Grace Gardner, Joe Buchanan,Casey Kristofferson
Pond Zooplankton Analysis at OX Ranch
Outline
• Background• Methods• Data• Results• Management • Summary
Background
• Purpose of ponds• Macrophytes• Location- middle pond• Zooplankton Assessment• October 7th and 8th
Methods
• Onshore vs. Offshore • Equipment• Sampling • Lab Analysis • Reasoning
X
X
X
X
X
X
Black X: Offshore sitesGray X: Onshore sites
Volume of offshore= 14015 m^3Volume of onshore =1300 m^3
Onshore vs. Offshore
vesr.ucnrs.org
wildco.com
Sampling
Reasoning: Daphnia
• Pond Community • Role of Daphnia
Trophic Level 4 Human
Trophic Level 3 Planktivore
Trophic Level 2 Zooplankton Daphnia
Trophic Level 1 Phytoplankton
Data and Results
• Comparisons of Offshore and Onshore zones– Abundances of all Zooplankton genera present– Average length of zooplankton – Average length of Daphnia specifically– Average biomass of Daphnia – If time permits: abundances between night and
day within the offshore zone
Daphnia Ceriodaphnia Alona Cyclopoid Chaoborus Odonata0
0.2
0.4
0.6
0.8
1
1.2
Zooplankton Abundance; Onshore vs Offshore
Onshore Offshore
Genera
Abun
dace
#/L
10
0.5
1
1.5
2
2.5
3
Length of Zooplankton; Offshore vs. Onshore
OffshoreOnshore
Pond Zone
Aver
age
Lent
h (m
m)
11
1.05
1.1
1.15
1.2
1.25
1.3
Daphnia Length: Offshore vs. Onshore
Offshore Onshore
Pond Zone
Leng
th (m
m)
10
1
2
3
4
5
6
7
8
9
Daphnia Biomass (mg/L) of Onshore vs. Offshore
OffshoreOnshore
Pond Zone
Biom
ass (
mg/
L)
Large-bodied Daphnia benefits
• Burns et al. 1968, found a correlation between length of zooplankton and diameter of particle able to filter
• This means that the larger-bodied zooplankton within onshore zone are providing top-down control upon algal blooms
• Management implications with removal of these zooplankton
(Burns 1968)
(Burns 1968)
Parameters Pond Total
Daphnia Biomass (mg/L) 11.77776678
Daphnia Abundance (#/L) 1.405452
Daphnia Average Length (mm) 1.193735
Zooplankton Length (mm) 1.86216
Daphnia length range: 0.30928- 2.7062mm
Management
• Ox Ranch Plan• Suggestions• Role of management plan
Pond Status
• Pond is in great condition for Daphnia.• High densities of Macrophytes
• Good for daphnia• Bad for fish
Management Suggestion
• Macrophyte removal• Dredging• Fish habitat• Fish stocking• Shading• Role
Macrophyte Removal
• Remove 30-40% of macrophytes• Mostly near/around dock• Significance
Dredging
• 3 meters deep• In front of dock• Depth for fish habitat
Fish habitat
• Brush piles in open water• In dredging area• Christmas trees, brush, anything.• (Bassett et al. 1994)
Stocking
• Conservative • Fish population boom at beginning• Ecosystem reaction
Shading
• Plant willows• Shading of pond• Bank stabilization
Role of Management plan
• Economically effective• Maintain balance• Supply fishing opportunities
Summary
• Background• Methods• Data• Results• Management• Questions?
Citations• Bassett, C. E. 1994. Use and evaluation of fish habitat structures in lakes of the eastern United States by the USDA Forest
Service. Bulletin of Marine Science, 55: 1137-1148. http://idahoid.library.ingentaconnect.com/content/umrsmas/bullmar/1994/00000055/F0020002/art00070
• Burks, R.L., Jeppersen, E., and Lodge, D.M. 2001. Littoral zone structure as Daphnia refugia against fish predators. Limnology and Oceanography 46: 230-237.
• Burns, C.W. 1968. The relationship between body size of filter-feeding cladocera and the maximum size of particle ingested. Limnology and Oceanography 13: 675-678.
• Wetzel, R.G. 2001. Limnology. 3rd Ed. Academic Press, San Diego, CA, U.S.A.
Daphnia Ceriodaphnia Alona Cyclopoids Chaoborus Odantata0
0.5
1
1.5
2
2.5
Zooplankton Abundance; Night vs. Day Offshore
NightDay
Species
Abun
danc
e (#
/L)