Status and Trends of Wetlands in Coastal Watersheds 2004-2009

National Fish Habitat BoardOctober, 2013

Susan-Marie Stedman, NOAA Fisheries ServiceThomas E. Dahl, U.S. Fish and Wildlife Service

Acknowledgements

This study has been supported by the Federal Interagency Coastal Wetlands Workgroup (EPA, Corps, NRCS, FHA, USGS, NOAA and FWS).

The study provides data on the areal extent of wetlands but does not assess wetland condition or other qualitative changes.

Expert subject matter peer review has been completed.

Coastal Watersheds of the Conterminous United States

• Defined by NOAA based on USGS 8-digit HUCs and head of tide.

• Coastal watersheds have 13% of the land area but 37% of the wetland area (conterminous U.S.)

• Coastal counties support 50% of the population and have economic activity of $4.5 trillion

Coastal Wetlands Include…

Salt marshes Brackish marshes Fresh tidal marshes Fresh tidal shrub Tidal riverine Non-tidal freshwater

wetlands

Wetlands in Coastal Watersheds are Important as:

• Habitat for recreational and commercial fisheries

• Habitat for wildlife• Recreation• Maintaining

environmental quality• Protection from coastal

storms and flooding

Study of Wetlands in Coastal Watersheds

FWS – NOAA original study covered 1998 – 2004

Scientific approach biological definition (not

regulatory), Federal Standard (FGDC)

Monitor all wetlands in coastal watersheds measure gain and loss of

wetland acreage by type

Updated Study of Coastal Watersheds - Trends

Considerable interest from key Federal agencies:

In some coastal watersheds, wetlands are vulnerable to both development and ocean processes.

Trend studies provide data that help in policy/management formulation.

Acreage trends provide a quantitative measure to evaluate status/progress.

Objectives for Follow-up Study

Update wetland change information between 2004 and 2009

Expand the study to include the Pacific coast

Determine the underlying causes of wetland loss and the role of wetland reestablishment

Updated Coastal Study 2004 - 2009

Total coastal area: 246.9 million acres

Data segmented by coastline – Atlantic, GOM, Great Lakes, Pacific

Sample plots: 2,614 (4 sq. mi.)

Field verification plots: 380 (15%)

Coastal Watersheds

Study Findings – Wetland Area (41 mil. Acres), 2009

Wetland Distribution by Coastal Region, 2009

Changes in the Coastal Watersheds 2004 - 2009

Coastal Region Wetland Area 2004 (acres)

Wetland Area 2009 (acres)

Net Change (acres)

Percent Change

Atlantic

15,980,550 15,868,594 -111,957 -0.7 %

Gulf of Mexico 15,668,626 15,411,472 -257,153 -1.6 %

Great Lakes

8,498,448 8,512,056 13,608 +0.2 %

Pacific

1,274,725 1,269,504 -5,221 -0.4 %

Total

41,422,348 41,061,625 -360,723 -0.9 %

Study Findings Between 2004 and 2009, the average annual rate of wetland

loss in the coastal watersheds was 80,160 acres, a 25 percent increase in the rate of wetland loss from 1998-2004.

Both saltwater and freshwater wetlands sustained net losses between 2004 and 2009. There were an estimated 95,000 acres of saltwater wetland losses and 265,720 acres of freshwater wetland losses. Saltwater loss was disproportionate in that ~26% of the loss was saltwater wetlands, which make up only ~16% of the wetlands studied.

In the upper portions of the coastal watersheds, stressors associated with residential and infrastructure development or silviculture were key factors in wetland loss.

Area Gains and Losses by Region, 2004 to 2009

Gulf of Mexico

Loss or Conversion of Saltwater Wetland, 2004-2009

Loss or Conversion of Freshwater Wetland, 2004-2009

What the Data Indicate About Wetlands in Coastal Watersheds…

Wetland trends in coastal watersheds do not follow national wetland trends - may face a different suite of stressors or other complicating factors.

What the Data Indicate continued…

Nationally, wetland reestablishment and creation actions on agricultural lands are helping keep pace with losses – not so much in coastal watersheds.

Stressors associated with development in the upper portion of coastal watersheds continue to affect wetland area.

What the Data Indicate continued…

In some coastal watersheds, wetlands are vulnerable to both development on the landward side and coastal ocean processes from the sea. This presents considerable challenges for wetland resource management, including mitigation options.

Summary

Wetlands in the coastal watersheds make up an increasingly fragile network of lands.

Wetlands declined by an estimated 80,160 acres per year. This rate of wetland loss was higher than the national loss rate over the same time period.

Both saltwater and freshwater wetlands sustained net losses between 2004 and 2009.

Wetland reestablishment in the coastal watersheds has lagged behind reestablishment rates nationally.

Coastal watersheds need greater (more forceful) or different measures to reverse these wetland loss trends.

Issues to be Addressed• Why some wetlands in silviculture are being

converted to uplands• Reestablishment in coastal wetlands not

enough to offset wetland losses• Losses to development, especially in non-

jurisdictional wetlands

0

5000

10000

15000

20000

25000

17650

7090

1450

5540

22300Saltmarsh Loss Rate (acres/year)

Time

loss

rate

(acr

es/y

ear)

1970s-1980s

1986-1997

1998-2004

2004-2009

1950s-1970s

• Increased losses of saltwater wetlands

Next Steps

• Silviculture – Interagency effort to hold discussions with USDA– Engage with state forestry experts– NOP pilot studies also studying this issue

• Reestablishment in coastal watersheds– Hold discussions with federal agencies on how to

increase reestablishment of coastal wetlands

Next Steps (cont.)

• Losses to development– NOP pilot studies are also studying this issue– Watershed planning and outreach to landowners

may be most valuable• Losses of saltwater wetlands

– Adaptation strategies for climate change may be helpful

– Living shorelines efforts (both interagency and NOAA-specific) will also help

Susan-Marie StedmanNOAA – National Marine FisheriesOffice of Habitat Conservation301-427-8649Susan.Stedman@noaa.gov

Contact Information

Thomas E. DahlU.S. Fish and Wildlife ServiceEcological Services608-238-9333 ext. 110Tom_Dahl@fws.gov