Wetlands, once disparaged as wastelands that produce little more than muck, stench, pestilence and swarms of mosquitos, are now recognized as one of the most important of natural habitats.
“Wetland” is a catchall term that encompasses tidal salt marshes, freshwater riverine marshes, riparian zones, sloughs, swamps, bogs, vernal pools, muskegs, fens and more.
Not only are wetlands highly productive ecologically – producing tons of biomass annually – but they are valuable in flood control, groundwater recharge, pollution cleanup, and as refugia for abundant populations of vertebrates and invertebrates. Picture a sandpiper (a vertebrate) plucking a worm (an invertebrate) from an exposed mudflat at low tide. Marshes often serve as “nurseries” for juvenile marine or anadromous fish ranging from Pacific salmon to halibut.
Over 50% of federally listed threatened or endangered species are found in wetland habitats.
Alas, like wetlands throughout the country, California’s were considered “good for nothing” throughout much of the 20th century. Misguided federal, state and local policy was to fill, drain or convert them to more "productive" uses, such as subdivisions and strip malls for the state’s burgeoning population. According to the California Resources Agency, 85-90% of California’s original endowment of wetlands have been lost – the highest percentage of any state in the nation.
Historically, California is believed to have contained between 3-5 million acres of wetlands; now less than half a million acres endure. Much of the Central Valley was one vast seasonal wetland: some 2-4 million acres in wet winters. Indeed, before it was drained and converted into an agricultural powerhouse, the valley supported one of the largest concentrations of wintering waterfowl in the world.
An estimated 40-50 million ducks and geese and swans once crowded down that aerial corridor known as the Pacific Flyway. Hailing from as far away as the arctic tundra and boreal forests of Alaska, they converged on the Central Valley. The din of ducks alone must have been deafening.
Nationally, more than half of America’s wetlands outside of Alaska have been lost, decreasing from about 220 million acres in the 18th century to 107 million acres today.
Since 1989, the federal government has had a policy of “no net loss” of wetlands, but this goal has been difficult to achieve in practice.
Now a recent federal study concludes that from 2004-2009, the U.S. lost more than 360,000 acres of tidal and freshwater wetlands to storms, sea-level rise and explosive coastal development.
Approximately 80,000 acres of wetlands disappeared annually during the years studied, an increase from an average annual loss of 60,000 acres per year previously.
Modest gains in wetland acreage were attributed to wetlands restoration programs, especially in the Great Lakes Region, South Carolina, Georgia and Florida.
But overall, the disappearance and degradation of so much wetland is a disturbing sign that government programs to protect and restore wetlands are falling behind more intense storms, a rising sea and a ballooning population. The 27 million new Americans added in the 2000-2010 decade all need land, water, food and energy, exerting ever more intensive development pressure on wetlands.
As with so many natural resources, halting California’s and America’s population growth will not ensure that wetlands are preserved, but not halting that growth virtually guarantees their continued diminishment.