Cat Island Chain Restoration in Lower Green Bay

Photo by Tom Erdman 1966

n Expansive emergent marshes (e.g., Duck Creek delta) n Numerous small islands n Beaches and mud flats n Submerged aquatic plant beds

Southern Green Bay historically provided diverse coastal wetland habitats for fish and wildlife

Photo by Tom Erdman 1966

1938

Brown County Aerial Photography , 1938

Cat  Island  

1960

Brown County Aerial Photography , 1960

Cat  Island  

Cat  Island     Lone  Tree  Island  

Willow  Island  

Bass  Islands  

Naviga6on  Channel  

Grassy  Island  

1966 during low water levels Islands extend 2.5 miles into Green Bay

Photo Courtesy of Tom Erdman , 1966

Duck  Creek  Delta  Marsh  

Cat  Island  

Long  Tail  Point  

I-­‐43  Construc6on  

Bass  Islands  

Landfill  

90% of Coastal Wetlands Lost from Southern Green Bay

Agriculture  

Photo by WDNR, 1969

Duck  Creek  Delta  

Municipal  incinerator  and  landfill  

Long  Tail  Point  

LiFle  Tail  Point  

Cat  Island  Chain  

Bayport  Dredge  Spoil  Disposal  in  Atkinson’s  Marsh  

Rock  dikes  hardened  the  shoreline  

Peter’s  Marsh  

Photo Courtesy of Tom Erdman , 1970

Islands survived historical water level fluctuations – Why not now?

Ø  Water levels rose rapidly to record highs and remained elevated for two decades

Ø  Repeated severe spring storms

Ø  Shorelines hardened by rip rap deflect wave energy and exacerbate erosion

Ø  Poor water clarity from runoff pollution reduced aquatic vegetation and their wave dampening benefits

Rising Great Lakes water levels and severe storms in 1970s caused wetland and island erosion

Green Bay islands during high water levels in 1976

Cat  Island  

Willow  Island  

Grassy  Island  

Photo Courtesy of Tom Erdman , 1976

Lost habitat effects:

Ø  Colonial Nesting Water Birds

Ø  Shorebirds Ø  Waterfowl Ø  Fish Spawning Ø  Fish Nurseries Ø  Turtles Ø  Amphibians Ø  Invertebrates

Lower Fox River Area of Concern

Photo by UW Sea Grant

Ø  The Cat Island Chain project developed out of the 1988 Lower Green Bay Remedial Action Plan (RAP) and was the top priority project for habitat restoration.

Members of the Citizens Advisory Committee and DNR staff worked together to develop the Lower Green Bay Remedial Action Plan. (Photo by Dave Crehore)

Project Beginning

q  RAP Key Action: Protect remaining wetland habitats and restore coastal habitats where possible q  1991 Risk Assessment identified habitat loss as the greatest threat to long-term ecosystem health of Green Bay q  1994 Habitat Restoration Workshop identified Cat Islands restoration as the top priority q  Runoff pollution also must be controlled

Goals

Ø Restore diversity of island and aquatic habitats Ø Recreate 1960s island “footprint” Ø Enhance spawning and nursery grounds for

various fish species (e.g. yellow perch, musky, pike, walleye, sunfish)

Photo by WDNR 1969

Ø  Today the project’s primary focus continues to be habitat restoration and now has added the beneficial reuse of dredge material as a means of accomplishing the project.

Ø  The project is a partnership between Brown County, WDNR, WDOT, US Fish & Wildlife Service, US Army Corps of Engineers, USEPA, UW-Sea Grant, UW-Green Bay, Port Operators and the Fox River Group of paper mills

Current Project

Annual Dredging

Ø  In order to maintain an active Port annual maintenance dredging is necessary

Ø  Annual dredging of 100,000 to 250,000 cy of sediment that has settled into the 14 mile long navigational channel

Project Outcomes Ø  30-50 years worth of disposal capacity

Ø Beneficial reuse of dredged material

Ø  2.5 mile wave barrier and re-establishment of 272 acres of islands

Ø Wave barrier will protect 1,400 acres and provide critical habitat for birds, fish and mammals

Ø Sustain jobs, industries and economic outputs of the Port of Green Bay for NE Wisconsin

Shipping Channel

Fisheries Benefits from Recreation of Cat Island Chain

Ø  Increased Vegetation

l  Nursery habitat l  Habitat for sunfish sp. l  Spawning habitat

Ø  Increased Water Clarity l  Predation by visual

predators

Muskellunge Spawning

Habitat

Improved Predation

Ø Visual predators l  Increased efficiency

Ø Reduced recruitment of Common Carp

Ø Reduction in l  Bullheads l  Gizzard Shad Photo from E. Engbretson

2000

Brown County Aerial Photography , 2000

Cat  Island  

Brown County Aerial Photography , 2008

Cat  Island  Willow  Island  

Grassy  Island  

2010

Brown County Aerial Photography , 2010

Cat  Island  

Brown County Aerial Photography , 2012

June 2012

Cat  Island  

December 17, 2012

December 17, 2012

May 16, 2013

Construction Spine & Long

Term Maintenance Access

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Tommy Thompson Park, Toronto Canada