Shellfish Filtration Rates

• I wanted to find out 2 things about local shellfish

1. Which shellfish filters and cleans water the fastest

2. Which shellfish cleans and filters water the best

• The shellfish I chose to compare were:• Mussels• Oysters• Hard Shell Clam• Soft Shell Clam

Getting Started

Location: Mt Sinai Harbor (Low tide)

Field work: Collect shellfish and algae rich seawater (algae is the primary food for filter feeding shellfish)

Collection Methods:

•Digging for clams and collecting Oysters and mussels

•Used an absorbent rag to wipe down and collect algae from tidal flats then rung out into bucket

Setting Up The Experiment1. Chose location with good natural light for

comparing water clarity (white background)

2. Mixed algae rich seawater for consistency

3. Placed 6 cups of seawater/Algae mixture into each tank

4. Placed shellfish of equal mass into each tank

5. Left one tank empty as control for comparison

6. Compare the clarity of water in each tank to the control tank at regular intervals to Judge filtration rate and effectiveness

20 Minutes

•Mussels are already feeding and the water in the Mussel tank is twice as clear as the others

•The other shellfish are not open and not feeding

60 Minutes

•Water in the Mussel tank looks completely clear

•Oysters are open but water in their tank does not look clear

2 Hours 30 Minutes

•Soft Shell Clam tank is getting more clear but not as good as the mussels

•Oysters and Hard Clam are open and feeding

5 Hours- End Experiment

•Mussels and Soft Shell Clam tanks are completely clean of algae

•Hard shell Clam water has improved a lot but there is still algae

• Oysters water is a little mire clear than the control tank

Speed and Quality of Filtration

0%

20%

40%

60%

80%

100%

120%

20 40 60 80 100 120 140 160 180 200 220 240 260 280 300

Mussel

Oysters

Hard shell Clam

Soft Shell Clam

Control

Minutes

Conclusion

• Mussels clean water the fastest.

• Mussels and Soft Shell Clams clean water the best