Nature-Friendly Canal Management

Florida Stormwater Association’s 2018 Annual Conference Thursday, June 14, 2018

Stormwater Environmental Utility

• Non-Ad Valorum Fee

• Flood Protection Level of Service

• Maintenance Operations

• Engineering

• Development Standards

• Flood Modeling

• Community Rating System

• Water Quality

• Planning

A 19 year old Estero angler caught a 16 3/4-pound largemouth bass in a private community pond. Dominic Montalto's catch comes close to the currently certified state record of 17 1/4 pound.

South Venice Civic Association – New Ideas

Wanted Living Streams Worked HARD

Communicated in a Positive Way Built partnerships

Mote dips net into canal fish survey

Urban Environments Human populations are logically centered at sites known to have high ecological productivity. Consequently these places are now “urbanized”

• River deltas

• Coastal habitat

• Tidal creeks

• Watershed

drainage canal habitat

Ecologically speaking, restoring urbanized habitats can have the biggest bang-for-the-buck

Conservation of undeveloped sites is great but…

The urbanized areas are usually situated at sites that were historically ecological “hotspots”, thus having higher productive potential

Urban restoration a major challenge, but if successful everyone wins

Fishery Production Estuaries and coastal habitats are major production centers for many species of fish which contribute to the $8 billion fishing industry

RESTORE FISHERIES ACCESS – RECONNECT HABITATS

Florida: “Fishing Capital of the World”

Recreational Fishing Economic impact: $8.0 billion saltwater; $1.7 billion freshwater

Florida Fishing Industry and Snook

Prized game fish: Top predator in estuarine and near-shore environments Presents a recreational challenge Lots of fighting attitude Attains large sizes: weights up to 27 kg; over 4’ long

Florida jobs: 114,898 (saltwater) 14,040 (freshwater) Saltwater Fishing Licenses $946,185 Annual

Larval Phase

Open Water

Benthic Habitats

Subadult Phase

Mortality

Migration

Ontogeny Estuary, Sea grass

Oyster bars

Reproduction

Migration

Mortality

Mortality

Movement

Development

Adults use a wider

array of habitats

Shallow, Coastal habitats:

Mangrove swamps, salt marshes, tidal creeks

Drainage canals

Snook Life History

Snook stocks are subjected to heavy fishing pressure and ongoing adaptive management. Fishing pressure continues to increase

Ongoing net loss of coastal rearing habitats due to urbanization and development

Snook Management in Florida 2015 FWC Stock Assessment

Harvest limits: narrow slot sizes 28-33” Gulf; 28-32” Atlantic bag limits 1 fish/angler/day extended closed seasons

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Fork Length (mm)

Legal Harvest slot

Adults spawn

Beaches

Passes

Larval Phase

Open Water

Benthic Habitats

Larval

Settlement:

Subadult Phase

Mortality

Migration

Ontogeny Sea grass

Oyster bars

Reproduction

Migration

Mortality

Mortality

Movement

Development

General Pattern of Snook Life History

Adults use a wider

array of habitats

High salinity marine water

Shallow, Coastal habitats:

Mangrove swamps, salt marshes, tidal creeks

Typical Juvenile

Snook Habitat:

• Tidal creeks with

shoreline vegetation

• Submerged

structure (branches,

aquatic plants

•Gently sloping banks

•Brackish water

•Abundant prey

Island Releases:

•Comparatively poor survival rates

•Adult snook abundant

Creek Releases:

•Highest survival rates

•Wild juvenile snook abundant

• Soft Sediment, flocculent

sediment, high sediment organic content

• Low salinity, low dissolved oxygen, higher water temperatures (“tough” abiotic conditions),

• High levels of vegetative cover

• Gently sloping banks

NCA

BCU

TIDYA

PCA

NCM

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Growth

What makes good snook juvenile habitat?

Snook Release Habitats

Developed Tidal Creeks ‘Unaltered’ Tidal Creeks

Barrier Island Shoreline Habitat

Drainage Canal Systems and Urban Restoration

Sarasota has over 100 miles of stormwater canal systems These canals route water to tidal creeks and estuaries through the city Snook and other high-value sportfish use these habitats as nursery habitats Fisheries production could be greatly enhanced with relatively minor adjustments to stormwater systems Much of this habitat is not accessible to snook and other marine species. Reconnecting to these habitats represents a net gain for fisheries production

Fisheries and Habitat Assessment of Phillippi Creek Canal System

Quantified fish communities and habitat parameters

Sediment traps can be productive

Habitat Connectivity and Enhancement – What’s the big deal?

More total habitat available access to additional habitat (predation, refuge, food) more prey available (species and numbers) Additional detritivores and herbivore species to” process”

Increased habitat diversity and biodiversity

Water quality and water chemistry improvements • Better dissolved oxygen, buffered temperatures • Nutrient uptake from plants • Particle catchment and sequestration

Well connected water is more stable from flooding - • more avenues for drainage • more acreage for energy release during storms

Society benefits from re-connected revitalized habitat life returns in vigor, birds, animals, fish

Cape Haze peninsula – incredible saltmarsh and mangrove habitats - extremely remote and relatively pristine

Charlotte Harbor Estuary

North Pond

South Pond

Limited connections are important for snook and

tarpon nurseries

Both ponds have a limited connection to the estuary

Seasonal Connection

Year-round Connection

South Pond - year-round tidal connection Through a shallow and very narrow tidal creek

Tidal Creek

Crystal

Lake

South

Ponds

Seasonally Tidal

Tidal

North Pond – seasonal tidal connection Summer rains on the marsh meet summer high tides

Black Mangrove Marsh

At opportunistic times during the summer season

Saltmarsh Pond

Marsh surface

Estuary

Summer Rains

Summer High Tides, Tropical storms, and Hurricanes

When the water’s up

Saltmarsh Pond Estuary Marsh surface

At other times during the summer season and for most of the rest of the year

When the water’s down

Estuary

Land

Brackish ponds

Tidal creek/river

Brackish ponds

Freshwater ponds

Limited Connections are everywhere in the wild

Freshwater floodplain

= limited connection with free exchange of freshwater and saltwater, and allows juvenile sport fish entrance into the places they really want to be

Brackish ponds Freshwater

runoff

Estuary

Land

Neighborhood Freshwater Lake

Saltwater Canals

Freshwater Retention Pond

Reservoir

Weir/Dam

Wide Open

Closed

Closed

Closed

Freshwater Canals

But limited connections are rare in urban landscapes

Urban landscapes are typically “wide open for saltwater” or “closed for saltwater” Most stormwater systems are set up to get rid of freshwater while not allowing brackish water in

Stormwater pipes or ditches

Stormwater pipes or ditches

Bokeelia Pond – Pine Island

Two separate projects connect: 1) Mosquito ditching 2) An upland pond created for fill

Big Jim Creek

Mosquito Ditching

Upland man-made pond at a trailer park

Wildflower Preserve – Lemon Bay Conservancy

Old golf course being converted into a nature preserve

4 Culverts that connect a series of ponds to Lemon Bay (culverts are marked in red)

Culverts can preform a similar function as the other connection (black mangrove forest, narrow tidal stream, mosquito ditch)

Can be useful for linking habitats when roads are in the way

They provide protection from large predators and restrict tidal flow

There is a great potential to enhance urban aquatic habitats by incorporating key principles found in nature and by finding creative engineering solutions that mimic certain natural landscape features

Urban watershed of Phillippi Creek

Restore weir with a fish step pool system

Expand fishery productivity with added nursery habitat

Maintain stormwater functionality Represents a model for this type of work Improve shoreline property value and added societal value

Umm…but Dad; its just a canal...!

Costa Rica Project demonstrates snook fish ladder and habitat creation

So, we’re looking for the high

potential snook habitat…

If we build it they will come… Let nature work for us!

35Lb +

• Urban canal habitat represents a valuable underutilized resource in Sarasota

• Enabling access to the canals for marine fish species could substantially improve the local fishery and economy

• Florida’s numerous retention ponds are vastly underutilized. Link these with fish friendly and ecofriendly corridors

• The celery fields are an excellent example of habitat creation and improved ecosystem functionality. Birds and fish thrive here and the site is a major attraction of the city

• Urban canal restoration represents a ecosystem engineering challenge for stormwater system managers, but we have lots of talented engineers that can certainly accomplish this

• Enhance the filtering capability of canals - restore sinuosity, add sediment traps, allow for plant filtration to occur

• Create deeper pools for year-round fisheries habitat (use vertical leeway in urban settings)

• Use terrace systems – slows flow, creates pools, traps sediment

Implications for canal management in Sarasota