They also call for help establishing such basic information tools as a mapped inventory of wetlands based on universally-accepted definitions, which as yet do not exist. They call on the 158 nations that are party to the Ramsar Convention to help remedy these and other yawning information gaps.

They warn against creating energy and food croplands at the expense of natural vegetation and of carelessly allowing agriculture to encroach on wetlands, which causes damage through sediment, fertilizer and pesticide pollution.

Development in and around wetlands must be preceded by "sound cost-benefit analyses, including environmental and social parameters," the statement says, adding that "mitigation of many negative side-effects is not possible" once the damage is done.

A recent study shows a large wetland in arid northern Nigeria yielded an economic benefit in fish, firewood, cattle grazing lands and natural crop irrigation 30 times greater than the yield of water being diverted from the wetland into a costly irrigation project.

And, at US$15 000 per hectare per year, the economic value of flood mitigation and other services provided by wetlands is greater than any other ecosystem – seven times that of the next most valuable, tropical rainforests.

The statement notes accelerating rates of biodiversity loss, saying "freshwater biodiversity is declining faster than terrestrial or marine biodiversity, and wetland species are especially prone to decline and extinction."

The rich biodiversity of wetlands mitigates the spread of disease from animal to human. The statement says that with warmer world temperatures water-borne diseases will expand into new areas.