Our goal is to improve water quality and rehabilitate the natural diversity of the Coves. We plan to achieve that through various projects around the Coves Subwatershed that improve and increase available habitat and protect water quality.
The issue of water quality in the Coves is complex - contributors to poor water quality in the Coves include, but are not limited to:
- Polluted stormwater from residential and commercial properities throughout the subwatershed
- Erosion and sedimentation resulting from high volume stormwater flows
- Overpopulation of Common Carp
- An insufficient percent coverage of natural vegetation across the subwatershed
- Lachate from former landfill/industrial lands
The Friends of the Coves have worked with the Upper Thames River Conservation Authority, the City of London, the Ministry of the Environment, the Ministry of Natural Resources, and several private consultants on the issue of the Coves water quality.
The first goal in our rehabilitation efforts is the restoration of conditions favourable to plant growth in the ponds. Aquatic vegetation provides the foundation for a healthy ecosystem upon which fish, birds and the entire food chain depend. Currently, vegetation growth in the Coves ponds is being hindered by unclear water that does not allow enough light to penetrate and physical disturbance by carp.
Early restoration efforts will focus on rehabilitating the shoreline and riparian zone of the ponds with native plant species, managing the invasive carp population, and mitigating polluted water runoff and erosion in the surrounding watershed.
The Common Carp
The diversity and health of the Coves is currently impaired by a high percentage of the fish community being Common carp.
- The European Common carp is not native to our area. It was introduced to North America in the mid-1800s as a commercial food fish.
- Common carp thrive in low-oxygen, sediment-laden environments, similar to the Coves.
- The omnivorous carp continually disturb soft sediment on the pond bottom as they forage for food. This sediment is up to 1.5 meters deep in some places due to rapid deposition from runoff. This behaviour introduces particles from the pond bottom into the water, degrading water clarity and quality. Contained in these suspended particles are nutrients, particularly phosphorus, which contribute to excessive algae growth.
- Poor water clarity reduces sunlight penetration to the bottom of the ponds which prevents the seeds of aquatic vegetation from germinating and/or establishing. This discourages other fish species native to the Coves from inhabiting the ponds because the appropriate habitat which usually contains plants is not available.
- Carp also directly uproot emergent and shorline plants and eat plant seeds and fish eggs.
The Friends of the Coves has developed a plan to manage the carp population. Please see the resource section to view a draft of the Coves Aquatic Rehabilitation Pilot PLan.
Surface Water Quality
- Excessive algae growth results in decreased water clarity and light penetration. This reduces plant growth and impairs the abilities of sight-feeding fish.
- Phosphorus levels in the Coves have been recorded at levels 6 times greater than the acceptable concentrations identified by provincial standards.
- The growth and decay of excessive amounts of algae depletes oxygen on the pond bottom required by aquatic insects, plants and fish. This encourages an environment favorable to the survival of less desirable fish such as carp.
Further information on future rehabilitation plans will be relayed both through our website and through community outreach actions.
London Community Foundation
The Ontario Trillium Foundation
Funds within London Community Foundation, including:
- The Richard and Beryl Ivey Fund
- The Haines Family Fund
- The Joseph Rea Environmental Fund