dreissenid mussel monitoring for the great lakes nutrient initiative (glni) 2012-2015

Water Quality Monitoring and Surveillance Division

Jillian Belcot BSc (Hons) & Zach Leslie BA (Hons)

Dreissenid Mussel Monitoring for the Great Lakes Nutrient Initiative (GLNI) 2012-2015

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Outline of Presentation

• Great Lakes Nutrient Initiative (GLNI) Objective • Nuisance Algae (Cladophora)• Background Research on Dreissena Mussels• Focusing on GLNI’s Nearshore Program

– Focusing on the phosphorus bioavailability from mussels

• Lab Procedures • Data Analysis and Interpretation • Conclusion

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The Great Lakes Nutrient Initiative (GLNI)

• GLNI’s goal is to set phosphorus concentration targets for the tributaries, nearshore and open waters of Lake Erie– These targets will help determine the best

management practices to limit the recurrence of nuisance (Cladophora) and harmful algae blooms

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Nuisance Algae(Cladophora)• Cladophora Glomerata forms extensive blooms

in nearshore areas of eastern Lake Erie• Implications:

– Restrict recreational uses of beaches– cause odor problems – create problems for water intakes – foul the nets of commercial fishermen– reduce property values

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Background: Nuisance Algae

After detaching, Cladophora accumulates and decomposes on shore.

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Background: Nuisance Algae

Cladophora often grows in the same vicinity as mussels.

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Mussel Background

• Zebra mussels (Dreissena polymorpha) were first discovered in Lake St. Clair in 1988

• Zebra and Quagga mussels filter 1L of water per day

• Female mussels can produce up to one million eggs each year

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Mussels as Biological Indicators

• The objective is to reduce algae (Cladophora)- The focus is on studying the relationship between mussels and Cladophora

• How?- Monitor mussel biomass and tissue phosphorus

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Nearshore Sites

End goal is to have biomass estimates at all Nearshore Sites!

We can estimate mussel biomass and total abundance in relation to Cladopohra

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Lab Procedures Standard Operation Procedures Implemented

Step 1 : Sieving

• Empty freeze-dried mussels into sieving nests

• Sieves range in size: 16 mm, 14mm, 12.5mm, 10 mm, 8mm, 6.3mm, 4mm, 2mm

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Lab Procedures

Step 2: Sorting

• From each size fraction, collect and remove all live mussels (shells containing tissue)

Standard Operation Procedures Implemented

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Lab Procedures Standard Operation Procedures Implemented

Step 3: Counting• Count the number of mussels in

each size fraction in the sample and accurately record in the data worksheet

• The total number of mussels (Total Abundance) will be automatically calculated

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Lab Procedures Standard Operating Procedures Implemented

Step 4: Weighing

• Weight of each size fraction is obtained

• The combined weight (Total Biomass) of all portions is the dry biomass for that sample.

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Step 5: Dividing Sub Sample

• Combine and gently mix the live mussels collected, counted, and weighted from all the sieved size fractions

• The transect selected for processing must be selected at random using a random number selector

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Step 6: Weighing Sub Sample

• A minimum of 20% of the samples total biomass will be subsampled randomly and processed

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Lab Procedures

Step 7: Shucking

• Using a No.10 Scalpel to cut mussel length wise, and extract the bulk of the mussel tissue

• Weighing by difference, weigh the vial + lid + extracted mussel tissue and from this subtract the weight of the empty vial

Standard Operating Procedures Implemented

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Step 8: Grinding

• Retch MM400 Mixing Mill is used to grind mussel tissue

• Sample is homogenized

Lab Procedures

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Step 9: TP Analysis

• Each sample submission requires between 1.0 to 2.0 mg of mussel tissue added to a 120mL French square glass bottle, and the addition of 1mL of 30% H2SO4 and 100mL of Milli-Q water

• Sent to NLET to determine the samples TP particulate concentration

Lab Procedures

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Lab Procedures: Mussel Processing Cycle

Sieve

Sort

Count

Weigh

Divide Sub

SampleWeigh Sub

Sample

Shuck Sub

Sample

Weigh Tissue

Grind

TP Analysis

Tissue P Concentration

Shell Free

Biomass Biomass

Abundance

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Data Analysis

Mussel Data Processing Worksheet

Station information includes the station number (PSN), sampling date, quadrat number (1, 2 or 3)

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2 mm 4 mm 6.3 mm 8 mm 10 mm 12.5 mm 14 mm 16 mm0.0000

0.0500

0.1000

0.1500

0.2000

0.2500

0.3000

0.3500

0.4000

Sieve Sizes (mm) vs. Relative Frequency from 2012-2015

2012201320142015

Sieve Size (mm)

Rela

tive

Freq

uenc

y

Data Interpretation: Size Distribution

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Data Interpretation: Biomass & Density

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Conclusion

• Environment Canada is working with provincial and U.S. federal counterparts to understand the relationships between phosphorus levels, invasive mussel species and nuisance algal growth

• The overall aim is to study the relationship between water quality and biological conditions

– May 3, 2023

Acknowledgments

• Special thanks to:- Alice Dove – Environmental Scientist, Project Lead - Sean Backus – Section Chief Great Lakes Watershed- John Struger – Environmental Scientist- Tina Hooey – Environmental Technician Supervisor- Andrew Mummery – Environmental Technician- Kyle Hamilton – Student