biology 3 - university of british columbia
TRANSCRIPT
Nutrient MeasurementsEOSC 473-573 Biology 3
Zooplankton Biomass and Abundance
Two Quantitative Procedures: • Biomass Determination (mg C per m3 or per m2) • Abundance (# individuals per m3 or per m2)
Biomass Determination by Volumetric Method
Measures the settling volume of a sample 1. Pour sample into a graduated cylinder 2. Mix sample 3. Particles settle by gravity over 24 hrs 4. Measure the settled volume 5. Convert settled volume (SV) to mg wet mass (WM)
or dry mass (DM) using conversion factors. 1 mg WM = 195 cm3 SV (or 195 mL) ICES Committee on Terms and Equivalents
Biomass Determination by Volumetric Method
• Rapid • Influenced by shape of
organisms • Any large gelatinous
Abundance Determination
Enumeration and identification of organisms in sample
1. Measure a subsample using a Folsom Splitter (coefficient of variation (CV) = 5- 18%)
Abundance Determination 2. Count at least 100 individuals of most abundant
groups (CV = 20%) 3. Estimations of other groups are less precise 4. Compute abundance # individuals m-3 = n k-1 V-1 n = number of counts k = fraction counted (e.g. 0.5 if counted half the
sample) V = volume filtered by the net
Abundance Determination Can obtain wet weight (WM) or dry weight (DM) by
multiplying individual species counts by the average WM or DM of an individual
WM or DM can be converted in Carbon weight e.g. DW has ≈ 50% of carbon, mg DW * 0.5 = mg C Time consuming, requires experience, but only method that
allows parallel quantification and identification
Estimates of zooplankton abundance or biomass are highly variable. Have a CV of at least 20%.
Zooplankton Conversion factors
Raymont, J.E.G. 1980. Plankton and productivity in the oceans. Volume 2. Zooplankton. 489 pp. Pergamon Press NY. ISBN 0080244041 Checkout R. Peters publications (allometry and zooplankton) Zooplankton biodiversity & trophic state in lakes [Ecology, 88(7), 2007, pp. 1675–1686]
Zooplankton Feeding Experiments For carnivorous zooplankton (ingestion rates)
To determine the type of functional response of a given zooplankton predator
Fe ed
in g
ra te
(p re
Zooplankton Feeding Experiments Herbivorous zooplankton (grazing rates)
Grazing by female Calanus hyperboreus on various food concentrations of (a) and (b) Thalassiosira [Mullin, 1963]. Solid lines: grazing rate = clearance rate; ml cop-1 d-1
Broken lines: rate of intake = ingestion rate; cells cop-1 d-1
@ low phytoplankton density zooplankton may
Increase F Keep max F Reduce F
Exploiting phyto to extinction
Lower grazing mortality
Zooplankton Feeding Experiments Grazing vs. Ingestion rates
Decide what organisms you want to investigate Ingestion Rates (eg.chaetognaths feeding on copepods) - Sample live zooplankton (see previous lecture) - Sort species of interest using a wide bore pipette - Incubate zooplankton in bottles with food and measure the decrease in [food] Grazing Rates (eg. copepods feeding on phytoplankton) - Sample live zooplankton (see previous lecture) - Sort species of interest using a wide bore pipette - Collect phytoplankton in the chl a maximum
Grazing Rates Experiments 1. Filter seawater through a Nitex screen (variety of porosities) to remove any possible phytoplankton grazers o
2. Pour seawater with phytoplankton in bottles (need initials, controls, & experimentals)
2.5 (if interested in the response of zoop to various [phyto] will need to prepare bottles w/ different phytoplankton densities, using 0.2 μm filtered seawater
3. Measure [chla] in these bottles, this is your initial phytoplankton abundance
4. Add predators at a reasonable [ ]: enough to see a decrease in phytoplankton & not too high to stress the predators themselves (search literature, due to low O2…)
5. Incubate for 24 hours, measure final [chla] (can also determine size-fractionated chla, as zoop have higher grazing rates on larger phytoplankton, if you do so…you’ll need more water)
Initial bottles for initial measurements, no zoop
1 L 1 L 1 L
Control bottles with no zoop to determine phytoplankton growth during experiment
1 L 1 L 1 L
Bottles with zoop 1 L 1 L 1 L
Ingestion Rate Experiments - Filter seawater to remove any possible predators and prey - Pour filtered seawater in bottles - Add prey at a reasonable [ ] (or at various concentrations in different
bottles) - Add predators at a reasonable [ ]: enough to see a decrease in prey
abundance and not too high to stress the predators themselves
Control bottles with only prey to determine prey growth/mortality during experiment
1 L 1 L 1 L
Bottles with prey and predator 1 L 1 L 1 L
Grazing/Ingestion Rate Experiments
• Bottles should be filled to the rim with SW & acclimated for 2 hrs before zoop are introduced
• Water T. has to be maintained as ambient (running a water bath or hanging bottles in the sea)
• Add zooplankton to incubation bottles using a wide bore pipette
• Maintain food in suspension by stirring or gentle bubbling (also keep zoop. happy)
Grazing Rates Experiments
Compute ingestion rate (I), amt. food cop-1 hr-1
I = (C0 - Ct)/n*t C0 = initial [Chl a] (better to use the final concentration in
control bottles!) Ct = final [Chl a] n = # of grazers per bottle t = incubation time
Gut fluorescence technique
2) Gut evacuation rate 3) Gut pigment degradation
• Collect animals every 4-6 hours • Measure individual or community
mean gut pigment content • Measure gut evacuation rate
experiment by monitoring gut pigment decline over time
• Optional: measure pigment degradation coefficient
y = 4.0439e-0.0061x
R2 = 0.5804
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
0 50 100 150 200 time (min)
gu t c
Pakhomov & Froneman (2004)
Predation rate calculations
Can be conducted as in previous slide: Instead of Chl a, measure copepod numbers (added to
control and experimental bottles) Instead of copepod grazers, add to experimental
bottles chaetognath, a predatory zooplankton
Dilution Rate Experiment (Landry & Hassett 1982)
Measures grazing rate of microzooplankton assemblage on Chl a (or bacteria)
1. Collect seawater from desired depth (chla
maximum is best) 2. Filter a fraction of SW through appropriate size
mesh to obtain SW with bulk microzooplankton assemblage and phytoplankton
Dilution Rate Experiment
4. Filter the remaining water through a cartridge filter (0.2 μm) to obtain particle free seawater (only nutrients)
5. Create a dilution series, can use 250 ml jars
1* grazing 0.75*grazing 0.50*grazing 0.25 *grazing
Grazing pressure decreases with increasing dilution, but NOT growth rate
Dilution Rate Experiment
6. Have an initial conditions bottle for each dilution rate
7. Make sure you have reps for each dilution 8. Measure initial [phyto] in each bottle 9. [phyto] can be bulk [chl a] or size
fractionated [chl a]
Dilution Rate Experiment
10. Incubate bottles for 24 hrs at in situ light and temperature conditions
11. Measure final [phyto] 12. Compute grazing rate In each bottle, phytoplankton grows according to
Pt = Po * ekt
Pt = final [phyto] Po = initial [phyto] k = apparent growth rate (hr-1)
t = incubation time (hr)
But k is an apparent growth rate k = r - g
r = rate of phyto growth (hr-1) g = grazing rate (hr-1)
Pt = Po * e(r-g)t
Pt = Po * e(r-1g)t
Pt = Po * e (r-0.75g)t
Pt = Po * e (r-0.5g)t
Pt = Po * e (r-0.25g)t
Dilution Rate Experiment Plot k vs. d to determine slope g by linear regression analysis
Ap pa
re nt
g ro
w th
ra te
d -1
Dilution factor
Landry & Hassett 1982
Dilution Rate Experiment
Dilution bottles have same growth rate (r), but different grazing rates (g) depending on dilution. Therefore, apparent growth rate (k) changes according to:
Y = interceptY – slope * X k = r - g*d
Equation of a line with k = y = apparent growth rate d = dilution factor; x (decimal fraction of unfiltered seawater) r (growth rate) = y-intercept g (grazing coefficient) = slope
Acoustics • Obtain rapid, synoptic
Acoustics
• Each animal in the water column scatters a wave back
• Its backscattering depends on its size, shape, internal structure, and material properties
• Zooplankton scattering is categorized into 3 main groups based on their material properties
Acoustics Organism
Acoustics • NEPTUNE is a network of ocean observatory
systems moored on the ocean floor in BC • Live data is gathered 24/7 and made freely
accessible to researchers • http://www.neptunecanada.ca/
Acoustics • The echo data is displayed through an echogram • A 2D representation of a succession of echo signals • Each signal is a single vertically oriented line with the
information on backscattering strength encoded by the degree of darkening or colour
e.g. of an echogram from NEPTUNE echosounder in Folger Passage
Acoustics
• During data analysis the echo data is allocated to specific scattering classes of organisms
• Models can be used to convert scatter into an estimate of zooplankton biomass
• Useful tool to look at diurnal migration of zooplankton
• Concurrent zooplankton net samples can be carried out to determine to what species the zooplankton backscatter corresponds to
Target Strength vs. frequency
Scattering volumes @ 3 different frequency transducers (higher kHz pings, bigger target (eg. fish)
Acoustic Doppler Current Profiler (ADCP)
-Hydroacoustic current meter, like a sonar, to measure water current velocities over a depth range using the Doppler effect of sound waves scattered back from particles within the water column.
-The working frequencies range from 38 kHz to several magahertz
4 transducers
What you can measure for your Bamfield project (underlined, things that we will be doing together as a group on Mon-Wed)
• Chlorophyll (total & size-fractionated) (BF) • Nutrients (Si, NO3
-, NO2 -, P, and NH4
+) (BF) • Salinity (BF) • Temperature (BF) • Oxygen (BF) • Light in Water • CDOM • Turbidity • Chlorophyll fluorescence (BF) • O2 evolution & consumption (BF) • Phytoplankton identification (BF) & counts using inverted microscope & settling chambers (UBC) • Growth rates of bacteria and phytoplankton, sinking rates of phytoplankton and • Grazing rates on bacteria and small phytoplankton • Bacteria counts using DAPI or Acridine Orange (UBC) • Zooplankton identification and counting (BF) • Estimate phytoplankton C from phytoplankton counts and estimate of size & volume (BF) • Estimate zooplankton C from conversion factors (BF) • Estimate bacterial C, from bacteria size estimates and conversion factors (UBC) • Distinguished between carnivorous and herbivorous zooplankton (BF) • - Wet weight (BF) dry weight (UBC) • Predation rates by zooplankton
Zooplankton Measurements
Abundance Determination
Abundance Determination
Abundance Determination
Zooplankton Feeding ExperimentsHerbivorous zooplankton (grazing rates)
Slide Number 11
Slide Number 12
Grazing Rates Experiments
Ingestion Rate Experiments
Grazing/Ingestion Rate Experiments
Grazing Rates Experiments
Slide Number 18
Predation rate calculations
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Scattering volumes @ 3 different frequency transducers (higher kHz pings, bigger target (eg. fish)
Acoustic Doppler Current Profiler (ADCP)
What you can measure for your Bamfield project (underlined, things that we will be doing together as a group on Mon-Wed)
Slide Number 39
Zooplankton Biomass and Abundance
Two Quantitative Procedures: • Biomass Determination (mg C per m3 or per m2) • Abundance (# individuals per m3 or per m2)
Biomass Determination by Volumetric Method
Measures the settling volume of a sample 1. Pour sample into a graduated cylinder 2. Mix sample 3. Particles settle by gravity over 24 hrs 4. Measure the settled volume 5. Convert settled volume (SV) to mg wet mass (WM)
or dry mass (DM) using conversion factors. 1 mg WM = 195 cm3 SV (or 195 mL) ICES Committee on Terms and Equivalents
Biomass Determination by Volumetric Method
• Rapid • Influenced by shape of
organisms • Any large gelatinous
Abundance Determination
Enumeration and identification of organisms in sample
1. Measure a subsample using a Folsom Splitter (coefficient of variation (CV) = 5- 18%)
Abundance Determination 2. Count at least 100 individuals of most abundant
groups (CV = 20%) 3. Estimations of other groups are less precise 4. Compute abundance # individuals m-3 = n k-1 V-1 n = number of counts k = fraction counted (e.g. 0.5 if counted half the
sample) V = volume filtered by the net
Abundance Determination Can obtain wet weight (WM) or dry weight (DM) by
multiplying individual species counts by the average WM or DM of an individual
WM or DM can be converted in Carbon weight e.g. DW has ≈ 50% of carbon, mg DW * 0.5 = mg C Time consuming, requires experience, but only method that
allows parallel quantification and identification
Estimates of zooplankton abundance or biomass are highly variable. Have a CV of at least 20%.
Zooplankton Conversion factors
Raymont, J.E.G. 1980. Plankton and productivity in the oceans. Volume 2. Zooplankton. 489 pp. Pergamon Press NY. ISBN 0080244041 Checkout R. Peters publications (allometry and zooplankton) Zooplankton biodiversity & trophic state in lakes [Ecology, 88(7), 2007, pp. 1675–1686]
Zooplankton Feeding Experiments For carnivorous zooplankton (ingestion rates)
To determine the type of functional response of a given zooplankton predator
Fe ed
in g
ra te
(p re
Zooplankton Feeding Experiments Herbivorous zooplankton (grazing rates)
Grazing by female Calanus hyperboreus on various food concentrations of (a) and (b) Thalassiosira [Mullin, 1963]. Solid lines: grazing rate = clearance rate; ml cop-1 d-1
Broken lines: rate of intake = ingestion rate; cells cop-1 d-1
@ low phytoplankton density zooplankton may
Increase F Keep max F Reduce F
Exploiting phyto to extinction
Lower grazing mortality
Zooplankton Feeding Experiments Grazing vs. Ingestion rates
Decide what organisms you want to investigate Ingestion Rates (eg.chaetognaths feeding on copepods) - Sample live zooplankton (see previous lecture) - Sort species of interest using a wide bore pipette - Incubate zooplankton in bottles with food and measure the decrease in [food] Grazing Rates (eg. copepods feeding on phytoplankton) - Sample live zooplankton (see previous lecture) - Sort species of interest using a wide bore pipette - Collect phytoplankton in the chl a maximum
Grazing Rates Experiments 1. Filter seawater through a Nitex screen (variety of porosities) to remove any possible phytoplankton grazers o
2. Pour seawater with phytoplankton in bottles (need initials, controls, & experimentals)
2.5 (if interested in the response of zoop to various [phyto] will need to prepare bottles w/ different phytoplankton densities, using 0.2 μm filtered seawater
3. Measure [chla] in these bottles, this is your initial phytoplankton abundance
4. Add predators at a reasonable [ ]: enough to see a decrease in phytoplankton & not too high to stress the predators themselves (search literature, due to low O2…)
5. Incubate for 24 hours, measure final [chla] (can also determine size-fractionated chla, as zoop have higher grazing rates on larger phytoplankton, if you do so…you’ll need more water)
Initial bottles for initial measurements, no zoop
1 L 1 L 1 L
Control bottles with no zoop to determine phytoplankton growth during experiment
1 L 1 L 1 L
Bottles with zoop 1 L 1 L 1 L
Ingestion Rate Experiments - Filter seawater to remove any possible predators and prey - Pour filtered seawater in bottles - Add prey at a reasonable [ ] (or at various concentrations in different
bottles) - Add predators at a reasonable [ ]: enough to see a decrease in prey
abundance and not too high to stress the predators themselves
Control bottles with only prey to determine prey growth/mortality during experiment
1 L 1 L 1 L
Bottles with prey and predator 1 L 1 L 1 L
Grazing/Ingestion Rate Experiments
• Bottles should be filled to the rim with SW & acclimated for 2 hrs before zoop are introduced
• Water T. has to be maintained as ambient (running a water bath or hanging bottles in the sea)
• Add zooplankton to incubation bottles using a wide bore pipette
• Maintain food in suspension by stirring or gentle bubbling (also keep zoop. happy)
Grazing Rates Experiments
Compute ingestion rate (I), amt. food cop-1 hr-1
I = (C0 - Ct)/n*t C0 = initial [Chl a] (better to use the final concentration in
control bottles!) Ct = final [Chl a] n = # of grazers per bottle t = incubation time
Gut fluorescence technique
2) Gut evacuation rate 3) Gut pigment degradation
• Collect animals every 4-6 hours • Measure individual or community
mean gut pigment content • Measure gut evacuation rate
experiment by monitoring gut pigment decline over time
• Optional: measure pigment degradation coefficient
y = 4.0439e-0.0061x
R2 = 0.5804
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
0 50 100 150 200 time (min)
gu t c
Pakhomov & Froneman (2004)
Predation rate calculations
Can be conducted as in previous slide: Instead of Chl a, measure copepod numbers (added to
control and experimental bottles) Instead of copepod grazers, add to experimental
bottles chaetognath, a predatory zooplankton
Dilution Rate Experiment (Landry & Hassett 1982)
Measures grazing rate of microzooplankton assemblage on Chl a (or bacteria)
1. Collect seawater from desired depth (chla
maximum is best) 2. Filter a fraction of SW through appropriate size
mesh to obtain SW with bulk microzooplankton assemblage and phytoplankton
Dilution Rate Experiment
4. Filter the remaining water through a cartridge filter (0.2 μm) to obtain particle free seawater (only nutrients)
5. Create a dilution series, can use 250 ml jars
1* grazing 0.75*grazing 0.50*grazing 0.25 *grazing
Grazing pressure decreases with increasing dilution, but NOT growth rate
Dilution Rate Experiment
6. Have an initial conditions bottle for each dilution rate
7. Make sure you have reps for each dilution 8. Measure initial [phyto] in each bottle 9. [phyto] can be bulk [chl a] or size
fractionated [chl a]
Dilution Rate Experiment
10. Incubate bottles for 24 hrs at in situ light and temperature conditions
11. Measure final [phyto] 12. Compute grazing rate In each bottle, phytoplankton grows according to
Pt = Po * ekt
Pt = final [phyto] Po = initial [phyto] k = apparent growth rate (hr-1)
t = incubation time (hr)
But k is an apparent growth rate k = r - g
r = rate of phyto growth (hr-1) g = grazing rate (hr-1)
Pt = Po * e(r-g)t
Pt = Po * e(r-1g)t
Pt = Po * e (r-0.75g)t
Pt = Po * e (r-0.5g)t
Pt = Po * e (r-0.25g)t
Dilution Rate Experiment Plot k vs. d to determine slope g by linear regression analysis
Ap pa
re nt
g ro
w th
ra te
d -1
Dilution factor
Landry & Hassett 1982
Dilution Rate Experiment
Dilution bottles have same growth rate (r), but different grazing rates (g) depending on dilution. Therefore, apparent growth rate (k) changes according to:
Y = interceptY – slope * X k = r - g*d
Equation of a line with k = y = apparent growth rate d = dilution factor; x (decimal fraction of unfiltered seawater) r (growth rate) = y-intercept g (grazing coefficient) = slope
Acoustics • Obtain rapid, synoptic
Acoustics
• Each animal in the water column scatters a wave back
• Its backscattering depends on its size, shape, internal structure, and material properties
• Zooplankton scattering is categorized into 3 main groups based on their material properties
Acoustics Organism
Acoustics • NEPTUNE is a network of ocean observatory
systems moored on the ocean floor in BC • Live data is gathered 24/7 and made freely
accessible to researchers • http://www.neptunecanada.ca/
Acoustics • The echo data is displayed through an echogram • A 2D representation of a succession of echo signals • Each signal is a single vertically oriented line with the
information on backscattering strength encoded by the degree of darkening or colour
e.g. of an echogram from NEPTUNE echosounder in Folger Passage
Acoustics
• During data analysis the echo data is allocated to specific scattering classes of organisms
• Models can be used to convert scatter into an estimate of zooplankton biomass
• Useful tool to look at diurnal migration of zooplankton
• Concurrent zooplankton net samples can be carried out to determine to what species the zooplankton backscatter corresponds to
Target Strength vs. frequency
Scattering volumes @ 3 different frequency transducers (higher kHz pings, bigger target (eg. fish)
Acoustic Doppler Current Profiler (ADCP)
-Hydroacoustic current meter, like a sonar, to measure water current velocities over a depth range using the Doppler effect of sound waves scattered back from particles within the water column.
-The working frequencies range from 38 kHz to several magahertz
4 transducers
What you can measure for your Bamfield project (underlined, things that we will be doing together as a group on Mon-Wed)
• Chlorophyll (total & size-fractionated) (BF) • Nutrients (Si, NO3
-, NO2 -, P, and NH4
+) (BF) • Salinity (BF) • Temperature (BF) • Oxygen (BF) • Light in Water • CDOM • Turbidity • Chlorophyll fluorescence (BF) • O2 evolution & consumption (BF) • Phytoplankton identification (BF) & counts using inverted microscope & settling chambers (UBC) • Growth rates of bacteria and phytoplankton, sinking rates of phytoplankton and • Grazing rates on bacteria and small phytoplankton • Bacteria counts using DAPI or Acridine Orange (UBC) • Zooplankton identification and counting (BF) • Estimate phytoplankton C from phytoplankton counts and estimate of size & volume (BF) • Estimate zooplankton C from conversion factors (BF) • Estimate bacterial C, from bacteria size estimates and conversion factors (UBC) • Distinguished between carnivorous and herbivorous zooplankton (BF) • - Wet weight (BF) dry weight (UBC) • Predation rates by zooplankton
Zooplankton Measurements
Abundance Determination
Abundance Determination
Abundance Determination
Zooplankton Feeding ExperimentsHerbivorous zooplankton (grazing rates)
Slide Number 11
Slide Number 12
Grazing Rates Experiments
Ingestion Rate Experiments
Grazing/Ingestion Rate Experiments
Grazing Rates Experiments
Slide Number 18
Predation rate calculations
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Dilution Rate Experiment
Scattering volumes @ 3 different frequency transducers (higher kHz pings, bigger target (eg. fish)
Acoustic Doppler Current Profiler (ADCP)
What you can measure for your Bamfield project (underlined, things that we will be doing together as a group on Mon-Wed)
Slide Number 39