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Mackie et al.- Trophic Status of lakes

Summary of morphometric, physical, chemical and biological criteria

Soil & Water Conservation Society of Metro Halifax (SWCSMH)

July 26, 2006

Source:

Mackie, G.L., Hincks, S., and Barker, D. 2000. Introduction to Aquatic Environments, Course Manual, Univeristy of Guelph. 11 chapters, 5 appendices., and

Mackie, G.L. 2001. Applied Aquatic Ecosystem Concepts. Kendall/Hunt Publishing Company. xxv, 744 pp. ISBN 0-7872-7490-9.

Mackie, G.L. 2004. APPLIED AQUATIC ECOSYSTEM CONCEPTS. Second Ed. Kendall/Hunt Publishing Company. 784pp. ISBN 0-7575-0883-9

Features Oligotrophic lakes Mesotrophic lakes Eutrophic lakes

Lake basin shape U-shaped Deep V-shape Shallow V-shape

Mean depth Very deep Moderately shallow Usually shallow

Hypolimnion temperature 4° C About 4° C Usually >4° C

Hypolimnion volume Large Moderately small Small

Thermocline depth High Moderately deep Shallow

Secchi depth >5 m 3-5 m <3 m

Dissolved oxygen profile Orthograde Clinograde Clinograde

RAHOD
mg O₂/m²/day <0.017 0.017-0.033 >0.033

Dissolved oxygen content 90-100% in hypolimnion 25-90% in hypolimnion <25% in hypolimnion

Calcium content Low
(usually <10 mg/L) Moderate
(10-25 mg/L) High
(>25 mg/L)

Total nitrogen content <300 µg/L 300-600 µg/L >600 µg/L

Total phosphorus <10 µg/L 10-30 µg/L >30 µg/L

Chlorophyll a <2 µg/L 2-5 µg/L >5 µg/L

Macrophyte diversity Many submerged spp. but low biomass, few/no floaters, emergents Many submerged, floating & emergent spp. & high biomass Few submerged sp; many floaters, emergents with high biomass

Profundal benthic diversity High diversity
(Log₂) >3 Moderate diversity
(Log₂) =1-3 Low, mean diversity
(Log₂) <1

Profundal indicator species Pisidium conventus, Sphaerium nitidum, Tubifex kessleri, Peloscolex variegatum, Diporeia hoyi, Mysis relicta, Hexagenia limbata Several tubificid spp., Pisidium casertanum, Sphaerium corneum, Caecidotea (Asellus) spp., several chironomid spp. Tubifex tubifex, Limnodrilus hoffmeisteri, Chironomus plumosus

Profundal fish diversity Many salmonids, white fish and cottids A few salmonids & cottids, walleye, pike, bass, gizzard shad abundant Coarse fish (perch, carp, suckers, minnows) or none

Mean diversity d= -Σ(n_i/N * log₂ n_i/N), where n_i= number of specimens in species i and N= total number of specimens in sample.

Features	Oligotrophic lakes	Mesotrophic lakes	Eutrophic lakes
Lake basin shape	U-shaped	Deep V-shape	Shallow V-shape
Mean depth	Very deep	Moderately shallow	Usually shallow
Hypolimnion temperature	4° C	About 4° C	Usually >4° C
Hypolimnion volume	Large	Moderately small	Small
Thermocline depth	High	Moderately deep	Shallow
Secchi depth	>5 m	3-5 m	<3 m
Dissolved oxygen profile	Orthograde	Clinograde	Clinograde
RAHOD mg O₂/m²/day	<0.017	0.017-0.033	>0.033
Dissolved oxygen content	90-100% in hypolimnion	25-90% in hypolimnion	<25% in hypolimnion
Calcium content	Low (usually <10 mg/L)	Moderate (10-25 mg/L)	High (>25 mg/L)
Total nitrogen content	<300 µg/L	300-600 µg/L	>600 µg/L
Total phosphorus	<10 µg/L	10-30 µg/L	>30 µg/L
Chlorophyll a	<2 µg/L	2-5 µg/L	>5 µg/L
Macrophyte diversity	Many submerged spp. but low biomass, few/no floaters, emergents	Many submerged, floating & emergent spp. & high biomass	Few submerged sp; many floaters, emergents with high biomass
Profundal benthic diversity	High diversity (Log₂) >3	Moderate diversity (Log₂) =1-3	Low, mean diversity (Log₂) <1
Profundal indicator species	Pisidium conventus, Sphaerium nitidum, Tubifex kessleri, Peloscolex variegatum, Diporeia hoyi, Mysis relicta, Hexagenia limbata	Several tubificid spp., Pisidium casertanum, Sphaerium corneum, Caecidotea (Asellus) spp., several chironomid spp.	Tubifex tubifex, Limnodrilus hoffmeisteri, Chironomus plumosus
Profundal fish diversity	Many salmonids, white fish and cottids	A few salmonids & cottids, walleye, pike, bass, gizzard shad abundant	Coarse fish (perch, carp, suckers, minnows) or none

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