Fish Habitat Restoration Scenarios in an Urban Impaired Waterway
Fish Habitat Restoration Scenarios in an Urban Impaired Waterway
Ecologically Functional Treatments for CAWS
Chicago Area Waterways System is Typical of other Working Waterways In a sustainable human environment, departure from the natural condition requires a management strategy that can maintain ecosystem function
Current Situation Affecting Waterways Artificial Canals Navigable Rivers Working Waterfronts Ports and Harbors Long History of Commerce and Development Patterns
Current Situation Affecting Waterways Policy and Economics Drivers Reinvestment in Ports/Harbors/Navigation Sustainable transportation method Shifts from “dirty waterfront” uses to high end real estate Recreational pressure Water Quality Compliance: No more free passes for working waterways!
Stewardship: Evolving Perception of the Opportunity for Restoration 1960’s: Legal function of river is waste conveyance & navigation 1970’s: Too bad we can’t have it all… 1980’s: How do we make smart trade-offs? 1990’s: Or can we have it all? 2000’s: Reclaiming waterfront land is happening We just forgot about dealing with the water itself because we never paused to devise a plan for effective restoration
How can we Restore Ecological Function Here? What would it look like? How would it function? What would it cost? Where has it been done before? How do we set clear goals and match expectations?
CAWS Habitat Study Limitations • Not to consider water quality improvement—Consent Order focused • Techniques implemented within banks • Original pre-CAWS hydrology/ecology not researched or considered • Techniques allow continued waterway use for navigation, stormwater conveyance, CSO overflows and WWTP discharge
Research Study to Identify, Document, and Evaluate Global Examples Netherlands Germany Japan Malaysia Miscellaneous US applications
Literature Search • Bibliography includes 71 references • 27 on assessing fish habitat, life history or natural environmental variables related to fish life stages or macroinvertebrates • 26 on fish habitat enhancement methods • 2 on improvement of aquatic or riparian vegetation • 4 on physical water quality property of suspended sediment
Objectives Reduce Negative Habitat Variables: • Navigation—direct wave impacts on fish, sediment resuspension and abrasion • Riprap Banks--reduces riparian vegetation, isolates channel from floodplain
Wave damping
Objectives Increase Positive Habitat Variables: • Overhanging Vegetation--provides shade, refuge, food source and plant debris • Natural Banks--dissipate waves, provides refuge and shallow littoral zone • Bank Pocket Areas--provides refuge and sheltered littoral zone
Habitat Functions Food Web: Phytoplankton Herbivores Zooplankton Carnivores Zooplankton Pelagic Non-carnivores Pelagic carnivores
Objectives Increase Positive Habitat Variables: • Large Substrate in Shallows—provides habitat structure and refuge • Plant Debris on Bed--provides food and habitat for macroinvertebrates • Off-Channel Bays--provides refuge and habitat
Colonization of macrozoobenthon and heterotrophic organisms Reports of more than 5000 Individuals (heterotrophic colonization) per cm2 proves high biological activity within constructed measures
Method
Location
Artificial Seaweed
Sunken Structures
Positive/Negative Effect
• • Along bank below water line, on • river bed • • • • On river bottom, submerged near • banks and within shallows • •
Floating Islands
Vegetated Revetment
Chamber Revetments (unvegetated)
)
Linear Constructed Shallows
Virtually anywhere in river where • their occurrence will not interfere • with navigation • • • • At the river’s edge and on the banks, • above and below the waterline •
• Below the waterline at the river’s • edge •
• • • Parallel to the canal bank • • •
Reduce Current Velocity/Turbulence Creates “drag” on sediment particles causing them to settle Creates riverbed depth diversity Increases density/stability of bottom sediments Fronds used as habitat for periphyton, microbes and fish Provides habitat/refugia for fish Provides protection from Wave Energy Attracts different species depending on the deployment method and location used Provides piscivores needed ambush points Provides habitat for many types of organisms: fish, birds, insects, herptiles, microorganisms Dissipates wave energy Provides shelter for aquatic organisms Provides isolated nesting areas for waterfowl Improves water quality Protects banks from erosion-dissipates wave energy Provides natural vegetation on the river bank Provides habitat diversity Allows for growth of stable riparian vegetative community, contributing shading, POC/detritus, and other plant debris
Dissipates wave energy Provides refuge for young fish Collects sediment
Dissipates wave energy Creates refugia Allows for aquatic plant growth and shallow water habitat Creates food source and source of plant debris Provides habitat for many types of organisms, including fish (many life forms), herptiles, insects/macroinvertebrates Introduction of shallow water breeding/nesting grounds
Habitat Objectives
Provides in-channel refuge Instream, near-shore structure for wave energy dissipation
Provide in-channel refuge Alternate overhanging cover Near-shore structure Large substrate in shallow areas
Provide in-channel refuge Increase riparian vegetation Near-shore structure for refuge/habitat Decrease impacts of wave energy
Increase bank slopes/Recontour banks Alternate overhanging cover Incorporate vegetation into unvegetated riparian area Dissipate wave energy
Large substrate in shallow areas Increase bank slopes Near-shore structure
Increase off channel refuge & shallow water habitat Increase bank slopes Near-shore structure to dissipate wave energy Provide near-shore cover and refuge Increase riparian vegetation Increase large substrate in shallow areas
Artificial Seaweed •Originally developed to mitigate scour around pipes and oil rig footings in the ocean •Attenuates wave energy •Entraps suspended sediment •Provides cover from and for predation •Provide surfaces for colonization by algae and microbes
Sunken Structures •Provides refugia for microorganisms, invertebrates and fish •Re-purpose precast concrete box culverts or other appropriate discarded materials •Recycle demolition debris, eg ceramic tubs and toilets etc •Purchase specially designed habitat modules
Floating Islands •Provides shade to water surface •Provides suitable area for emergent macrophytes •Reduced disturbance zone for birds and herptiles •Increases oxygen locally for fish •Substrate for aquatic macroinvertebrates and microbes
Varying degrees of shelter habitat under water:
Chamber Revetments •Employed in high energy areas to attenuate waves •Provide surface structure for microorganisms to colonize •Controls erosion •Used by zoo/phytoplankton •Enhances oxygenation
Vegetated Revetments •Adds structure to the littoral bank zone •Dampens wave reflection •Mitigates erosion •Provide habitat for birds and reptiles •Enhances food supply for fish •Adds oxygenation •Enhances macroivertebrate habitats
Linear Shallows •Provides spawning and nesting habitat for multiple species •Provide temporary refugia for adult fish •Provides soft substrate for herptile burrows •Provide habitat for rooted aquatic and emergent macrophytes
Next Steps
Implement pilot projects Monitor Aquatic habitat functions Monitor physical and social performance Adapt and refine approaches Identify further sites that would benefit
Closing Restoration Opportunity Exists: • To demonstrate and evaluate habitat improvement • To document costs, including O&M • To assess issues affecting navigation, recreation, tax base, etc. • To increase awareness & support
QUESTIONS?
2011 ADC WINTER FORUM | PAGE 35
Ecologically Functional Treatments for CAWS
Chicago Area Waterways System is Typical of other Working Waterways In a sustainable human environment, departure from the natural condition requires a management strategy that can maintain ecosystem function
Current Situation Affecting Waterways Artificial Canals Navigable Rivers Working Waterfronts Ports and Harbors Long History of Commerce and Development Patterns
Current Situation Affecting Waterways Policy and Economics Drivers Reinvestment in Ports/Harbors/Navigation Sustainable transportation method Shifts from “dirty waterfront” uses to high end real estate Recreational pressure Water Quality Compliance: No more free passes for working waterways!
Stewardship: Evolving Perception of the Opportunity for Restoration 1960’s: Legal function of river is waste conveyance & navigation 1970’s: Too bad we can’t have it all… 1980’s: How do we make smart trade-offs? 1990’s: Or can we have it all? 2000’s: Reclaiming waterfront land is happening We just forgot about dealing with the water itself because we never paused to devise a plan for effective restoration
How can we Restore Ecological Function Here? What would it look like? How would it function? What would it cost? Where has it been done before? How do we set clear goals and match expectations?
CAWS Habitat Study Limitations • Not to consider water quality improvement—Consent Order focused • Techniques implemented within banks • Original pre-CAWS hydrology/ecology not researched or considered • Techniques allow continued waterway use for navigation, stormwater conveyance, CSO overflows and WWTP discharge
Research Study to Identify, Document, and Evaluate Global Examples Netherlands Germany Japan Malaysia Miscellaneous US applications
Literature Search • Bibliography includes 71 references • 27 on assessing fish habitat, life history or natural environmental variables related to fish life stages or macroinvertebrates • 26 on fish habitat enhancement methods • 2 on improvement of aquatic or riparian vegetation • 4 on physical water quality property of suspended sediment
Objectives Reduce Negative Habitat Variables: • Navigation—direct wave impacts on fish, sediment resuspension and abrasion • Riprap Banks--reduces riparian vegetation, isolates channel from floodplain
Wave damping
Objectives Increase Positive Habitat Variables: • Overhanging Vegetation--provides shade, refuge, food source and plant debris • Natural Banks--dissipate waves, provides refuge and shallow littoral zone • Bank Pocket Areas--provides refuge and sheltered littoral zone
Habitat Functions Food Web: Phytoplankton Herbivores Zooplankton Carnivores Zooplankton Pelagic Non-carnivores Pelagic carnivores
Objectives Increase Positive Habitat Variables: • Large Substrate in Shallows—provides habitat structure and refuge • Plant Debris on Bed--provides food and habitat for macroinvertebrates • Off-Channel Bays--provides refuge and habitat
Colonization of macrozoobenthon and heterotrophic organisms Reports of more than 5000 Individuals (heterotrophic colonization) per cm2 proves high biological activity within constructed measures
Method
Location
Artificial Seaweed
Sunken Structures
Positive/Negative Effect
• • Along bank below water line, on • river bed • • • • On river bottom, submerged near • banks and within shallows • •
Floating Islands
Vegetated Revetment
Chamber Revetments (unvegetated)
)
Linear Constructed Shallows
Virtually anywhere in river where • their occurrence will not interfere • with navigation • • • • At the river’s edge and on the banks, • above and below the waterline •
• Below the waterline at the river’s • edge •
• • • Parallel to the canal bank • • •
Reduce Current Velocity/Turbulence Creates “drag” on sediment particles causing them to settle Creates riverbed depth diversity Increases density/stability of bottom sediments Fronds used as habitat for periphyton, microbes and fish Provides habitat/refugia for fish Provides protection from Wave Energy Attracts different species depending on the deployment method and location used Provides piscivores needed ambush points Provides habitat for many types of organisms: fish, birds, insects, herptiles, microorganisms Dissipates wave energy Provides shelter for aquatic organisms Provides isolated nesting areas for waterfowl Improves water quality Protects banks from erosion-dissipates wave energy Provides natural vegetation on the river bank Provides habitat diversity Allows for growth of stable riparian vegetative community, contributing shading, POC/detritus, and other plant debris
Dissipates wave energy Provides refuge for young fish Collects sediment
Dissipates wave energy Creates refugia Allows for aquatic plant growth and shallow water habitat Creates food source and source of plant debris Provides habitat for many types of organisms, including fish (many life forms), herptiles, insects/macroinvertebrates Introduction of shallow water breeding/nesting grounds
Habitat Objectives
Provides in-channel refuge Instream, near-shore structure for wave energy dissipation
Provide in-channel refuge Alternate overhanging cover Near-shore structure Large substrate in shallow areas
Provide in-channel refuge Increase riparian vegetation Near-shore structure for refuge/habitat Decrease impacts of wave energy
Increase bank slopes/Recontour banks Alternate overhanging cover Incorporate vegetation into unvegetated riparian area Dissipate wave energy
Large substrate in shallow areas Increase bank slopes Near-shore structure
Increase off channel refuge & shallow water habitat Increase bank slopes Near-shore structure to dissipate wave energy Provide near-shore cover and refuge Increase riparian vegetation Increase large substrate in shallow areas
Artificial Seaweed •Originally developed to mitigate scour around pipes and oil rig footings in the ocean •Attenuates wave energy •Entraps suspended sediment •Provides cover from and for predation •Provide surfaces for colonization by algae and microbes
Sunken Structures •Provides refugia for microorganisms, invertebrates and fish •Re-purpose precast concrete box culverts or other appropriate discarded materials •Recycle demolition debris, eg ceramic tubs and toilets etc •Purchase specially designed habitat modules
Floating Islands •Provides shade to water surface •Provides suitable area for emergent macrophytes •Reduced disturbance zone for birds and herptiles •Increases oxygen locally for fish •Substrate for aquatic macroinvertebrates and microbes
Varying degrees of shelter habitat under water:
Chamber Revetments •Employed in high energy areas to attenuate waves •Provide surface structure for microorganisms to colonize •Controls erosion •Used by zoo/phytoplankton •Enhances oxygenation
Vegetated Revetments •Adds structure to the littoral bank zone •Dampens wave reflection •Mitigates erosion •Provide habitat for birds and reptiles •Enhances food supply for fish •Adds oxygenation •Enhances macroivertebrate habitats
Linear Shallows •Provides spawning and nesting habitat for multiple species •Provide temporary refugia for adult fish •Provides soft substrate for herptile burrows •Provide habitat for rooted aquatic and emergent macrophytes
Next Steps
Implement pilot projects Monitor Aquatic habitat functions Monitor physical and social performance Adapt and refine approaches Identify further sites that would benefit
Closing Restoration Opportunity Exists: • To demonstrate and evaluate habitat improvement • To document costs, including O&M • To assess issues affecting navigation, recreation, tax base, etc. • To increase awareness & support
QUESTIONS?
2011 ADC WINTER FORUM | PAGE 35
