NAIROBI, March 13 (Xinhua) -- The UN Environment Programme (UNEP) on Wednesday urged African countries to put in place policies to protect their wetlands.

Joakim Harlin, head of freshwater ecosystems division at UNEP, told Xinhua in Nairobi that wetlands are critical resources because of their role in helping to clean the environment.

"African governments need to put in place regulations that will reverse the decline of wetlands," Harlin said on the sidelines of the ongoing fourth session of the United Nations Environment Assembly (UNEA) in Nairobi.

He added that the laws should also be complemented with strict enforcement measures to prevent encroachment in wetlands, noting that successful protection of wetlands will be achieved if land and water regulations work in tandem.

Harlin said that wetlands are typically located on the shore zones of lakes and rivers.

The official said that wetlands act like natural waste water treatment facilities as they contain vegetation such as papyrus and mangrove that suck pollutants out of water.

He observed that nature retains a critical balance because it has mechanisms to absorb both drought and flood shocks.

According to the UNEP official, encroachment of wetlands by local communities as well as industries is one of the biggest threats to the survival of the continent's wetlands.