Collection, Enumeration, and Biomass of Zooplankton
177
dry weights? What are the disadvantages of drying at temperatures less than the boiling
point of water?
9. Likens and Gilbert (1970) suggested that the pore size of plankton nets could seriously
affect calculations of productivitty in zooplankton. Why?
10. Why should nets not be towed too fast? Or too slow?
II. How does the predominance of species vary according to density and biomass? Which
parameter (density or mass) is more important for the metabolism of the lake? Why?
12. What was the filtration efficiency for the samplers used?
Apparatus and Supplies
1. Zooplankton collection apparatus [e.g., Clarke-Bumpus plankton sampler (available from
Wildco Instruments, Saginaw, MI, Isaacs-Kidd sampler (Isaacs and Kidd, 1953), 0.5-m
diamter vertical townet (available from Wildco Instruments), Schindler trap (Schindler,
1969), Likens-Gilbert water bottle and plantkon funnel (Likens and Gilbert, 1970)].
2. Clinometer (available from Wildco Instruments).
3. Automatic, volumetric pipets or Hensen-Stempel pipet (1-ml) (available from Wildco
Instruments).
4. Graduated cylinders (50-, 100-, and 200-ml).
5. Sedgwick-Rafter cells (I-ml) (see Exercise 10).
6. Hand tallies.
7. Wash bottles and filtered water.
8. Dissecting needles or fine insect needles with heads removed and inserted into matchsticks.
9. Buffered formalin (5%): Dilute 40% formaldehyde with water and add sufficient sodium
acetate to yield a final pH of 7.5 to 8.0 in the preserved sample (see Exercise 10).
10. Compound microscopes (high and low power objectives and mechanical stage).
11. Stage micrometer (see Exercise 10).
12. Whipple disc (see Exercise 10).
13. Plastic rulers.
14. Wide mouth bottles, 8-oz, with screw-top caps.
15. Winch, meter wheel register, line, weight or depressor (available from Wildco Instruments)
for zooplankton collection apparatus.
16. Small boat with motor (or untiring persons with oars!).
17. Hand tools (e.g., screw driver, pliers, and adjustable end wrench).
References
Ahlstrom, E.H., J.D. Isaacs, J.R. Thrakill, and L.W. Kidd. 1958. High-speed plankton sampler.
Fish Bull. Fish Wildl. Servo 58(132):187-214.
de Bernardi R. 1984. Methods for the estimation of zooplankton abundance. pp. 59-86. In:
J.A. Downing and F.H. Rigler, Editors. A Manual on Methods for the Assessment of
Secondary Productivity in Fresh Waters. Blackwell, Oxford.
Clutter, R.I. and M. Anraku. 1968. Avoidance of samplers. pp. 57-76. In: D.J. Tranter and
J.H. Fraser, Editors. Zooplankton Sampling. UNESCO Press, Paris.
Dumont, H.J., I. Van de Vel de, and S. Dumont. 1975. The dry weight estimate of biomass in
a selection of Cladocera, Copepoda and Rotifera from the plankton, periphyton and benthos
of continental waters. Oecologia 19:75-97.
Edmondson, W.T. and G.G. Winberg (eds). 1971. A Manual on Methods for the Assessment
of Secondary Productivity in Fresh Waters. IBP Handbook No. 17. Blackwell, Oxford.
358 pp.
Hall, D.J., W.E. Cooper, and E.E. Werner. 1970. An experimental approach to the production
dynamics and structure offreshwater animal communities. Limnol. Oceanogr. 15: 839-928.
Isaacs, J.D. and L.W. Kidd. 1953. Isaacs-Kidd midwater trawl. Final report. Scripps Inst.
Oceanogr. (Ref. 53-3, 1-18. Oceanographic Equipment Rept. No. 1).
177
dry weights? What are the disadvantages of drying at temperatures less than the boiling
point of water?
9. Likens and Gilbert (1970) suggested that the pore size of plankton nets could seriously
affect calculations of productivitty in zooplankton. Why?
10. Why should nets not be towed too fast? Or too slow?
II. How does the predominance of species vary according to density and biomass? Which
parameter (density or mass) is more important for the metabolism of the lake? Why?
12. What was the filtration efficiency for the samplers used?
Apparatus and Supplies
1. Zooplankton collection apparatus [e.g., Clarke-Bumpus plankton sampler (available from
Wildco Instruments, Saginaw, MI, Isaacs-Kidd sampler (Isaacs and Kidd, 1953), 0.5-m
diamter vertical townet (available from Wildco Instruments), Schindler trap (Schindler,
1969), Likens-Gilbert water bottle and plantkon funnel (Likens and Gilbert, 1970)].
2. Clinometer (available from Wildco Instruments).
3. Automatic, volumetric pipets or Hensen-Stempel pipet (1-ml) (available from Wildco
Instruments).
4. Graduated cylinders (50-, 100-, and 200-ml).
5. Sedgwick-Rafter cells (I-ml) (see Exercise 10).
6. Hand tallies.
7. Wash bottles and filtered water.
8. Dissecting needles or fine insect needles with heads removed and inserted into matchsticks.
9. Buffered formalin (5%): Dilute 40% formaldehyde with water and add sufficient sodium
acetate to yield a final pH of 7.5 to 8.0 in the preserved sample (see Exercise 10).
10. Compound microscopes (high and low power objectives and mechanical stage).
11. Stage micrometer (see Exercise 10).
12. Whipple disc (see Exercise 10).
13. Plastic rulers.
14. Wide mouth bottles, 8-oz, with screw-top caps.
15. Winch, meter wheel register, line, weight or depressor (available from Wildco Instruments)
for zooplankton collection apparatus.
16. Small boat with motor (or untiring persons with oars!).
17. Hand tools (e.g., screw driver, pliers, and adjustable end wrench).
References
Ahlstrom, E.H., J.D. Isaacs, J.R. Thrakill, and L.W. Kidd. 1958. High-speed plankton sampler.
Fish Bull. Fish Wildl. Servo 58(132):187-214.
de Bernardi R. 1984. Methods for the estimation of zooplankton abundance. pp. 59-86. In:
J.A. Downing and F.H. Rigler, Editors. A Manual on Methods for the Assessment of
Secondary Productivity in Fresh Waters. Blackwell, Oxford.
Clutter, R.I. and M. Anraku. 1968. Avoidance of samplers. pp. 57-76. In: D.J. Tranter and
J.H. Fraser, Editors. Zooplankton Sampling. UNESCO Press, Paris.
Dumont, H.J., I. Van de Vel de, and S. Dumont. 1975. The dry weight estimate of biomass in
a selection of Cladocera, Copepoda and Rotifera from the plankton, periphyton and benthos
of continental waters. Oecologia 19:75-97.
Edmondson, W.T. and G.G. Winberg (eds). 1971. A Manual on Methods for the Assessment
of Secondary Productivity in Fresh Waters. IBP Handbook No. 17. Blackwell, Oxford.
358 pp.
Hall, D.J., W.E. Cooper, and E.E. Werner. 1970. An experimental approach to the production
dynamics and structure offreshwater animal communities. Limnol. Oceanogr. 15: 839-928.
Isaacs, J.D. and L.W. Kidd. 1953. Isaacs-Kidd midwater trawl. Final report. Scripps Inst.
Oceanogr. (Ref. 53-3, 1-18. Oceanographic Equipment Rept. No. 1).