Ecological Benchmarking Assessment for an Urbanized Estuarine River

J.K. Shisler, T.J. Iannuzzi, A.D. Standbridge, J.M. Gonzalez, and D.F. Ludwig

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What are Some Impacts to the Lower Passaic River (LPR)?

Shoreline features/impacts – lower 6 milesRight* Left*

Bulkhead 52.5% 51.9%

RipRap 32.3% 28.5%

Vegetation with RipRap 9.2% 13.8%

Aquatic Vegetation 6.0% 5.8%

*Facing Up-River from Newark Bay

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Wetlands Loss in the Region

Mid-19th Century Today

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Loss of Historic Tributaries in Region

River/Creek Estimated Length Lost (mi)

Bound Creek and Tributaries 18.1

Maple Island Creek and Tributaries 13.2

First River and Tributaries 6.0

Unnamed Passaic Tributary Creeks 0.7

Kearny Marsh Tributaries 1.2

Great Meadow Brook and Tributaries 6.3

Oyster Creek and Tributaries 2.3

Upper Newark Bay Tributaries 10.9

Other Newark Bay Tributaries 20.2

Total Lost 76.6

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Can We Restore This System?

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To What?

• It won’t look like this again• Many system constraints in an

urban river such as the LPR• Goal is to create an ecosystem

balanced for biological production, and human and wildlife use

• So, restoration requires:– Value judgments

– Ecological benchmarking

– Creative engineering

• Scope for restoration is substantial

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Expected Natural Habitats

• Mudflat• Salt marsh – low marsh• Salt marsh – high marsh• Estuarine scrub-shrub• Transitional tidal marsh• Freshwater tidal marsh• Transitional and freshwater scrub-shrub• Floodplain forest

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Objectives

• Examine existing habitats• Characterize and quantify physical and ecological

attributes or “benchmarks”• Use benchmarks as foundation for evaluating the likely

success of potential restoration projects

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What is an ecological benchmark?

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LPR Salinity Gradient

Salinity (ppth) River Mile

• Polyhaline 18 - 30 0.5

• Mesohaline 5 -18 5.1

• Oligohaline 0.5 - 5 6.8

• Freshwater >0.5 11.1

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What Information Do We Need to Get Started?

• Know the constraints• Can we modify constraints to meet restoration goals?• Benchmark local reference wetlands

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Limitations to Restoration in LPR

• Shoreline use/configuration• Geomorphic setting • Tidal zone • Flooding/inundation • Elevation• Salinity • Shade/sun • Substrate• Water velocity

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Natural Salt Marsh is an Objective

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Where is Spartina?

• Upper limit at about river

mile 2.7• Habitat conditions are a factor

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Lower (i.e., Polyhaline) Section of LPR

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RipRap Shoreline Edge

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Old Bulkhead

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Urban Tidal River

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Can We Restore A Salt Marsh Habitat?

• The quick answer is yes, BUT• Location is critical• Will not have high marsh habitat since the area has been

lost due to development• Will be narrow bands with riprap as the ecotonal edge• Limited wildlife use• May require breakwater in front of the wetland

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Local Wetland Restoration Effort - Why did it Fail?

• Located above elevation benchmarks for S. alterniflora in system

• Constraints from outside impacts– Geese– Floatables– Ice

• Requires extensive engineeringto overcome constraints

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Where is the Brackish Water Tidal Wetland?

• Very limited locations within the LPR

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Urban Impacts

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Transitional-Freshwater Section Goal

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Observed Habitat

Transitional-Freshwater Section of LPR

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OBSERVED RIPARIAN HABITAT

Existing Transitional-Freshwater Habitat

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Urban River Restoration Concepts and Conclusions

• Set realistic goals• Use benchmarking of

existing habitat attributes• Focus on function• Restoration vs. Creation• Adaptive Management

• Stakeholder Commitment

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Questions?