The Importance of Wetlands

Wetland definition:

Wetlands are the interface between terrestrial and aquatic habitats and are difficult to define due to their temporal and spatial variability.  The Canadian Wetland Classification System (CWCS), established in 1997, defines a wetland as “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 a wet environment”. 

Hydrology:

Wetland formation is driven by hydrology – input from lake flooding, surface water runoff, ground water, or ocean tides creates and maintains wetlands. Because we are focusing on inland areas around the Okanagan, I will only describe the influences of surface water and ground water on wetlands.

Surface water input from snow melt or rainfall collects in depressional wetlands or flows into rivers or lakes, sometimes causing flooding and bank overflow into floodplain wetlands. Groundwater can either flow directly into depressional wetlands or cause sloping wetlands when seepage or springs occur on slopes.

The water table cycles between high levels due to snow melt and rain to low levels in the drier, hotter months. Lower temperatures during the fall and winter allow the water table to recharge due to low evaporation, decreased plant activity and increased precipitation. With spring snow melt and increased rain events, the water table is resultingly high. With plant growth and increasing temperatures, evapotranspiration causes the water table to drop in the summer and into the fall.

It is important to note that wetlands play a key part in groundwater discharge and recharge and that by modifying a wetland in one area, it may have significant downstream impacts.

Wetland function and importance:

Wetlands are considered one of Earth’s most productive ecosystems, supporting a surprisingly high number of species compared to their area (Zedler & Kercher, 2005).  These species include significant numbers of migratory birds, fish, amphibians, and a wide diversity of plants, many of which are at risk (Rochon et al., 2010).  Although difficult to quantify, wetlands were deemed the second highest-value ecosystem contributing US $14,785 worth of services annually per hectare (Costanza et al., 1997).  These essential services include flood control, groundwater recharge, water purification, nutrient cycling, erosion control, shoreline stabilization and carbon sequestration (Ramsar Convention Secretariat, 2016; Rochon et al., 2010).  They also have social values such as wildlife viewing and hunting and hold spiritual and cultural importance.  Adding to the urgency to protect these highly productive features is the increasing demand for water and risks to water security in our changing climate (Connor, 2015).

Wetlands and climate change:

Wetlands are critically important for mitigating the effects of climate change and water management issues. This is due to their contribution to services such as ground water recharge, shoreline erosion protection, water purification and flood control (Connor, 2015). Climate change forecasting predicts precipitation and temperature regimes will change with global variability (Connor, 2015). Because wetland systems are vulnerable to changes in water supply and ambient temperature, they will be affected in two fundamental ways: first, the number and functional capacity of wetlands within most ecoregions will decline; and second, the types and location of wetlands will shift (Connor, 2015). There should be strong incentive to protect existing wetlands and restore those that have been degraded.

Wetland losses:

Although the benefits and values of these ecosystems are understood, wetlands are amongst the most threatened ecosystems with recent loss or impairment estimated at 70 % in Canada (Kingsford et al., 2016).  Freshwater wetlands cover approximately 16 % of the land area in Canada, representing 25 % of the world’s remaining wetlands (Rochon et al., 2010).  Wetland loss appears to be pronounced near urban centers with estimates of 80 – 98 % of original wetlands having been lost or modified near large urban centers in Canada (Rochon et al., 2010).  Determining spatial extent and location of wetlands is the first step in protecting these important ecosystems, which are steadily disappearing.  

Wetland policies and initiatives in Canada and BC:

There is strong incentive to protect wetlands from ongoing threats such as land development, pollution, agriculture, invasive species and climate change. Lack of sufficient inventories impedes efforts to monitor, conserve, restore and manage wetlands. Canada reported one of the greatest difficulties in halting wetland loss and degradation was the lack of data detailing extent, status and trend of wetlands (Hess, 2018). The lack of wetland inventories can be attributed to several challenges; namely, the size and scale at which wetlands occur across the landscape and their dynamic nature across time, weather and seasons (Wulder et al., 2018).  

In 1981, Canada became a signatory to the international Ramsar Convention on Wetlands, an initiative devoted to the conservation of wetlands. Canada monitors and protects 37 Ramsar-designated “wetlands of international importance” and has committed to protect wetlands through various other means. The objective of the Canadian Federal Government Policy on Wetland Conservation is to: “promote the conservation of Canada’s wetlands to sustain their ecological and socioeconomic functions, now and in the future.” Goals include but are not limited to:

• Maintenance of the functions and values derived from wetlands throughout Canada.
• No net loss of wetland functions on all federal lands and waters.
• Enhancement and rehabilitation of wetlands in areas where the continuing loss or degradation of wetlands or their functions have reached critical levels.

Recent funding support:

Since 1986, over $2.5 billion has been invested in wetland conservation in Canada under the North American Waterfowl Management Plan. The plan focusses on conservation and protection of wetland and upland habitats and their waterfowl populations by securing and improving wetlands. This plan has resulted in over 9.2 million hectares of wetlands and associated uplands habitat being conserved in Canada. Most recently, in 2019, the Government of Canada announced that $10 million would be released over two years to further support the North American Waterfowl Management Plan.

In addition to the protection of wetlands through waterfowl populations, in 2020, the Government of Canada announced it will invest $3.9 billion over ten years to support the implementation of nature-based climate solutions. This includes support for planting two billion trees along with investments in efforts to protect, restore, and improve the management of Canada’s grasslands, wetlands, peatlands, and farmlands.

In British Columbia, an Economic Recovery Plan consisting of $27 million has been dedicated to about 70 watershed and wetland initiatives to ensure B.C.’s water stays healthy and resilient in a changing climate. The projects will take place in or near rural, urban and Indigenous communities hit hard by COVID-19 by December 2021. The projects include:

• supporting the recovery of healthy and abundant fish stocks by restoring spawning and rearing habitats and improving fish passage in critical areas;
• strengthening natural carbon sinks by restoring wetlands throughout the province;
• restoring watersheds to improve the ability to mitigate and adapt to climate change; and
• providing natural flood management and prevention by restoring riparian areas and stabilizing riverbanks.

Legislation to protect wetlands

The three main pieces of federal legislation that may apply to wetlands are the Canada Fisheries Act, Migratory Birds Convention Act, and the Canada Species At Risk Act (SARA). Provincial protection of wetlands comes from the following Acts and Regulations:

• Water Sustainability Act;
• Fish Protection Act;
• Riparian Areas Regulation;
• Wildlife Act and Wildlife Amendment Act;
• Forest and Range Practices Act and;
• Environmental Management Act.

At a municipal level, policies that are in place to protect wetlands include:

• Development Permit Areas (and Environmental Development Permit Areas if a property gets flagged with having a watercourse or ecosystem of concern on/near it)
• Zoning Bylaws
• Official Community Plans (including Local Area & Watershed Plans)
• Soil Removal & Deposit Bylaw
• Pesticide Use Bylaw
• Landscaping Bylaw
• Tax Exemptions for Conservation

To better understand wetland protection in Canada, the BC Wildlife Federation has a great blog about it.