america's wetland Official Numbers

(last updated: 7-16-12)

Any student of the changes that are happening to America's WETLAND knows that there are conflicting numbers floating about everywhere. They are spoken every moment of every day, and are posted on a variety of websites. We hear them on radio, TV, and read them in the newspaper. The following is a listing of important numbers and data that are most frequently used when people try to communicate the dire straights of the gradual demise of America's WETLAND.

Many experts have contributed to this list, and it should be viewed as a living document, i.e., as new information and/or interpretations become available, the Official Numbers List will be edited. Please consult this page anytime you need the most up-to-date numbers regarding changes in America's WETLAND.

VERY IMPORTANT TO UNDERSTAND:  THE SCIENTIFIC COMMUNITY IS CONSTANTLY RECEIVING NEW INFORMATION AND FOLDING IT INTO THEIR UNDERSTANDING OF THIS VERY DYNAMIC ECOSYSTEM.  THERE IS A GIVE-AND-TAKE THAT EXISTS BETWEEN THE PUBLIC AND THE SCIENTIFIC COMMUNITY IN RESPECT TO COASTAL WETLAND LOSS.  THE PUBLIC  HAS A NEED FOR DEFINITIVE NUMBERS TO GAIN A CLEARER UNDERSTANDING OF WHAT IS HAPPENING, WHEREAS THE SCIENTIFIC COMMUNITY NEEDS TO  CONTINUE TO STRESS THAT COASTAL WETLANDS LOSS IS A PROCESS THAT IS EVER CHANGING.  FOR THAT REASON, THE PERIODIC UPDATES BELOW ATTEMPT TO GIVE CONCRETE NUMBERS THAT ENHANCE PUBLIC UNDERSTANDING.

The Louisiana Coastal Area now has 5727 sq mi of wetlands.

Loss rate per year over various measured periods:

  • 1956-78 – 39 sq mi = 25,000 acres
  • 1990-2000 – 24 sq mi = 15,360 acres
  • 1956-2000 – 27 sq mi = 17,280 acres (John Barras, personal communication, 4-22-05)
  • 2000-2006 - 10.3 sq mi = 6,592 acres (John Barras, personal communication, 4-18-06)
  • 1985-2010 - 16.57 sq mi = 10,605 acres (Louisiana Coastal Facts)

Loss over time:

  • 1932-2000 – 1900 sq mi = 1.2 million acres = Delaware
  • 2000-2050 – 700 sq mi = 448,000 acres = Washington, DC/Baltimore Metro area

According to Field et al. (1991), the continental U.S. (lower 48 states) has the following acreage:

  • Forested & scrub/shrub 17,300,000 acres
  • Fresh marsh 4,500,000 acres
  • Non-fresh (tidal) marsh 4,000,000 acres
  • TOTAL 25,800,000 acres

According to USGS & LDWF, Louisiana has the following acreage:

  • Forested & scrub/shrub 1,150,000 acres
  • Fresh marsh 878,000 acres
  • Non-fresh (tidal) marsh 1,630,000 acres
  • TOTAL 3,670,000 acres

Thus, in the continental U.S., Louisiana accounts for 26% of total marshes and 40% of coastal tidal marshes.

If one includes all coastal wetlands (marshes, mangroves, forested wetlands), then Louisiana has 14% of the total in the continental U.S.

Louisiana is now experiencing 90% of the total coastal marsh loss in the continental U.S.

Louisiana’s Hot Spot – Barataria-Terrebonne Estuary:

  • 1956-78 – 43% of Louisiana’s loss
  • 1978-90 – 61% of Louisiana’s loss
  • 1990-00 – 66% of Louisiana’s loss
  • 2000-50 – projected to 80% of Louisiana’s loss

WHAT INFRASTRUCTURE VALUE IS AT RISK IF WE DO NOTHING? If America’s WETLAND continues to erode at present rates, $103 billion in assets will experience increased flood risks.

DO WE KNOW THE VALUES OF THE PRODUCTIVITY OF AMERICA'S WETLAND BETWEEN NOW AND 2050? It is often said that the values of America's WETLAND over that period of time is $300 billion. There is no study that corroborates that figure, and no one claims it as fact. However, America's WETLAND has very high value to the nation.

IMPORTANCE OF PORTS IN AMERICA’S WETLAND (source:  http://www.iwr.usace.army.mil/ndc/wcsc/oortton03.htm):

  • America's WETLAND is the location of the most important ports in the U.S. for total tonnage shipped.
  • America's WETLAND is home to NUMBER ONE - The Port of South Louisiana.
  • America's WETLAND is home to 5 of the top 12.