Draft Credit River Fish Community Objectives

Fish Community Objectives provide guidance and establish priorities for fish communities in each Fisheries Management Zone of the Credit River. The Niagara Escarpment and Oak Ridges Moraine are dominant land forms within the watershed. Significant portions of the watershed are influenced by urban land uses. These natural features and land use effects in turn influence fish communities and habitat. The Fish Community Objectives for riverine zones have been associated with these physiographic features and land use influences.

Zone 1 Objectives: Riverine and Lake Communities – above the Niagara Escarpment

Small Coldwater Riverine Objective – Increase the capacity for brook trout. Brook trout should be a prominent species in most of these streams.

  • In Caledon Creek, Redside Dace populations should be protected and restored in accordance with the Government Response Statement to the Redside Dace Recovery Strategy.

  • Brook trout should be given priority in those streams with greater potential for lower water temperatures.

  • Redside Dace should be given priority in those coldwater streams with less potential for lower water temperatures.

  • Juvenile Atlantic salmon are included in this fish community where access above the escarpment was historically feasible (West Credit River, Black and Silver Creeks).

  • Restore connectivity between reaches that have been isolated by the construction of dams.

Intermediate Coldwater Riverine Objective – Increase the capacity for brook trout. Brook trout should be a prominent species in most of these streams.

  • Priority should be placed on protecting the Credit River from harmful contaminants coming from Water Pollution Control Plants (WPCP) in Orangeville and Acton as well as restoring connectivity between reaches that have been isolated by the construction of dams.

  • Juvenile Atlantic salmon are included in this fish community where historical access above the escarpment was feasible (West Credit River, Black and Silver Creeks).

Small and Intermediate Warmwater Riverine Objective – Maintain capacity for native coolwater and warmwater fishes (e.g. minnows and darters).

  • If the stream has potential to become a coldwater stream, then priority should be given to brook trout as the physical habitat determines.

Inland Lakes and Reservoirs Objective – Northern pike, smallmouth bass, largemouth bass, and sunfishes can provide angling opportunities where they currently exist in the larger inland lakes and reservoirs (Fairy Lake and Island Lake).

  • Range expansion of these species into the adjoining lakes, rivers and streams should be prevented. Caledon Lake is managed as a put-and-take fishery for brook trout through private stocking licenced by MNR.

  • The objectives for smaller on-line ponds are the same as the stream that flows through them.

Zone 2 Objectives: Riverine Communities – below the Niagara Escarpment

The high stream gradient and larger substrates found below the Niagara Escarpment are especially suited to Atlantic salmon and trout species. However, elevated summer temperatures, habitat fragmentation and silt deposition currently still hinder restoration of these species. Since water flows downstream, impacts to the river are carried downstream. The river mouth (Credit River Marshes) plays an important role in meeting the fish community objectives for the watershed and Lake Ontario (FMZ 20), by acting as a migratory corridor, and for providing spawning and nursery habitat for some fish species that reside elsewhere for other parts of their life cycle.

Small Coldwater Riverine Objective – Increase capacity for Atlantic salmon and brook trout.

  • These species should be priority in the reaches of these streams that are not greatly influenced by the presence of rainbow trout and brown trout.

  • Redside Dace populations should be protected and restored in accordance with the Government Response Statement.

  • Brook trout are to be protected from the negative competition effects from non-native naturalized species (e.g. brown trout and rainbow trout)

Intermediate Coldwater Riverine Objective (Cataract to Norval Dam)- Atlantic salmon restoration is the priority for this management zone.

  • The capacity for brook trout should also be increased where possible, and they should be a priority species in most of these streams where inputs of urban storm water is absent or minimal.

  • Priority should be placed on protecting the Credit River from harmful contaminants coming from the Water Pollution Control Plants (WPCP) in Georgetown.

  • Likewise, in areas where urban storm water effluent is absent, brown trout presence should be decreased by allowing harvest.

  • The capacity for juvenile rainbow trout production and resident brown trout should be maintained in areas that are highly influenced by urban storm water effluent, such as Black Creek between 8th Line and the Stewarttown Dam.

  • Redside Dace populations should be protected and restored in accordance with the Government Response Statement.

  • Effort is required to reduce the presence of rainbow trout and brown trout in Silver Creek in order to avoid negative impacts to brook trout and Redside Dace recovery.

  • American eel is a target recovery species for this fish community zone.

  • Brook trout and Atlantic salmon are to be protected from the negative competition effects from non-native naturalized species (e.g. brown trout and rainbow trout)

Large Coldwater Riverine Objective (Norval Dam to Steeles Ave) – Increase the capacity for juvenile rainbow trout production, resident brown trout and smallmouth bass.

  • These species should be priority in most of the river within this community where urban storm water is present.

  • American eel and lake sturgeon are target recovery species for this fish community zone dependent on passage improvements at Streetsville fishway.

  • This is a migratory corridor for salmon, trout and smallmouth bass

Small Warmwater Riverine Objective – Increase capacity for native coolwater and warmwater fishes (e.g. minnows and darters).

  • Redside Dace populations should be protected and restored in accordance with the Government Response Statement.

  • If the stream has potential to become a coldwater stream, then priority should be given to Redside Dace or rainbow trout, as the physical habitat determines.

Intermediate Warmwater Riverine Objective – Increase capacity for native coolwater and warmwater fishes (e.g. minnows and darters).

  • Redside Dace populations should be protected and restored in accordance with the Government Response Statement. If potential exists to convert a warmwater reach to a coldwater reach, then priority should be given to Redside Dace and rainbow trout as the physical habitat determines (e.g. Levi Creek).

Large Warmwater Riverine Objective (Steeles Ave to QEW) – Increase the capacity for smallmouth bass production and residence.

  • Increase the spawning and nursery capacity for migrants from Lake Ontario, such as American eel, lake sturgeon, and white sucker.

  • Improve passage for non-jumping species at Streetsville fishway.

  • Smallmouth bass should be prominent in most of the river where urban storm water is present.

  • Lake Sturgeon habitat restoration is a priority for this community.

  • This is a migratory corridor for salmon, trout and smallmouth bass

River Mouth (Credit River Marshes) Objective (QEW to Lake Ontario) – Maintain migratory corridor for all native and naturalized species that use Lake Ontario and the Credit River.

  • Increase the spawning capacity for migrants from Lake Ontario, such as northern pike and largemouth bass.
  • Reduce carp populations.

 

­­­­­­­­­­———————————————–

 

 

Fish community management zones of the Credit River watershed.

 

Coldwater

Brook trout are the indicator species.

Sculpins although often associated with brook trout are not found above the Niagara

Escarpment and more common in Cool / Coldwater.

Species diversity can be naturally very low in pristine cold headwaters.

Brown and rainbow trout may be present but are more dominant in Cool / Coldwater

Includes all tributaries above the Escarpment (Monora, Mill, Shaws, lower reaches of

Caledon Creek, West Credit, East or Little Credit, Black and portions of Silver Creek). Only those small tributaries that have their headwaters above the Escarpment, such as Rogers Creek have brook trout. The main River from Orangeville to Inglewood is also Coldwater habitat.

Only Huttonville Creek has potential brook trout habitat that is now utilized by migratory

rainbow trout.

 

Mixed Cold / Coolwater

Provides coldwater refuge areas and relatively less trout production than Coldwater

streams. Brook trout are rare and do not reproduce in these areas.

Brown and rainbow trout have adapted to these reaches and are the primary indicator

species along with mottled sculpin and American brook lamprey.

Other common species include rainbow and fantail darter, northern hog sucker and

stonecat.

Overall species diversity is higher than Coldwater streams.

The main river from Inglewood to Huttonville is classified as Cold / Coolwater.

 

Mixed Cool / Warmwater

Seasonal use by brook trout in headwater areas draining to Coldwater habitats including some tributaries of the West Credit, Silver and Black Creeks.

Utilized by migratory trout and salmon in lower reaches of watershed including Levis, Mullet and Fletchers Creeks. Reproduction is suspected but the relatively cooler waters to the main river can provide important refuge habitat for these young migratory species.

Cool / Warmwater habitat extends to the upper reaches of Levis and Mullet Creeks. Cooler temperatures and better baseflows (associated with silt/sand/gravel lenses or wetland storage) than Small Warmwater streams should exist, but existing fish communities may not reflect this due to extensive land use impacts.

Normally species associated with groundwater discharge headwater wetland areas such as central mudminnow and northern redbelly dace are common. However, these species are absent below the Niagara Escarpment in the Credit watershed.

The redside dace should also be best associated with Cool \ Warmwater habitats but has also been reported in other stream types.

Both Cool \ Warmwater and Small Warmwater streams have intermittent headwaters that certain species will utilize on a seasonal basis.

 

Small Warmwater

The most dominant species found include creek chub and blacknose dace . These species are also found in other stream types and best utilize intermittent reaches along with brook stickleback. Other species tolerant of warm temperatures and lower dissolved oxygen include bluntnose and fathead minnows. White sucker is also often common.

A greater diversity of minnows, some habitat specialists and water quality sensitive species may also be present, especially where access to larger Mixed or Warmwater streams are available.

Most typical of clay till plains with few silt/sand/gravel components such as Fletchers and upper Mullet Creeks and other smaller streams. Caledon Creek is classified as Small Warmwater due to some till material but more so because watertables are often below streambed elevations, particularly along the main branch which can dry-up and thenresurfaces as a Coldwater stream.

 

Large Warmwater

 

A large order river or lake, often with wetland habitats and a diversity of common species and habitat specialists and including top predatory fish such as bass and pike.

The best indicator species for the lower Credit is the smallmouth bass, its distribution is

limited upstream by the Streetsville Dam. Its introduction above and upstream to the Norval Dam is recommended.

A number of species are only found in the lower Credit and may be associated with access from Lake Ontario including river chub, emerald, spottail, rosyface and spotfin shiners. Many additional lake species not normally associated with the river will utilize the most lower reaches.

  • Sunfish, perch and bullhead catfish seem to be more common in pond habitats.
  • Includes a migratory corridor for salmonids.