology.
Fisheries Enhancement Fund - AIS funded projects (2007 to 2013)
Year Project Description Organization Amount($)
2008 AIS Prevention Initiatives MB Fisheries Branch $24,300
2010 AIS Tackle Box Id Cards MB Water Stewardship - Water
Quality Branch
$20,000
AIS in MB - Awareness & Monitoring Invasive Species Council of
Manitoba
$25,000
2012 AIS Outreach MB CWS - Water Science &
Management Branch
$72,125
2013 AIS Watercraft Student MB Fisheries Branch $26,646
Reallocated funding from other Fisheries
Branch Projects to Zebra Mussels
MB Fisheries Branch $58,055
Total $226,126
Note: an additional $91,010 in funding was provided to Rusty Crayfish projects
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Overall, in the last five years the Department has invested ~ $180,000/year on the provincial aquatic invasive species education and prevention program.
30) A very brief description of the potash potential and the chances of success as well as its
uniqueness and cost.
Liquid potash was recommended by the Manitoba Zebra Mussel Science Advisory Committee
because it was used successfully to eradicate Zebra Mussel in Millbrook Quarry, Virginia, USA
and its relatively high toxicity to Zebra Mussel and low toxicity to other aquatic animals at the
proposed concentration (100 ppm K+). The volume of the recreational quarry is larger
(~680,000 m3) than the total estimated volume of the four harbours being treated (~427 ,000
m3) with the volume being 10 times greater than the estimated volume of the Gimli Harbour –
the largest of the four harbours.
It is our understanding that this is the first time in Canada where an open water application of
potash could be considered given the ability to contain the areas where zebra mussels were
found. The eradication effort will cost ~$600,000. The treatment would be undertaken by ASI
Group Ltd. The same group that applied this technology in Virginia.
31) Have all approvals been provided?
We are satisfied that we have addressed all the appropriate provincial and federal regulatory
requirements.
32) Has there been any consideration given to safety and how the Canadian Coast Guard
and Search and Rescue auxiliary that operate out of Gimli will operate during the
harbour closure?
Human safety is a number one priority. Originally Small Craft Harbours was working with the
Canadian Coast Guard to re-locating the Vakta out of another harbour. With the “gated” barrier
now the Vakta and the Lady Roberta, the vessel currently registered with the Search and Rescue
Auxiliary as a backup for the Vakta will be moored at the Gimli harbour and in a position to
respond in the event of an emergency.
33) What about the safety of boaters who are out and unaware that the harbours are
closed?
Human safety is a number one priority. To avoid this situation from occurring signage will be
placed at all launching facilities and notices will be put up throughout the communities advising
of the harbour treatment. While the duration of the treatment is dependent on water
temperature, the intent is for the treatments to be done before the start of the prime boating
season (middle to end of June). Additionally the “gated” barriers at three of the harbours will be
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staffed and passage will be allowed in the event of any emergency. Staff will also be present at
the Balsam Bay harbour when the barricade is in place.
34) The number of marinas.
There is a provincially leased marina that is adjacent to the Winnipeg Beach Harbour and a
privately owned marina adjacent to the Arnes (Drunken) Harbour.
35) The plan to minimize impacts on marina owners.
Recreational boat owners who have paid slips will have the option to moor their boats in the
marinas either before or immediately after the harbours are treated for the duration of the
treatment. Recreational boaters are encouraged not to leave the harbour during the treatment
period.
Larger keeled boats, such as most sailboats, will not be allowed to leave the harbours due to the
depth of the keel potentially catching on the gate structure below the water.
All recreational boaters will have access from the harbour locations during the prime boating
season once treatment ends as estimated in mid-June.
36) What has the extent of discussion been with Lake Wpg Research Consortium?
Department staff have met with the research consortium a number of times since zebra mussels
were first identified in Lake Winnipeg as well as presented an update at the LWRC annual
meeting. LWRC has agreed to work within whatever strategy the province decides to
implement. The research vessel, the Namao, will be fully treated when Gimli harbour is treated
as it is moored in waters in the treatment area.
37) Will the treatment have any effect on either the boat finish, softer metals on the
boats and /or anodes?
An aquatic chemist has looked at the concentration of the proposed treatment and the
potential to damage the boat material or finish particularly if moored for during the time of the
treatment. The chemist has indicated that “at these relatively low concentrations both K and Cl
will be present almost entirely as free ions. There are some concerns with aluminum boats
running in sea water (~100x the proposed ionic concentration) such that boat design avoids
direct contact between aluminum and other metals. In some cases sacrificial electrodes are
mounted on aluminum hulls to protect the aluminum. These concerns are for vessels run
constantly in waters with 100x the ionic strength proposed here. The proposed ionic strength is
only 3X that found along the west shore of Lake Winnipeg in the vicinity of the mouth of the
Dauphin River. I am not aware of any special precautions being taken by fishers in this region.”
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38) How will you know when the treatment is 100% effective?
ASI will determine when the treatment ends and is considered 100% effective within the
harbours through the use of bioassays.
Live zebra mussels collected from either Lake Simcoe or Wolfe Lake, Ontario will be transported
to Manitoba. Prior to transporting the collected mussels will first be contained in flow through
aquariums at ASI. The source flow through water is treated to drinking water standards and will
be UV treated to ensure that any potential foreign biota that may have been collected with or
carried on or in the zebra mussels is removed/dies. The zebra mussels will then be transferred
into fresh water, bagged and sealed within sealable plastic containers.
Upon arrival at the harbours, the zebra mussels will be placed in a flow through aquarium set up
on site (set up described below). A random sample of zebra mussels will be placed in bioassay
cages. The cages will have mesh on both ends to allow water/food to flow through. The mesh
screen will be smaller than the smallest literature value recorded for zebra mussel eggs to
prevent any life stage escaping into the harbour.
There will be two bioassay cages spaced apart and attached to an anchored and buoyed line.
There will be up to 10 lines placed at various locations within each harbour.
The bioassay cages will not be placed in the harbour until after each harbour has been charged
with potash.
There will be a control group of zebra mussels in a flow through aquarium in an onsite trailer.
Water will be pumped in from the lake side and released through a pipe fitted with filters of
decreasing size and ending with the same size of mesh used on the bioassay cages to prevent
any transfer of eggs. The filtered water will be released into the treated harbour. Any material
captured in the filters will be disposed of in the garbage.
Over the duration of the treatment the cages will be checked. Any zebra mussels that appear
dead will be removed and taken into the trailer where they will be flushed with clean water. This
needs to be done as the potassium first acts as a muscle relaxant and therefore any “open shell”
appearance typically associated with the mussel being dead may be a temporary side effect of
the treatment. If the mussel does not respond to fresh water it is dead.
Once all the zebra mussels in the bioassay cages are dead the treatment is considered to be
complete and 100% effective. The control zebra mussels will be euthanized and either retained
as samples or destroyed.
Ongoing monitoring within the harbours will provide an indication of the duration of success.
Monitoring will also occur within the lake basin to try and determine if a zebra mussel
population exists at depth.
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39) What is Manitoba Hydro doing to prepare for potential effects of Zebra Mussels?
In a precautionary approach based on experiences in other jurisdictions, Hydro has been
exploring options to address potential site-specific fixed infrastructure requirements, including
those associated with dealing with fouling if zebra mussels become well established. The control
measures discussed will be commonly applied measures at industrial facilities (copper based
paints and linings, chlorine treatments, Zequanox). As a water-based enterprise, Hydro is
exploring a range of options in order to be prepared to react, only if required.
There are items that Hydro will continue to work with the Department on.
The first is an enhanced mechanism to report presence/absence of zebra mussels, which already
exists informally through our normal lines of communication. A hydro employee, for example,
identified and reported the first zebra mussel at Winnipeg Beach Harbour.
The second is containment involving adoption and implementation of cleaning protocols for
water-based equipment recommended by internal experts as well as external proposals that are
being received to prevent the further spread of zebra mussels. This will be discussed at a future
Co-ordinated Aquatic Monitoring Program meeting, which is an excellent multi-partner venue to
raise this subject (staff with Environment Canada, Department of Fisheries and Oceans, MB
Hydro, CWS and several consulting firms attend these meetings). We'll also need to involve
other government departments, such as MIT, on this item as they do much work around water.