Size%20distribution%20and%20sinking%20velocity%20of%20the%20feces%20and%20pseudofeces%20of%20the%20blue%20mussel,%20Mytilus%20edulis - PowerPoint PPT Presentation
Title:
Size%20distribution%20and%20sinking%20velocity%20of%20the%20feces%20and%20pseudofeces%20of%20the%20blue%20mussel,%20Mytilus%20edulis
Description:
... sinking velocity of the feces and pseudofeces of the blue mussel, Mytilus edulis ... Mussels in open tube for 12 hours. Remove animals and rotate tube ... – PowerPoint PPT presentation
Number of Views:112
Avg rating:3.0/5.0
Title: Size%20distribution%20and%20sinking%20velocity%20of%20the%20feces%20and%20pseudofeces%20of%20the%20blue%20mussel,%20Mytilus%20edulis
1
Size distribution and sinking velocity of the
feces and pseudofeces of the blue mussel, Mytilus
edulis
- Megan Cahill
- Supervisor Dr. Jonathan Grant
- Department of Oceanography, Dalhousie University
2
Outline
- Background
- Purpose
- Materials and Methods
- Results
- Practical Applications
3
Background
- Mytilus edulis as an aquaculture species
- Filter feeder
- Fate of material sorted, adsorbed, defecated
- Anything not adsorbed is released
- Falls through the water column
4
Materials and Methods
- Modes of particle capture
- Sediment traps
- In situ observation
- Collection
- Degradation during storage
5
- Transverse Niskin
- Collective device
- Transparent walls
- Rectangular
- Horizontal alignment during gathering
- Vertical to induce sinking
- Use in the field and the lab
6
(No Transcript)
7
- Laboratory work
- Large tank
- Flow through of unfiltered seawater
- Mussels in open tube for 12 hours
- Remove animals and rotate tube
8
- Image collection
- Digital camera
- Series of pictures at known intervals
- One image every two seconds
- Inclusion of ruler in the picture for image
calibration
9
- Image analysis
- SigmaScan Pro 5 software
- Calibration of distance
- Select particles based on pixel intensity
- Automatically calculates area from calibration
- Track through time to determine rate
10
(No Transcript)
11
Results
- Pilot data
- area of smallest particle detected is
- 0.036 mm2
- mean area 0.2 mm2
- mean sinking rate 2.17 mm sec-1
- limited data set
12
(No Transcript)
13
(No Transcript)
14
- Other components to sinking rate
- Particle density
- Feces versus pseudofeces
- Viscosity of medium
- Temperature and salinity measured by Aquatron
- Particle shape
15
- Difficulties
- Particles are not necessarily discrete
- Inclusion of organic matter
- Diffuse
- Trace function more subjective
- Focus!
16
Still to Come
- Field work
- Pseudofeces?
- Turbid conditions
- Analyze results
17
Importance
- Aquaculture systems
- Large areas with many animals
- Alter flow regimes and depletes seston
- Significant pelagic-benthic flux
18
- Pelagic-benthic flux
- Nutrient loading
- Nutrient source for benthic/demersal organisms
- Implications for polyculture?
19
- Modeling
- Dynamic systems
- Coastal zone management
- Outside influences
- Contaminant concentration
20
Acknowledgements
- Thank you to Dr. Grant and
- Marie Archambault
Recommended
CrystalGraphics Presentations
