This document discusses wetlands and challenges with biodiversity offsets. It begins by defining wetlands and describing Canada's five main wetland classes: bogs, fens, swamps, marshes, and shallow open waters. It then discusses key challenges with wetland offsets, including issues with equivalency between impacted and offset wetlands, the scale at which wetland benefits accrue, differences in how quickly benefits develop, and ensuring offsets are additional to what would occur anyway. The document also provides examples of wetland offset policies from Atlantic Canada and Alberta, and notes that finding an appropriate organization to deliver offset projects can be a challenge.

1. Wetlands:
Biodiversity Offsets: Challenges and
considerations
Wetlands:
David Howerter & Karla Guyn, Ducks Unlimited Canada
ecology of prairie wetlands and their
importance to waterfowl

2. Outline
Wetland definition
Wetland Classification
Wetland Values
Offset Challenges
DUC Experiences
 Atlantic Canada
 Alberta

3. What is a wetland?
 “ …. land that is saturated with water
long enough to promote wetland or
aquatic processes as indicated by
poorly drained soils, hydrophytic
vegetation, and various kinds of
biological activity which are adapted
to the wet environment.”
(Wetlands of Canada, 1988, page 416)

4. Canada’s Wetlands
• there are five classes
of wetlands in the
Canadian Wetland
Classification System:
bogs, fens, swamps,
marshes, & shallow
water wetlands

5. Canada’s Wetlands
• organic wetlands (> 40 cm of peat):
- bogs
- fens
peatlands

6. Bogs

7. Bogs
 peat-covered wetland
 wetland isolated from ground water
 low nutrients
 water and peat usually acidic
 dominated by Sphagnum mosses with
tree, shrub or treeless vegetation cover

8. Fens

9. Fens
 peat-covered wetland
 wetland exposed to groundwater
 more nutrients than bogs
 less acidic
 greater variety of plants than bogs: grass
meadows, shrubs, and trees

10. Canada’s Wetlands
• organic wetlands (> 40 cm of peat):
- bogs
- fens
peatlands
• mineral wetlands:
- swamps
- marshes
- shallow open water

11. Swamps

12. Swamps
 non-peat forming wetland
 waterlogged soil, often with standing water
 vegetation is dense coniferous or deciduous
trees, or tall shrub thickets
 water-loving plants

13. Marshes

14. Marshes
 non-peat forming wetland
 waterlogged soil in plant rooting zone, often
with standing water
 nutrient rich water offering greater plant
diversity: emergent reeds, rushes or sedges
 surface water level may fluctuate seasonally

15. Shallow open waters

16. Shallow open waters
 non-peat forming wetlands
 locally known as ponds or sloughs
 standing water, often a transition between
lake and marsh
 fewer emergent plants but submersed plants
may be present
 water depth usually < 2 meters

17.  Canada has approx. 127 million ha of
wetlands (24% of all the world’s
wetlands)

18. Prairie Pothole Region
Manitoba
Montana
North
Dakota
Minnesota
South
Dakota
approximately 715,000
km2
Iowa

20. Stewart and
Kantrud (1971)
 based on vegetative growth
 allows for a more detailed
classification
Stewart, R. E. and H. A. Kantrud. 1971. Classification of Natural Ponds and Lakes in the Glaciated Prairie Region.
Resource Publication 92, Bureau of Sport Fisheries and Wildlife, U.S. Fish and Wildlife

21. Permanent Ponds
(Class V)

22. Semi-permanent Ponds
(Class IV)

23. Seasonal Ponds
(Class III)

24. Temporary Ponds
(Class II)

25. Ephemeral Ponds
(Class 1)

26. Relationship Between # Mallard Pairs/Ha of Wetland
and Individual Wetland Size (in Ha)
1
0.9
Mallard Pairs/Ha
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
6
Wetland Size (in Ha)
Wetland Area = 10 Ha
Wetland Area = 10 Ha
Wetland Area = 10 Ha
One 10 Ha wetland
= 1 Mallard Pair
Ten 1 Ha wetlands
= 3 Mallard Pairs
One Hundred 0.1 Ha wetlands
= 9 Mallard Pairs
Source: Reynolds, R.E., D.R. Cohan, and M.A. Johnson. 1996. Using landscape information approaches to increase duck
recruitment in the Prairie Pothole Region. Trans. N. Amer. Wildl. And Nat. Resour. Conf.

27. Wetland Offset Challenges
1. Equivalency
– Variability
– Clear Objectives, Agreement on Currency

28. Wetland Values
Water Quality
 Nutrients
 Chemicals
 Sediments
Water quantity
 Flood prevention
 Groundwater recharge
GHG sequestration
Recreation
Biodiversity

29. Hydrologic Response To Draining Wetlands
current drainage area boundary
wetlands
stream

30. Hydrologic Response To Draining Wetlands

31. Hydrologic Response To Draining Wetlands
New drainage area boundary

32. Wetland Offset Challenges
1. Equivalency
– Variability
– Clear Objectives, Agreement on currency
2. Proximity
– Benefits accrue at different scales

33. Wetland Restoration vs. Securement
A) Fall 2008
B) Spring 2009
C) Fall 2011

34. Wetland Offset Challenges
1. Equivalency
– Variability
– Clear Objectives, Agreement on currency
2. Proximity
– Benefits accrue at different scales
3. Timing
– Benefits accrue at different rates
4. Additionality
– Expected rates of loss

35. Offset rules
cabaysdirt works.com

36. Wetland Offset Challenges
1. Equivalency
– Variability
– Clear Objectives, Agreement on currency
2. Proximity
– Benefits accrue at different scales
3. Timing
– Benefits accrue at different rates
4. Additionality
– Expected rates of loss
5. Equitability

37. Wetland Offset Challenges
1. Equivalency
– Variability
– Clear Objectives, Agreement on currency
2. Proximity
– Benefits accrue at different scales
3. Timing
– Benefits accrue at different rates
4. Additionality
– Expected rates of loss
5. Equitability
6. Lack of wetland inventory/monitoring

38. Atlantic Province Offset Similarities
NB, NS and PEI:
 Wetland and Watercourse Alteration
Regulation
 Mitigation Sequence in place
 Ratios established
 NB 2:1, NS 2:1, PE 3:1

40. Alberta Offset rules
 Mitigation Sequence in place
 Variable Ratios
 Within same watershed

41. Wetland Offset Challenges
1. Equivalency
– Variability
– Clear Objectives, Agreement on currency
2. Proximity
– Benefits accrue at different scales
3. Timing
– Benefits accrue at different rates
4. Additionality
– Expected rates of loss
5. Equitability
6. Lack of wetland inventory/monitoring
7. Finding a qualified delivery agent!

42. Delivery Agent





Identify suitable projects
Manage and maintain projects as required
Provide long-term security
Monitor projects
Provide effective and efficient process

43. Ducks Unlimited Canada, a private, non-profit charitable
organization, conserves, restores and manages wetlands and
associated habitat for North America’s waterfowl. These habitats
also benefit other wildlife and people.