Status and Trends of Wetlands in the Coastal Watersheds of the Eastern United States

Status and Trends of Wetlands in the Coastal Watersheds of the Eastern United States Susan-Marie Stedman, NOAA Fisheries ServiceTom Dahl, US Fish and Wildlife Service

Some Background.National Wetlands Trends (US FWS)

Time Periodacres/year net change1955-1975-458,000 1973-1983-290,000 1986-1997 -58,550------------ No net loss1998-2004 +32,000

Coastal Wetlands TrendsGosselink and Bauman, 1980 (mostly tidal wetlands)1922-1954: 19,000 ac/yr loss1954-1974: 46,000 ac/yr loss

Brady and Flather, 1994 (mostly tidal wetlands)1982-1987: 19,000 ac/yr loss

Brady and Goebel, 2002 (wetlands in coastal counties)1992-1997: 32,600 ac/yr loss

Coastal Wetlands are Important as:Habitat for commercial and recreational fish98% of Chesapeake Bay commercial landings and 97% in the Gulf of Mexico are estuarine-dependentHabitat for waterfowlmajority of black ducks winter on Atlantic coastmajority of gadwalls winter along Gulf CoastProtection from coastal storms and floods - $23B/yrRecreationAnd more

Defining Coastal

Coastal Wetlands are.Salt marshesBrackish marshesFresh tidal marshesFresh tidal scrub/scrubTidal riverine

As well as.Non-tidal fresh wetlands

National data points vs. Coastal data pointsTotal coastal drainage area: 212.6 million acres

Data segmented by coastline Great Lks., Atlantic, Gulf

Sample plots:2,265 (48 % of national total)

Field verification plots: 824 (36%)

Coastal Wetlands Status 2004

Coastal Wetlands Trends 1998-2004(including Great Lakes)Average annual net loss of 60,000 acres per year

Freshwater wetlands experienced 82% of that loss

About 70% of the loss was due to development

The Gulf of Mexico experienced the majority of the wetland loss

Chart1

70

5

25

Wetland Categories 1990s

Inland~70%

Estuarine Marine5%

Coastal~30%

Coastal30%

Chart2

191750

-373080

-14760

42080

Acres

Net change in wetlands by region

Chart3

67103600

5730880

34865520

Wetland Categories 2004

Estuarine Marine5%

Inland62%

Freshwater coastal33%

Eastern Coastal38%

Chart4

1981

4159

3763

2278

Coastal

Inland

Sheet1

Wetland TypePercentage of Total

Inland70

Estuarine5based on Field et al and FWS national studies

Freshwater coastal25

acrespercent

All land in Coterminous US18938009602,959,064sq miles

Wetland typeloss (ac)%All land in eatserns US coastal watersheds212,600,00011%of coterminous US is in eastern US Coastal watersheds

All eastern coastal353670Wetlands in eastern US coastal watersheds4059640019%of all land in eastern US Coastal watersheds is wetland

intertidal6390018%Wetlands in coterminous US10770000038%of all wetlands in coterminous US are in eastern US Coastal watersheds

freshwater353670100%6%of all land in coterminous US is wetland

GOM37308096%

Atlantic147604%Gross lossGross gainNet

total marine coast387840Eastern US Coastal

Coterminous US

Total eastern coastal-353670

National191750

Gulf of Mexico-373080105%

Atlantic-14760

Great Lakes42080

Status in 2004

total coterminous US wetlands107700000

Inland6710360062%

Estuarine Marine57308805%

Freshwater coastal3486552032%

Coastal4059640038%

CoastalConterminous USPercent coastalPercent coastalPercent Inland

Fresh non-veg1238020622960020Fresh non-veg1981

Fresh forest213821005203140041Fresh forest4159

Fresh shrub64473601764140037Fresh shrub3763

Fresh marsh57980402614700022Fresh marsh2278

Gains and Losses by Coastal Region

Attribution of fresh water wetland losses: Atlantic, Gulf of Mexico, and Great Lakes

Gulf Coast Wetland Change Regions

Coastal development

Coastal development

Attribution of saltwater wetland losses Atlantic and Gulf Coasts

Atlantic Coast Inundation Regions

Focus on Coastal AreasCoastal watersheds of the eastern coterminous US:

Have 12% of the land area

Have 38% of the wetlands

Have >50% of the people

Support about 70% of the fish landings

Experienced approximately the same average annual net wetland loss from 1998-2004 as the entire coterminous US from 1986-1997

Conclusions:Although wetland loss has reversed on a national basis, it continues at an alarming rate in coastal areas.Coastal areas need greater efforts to reverse the trend of continuing wetland loss.

What next? Can we increase coastal wetland conservation through existing programs? Do we need new programs focused on coastal wetlands? How can we quantify coastal wetland trends on the Pacific coasts?

Questions?

Attempts to evaluate trends in coastal wetlands also have been hampered by a lack of consistency in defining the term coastal.

Gosselink and Bauman compiled information from the USDAs swamplands survey of 1922 with the first National Wetlands inventory in 1954 and state surveys made in the early 1970s. They did not included the Great Lakes in their study. They calculated two coastal wetland loss rates. 19,000 ac/yr for 1922-1954 and 46,000 ac/yr from 1954-1974. Steve Bradys two studies yielded estimates of 19,000 acres per year for 1982-187 and 32,600 acres per year for 1992-1997. However, its important to remember that none of these studies, not even the two conducted by Steve Brady, used consistent methodologies, so these rates are not comparable and can used only as estimates of the order of magnitude of coastal wetland loss in those time periods.Before we talk about coastal wetlands, we need to have a common understanding of the term coastal. Various federal and state programs use different definitions of the term. NOAA has defined coastal using the USGS 8-digit hydrologic units and information about drainage patterns and tidal influence. Every watershed that drains to the ocean, an estuary, or a Great Lake and contains head of tide is considered a coastal watershed. And all wetlands within these coastal watersheds are considered coastal wetlands.What that means is that coastal wetlands include not only the obvious ones like salt marshes, but some less obvious ones like the pocosins in the coastal plain of the southeast US and the tidal portions of the Hudson River, which go all the way up to Albany. The reason we need to consider all these wetlands as coastal wetlands is because they function together as one hydrologic unit, and changes in even the non-tidal freshwater wetlands affect coastal ecosystems.The assessment shows that in 2004 about 38% of all wetlands in the conterminous US were coastal. As has been reported in other Status and Trends studies, estuarine and marine wetlands make up only about 5% of the nations wetlands, meaning that the majority of the coastal wetlands are fresh tidal fresh marshes, non-tidal forested palustrine wetlands, and many other types.The results of this study show that coastal areas experienced an annual net loss of about 59,000 acres per year between 1998 and 2004. Most of that loss was in freshwater wetlands and occurred in the Gulf of Mexico.In stark contrast to the national net gain of wetlands between 1998 and 2004, coastal areas saw a significant net loss during that same time period. The majority of that loss was in the Gulf of Mexico region, which lost about 373,000 acres of wetlands. The Atlantic coast saw a decrease of about 15,000 acres. The Great Lakes experienced a net increase of about 42,000 acres of wetlands. Most of that gain can be explained by an increase in the area of ponds, which increased by 30% in the Great Lakes coastal area.To bring us back to a more big-picture perspective, here is one way to think about coastal areas:

Coastal watersheds contain 12% of the land area in the lower 48 states, 38% of the wetlands, over 50% of the people, and experienced about the same amount of wetlands loss as occurred in the entire nation in the 1990s.

In other words, there is a concentration of wetlands in coastal areas, and a concentration of loss in those wetlands that contrasts with the most recent national trend of a net increase in wetlands. Thats not to say that wetland loss isnt occurring in inland areas too. But wetland gains in inland areas are offsetting those losses, whereas in coastal areas they are not.

A few points on where to go from here:A few points on where to go from here: